Fermentation

18 pages, 2013 KiB

Open AccessArticle

Enhancing Nutritional Value and Sensory Quality of Spirulina (Arthrospira platensis) Through Preharvest Co-Cultivation with Yeast Saccharomyces cerevisiae

by Yue Zhao, Jikang Sui, Yuxuan Cui, Mingyong Zeng, Haohao Wu, Guangxin Feng and Xiangning Lu

Fermentation 2025, 11(8), 462; https://doi.org/10.3390/fermentation11080462 - 11 Aug 2025

Abstract

Spirulina’s (Arthrospira platensis) use in food applications is limited by its dark color and sulfurous odor. This study aimed to develop a preharvest bioprocessing strategy using Saccharomyces cerevisiae co-cultivation to address these limitations. At a yeast/microalgae biomass ratio of 10:1000 with [...] Read more.

Spirulina’s (Arthrospira platensis) use in food applications is limited by its dark color and sulfurous odor. This study aimed to develop a preharvest bioprocessing strategy using Saccharomyces cerevisiae co-cultivation to address these limitations. At a yeast/microalgae biomass ratio of 10:1000 with 5 g/L of glucose supplementation, co-cultivation for 24 h induced a rapid color transition from dark blue–green to light green and imparted “floral–fruity” aromas. Major bioactive compounds, including β-carotene, linoleic acid, and γ-linolenic acid, increased significantly, while volatile sulfur compounds were eliminated. Chlorophyll a and carotenoid contents rose by over two fold, reflecting enhanced photosynthetic efficiency. Mechanistic analyses revealed that yeast-derived acetic acid upregulated genes involved in flavor precursor biosynthesis and promoted biomass accumulation. This strategy integrates sensory improvement with nutritional enhancement, providing a sustainable approach for developing spirulina-based functional foods. Full article

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14 pages, 1712 KiB

Open AccessArticle

The Role of Quorum Sensing in Enhancing Lovastatin and Pigment Production in Monascus purpureus C322

by Sirisha Yerramalli, Stephen J. Getting, Godfrey Kyazze and Tajalli Keshavarz

Fermentation 2025, 11(8), 461; https://doi.org/10.3390/fermentation11080461 - 11 Aug 2025

Abstract

Monascus purpureus is a filamentous fungus known for producing pharmaceutically valuable secondary metabolites, including azaphilone pigments and lovastatin. Lovastatin is an HMG-CoA reductase inhibitor widely used to manage hypercholesterolaemia, while Monascus pigments serve as natural colourants with antioxidant and antimicrobial properties. This study [...] Read more.

Monascus purpureus is a filamentous fungus known for producing pharmaceutically valuable secondary metabolites, including azaphilone pigments and lovastatin. Lovastatin is an HMG-CoA reductase inhibitor widely used to manage hypercholesterolaemia, while Monascus pigments serve as natural colourants with antioxidant and antimicrobial properties. This study evaluated the impact of quorum-sensing molecules (QSMs)—tyrosol (0.3 mM), farnesol (0.2 mM) and linoleic acid (0.4 mM)—on pigment and lovastatin yields in shake flasks and 2.5 L stirred-tank bioreactors. QSMs were introduced 48 h post-inoculation in shake flasks and 24 h in bioreactors. All QSMs increased yellow (OD₄₀₀), orange (OD₄₇₀), and red (OD₅₁₀) pigments and lovastatin concentration relative to the control, with scale-up further enhancing yields. Farnesol produced the most pronounced effect: in flasks, OD₄₀₀ 7.10 (1.86-fold), OD₄₇₀ 8.00 (2.12-fold), OD₅₁₀ 7.80 (2.08-fold), and 74.6 mg/L lovastatin (2.05-fold); in bioreactors, OD₄₀₀ 11.9 (2.06-fold), OD₄₇₀ 15.1 (2.71-fold), OD₅₁₀ 13.7 (2.47-fold), and 97.2 mg/L lovastatin (2.48-fold). This was followed by tyrosol treatment and then linoleic acid. These findings demonstrate that QSMs—particularly farnesol—significantly (p < 0.01) stimulate pigment and lovastatin biosynthesis in M. purpureus. Quorum sensing modulation represents a promising, scalable strategy to optimise fungal fermentation for industrial metabolite production. Full article

(This article belongs to the Special Issue Scale-Up Challenges in Microbial Fermentation)

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14 pages, 2312 KiB

Open AccessArticle

Isolation and Characterization of Bacteriocin-like-Producing Companilactobacillus farciminis YLR-1 and the Inhibitory Activity of Bacteriocin Against Staphylococcus aureus

by Lirong Yang, Hui Su, Jiayue Wang, Sijia Sun, Sibo Liu, Baishuang Yin, Wenlong Dong and Guojiang Li

Fermentation 2025, 11(8), 460; https://doi.org/10.3390/fermentation11080460 - 11 Aug 2025

Abstract

This study aimed to identify a probiotic bacterium with antagonistic activity against the foodborne pathogen Staphylococcus aureus (S. aureus) and investigate the mechanism of its antibacterial components. Growth kinetics were analyzed to assess bacterial proliferation. Acid and bile salt tolerance are [...] Read more.

