Fermentation

18 pages, 5995 KiB

Open AccessArticle

Pretreatment of Luzhou Distiller’s Grains with Crude Enzyme from Trichoderma harzianum for Feed Protein Production

by Xueke Bai, Jiaxin Wang, Xi Wang, Shuai Li, Yanni Yang, Ruoya Sun, Shilei Wang, Xiaoling Zhao, Zhi Wang, Yafan Cai, Jingliang Xu and Hanjie Ying

Fermentation 2025, 11(5), 294; https://doi.org/10.3390/fermentation11050294 - 21 May 2025

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Abstract

This study developed a solid-state fermentation system based on Trichoderma harzianum, which significantly enhanced the nutritional value of distiller’s grain (DG) feed through a multi-stage synergistic treatment process. During the cellulase production phase, rice husk was used as an auxiliary material, and [...] Read more.

This study developed a solid-state fermentation system based on Trichoderma harzianum, which significantly enhanced the nutritional value of distiller’s grain (DG) feed through a multi-stage synergistic treatment process. During the cellulase production phase, rice husk was used as an auxiliary material, and specific degradation of DGs was effectively enhanced. Through optimization using response surface methodology, the optimal enzyme production conditions were determined. The filter paper enzyme activity reached a peak of 1.45 U/gds (enzyme activity per gram of dry substrate) when the moisture content was 53%, the fermentation time was 3 days, and the Tween-80 dosage was 0.015 mL/g (dry weight basis). Under these conditions, the crude enzyme solution was used to hydrolyze DGs. Compared to original DGs, the content of reducing sugars increased by 10.75%. In the stage of protein production, segmented hydrolysis fermentation (SHF) and simultaneous saccharification fermentation (SSF) processes were employed using yeast. The results showed that SSF pathway showed better performance, and the true protein content reached 15.16% after 11 days, an increase of 41.5% compared to the control. Finally, through secondary fermentation regulated by Lactobacillus fermentum, the flavor of the feed was significantly improved. This study innovatively integrated bio-enzymatic hydrolysis and multi-strain synergistic fermentation technologies, providing a novel strategy for the efficient and sustainable production of protein feed based on DGs. Full article

(This article belongs to the Special Issue Application and Research of Solid State Fermentation, 2nd Edition)

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18 pages, 2211 KiB

Open AccessArticle

Early Fermentation Dynamics and Aerobic Stability of Maize Silage Improved by Dual-Strain Lactic Acid Bacteria Inoculation

by Jonas Jatkauskas, Rafael Camargo do Amaral, Kristian Lybek Witt, Jens Noesgaard Joergensen, Ivan Eisner and Vilma Vrotniakiene

Fermentation 2025, 11(5), 293; https://doi.org/10.3390/fermentation11050293 - 21 May 2025

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Abstract

This study aimed to provide deeper insights into fermentation dynamics, aerobic stability, and bacterial community composition during the short-term ensiling of maize forage with lactic acid bacteria-based inoculants. A 50:50 combination of Lentilactobacillus buchneri DSM2250 and Lactococcus lactis DSM11037 (LBL target application: 150,000 [...] Read more.

This study aimed to provide deeper insights into fermentation dynamics, aerobic stability, and bacterial community composition during the short-term ensiling of maize forage with lactic acid bacteria-based inoculants. A 50:50 combination of Lentilactobacillus buchneri DSM2250 and Lactococcus lactis DSM11037 (LBL target application: 150,000 CFU per 1 g forage) was tested alongside an untreated control (C) over fermentation periods of 2, 4, 8, 16, and 32 days. A total of 50 3 L mini-silos were filled with 2 kg of fresh maize each and stored at 20 °C. The pH, dry matter, nutrient profiles, volatile fatty acids, lactic acid, alcohols, ammonia-N, microbiological counts (yeast and mold), and aerobic stability of all samples were analyzed after seven days of air exposure. LBL silage showed higher average dry matter content (DMc) and crude protein (CP) levels by 1.5%, p < 0.001, and 10.8%, p < 0.001, respectively, as well as reduced average dry matter (DM) losses by half (p < 0.001) compared to pure silage. The beneficial effects of inoculation became more pronounced with prolonged storage, particularly by day 32 of fermentation. LBL silage showed increased production of lactic and acetic acids by an average of 55.5% and 5.0%, respectively, (p < 0.01) and significantly reduced butyric acid formation by approximately 14 times. Ethanol and ammonia-N concentrations were also reduced by 55.4% and 25.6%, respectively (p < 0.001), while the pH value remained 0.17 units lower (p < 0.001) compared to the control. The combination of the two strains improved silage aerobic stability by 2.4 days (p < 0.001) and extended shelf life by reducing yeast counts (8.02 vs. 7.35 log₁₀CFU g⁻¹ FM, p < 0.001), while maintaining the pH value close to its initial level. Therefore, compared to the untreated control, the inoculated silage exhibited higher nutritional value, reduced fermentation losses, and suppressed undesirable microbial activity. The positive effects of inoculation became increasingly evident over time, particularly by day 32, highlighting the synergistic benefits of using mixed-strain lactic acid bacteria. These findings support the use of LBL inoculants as an effective strategy to enhance short-term silage quality and stability. Full article

(This article belongs to the Special Issue The Use of Lactobacillus in Forage Storage and Processing, 2nd Edition)

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20 pages, 734 KiB

Open AccessArticle

Effect of Sewage Sludge Compost and Urban Pruning Waste on Agronomic Parameters and Wine Composition in Arid Zones Under Climate Change

by Fernando Sánchez-Suárez, María del Valle Palenzuela, Antonio Rosal and Rafael Andrés Peinado

Fermentation 2025, 11(5), 292; https://doi.org/10.3390/fermentation11050292 - 21 May 2025

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Abstract

Soil degradation is caused by climate change and some agricultural practices. The use of compost from organic waste can be a sustainable solution, but poses risks to soil, crops and fruit. This article examined vineyard yield, vine and wine composition when compost from [...] Read more.

Soil degradation is caused by climate change and some agricultural practices. The use of compost from organic waste can be a sustainable solution, but poses risks to soil, crops and fruit. This article examined vineyard yield, vine and wine composition when compost from sewage sludge and urban waste was applied to two soils. One rainfed plot received 80 UFN kg/ha, while two irrigated plots received 40 and 80 UFN kg/ha. Compared to mineral fertilizer, compost increased crop yield (+60% in rainfed conditions) and above-ground biomass (+15% in rainfed conditions). Aromatic series were obtained by grouping the aroma compounds according to their aroma descriptor. In both rainfed and irrigated trials, higher values were observed in the fruity, green, waxy and floral series in wines from vines fertilized with compost compared to the control and chemical fertilization. The compounds with a higher influence in such series were ethyl butanoate, ethyl hexanoate, ethyl octanoate, hexanal, phenylacetaldehyde and 2-phenylethanol. Organoleptically, wines from compost were preferred to those from mineral fertilizer, with ratings close to the control wine, particularly in aroma, flavor and overall impression. Although further studies are needed, compost fertilization appears on the one hand to improve wine quality and, on the other hand, is a suitable alternative that reduces municipal waste. Full article

(This article belongs to the Special Issue Sustainable Grape Production, Climate Change, and Wine Quality)

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20 pages, 1165 KiB

Open AccessArticle

Comparative Study of the Consumer Acceptance and Health-Promoting Properties of Yogurts Containing Coffee and Wine-Making Byproduct Extracts

by Maite Iriondo-DeHond, Amaia Iriondo-DeHond, Teresa Herrera, Eugenio Miguel and María Dolores del Castillo

Fermentation 2025, 11(5), 291; https://doi.org/10.3390/fermentation11050291 - 20 May 2025

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Abstract

This study compared yogurts containing coffee (cascara and silverskin) and wine-making (pomace, skin, and seed) byproduct extracts as novel ingredients. For this purpose, the analysis of the sensory acceptance, basic information on phytochemical profile, and health-promoting properties of novel yogurt formulations were carried [...] Read more.

This study compared yogurts containing coffee (cascara and silverskin) and wine-making (pomace, skin, and seed) byproduct extracts as novel ingredients. For this purpose, the analysis of the sensory acceptance, basic information on phytochemical profile, and health-promoting properties of novel yogurt formulations were carried out. The antioxidant (ORAC, ABTS, DPPH, and intracellular ROS), antidiabetic (α-glucosidase inhibition), and anti-inflammatory (NO assay) properties of the yogurts depended on the type of byproduct extract and concentration used. Among the studied formulations, coffee cascara yogurt showed a high sensory acceptance (6.96), high overall antioxidant capacity (significantly higher (p < 0.05) values of TPC and antioxidant capacity measured by ORAC, ABTS, and DPPH than control yogurt), the best antidiabetic properties (inhibition of α-glucosidase activity of 83%), and a significant (p < 0.05) anti-inflammatory effect used as an ingredient at a final concentration of 10 mg/mL of food. The antioxidant and antidiabetic properties of cascara yogurt were also observed after in vitro digestion, which may be ascribed to unidentified bioactive compounds such as metabolites of phytochemicals and proteins generated during the physiological process. Overall, we developed a healthy, tasty, and sustainable coffee cascara yogurt containing antioxidant and antidiabetic compounds, which may be bioaccessible for their in vivo effects. The cascara yogurt can be consumed by the general public since the caffeine concentration in the food is within the recommended range for all population groups and it does not seem bioaccessible after the digestion of the food. Full article

(This article belongs to the Special Issue Dairy Fermentation, 3rd Edition)

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14 pages, 2606 KiB

Open AccessArticle

From Pollen to Bee Bread: A Reservoir of Functional Yeasts

by Alice Agarbati, Laura Canonico, Silvia Gattucci, Maurizio Ciani and Francesca Comitini

Fermentation 2025, 11(5), 290; https://doi.org/10.3390/fermentation11050290 - 16 May 2025

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Abstract

Nowadays, yeasts are widely used for food and beverage fermentation as well as for their functional traits, as there has been an increase in scientific interest in their contributions to human health. Microbial competition in habitats with adverse abiotic factors could force yeasts [...] Read more.

Nowadays, yeasts are widely used for food and beverage fermentation as well as for their functional traits, as there has been an increase in scientific interest in their contributions to human health. Microbial competition in habitats with adverse abiotic factors could force yeasts to activate competitive tools, such as bioactive compound production. Here, bee pollen, fresh bee bread, and aged bee bread were analyzed as a reservoir of potential new functional yeasts. Microbiological analyses of pollen showed a dominance of bacteria and molds, although yeasts were present in all samples and increased in fresh and aged bee bread where osmophilic yeasts appeared. Functional traits such as antioxidant activity; polyphenol and flavonoid production; antimicrobial activity toward molds, yeast, and pathogenic bacteria; phytase activity; and potential probiotic aptitude were studied. Out of fifty-eight isolated yeasts, four showed antioxidant activity higher (around 70%) than Codex^® due to having the highest levels of polyphenols or flavonoids. One strain possessed phytase activity, and three strains belonging to Starmerella and Metschnikowia genera had wide antimicrobial activity. Nine strains exhibited the ability to resist gastrointestinal conditions, and four possessed all probiotic traits tested. All these findings demonstrate the effectiveness of pollen and bee bread as natural sources for new bioactive and functional yeasts. Full article

(This article belongs to the Special Issue Recent Advances in Microbial Fermentation in Foods and Beverages)

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12 pages, 5962 KiB

Open AccessArticle

Metabolic Engineering of Escherichia coli Nissle 1917 for the Production of Heparosan Using Mixed Carbon Sources

by Fangqi Shao, Ruiji Wu and Zheng-Jun Li

Fermentation 2025, 11(5), 289; https://doi.org/10.3390/fermentation11050289 - 16 May 2025

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Abstract

Heparosan, a microbially synthesized capsular polysaccharide, possesses a polysaccharide backbone structurally analogous to heparin. Its biosynthesis holds significant importance for achieving the chemoenzymatic synthesis of heparin. Here, we developed a systematic metabolic engineering strategy in Escherichia coli Nissle 1917 to establish an efficient [...] Read more.

Heparosan, a microbially synthesized capsular polysaccharide, possesses a polysaccharide backbone structurally analogous to heparin. Its biosynthesis holds significant importance for achieving the chemoenzymatic synthesis of heparin. Here, we developed a systematic metabolic engineering strategy in Escherichia coli Nissle 1917 to establish an efficient heparosan production platform. Through the systematic engineering of the glycolytic pathway involving the targeted knockout of zwf, pfkAB, pgi, and fruA (or alternatively fbaA) genes, we generated recombinant strains that lost the capacity to utilize glucose or fructose as sole carbon sources in a minimal medium. This metabolic reprogramming established glycerol as the exclusive carbon source for cell growth, thereby creating a tripartite carbon allocation system, including glycerol for biomass, glucose for UDP-glucuronic acid, and fructose for UDP-N-acetylglucosamine. Therefore, heparosan production was significantly improved from 137.68 mg/L in the wild type to 414.40 mg/L in the recombinant strain. Building upon this foundation, the overexpression of glmM, pgm, and galU genes in the biosynthetic pathway enabled a heparosan titer of 773.78 mg/L in shake-flask cultures. Temporal induction optimization further enhanced titers to 1049.96 mg/L, representing a 7.60-fold enhancement compared to the wild-type strain. This study establishes a triple-carbon-source co-utilization strategy, which holds promising implications for the biosynthesis of heparosan-like microbial polysaccharides. Full article

(This article belongs to the Special Issue Microbial Cell Factories for the Production of Functional Compounds)

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16 pages, 3651 KiB

Open AccessArticle

Predicting Organic Acid Variation in White Wine Malolactic Fermentation Using a Logistic Model

by Aikaterini Karampatea, Adriana Skendi, Maria Manoledaki and Elisavet Bouloumpasi

Fermentation 2025, 11(5), 288; https://doi.org/10.3390/fermentation11050288 - 15 May 2025

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Abstract

The variation in organic acids during malolactic fermentation (MLF) affects the wine’s quality, presenting a challenge for the wine industry. This study aimed to investigate the kinetics of organic acids during MLF using two Oenococcus oeni strains under different barrel conditions. The study [...] Read more.

The variation in organic acids during malolactic fermentation (MLF) affects the wine’s quality, presenting a challenge for the wine industry. This study aimed to investigate the kinetics of organic acids during MLF using two Oenococcus oeni strains under different barrel conditions. The study examined the variation in pH, total and volatile acidity, and concentration of tartaric, malic, lactic, and citric acid during MLF in the identical initial wine. In addition, the aromatic profile of the final wines was evaluated. The fermentation occurred in new and used French oak barrels. Two strains of O. oeni were used: (a) citrate-negative O. oeni (CINE) and (b) O. oeni, commonly used in the wine industry. The experimental data obtained were fitted to the logistic model for each monitored parameter. The degree of fitting R2 was higher than 92.79%, indicating good predictive accuracy for substrate consumption (malic and citric acid), as well as product formation (lactic and acetic acid). The mean values of O. oeni and O. oeni CINE differ in acetic (0.29 and 0.15 g/L) and citric acid (0.13 and 0.18 g/L), respectively. The logistic model effectively predicted the change in acid content during fermentation, describing the changes in organic acid levels during the MLF conducted in barrels. Modeling can be useful in forecasting industrial-scale production. Full article

(This article belongs to the Special Issue Lactic Acid Bacteria Metabolism)

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14 pages, 1061 KiB

Open AccessArticle

The Probiotic Potential, Safety, and Immunomodulatory Properties of Levilactobacillus brevis ZG2488: A Novel Strain Isolated from Healthy Human Feces

by Zhijie Cao, Mengshan Chen, Yulu Chen and Hui Sun

Fermentation 2025, 11(5), 287; https://doi.org/10.3390/fermentation11050287 - 15 May 2025

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Abstract

Probiotics exert beneficial effects on health improvement, infection prevention, and disease management. This study investigated the probiotic characteristics and safety parameters of Levilactobacillus brevis ZG2488, a novel strain isolated from healthy human feces. The strain exhibited robust tolerance to simulated gastrointestinal conditions, maintaining [...] Read more.

Probiotics exert beneficial effects on health improvement, infection prevention, and disease management. This study investigated the probiotic characteristics and safety parameters of Levilactobacillus brevis ZG2488, a novel strain isolated from healthy human feces. The strain exhibited robust tolerance to simulated gastrointestinal conditions, maintaining survival rates of 87.20% in artificial gastric juice (pH 3.0; 3 h) and 95.32% in 0.3% bile salt (24 h). Notably, L. brevis ZG2488 displayed superior microbial adhesion properties with high cell surface hydrophobicity (87.32%), auto-aggregation (81.15% at 24 h), and co-aggregation capacities with Escherichia coli ATCC 43895 (63.90%) and Salmonella typhimurium SL1344 (59.28%). Its adhesion to HT-29 cells (7.15%) surpassed that of the reference strain Lactobacillus rhamnosus GG (1.26%). Antimicrobial testing revealed broad-spectrum inhibitory effects against multidrug-resistant Klebsiella pneumoniae NK04152 and other pathogens. Comprehensive safety assessments confirmed the absence of hemolytic or DNase activity, along with appropriate antibiotic susceptibility to most antibiotics, except kanamycin, streptomycin, vancomycin, and penicillin G. Furthermore, L. brevis ZG2488 significantly enhanced nitric oxide production and upregulated the gene expression of nitric oxide synthase (iNOS) and proinflammatory cytokines (IL-1β, IL-6, and TNF-α) in RAW264.7 macrophages. These findings underscore L. brevis ZG2488 as a promising probiotic candidate with functionality in pathogen inhibition and immune modulation. Full article

(This article belongs to the Section Probiotic Strains and Fermentation)

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17 pages, 4682 KiB

Open AccessArticle

Fermentation and Functional Properties of Plant-Derived Limosilactobacillus fermentum for Dairy Applications

by Batchimeg Namshir, Gil-Ha Kim, Natsag Lkhagvasuren, Seon-A Jeong, Narangerel Mijid and Woan-Sub Kim

Fermentation 2025, 11(5), 286; https://doi.org/10.3390/fermentation11050286 - 15 May 2025

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Abstract

Lactic acid bacteria (LAB) isolated from plant sources are gaining increasing attention due to their potential probiotic and postbiotic functionalities. In the present study, Limosilactobacillus fermentum isolated from Prunus padus (bird cherry) was evaluated for its physiological, functional, and technological attributes for application [...] Read more.

Lactic acid bacteria (LAB) isolated from plant sources are gaining increasing attention due to their potential probiotic and postbiotic functionalities. In the present study, Limosilactobacillus fermentum isolated from Prunus padus (bird cherry) was evaluated for its physiological, functional, and technological attributes for application in fermented dairy products. The strain was isolated through anaerobic fermentation and identified using API 50 CHL and 16S rRNA sequencing. Its acid tolerance, antioxidant capacity, antibacterial effects, and hemolytic activity were assessed. The cell-free supernatant (CFS) was evaluated for thermal and pH stability. Fermentation trials were conducted using both mono- and co-culture combinations with the commercial yogurt starter strain YC-380. Physicochemical properties, viable cell counts, and viscosity were monitored throughout fermentation and refrigerated storage. The L. fermentum isolate exhibited strong acid resistance (48.28% viability at pH 2.0), non-hemolytic safety, and notable DPPH radical scavenging activity. Its CFS showed significant antibacterial activity against five Escherichia coli strains, which remained stable after heat treatment. Co-cultivation with YC-380 enhanced fermentation efficiency and improved yogurt viscosity (from 800 to 1200 CP) compared to YC-380 alone. During 24 days of cold storage, co-cultured samples maintained superior pH and microbial stability. Additionally, the moderate acidification profile and near-neutral pH of L. fermentum created favorable conditions for postbiotic compound production. These results indicate that L. fermentum derived from P. padus holds considerable promise as a functional adjunct culture in yogurt production. Its postbiotic potential, technological compatibility, and heat-stable bioactivity suggest valuable applications in the development of safe, stable, and health-promoting fermented dairy products. Full article

(This article belongs to the Special Issue Fermented Dairy Products: Processing Technology, Microbiology and Health Benefits: 2nd Edition)

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11 pages, 797 KiB

Open AccessArticle

Comparison of In Vitro Fermentation Characteristics Among Five Maize Varieties

by Fabio Zicarelli, Serena Calabrò, Piera Iommelli, Micaela Grossi, Federico Infascelli and Raffaella Tudisco

Fermentation 2025, 11(5), 285; https://doi.org/10.3390/fermentation11050285 - 15 May 2025

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Abstract

Maize (Zea mays L.) silage in the irrigated and flat areas of Italy represents the most important large ruminant feed crop due to the high dry matter yield and nutritive value per hectare. The aim of the investigation was to evaluate the [...] Read more.

Maize (Zea mays L.) silage in the irrigated and flat areas of Italy represents the most important large ruminant feed crop due to the high dry matter yield and nutritive value per hectare. The aim of the investigation was to evaluate the chemical composition and the in vitro fermentation patterns of five maize varieties (Tiesto, R700 1, MAS 78.T, DKC 7074 and KWS Kantico) freshly chopped and preserved via ensiling. The results indicated that the chemical composition was not significantly different among varieties. The substrates were incubated for 72 h with buffered rumen fluid collected from cow. The ensiling process slightly reduced gas production and fermentation kinetics, likely due to the consumption of soluble sugars during fermentation. Organic matter loss (OM loss) differed significantly (p < 0.01) among varieties in ensiled maize, correlating with their neutral detergent fiber (NDF) content. While total volatile fatty acid (VFA) production showed no significant differences between varieties, the buffer capacity ratio (BCR), an indicator of protein degradation, varied significantly. Ammonia production (NH₃) was significantly higher in ensiled samples, supporting previous findings that ensiling increases non-protein nitrogen (NPN) due to microbial proteolysis and plant enzyme activity. The gas production profiles and fermentation rates over time showed minor differences between fresh and ensiled samples, with fresh material exhibiting faster fermentation kinetics due to the presence of soluble sugars. These findings highlight the importance of evaluating maize silage quality to optimize ruminant nutrition and feed efficiency. Full article

(This article belongs to the Special Issue Ruminal Fermentation)

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14 pages, 2486 KiB

Open AccessArticle

A Photosynthetic Bacterium Suitable for Treating High-Salinity Sea Cucumber Boiling Broth

by Shaokun Dong, Yusi Guo, Jinrui Ji, Pu Song, Ning Ma, Hongjin Qiao and Jinling Cai

Fermentation 2025, 11(5), 284; https://doi.org/10.3390/fermentation11050284 - 14 May 2025

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Abstract

Photosynthetic bacteria exhibit significant bioremediation potential and resource recycling characteristics, rendering them valuable candidates for sustainable wastewater treatment applications. Sea cucumber boiling broth (SCBB) contains high concentrations of organic compounds and nutrient salts, whose indiscriminate discharge poses serious environmental risks. This study aimed [...] Read more.

Photosynthetic bacteria exhibit significant bioremediation potential and resource recycling characteristics, rendering them valuable candidates for sustainable wastewater treatment applications. Sea cucumber boiling broth (SCBB) contains high concentrations of organic compounds and nutrient salts, whose indiscriminate discharge poses serious environmental risks. This study aimed to evaluate a photosynthetic bacterium capable of effectively treating SCBB, which was isolated from the intertidal sediment samples. The bacterial strain was identified using 16S rDNA sequencing, and optimal growth conditions, including light, pH, and temperature, were determined. Finally, a small-scale trial was conducted in a fed-batch fermenter. The results showed that 16S rDNA analysis placed this strain in the Chromatiaceae family, forming a distinct lineage from the closest related species Marichromatium purpuratum and M. gracile, and was tentatively named Marichromatium sp. DYYC01. The strain exhibited optimal growth under anaerobic conditions at 30 °C, light intensity of 100 μmol photons/m²/s, and pH 7.0. Batch culture experiments demonstrated maximum biomass accumulation (OD₆₆₀ = 0.831) in SCBB medium with an initial COD loading of 3913 mg L⁻¹, concomitant with significant nutrient removal efficiencies: 76.45% COD, 55.82% total nitrogen (TN), and 56.67% total phosphorus (TP). Scaling up to fed-batch fermentation enhanced bioremediation performance, achieving removal rates of 83.13% COD, 72.17% TN, and 73.07% TP with enhanced growth (OD₆₆₀ = 1.2). This study reveals Marichromatium sp. DYYC01’s exceptional halotolerance in high-salinity organic wastewater treatment. The strain’s capacity for simultaneous biomass production and efficient nutrient recovery from hypersaline processing effluent positions it as a promising candidate for developing circular bioeconomy strategies. Full article

(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)

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18 pages, 1806 KiB

Open AccessArticle

Flavonoid Profiling of Aglianico and Cabernet Sauvignon Cultivars from Campania, Sicily, and Molise, Three Regions of Southern Italy

by Francesca Coppola, Angelita Gambuti, Bruno Testa, Mariantonietta Succi, Alessandra Luciano, Luigi Picariello and Massimo Iorizzo

Fermentation 2025, 11(5), 283; https://doi.org/10.3390/fermentation11050283 - 14 May 2025

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Abstract

In the 2020 and 2021 vintages, some chemical and phytochemical parameters of the Aglianico and Cabernet Sauvignon cultivars grown in three regions of Southern Italy (Campania, Molise, and Sicily) were determined. In particular, the aim of this study was the investigation of flavanol, [...] Read more.

In the 2020 and 2021 vintages, some chemical and phytochemical parameters of the Aglianico and Cabernet Sauvignon cultivars grown in three regions of Southern Italy (Campania, Molise, and Sicily) were determined. In particular, the aim of this study was the investigation of flavanol, monomeric anthocyanin, and pigment contents in grapes and wines. The data collected showed that the main chemical parameters and flavonoids analyzed in the grapes and wines were influenced by the vintage, grape variety, and geographical location. Specifically, in the Aglianico grapes, the latitude and vintage highly influenced the titratable acidity and flavonoids in terms of richness in flavanols, compared to Cabernet Sauvignon. On the other hand, the location of the vineyard influenced monomeric anthocyanins in both varieties, highlighting a relationship of these phytochemicals with soil fertility and availability of certain chemical elements such as nitrogen and iron. All results support the idea that the interaction between grape variety, soil type, and geographical origin plays a decisive role in shaping the characteristics of wine. Full article

(This article belongs to the Section Fermentation for Food and Beverages)

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18 pages, 1145 KiB

Open AccessArticle

Enhancing Mead Aroma Using Non-Saccharomyces Yeast β-Glucosidase Producers Isolated from Honey: A Case Study in the Upper Turi Region

by Josilene Lima Serra, Alicinea da Silva Nojosa, Aparecida Selsiane Sousa Carvalho, Lucy Mara Nascimento Rocha, Anderson Lopes Pereira, Fernanda Carneiro Bastos and Walter José Martínez-Burgos

Fermentation 2025, 11(5), 282; https://doi.org/10.3390/fermentation11050282 - 14 May 2025

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Abstract

The Upper Turi region in the Maranhão Amazon is a significant producer of honeybees, and mead production represents a cost-effective means of adding value to the honey production chain. This study investigates non-Saccharomyces yeasts isolated from honey as β-glucosidase producers to enhance [...] Read more.

The Upper Turi region in the Maranhão Amazon is a significant producer of honeybees, and mead production represents a cost-effective means of adding value to the honey production chain. This study investigates non-Saccharomyces yeasts isolated from honey as β-glucosidase producers to enhance the mead aroma. Sixty-five honey samples from the Upper Turi in Maranhão underwent yeast screening. Biochemical tests identified isolated yeasts, and β-glucosidase-producing strains were selected via esculin agar. Meads were produced using selected strains of Saccharomyces cerevisiae. Fermentation analyses included pH, °Brix, temperature, conductivity, dissolved oxygen, and volatile compounds (GC-MS). Thirty-six yeasts were isolated, with three identified as β-glucosidase producers. Strain 20 (Saccharomycopsis fibuligera) was selected for mead production due to its fermentative capacity, tolerance to pH and ethanol, and its ability to produce β-glucosidase, which hydrolyzes the glycosidic precursors in honey. During alcoholic fermentation, Saccharomycopsis fibuligera exhibited lower fermentative potential compared to Saccharomyces cerevisiae, reducing only 3.7% of the initial soluble solids (°Brix). The pH and temperature remained relatively stable throughout the fermentation for both yeast strains. The levels of dissolved oxygen and conductivity in the fermented mead were higher for S. cerevisiae than for Saccharomycopsis fibuligera. Specifically, S. cerevisiae showed reductions of 52.85% in dissolved oxygen and conductivity of 1115 µS/cm, while Saccharomycopsis fibuligera exhibited reductions of 33.0% in dissolved oxygen and conductivity of 511 µS/cm. Although the β-glucosidase-producing yeast yielded a mead with a low ethanol concentration, it contributes a unique fruity compound (ethyl hexanoate) and avoids high acetic acid production, providing a distinct aromatic profile that can be explored. Full article

(This article belongs to the Special Issue Biotechnology in Winemaking)

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14 pages, 2788 KiB

Open AccessArticle

Consortium of Candida utilis, Kluyveromyces marxianus and Saccharomyces cerevisiae Yeasts for Vinasse Fermentation of Agave americana L. Liquor for Biomass Production and Reduction in Chemical Oxygen Demand

by Roberto Robles Calderón, Francisco Alcántara Boza, Elmer Benmites-Alfaro, Oscar Tinoco Gómez and Jaqueline Chirre Flores

Fermentation 2025, 11(5), 281; https://doi.org/10.3390/fermentation11050281 - 14 May 2025

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Abstract

The vinasse from Agave americana L. (blue cabuya) liquor has a high concentration of organic matter, nutrients with high chemical oxygen demand (COD), and low pH, properties that give it the potential to generate adverse impact on the environment if improperly [...] Read more.

The vinasse from Agave americana L. (blue cabuya) liquor has a high concentration of organic matter, nutrients with high chemical oxygen demand (COD), and low pH, properties that give it the potential to generate adverse impact on the environment if improperly disposed of. In other countries, studies have been conducted on yeast strain combinations in vinasses to produce biomass and reduce organic load, but there are no studies of the aforementioned yeast consortium in blue cabuya liqueur vinasses to produce biomass and reduce COD. Given this problem, the objective of the research was to reduce this adverse environmental impact through aerobic fermentation of this vinasse with the yeast consortium Candida utilis, Kluyveromyces marxianus and Saccharomyces cerevisiae (D 47-Lalvin). As a result, biomass production and COD reduction were achieved. The study evaluated temperature variables of 28 °C, 30 °C, and 32 °C, and pH values of 3, 4, and 5 under conditions of consortium and nutrient diammonium phosphate (DAP) concentrations of 1.32 g/L and 1.5 g/L, respectively, in a bioreactor with automatic control of temperature, time, stirring speed of 100 RPM, and air flow of 1 VVM. The result was a biomass yield of 93.4% and a COD reduction of 33.3%. It is concluded that the aerobic fermentation process of blue cabuya liquor vinasse with the yeast consortium employed produces a high biomass yield, which can be used for its protein value as an animal feed supplement and, due to its low COD value, as an agricultural fertilizer. Full article

(This article belongs to the Special Issue Food Wastes: Feedstock for Value-Added Products: 5th Edition)

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20 pages, 2401 KiB

Open AccessArticle

Catabolism Mechanism and Growth-Promoting Effect of Xylooligosaccharides in Lactiplantibacillus plantarum Strain B20

by Yini Shi, Huan Wang, Zhongke Sun, Zifu Ni and Chengwei Li

Fermentation 2025, 11(5), 280; https://doi.org/10.3390/fermentation11050280 - 13 May 2025

Viewed by 338

Abstract

Prebiotics are food ingredients that result in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefits upon host health. Xylooligosaccharides (XOS) are prebiotic fibers made from xylan. Commercial XOS are mixtures of oligosaccharides containing β-1,4–linked xylose residues. Though [...] Read more.

Prebiotics are food ingredients that result in specific changes in the composition and/or activity of the gastrointestinal microbiota, thus conferring benefits upon host health. Xylooligosaccharides (XOS) are prebiotic fibers made from xylan. Commercial XOS are mixtures of oligosaccharides containing β-1,4–linked xylose residues. Though they are widely added to foods at different doses, the molecular mechanisms of the catabolism and growth promotion of XOS in the innate gut microbes Lactobacillus spp. remain unknown. In this study, we evaluated the growth-promoting effect using a human fecal isolate, Lactiplantibacillus plantarum strain B20 (Lb. plantarum B20). Assays of bacterial growth and lactic acid production showed stronger growth promotion of XOS than other oligosaccharides did, in a dose- and fraction-dependent pattern. Using the Lb. plantarum strain SK151 genome as a reference, bioinformatic analysis failed to identify any previously characterized genes responsible for the uptake and catabolism of XOS. However, transcriptomic analysis of Lb. plantarum B20 yielded numerous differentially expressed genes (DEGs) during fermentation of XOS. Among these, an oligopeptide ABC transporter (RS03575-03595, composed of five proteins) and a hydrolase (RS06170) were significantly upregulated. Molecular docking analysis indicated that the substrate-binding protein RS03575 may mediate the import of XOS into the cell. Enzymatic assays further demonstrated that RS06170 possesses β-xylosidase activity and can effectively degrade XOS. In addition, functional enrichment analysis suggested that the growth-promoting effect of XOS may be attributed to the upregulation of genes involved in cellular component biogenesis and cell division, potentially through modulation of ribosome function and carbohydrate metabolism in Lb. plantarum B20. These results provide valuable insights into the mechanisms by which XOS promote growth and highlight potential targets for enhancing prebiotic–probiotic interactions. Full article

(This article belongs to the Special Issue 10th Anniversary of Fermentation: Feature Papers in Section "Probiotic Strains and Fermentation")

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18 pages, 7788 KiB

Open AccessArticle

Non-Targeted Metabolomics Analysis Unravels Changes in Non-Volatile Metabolites in Folium nelumbinis (Lotus Leaf) Induced by Aspergillus cristatus-Mediated Fermentation

by Wei Dai, Yumei Tan, Shengling He, Luona Zhou, Xiyi Ren, Yonghui Huang, Li Song and Yongxiang Liu

Fermentation 2025, 11(5), 279; https://doi.org/10.3390/fermentation11050279 - 13 May 2025

Viewed by 243

Abstract

This study employed non-targeted metabolomics to investigate the impact of solid-state fermentation by Aspergillus cristatus on the major non-volatile metabolites in lotus leaves (Folium nelumbinis). Sensory evaluation and metabolomic analysis of the leaves before and after fermentation revealed that the fermentation [...] Read more.

This study employed non-targeted metabolomics to investigate the impact of solid-state fermentation by Aspergillus cristatus on the major non-volatile metabolites in lotus leaves (Folium nelumbinis). Sensory evaluation and metabolomic analysis of the leaves before and after fermentation revealed that the fermentation process significantly enhanced the sensory quality of lotus leaf tea, resulting in a brighter infusion color, a mellow flavor profile, and a notable reduction in astringency. The fermentation also induced the production of several potentially bioactive metabolites, including chlorogenic acid and sphondin, and stimulated the expression of genes related to the phenylpropanoid pathway, thereby promoting the synthesis of chlorogenic acid. Additionally, the fermentation led to a marked decrease in the content of flavonoids, while the content of alkaloids remained relatively unchanged. This study provides a theoretical basis for the in-depth development and utilization of lotus leaves and offers a novel approach to applying microbial fermentation technology to medicinal and edible materials. Full article

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17 pages, 2845 KiB

Open AccessArticle

Staged Fermentation with a Saccharomyces cerevisiae Consortium and Monascus purpureus for Sustainable Valorization of Persimmon into High-Quality Wine

by Yamin Du, Yangyang Sun, Rongqi Chen, Ruoxuan Xu, Qing Li, Xiuhe Liu, Lanxiao Li and Tao Zhao

Fermentation 2025, 11(5), 278; https://doi.org/10.3390/fermentation11050278 - 13 May 2025

Viewed by 272

Abstract

Persimmon waste, accounting for up to 30% of annual harvests, presents economic and environmental challenges due to limited processing options. This study introduces a staged fermentation process to transform persimmon into high-quality wine using a Saccharomyces cerevisiae consortium (EC/Aq/F33 = 4/4/7) followed by [...] Read more.

Persimmon waste, accounting for up to 30% of annual harvests, presents economic and environmental challenges due to limited processing options. This study introduces a staged fermentation process to transform persimmon into high-quality wine using a Saccharomyces cerevisiae consortium (EC/Aq/F33 = 4/4/7) followed by Monascus purpureus. The process decouples ethanol production and esterification to avoid nutrient competition: an 8-day yeast phase (21.11 °Brix, 0.29 g kg⁻¹ yeast, 19.90 °C, pH 3.8) yields 12.12% (v/v) ethanol, followed by M. purpureus (1.56% inoculation, 22.6 °C, pH 4.0) on day 8 for 10 days, producing 3.56 g L⁻¹ esters. This results in 32 volatile compounds (e.g., phenethyl acetate), achieving a sensory score of 90.9/100–43% higher in aromatic diversity than single-strain fermentation. By shortening fermentation time by 40% compared with traditional methods (>25 days) and enhancing flavor complexity, this scalable approach offers a sustainable solution for upcycling persimmon and other tannin-rich perishables, supporting eco-friendly food production. Full article

(This article belongs to the Special Issue Science and Technology of Winemaking)

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15 pages, 3853 KiB

Open AccessArticle

Fermented Chive (Allium schoenoprasum) with Lactobacillus plantarum: A Potential Antibiotic Alternative Feed Additive for Broilers Challenged with Escherichia coli

by Phan Vu Hai, Le Xuan Anh and Nguyen Xuan Hoa

Fermentation 2025, 11(5), 277; https://doi.org/10.3390/fermentation11050277 - 12 May 2025

Viewed by 311

Abstract

This study aimed to evaluate the effects of fermented chive (Allium schoenoprasum) with Lactobacillus plantarum 1582 (FC) as an alternative to antibiotics for controlling Escherichia coli infection in broiler chickens. A total of 250 J-Dabaco male chickens were allocated into five [...] Read more.

This study aimed to evaluate the effects of fermented chive (Allium schoenoprasum) with Lactobacillus plantarum 1582 (FC) as an alternative to antibiotics for controlling Escherichia coli infection in broiler chickens. A total of 250 J-Dabaco male chickens were allocated into five experimental groups: NC (negative control), PC (positive control), FC1 (1% FC), FC3 (3% FC), and AB (antibiotic treatment). The PC, FC1, FC3, and AB groups were challenged with E. coli ExPEC_A338 on day 8 and monitored until day 35. The results indicated that FC supplementation, particularly at 3% (FC3 group), significantly improved body weight gain, feed intake, the survival rate, and the production efficiency index (PEI). The FC3 group exhibited optimal performance, potentially due to enhanced immune responses, as evidenced by higher IgA and IgG levels, and favorable cytokine regulation. Additionally, FC maintained intestinal epithelial integrity by upregulating tight junction proteins (ZO-1, Claudin-2) and reducing inflammatory responses (IFN-γ, TNF-α). Furthermore, FC3 demonstrated the ability to inhibit pathogenic bacteria (Salmonella spp., E. coli), promote beneficial Lactobacillus spp., and enhance intestinal mucosal morphology (villus height and crypt depth). These findings suggest that FC supplementation, particularly at 3%, is a promising natural alternative to antibiotics for controlling E. coli infections in broiler production. Full article

(This article belongs to the Special Issue Application of Fermentation Technology in Animal Nutrition: 2nd Edition)

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16 pages, 1903 KiB

Open AccessArticle

Species and Harvest Time of Fresh Tropical Grasses Affect Rumen Fermentation as Determined by In Sacco and In Vitro Incubations

by Huyen Thi Duong Nguyen, Jill Derix, Wouter Hendrikus Hendriks, Jan Thomas Schonewille, Trach Xuan Nguyen and Wilbert Frans Pellikaan

Fermentation 2025, 11(5), 276; https://doi.org/10.3390/fermentation11050276 - 12 May 2025

Viewed by 270

Abstract

The consumption of forages high in slow-degradable carbohydrates by dairy cattle leads to greater ruminal acetate production, which benefits milk fat content. Although tropical grasses are typically rich in fibrous materials, the milk fat content of dairy cows in Southeast Asia is low. [...] Read more.

The consumption of forages high in slow-degradable carbohydrates by dairy cattle leads to greater ruminal acetate production, which benefits milk fat content. Although tropical grasses are typically rich in fibrous materials, the milk fat content of dairy cows in Southeast Asia is low. Here, we investigate the effects of the species and harvest time of three common tropical grasses (Guinea, King, and Mulato II) harvested at three instances (early, normal, late) on in sacco degradation kinetics and in vitro gas production (IVGP) characteristics. Grass samples were subjected to (1) chemical analysis, (2) a fully automated in vitro gas recording system using rumen fluid to measure fermentation characteristics over 72 h, and (3) in sacco degradation using the nylon bag technique, employing seven incubation times up to 336 h. Forage quality decreased with maturity, as reflected in changes to digestibility and fiber content. Overall, early harvested grasses yielded the highest total gas production (311 ± 12.5 mL/g OM) followed by normal (300 ± 45.7 mL/g OM) and late (273 ± 19.5 mL/g OM) harvested grasses. The in vitro fermentable fraction (A1 + A2) was the highest for early harvested grasses, with the A2 parameter, relevant for milk fat content, being the highest for Guinea (81.6% A2/(A1 + A2)) and the lowest for King grass (71.0% A2/(A1 + A2)). Consequently, early harvested Guinea had the longest incubation times (10.5 h) and lowest fermentation rates (Rmax2 = 12.8 mL/g OM/h). Regression analysis showed relationships between NDF content and degradability. Harvesting tropical grass earlier than customarily practiced enhanced forage quality and ruminal degradability. Of the three grasses studied, each at three levels of maturity, early harvested Guinea grass was the most promising candidate for improving milk fat content in Southeast Asian dairy cows. This grass showed a high fermentable OM content, with a large proportion of slow-degradable carbohydrates. Full article

(This article belongs to the Special Issue Ruminal Fermentation)

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18 pages, 985 KiB

Open AccessArticle

Exploring Volatile Profiles in Cactus-Based Fermented Beverages: Effects of Fermentation Method

by César Ojeda-Linares, Alejandro Casas, Patricia Severiano-Pérez, Marcela Sandoval-Velasco, Yolanda M. García-Rodríguez and Francisco J. Espinosa-García

Fermentation 2025, 11(5), 275; https://doi.org/10.3390/fermentation11050275 - 12 May 2025

Viewed by 244

Abstract

Mexico is home to a rich variety of fermented beverages made from both wild and domesticated plant species. Fermentation practices vary, with producers using either wild or inoculated techniques to obtain culturally valued final products. It is generally assumed that wild fermentations yield [...] Read more.

Mexico is home to a rich variety of fermented beverages made from both wild and domesticated plant species. Fermentation practices vary, with producers using either wild or inoculated techniques to obtain culturally valued final products. It is generally assumed that wild fermentations yield a greater diversity of volatile compounds compared to inoculated fermentations, as the latter tend to reduce microbial diversity throughout the process. However, this pattern remains largely unexplored in relation to the volatile profiles of traditionally fermented cactus-based beverages. Despite this assumption, comparative studies examining these profiles across different fermentation methods are scarce, especially given that these beverages are not produced under standardized conditions. To investigate this, we used GC-MS to characterize the aroma profile of colonche, a traditional fermented beverage made primarily from Opuntia streptacantha fruits. Colonche is produced by both wild and inoculated fermentation methods. In addition, a rapid sensory evaluation using the modified Flash Profile (mFP) technique was performed to evaluate flavor differences between the fermentation methods. A total of 55 volatile compounds were identified, with wild fermentations showing greater diversity (55) than inoculated fermentations (50). Most compounds overlapped, but five were unique to spontaneous fermentations, contributing to distinct sensory profiles. The mFP results also indicate that sensory attributes vary by fermentation type, with wild fermentations being more strongly associated with positive descriptors such as taste and smell, while inoculated samples have a distinctly pungent aftertaste. These findings highlight colonche not only as a reservoir of microbial diversity in arid regions but also as a culturally significant beverage with complex sensory attributes. Recognizing and preserving these attributes is essential for safeguarding traditional foodscapes. Full article

(This article belongs to the Special Issue Nutrition and Health of Fermented Foods—4th Edition)

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20 pages, 8014 KiB

Open AccessArticle

Improved Cellulolytic Activity of Alternaria citri: Optimization and EMS Treatment for Enhanced Cellulase Production

by Sibtain Ahmed, Hina Andaleeb, Aqsa Aslam, Junaid Ahmad Raza, Sheikh Muhammad Yahya Waseem, Atayyaba Javaid and Chand Talib

Fermentation 2025, 11(5), 274; https://doi.org/10.3390/fermentation11050274 - 11 May 2025

Viewed by 461

Abstract

Fungal species secrete various enzymes and are considered the primary sources of industrially important cellulases. Cellulases are essential natural factors for cellulose degradation and have attracted significant interest for multiple applications. However, reducing the cost and enhancing cellulase production remains a significant challenge. [...] Read more.

Fungal species secrete various enzymes and are considered the primary sources of industrially important cellulases. Cellulases are essential natural factors for cellulose degradation and have attracted significant interest for multiple applications. However, reducing the cost and enhancing cellulase production remains a significant challenge. Mutagenesis has opened a new window for enhancing enzyme secretion by modifying the organism’s genome. In this study, cellulases from Alternaria citri were produced and characterized, and the optimization for ideal fermentation conditions was performed for three types of cellulases (endoglucanase, exoglucanase, and β-glucosidase) by a wild-type (A. citri) and a mutant strain (A. citri 305). Ethyl methanesulfonate, a chemical mutagen, was used to enhance cellulase production by A. citri. The results demonstrate the improved cellulolytic ability of the mutant strain A. citri 305 utilizing lignocellulosic waste substances, particularly, orange-peel powder, wheat straw, sugarcane bagasse, and sawdust, making this study economically valuable. This evokes the potential for multi-dimensional applications in enzyme production, waste degradation, and biofuel generation. This study highlights that the activity of cellulases to hydrolyze various lignocellulosic substrates is enhanced after mutagenesis. Full article

(This article belongs to the Collection Bioconversion of Lignocellulosic Materials to Value-Added Products)

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12 pages, 3066 KiB

Open AccessArticle

Evaluation of Carboxymethyl Cellulose as an Additive for Selective Protein Removal from Wine

by Stephan Sommer

Fermentation 2025, 11(5), 273; https://doi.org/10.3390/fermentation11050273 - 10 May 2025

Viewed by 372

Abstract

Achieving protein stability is one of the main objectives before bottling wine. Traditionally, this is accomplished via bentonite fining, but the application has drawbacks and is not the most sustainable practice. A promising alternative was previously identified in modified cellulose, which is approved [...] Read more.

Achieving protein stability is one of the main objectives before bottling wine. Traditionally, this is accomplished via bentonite fining, but the application has drawbacks and is not the most sustainable practice. A promising alternative was previously identified in modified cellulose, which is approved for tartrate stabilization but, as a side activity, could also help remove protein from wine. This study was designed to evaluate powdered carboxymethyl cellulose (CMC) and a liquid formulation in model wine using bovine serum albumin (BSA) and egg white as model proteins. The solubility of BSA proved to be insufficient, so experiments in wine were conducted with egg white protein only. Low-addition levels of liquid CMC showed the highest protein removal rates in real wine, so final trials were conducted with 13 commercial wines to evaluate the performance in different wine styles. The protein removal rate ranged from 12% to 84%, with an overall average of 57%. While these results do not reach the efficiency of bentonite, CMC is showing promise as an additional stabilization tool for a wide variety of wines. It can stabilize over the entire pH range of wine between 2.9 and 4.1, which is a unique feature of this method. Full article

(This article belongs to the Special Issue Wine and Beer Fermentation, 2nd Edition)

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17 pages, 1797 KiB

Open AccessArticle

Enhanced Antioxidant Properties of Saccharomyces-Fermented Defatted Tenebrio molitor Larvae Extract: A Sustainable Alternative Protein Source

by Kyung-Yun Kang, Beom-Gyun Jeong, Jeong-Ho Kim and Kyung-Wuk Park

Fermentation 2025, 11(5), 272; https://doi.org/10.3390/fermentation11050272 - 9 May 2025

Viewed by 438

Abstract

The study aims to evaluate the feasibility of using defatted Tenebrio molitor larvae proteins as substrates in microbial fermentation, targeting the development of high-value products to combat age-related health issues. Amid increasing demand for sustainable and nutrient-dense food sources, this study investigates the [...] Read more.

The study aims to evaluate the feasibility of using defatted Tenebrio molitor larvae proteins as substrates in microbial fermentation, targeting the development of high-value products to combat age-related health issues. Amid increasing demand for sustainable and nutrient-dense food sources, this study investigates the potential of extracts from Tenebrio molitor larvae as functional bioactive materials. Specifically, it compares the biological antioxidant activities of defatted Tenebrio molitor larvae extracts before (SMNFE) and after (SMFE) fermentation with Saccharomyces cerevisiae. Defatting removes lipids, while fermentation enhances the extract’s bioactivity. Biochemical analyses showed that SMFE had significantly higher total polyphenol (36.04 ± 1.04 μg GAE/mg) and flavonoid (12.69 ± 0.76 μg QE/mg) contents—over three times those of SMNFE. In addition, SMFE exhibited superior radical scavenging activity, reducing power, and electron-donating ability. The total amino acid content also increased by about 18% post-fermentation, with all measured amino acids except arginine showing elevated concentrations. These enhancements demonstrate the effectiveness of yeast fermentation in improving the nutritional and functional properties of insect-derived materials. The findings support the application of fermented insect extracts in medical foods and functional cosmetics, offering a promising direction for future bioconversion technologies. Full article

(This article belongs to the Section Fermentation for Food and Beverages)

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16 pages, 1555 KiB

Open AccessArticle

Improving Nutrition Facts of Cassava and Soybean Residue Through Solid-State Fermentation by Pleurotus ostreatus Mycelium: A Pathway to Safety Animal Feed Production

by Nguyen Thi Bich Hang and Chi Cuong Doan

Fermentation 2025, 11(5), 271; https://doi.org/10.3390/fermentation11050271 - 9 May 2025

Viewed by 341

Abstract

The overwhelming amount of cassava residues and okara are a foremost challenge for the food processing industry environmental loading. The purpose of this article is to utilize Pleurotus ostreatus mycelium to ferment solid cassava and soybean residue, resulting in mycelial biomass with nutritional [...] Read more.

The overwhelming amount of cassava residues and okara are a foremost challenge for the food processing industry environmental loading. The purpose of this article is to utilize Pleurotus ostreatus mycelium to ferment solid cassava and soybean residue, resulting in mycelial biomass with nutritional values and promising prebiotic activities from fermented waste sources. By blending a ratio of 80% cassava and 20% soybean residues, the mycelium spread rapidly after 3 days of culture, from 1.73 mm on the first day to 13.32 mm on the third day, and completely covered the surface after 9 days of culture (120 mm). Using the solid-state fermentation (SSF) method allowed us to improve the content of substances isolated from mycelium biomass, where polysaccharide content rose by 2.1 times to 3.44 mg/g, and the protein content increased by 1.84 times over the initial substrate. The prebiotic activity of extracted PS was greatest in P. acidilactici NBD8 (1.58); for L. pentosus NH1, L. argentoraten NH15, and L. plantarum WCFS1 strains, the indices were 0.11, 0.17, and 0.3, respectively. The SSF process with P. ostreatus mycelium has the potential to be an effective method for improving the nutrition and digestibility of soybean and cassava residues for application in the production of nature-derived animal feed, as well as contributing to fully utilized agricultural residue, agriculture’s circular economy, reducing environmental issues, and achieving the net-zero carbon emissions target by 2050, as the Vietnam government committed to achieving during the COP26 World Leaders’ Summit in 2021. Full article

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16 pages, 775 KiB

Open AccessArticle

Integrated Process Combining High-Temperature Fermentation and Extractive Ethanol Removal via CO₂ Stripping

by Jorge Luíz Silveira Sonego, Jaqueline Machado de Moraes, Nayana Simon de Vargas, Anderson Ferreira da Cunha, Rosineide Gomes da Silva Cruz, Antonio José Gonçalves Cruz and Alberto Colli Badino

Fermentation 2025, 11(5), 270; https://doi.org/10.3390/fermentation11050270 - 9 May 2025

Viewed by 332

Abstract

Fermentation at high temperatures may be a viable alternative for ethanol production, especially in tropical climate regions. This work describes the evaluation of ethanol production through extractive fermentation at high temperatures using thermotolerant Kluyveromyces marxianus. An experimental design was applied to assess [...] Read more.

Fermentation at high temperatures may be a viable alternative for ethanol production, especially in tropical climate regions. This work describes the evaluation of ethanol production through extractive fermentation at high temperatures using thermotolerant Kluyveromyces marxianus. An experimental design was applied to assess the effect of temperature on the ethanol removal process by CO₂ stripping. Subsequently, kinetic modeling of conventional batch ethanol fermentation at high temperatures was performed, and the hybrid Andrews−Levenspiel model was found to be suitable for describing the kinetics of this process. Experiments were conducted to evaluate ethanol production at high temperatures using thermotolerant yeast, specifically evaluating the effects of different specific CO₂ flow rates (ϕ = 1.0, 1.5, and 2.0 vvm) on ethanol stripping. The results indicated that in all the extractive fermentations conducted with K. marxianus, there was faster substrate uptake and earlier substrate exhaustion compared to conventional fermentation. Significant ethanol removal by stripping was achieved using a CO₂ flow rate of 1.0 vvm (EF_HT1), and complete substrate consumption was observed by the end of 12 h of fermentation. This result highlights the positive effect of temperature on ethanol entrainment. In addition, integrating the CO₂ stripping technique with high-temperature fermentation (T = 40 °C) improves process efficiency with a lower gas flow rate. This is advantageous, especially for industrial-scale applications, as it can reduce equipment costs associated with the CO₂ feed. Full article

(This article belongs to the Special Issue YBC2025: Yeast in Bioeconomy)

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14 pages, 277 KiB

Open AccessArticle

Effects of Lactiplantibacillus plantarum from Homemade Pickles on Mixed Maize–Soybean Silage Quality

by Hayrettin Çayıroğlu

Fermentation 2025, 11(5), 269; https://doi.org/10.3390/fermentation11050269 - 8 May 2025

Viewed by 367

Abstract

This study was conducted to determine the influence of Lactiplantibacillus plantarum (LpP) isolated from homemade pickles on chemical, physical, and microbiological properties, in vitro digestibility and feed value, and aerobic stability in pure maize and mixture silages of maize and soybean. The treatment [...] Read more.

This study was conducted to determine the influence of Lactiplantibacillus plantarum (LpP) isolated from homemade pickles on chemical, physical, and microbiological properties, in vitro digestibility and feed value, and aerobic stability in pure maize and mixture silages of maize and soybean. The treatment groups were inoculated maize silage, inoculated soybean silage, inoculated 75% Maize + 25% Soybean silage, inoculated 50% Maize + 50% Soybean silage, inoculated 25% Maize + 75% Soybean silage, and their respective uninoculated control silages. By inoculating maize and soybean combination silages with LpP, these silages’ organic matter content increased, and their neutral and acid detergent fiber contents decreased. In these silages, lactic acid bacteria content and relative feed value increased, while yeast levels decreased, compared to the control silage. Inoculation improved silage quality and aerobic stability by reducing CO₂ production, especially in pure soybean silage, and reduced the in vitro digestible organic matter and net energy lactation value of pure maize and pure soybean silages but did not affect maize-soybean mixed silages. The results showed that LpP isolated from homemade pickles can contribute to increase silage quality with respect to aerobic stability in low-structural carbohydrate contained silage materials, and maize itself for these materials. It can be suggested that LpP isolated from homemade pickles can be safely used as a bacterial inoculant for ensiling crops such as soya crops, which are difficult and risky to ensilage, alone or in mixtures with maize. Full article

17 pages, 1891 KiB

Open AccessArticle

Ultrasound-Assisted Kinetics of Alcoholic Fermentation at Varying Power Levels for the Production of Isaño Wine (Tropaeolum tuberosum)

by Alejandro Coloma, Maria Mamani-Mamani, Cristina Valencia-Sullca, Javier Mamani Paredes, Herbert Callo, Nancy Curasi Rafael, Wilber Cesar Calsina Ponce and Ulises Alvarado

Fermentation 2025, 11(5), 268; https://doi.org/10.3390/fermentation11050268 - 8 May 2025

Viewed by 420

Abstract

Ultrasound is considered a physical technology that can be applied at various stages of food processing to optimise resources and reduce production time. In this study, the influence of ultrasonic treatments at different power levels (0 W, 100 W, 200 W, and 300 [...] Read more.

Ultrasound is considered a physical technology that can be applied at various stages of food processing to optimise resources and reduce production time. In this study, the influence of ultrasonic treatments at different power levels (0 W, 100 W, 200 W, and 300 W) on three Isaño genotypes (yellow, yellow with purple eyes, and purple) during alcoholic fermentation was investigated. The main parameters assessed were yeast growth kinetics, ethanol production, and substrate consumption in an ultrasonic bath operating at a frequency of 50 kHz. The findings demonstrated enhanced yeast growth, accelerated substrate consumption, and increased ethanol production compared to the control (untreated sample). However, the impact of ultrasound on fermentation decreased as the power level increased. Notably, an ultrasonic power of 100 W applied over 84 h of fermentation resulted in the highest ethanol yield (10.36% v/v) in the purple Isaño genotype. In conclusion, ultrasonic treatment is a promising approach to improve the fermentation process of Isaño, potentially enabling its development as a functional beverage with both nutritional and therapeutic properties. Full article

(This article belongs to the Special Issue 10th Anniversary of Fermentation: Feature Papers in the "Fermentation for Food and Beverages" Section)

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14 pages, 3823 KiB

Open AccessArticle

Improvement of L-Tryptophan Production in Escherichia coli Using Biosensor-Based, High-Throughput Screening and Metabolic Engineering

by Zhenghao Gao, Fengli Wu, Zhidan Zhang, Xu Zhang, Yuansen Hu, Qinhong Wang and Shuaibing Zhang

Fermentation 2025, 11(5), 267; https://doi.org/10.3390/fermentation11050267 - 7 May 2025

Viewed by 274

Abstract

The demand for L-tryptophan (L-Trp) has been rapidly increasing across various industries, including pharmaceuticals, food, and animal feed. However, traditional production methods have been unable to efficiently meet this growing demand. Hence, this study aimed to develop strategies for enhancing L-Trp production in [...] Read more.

The demand for L-tryptophan (L-Trp) has been rapidly increasing across various industries, including pharmaceuticals, food, and animal feed. However, traditional production methods have been unable to efficiently meet this growing demand. Hence, this study aimed to develop strategies for enhancing L-Trp production in Escherichia coli. Firstly, an L-Trp-producing strain was selected and subjected to atmospheric and room temperature plasma (ARTP) mutagenesis to generate a mutant library. This was followed by high-throughput screening using an L-Trp-specific riboswitch and a yellow fluorescent protein (YFP)-based biosensor in a flow cytometric cell sorting (FACS) system. Among the screened mutants, GT3938 exhibited a 1.94-fold increase in L-Trp production. Subsequently, rational metabolic engineering was applied to GT3938 by knocking out the L-Trp intracellular transporter gene (tnaB), enhancing the expression of the aromatic amino acid exporter (YddG) and optimizing precursor supply pathways. The resulting strain, zh08, achieved an L-Trp titer of 3.05 g/L in shake-flask fermentation, representing a 7.71-fold improvement over the original strain. This study demonstrated an effective strategy for industrial strain development by integrating biosensor-assisted, high-throughput screening with rational metabolic engineering. Full article

(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)

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16 pages, 1886 KiB

Open AccessArticle

Enhancing Single-Cell Protein Yield Through Grass-Based Substrates: A Study of Lolium perenne and Kluyveromyces marxianus

by Tianyi Guo, Joshua Bode, Katrin Kuka and Nils Tippkötter

Fermentation 2025, 11(5), 266; https://doi.org/10.3390/fermentation11050266 - 7 May 2025

Viewed by 256

Abstract

This study evaluated Lolium perenne press juice as a sustainable substrate for Single-Cell Protein (SCP) production using Kluyveromyces marxianus. Key fermentation parameters were systematically optimized, including microbial reduction, dilution ratios, temperature, and nutrient supplementation. Pasteurization at 75 °C preserved essential nutrients better [...] Read more.

This study evaluated Lolium perenne press juice as a sustainable substrate for Single-Cell Protein (SCP) production using Kluyveromyces marxianus. Key fermentation parameters were systematically optimized, including microbial reduction, dilution ratios, temperature, and nutrient supplementation. Pasteurization at 75 °C preserved essential nutrients better than autoclaving, resulting in a 27.8% increase in biomass yield. A 1:2 dilution of press juice enhanced fermentation efficiency, achieving 20.2% higher biomass despite a lower initial sugar content. Cultivation at 30 °C enabled sustained substrate utilization and outperformed 40 °C fermentation, increasing final biomass by 43.4%. Nutrient supplementation with yeast extract, peptone, and glucose led to the highest biomass yield, with a 71% increase compared to unsupplemented juice. Press juice from the tetraploid variety, Explosion, consistently outperformed the diploid Honroso, especially when harvested early, reaching up to 16.62 g·L⁻¹ biomass. Early harvests promoted faster growth, while late harvests exhibited higher biomass yield coefficients due to improved sugar-to-biomass conversion. Compared to a conventional YM medium, fermentation with L. perenne press juice achieved up to a threefold increase in biomass yield. These findings highlight the potential of grass-based substrates for efficient SCP production and demonstrate how agricultural parameters like variety and harvest timing influence both quantity and quality. The approach supports circular bioeconomy strategies by valorising underutilized biomass through microbial fermentation. Full article

(This article belongs to the Special Issue Fermentation-Driven Biological Structural Modification of Natural Products)

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18 pages, 2023 KiB

Open AccessArticle

Enhancing Kefir with Raspberry Pomace: Storage-Dependent Changes in Quality and Stability

by Sandra Stamenković Stojanović, Ljubica Živković, Jelena Stanojević, Bojana Danilović, Stojan Mančić and Ivana Karabegović

Fermentation 2025, 11(5), 265; https://doi.org/10.3390/fermentation11050265 - 7 May 2025

Viewed by 156

Abstract

This study evaluated the effects of raspberry pomace addition on kefir’s chemical, microbiological, and sensory properties during a 14-day refrigerated storage. Kefir samples were prepared using 10% and 20% raspberry pomace, either retaining or straining out pomace after fermentation. Raspberry pomace notably enhanced [...] Read more.

This study evaluated the effects of raspberry pomace addition on kefir’s chemical, microbiological, and sensory properties during a 14-day refrigerated storage. Kefir samples were prepared using 10% and 20% raspberry pomace, either retaining or straining out pomace after fermentation. Raspberry pomace notably enhanced antioxidant activity, peaking at 95.91% DPPH radical reduction on day 10, and increased total polyphenol content to 78.24 mg gallic acid/L. Pomace addition also improved microbiological stability, maintaining higher lactic acid bacteria (7.48 log CFU/mL) and stable yeast counts. Repeated measures ANOVA revealed a significant effect of storage duration on the concentrations of all analyzed parameters. Results showed that pomace-enriched samples, particularly those retaining pomace during storage, exhibited significantly higher levels of lactic, acetic, and citric acids, as well as ethanol and residual sugars. Sensory evaluations revealed kefir samples with strained raspberry pomace had the highest consumer acceptability, scoring 7.8 out of 9 for overall acceptance due to balanced flavor and improved texture. These results highlight raspberry pomace’s potential as a valuable ingredient for improvement in kefir, offering a promising approach to functional dairy innovation. Full article

(This article belongs to the Topic Fermented Food: Health and Benefit)

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Fermentation, Volume 11, Issue 5 (May 2025) – 61 articles

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