This study aimed to identify a probiotic bacterium with antagonistic activity against the foodborne pathogen Staphylococcus aureus (S. aureus) and investigate the mechanism of its antibacterial components. Growth kinetics were analyzed to assess bacterial proliferation. Acid and bile salt tolerance are vital indicators for evaluating probiotic survival in the gastrointestinal tract. The results indicated that Companilactobacillus farciminis (C. farciminis) YLR-1 not only had high tolerance to salt conditions (0.03%, 0.3%, and 0.5%) but also has a high survival rate at pH 3–4. The bacteriocin-like inhibitory substance (BLIS) isolated from C. farciminis YLR-1 was dialyzed using a membrane with a molecular weight cut-off (MWCO) of 500 Da, followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The results indicate that the BLIS produced by C. farciminis YLR-1 is a small-molecule peptide. BLIS displayed pH tolerance within acidic and neutral environments (4–8) and exhibited thermostability. When treated with proteinase K, the antibacterial action of BLIS was found to be inactivated. Membrane disruption mechanisms were examined using fluorescence imaging and scanning electron microscopy (SEM). SEM and fluorescence imaging revealed that BLIS-induced membrane damage in S. aureus ATCC 25923 causes cytoplasmic leakage and cell death. Full article

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

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18 pages, 2191 KiB

Open AccessArticle

Neuroprotective Properties of Fermented Malted Rice Obtained Under Different Processing Conditions

by Micaela Albarracín, Franco Van de Velde, Raúl E. Cian and Silvina R. Drago

Fermentation 2025, 11(8), 459; https://doi.org/10.3390/fermentation11080459 - 10 Aug 2025

Abstract

Two products fermented with lactic acid bacteria (LAB) were obtained using malted rice (FR) and mashed malted rice (FMR). Peptide, phenolic acids, and γ-aminobutyric acid (GABA) contents and neuroprotective activities were evaluated before and after simulated gastrointestinal digestion. GABA contents of fermented products [...] Read more.

Two products fermented with lactic acid bacteria (LAB) were obtained using malted rice (FR) and mashed malted rice (FMR). Peptide, phenolic acids, and γ-aminobutyric acid (GABA) contents and neuroprotective activities were evaluated before and after simulated gastrointestinal digestion. GABA contents of fermented products were 45 and 51 mg 100 g⁻¹, with a bioaccessibility of 51 and 45% for FR and FMR, respectively. Both fermented malted rice products exhibited inhibitory effects against tyrosinase, acetylcholinesterase, and prolyl oligopeptidase, with FR demonstrating the highest inhibitory activity. The neuroprotective properties were increased after digestion and could potentially be attributed to bioactive peptides generated by germination, fermentation, and digestion, as well as free phenolic acids. These findings suggest that fermented malted rice possesses promising biofunctional properties and may serve as suitable dietary options for individuals with gluten and lactose intolerance, offering additional neuroprotective benefits. Full article

(This article belongs to the Special Issue Recent Trends in Lactobacillus and Fermented Food, 3rd Edition)

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26 pages, 1638 KiB

Open AccessReview

In Silico Modeling of Metabolic Pathways in Probiotic Microorganisms for Functional Food Biotechnology

by Baiken B. Baimakhanova, Amankeldi K. Sadanov, Irina A. Ratnikova, Gul B. Baimakhanova, Saltanat E. Orasymbet, Aigul A. Amitova, Gulzat S. Aitkaliyeva and Ardak B. Kakimova

Fermentation 2025, 11(8), 458; https://doi.org/10.3390/fermentation11080458 - 7 Aug 2025

Viewed by 319

Abstract

Recent advances in computational biology have provided powerful tools for analyzing, modeling, and optimizing probiotic microorganisms, thereby supporting their development as promising agents for improving human health. The essential role of the microbiota in regulating physiological processes and preventing disease has driven interest [...] Read more.

Recent advances in computational biology have provided powerful tools for analyzing, modeling, and optimizing probiotic microorganisms, thereby supporting their development as promising agents for improving human health. The essential role of the microbiota in regulating physiological processes and preventing disease has driven interest in the rational design of next-generation probiotics. This review highlights progress in in silico approaches for enhancing the functionality of probiotic strains. Particular attention is given to genome-scale metabolic models, advanced simulation algorithms, and AI-driven tools that provide deeper insight into microbial metabolism and enable precise probiotic optimization. The integration of these methods with multi-omics data has greatly improved our ability to predict strain behavior and design probiotics with specific health benefits. Special focus is placed on modeling probiotic–prebiotic interactions and host–microbiome dynamics, which are essential for the development of functional food products. Despite these achievements, key challenges remain, including limited model accuracy, difficulties in simulating complex host–microbe systems, and the absence of unified standards for validating in silico-optimized strains. Addressing these gaps requires the development of integrative modeling platforms and clear regulatory frameworks. This review provides a critical overview of current advances, identifies existing barriers, and outlines future directions for the application of computational strategies in probiotic research. Full article

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

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20 pages, 3734 KiB

Open AccessReview

Microbial Community and Metabolic Pathways in Anaerobic Digestion of Organic Solid Wastes: Progress, Challenges and Prospects

by Jiachang Cao, Chen Zhang, Xiang Li, Xueye Wang, Xiaohu Dai and Ying Xu

Fermentation 2025, 11(8), 457; https://doi.org/10.3390/fermentation11080457 - 7 Aug 2025

Viewed by 315

Abstract

Anaerobic digestion (AD) is a sustainable and widely adopted technology for the treatment of organic solid wastes (OSWs). However, AD efficiency varies significantly across different substrates, primarily due to differences in the microbial community and metabolic pathways. This review provides a comprehensive summary [...] Read more.

Anaerobic digestion (AD) is a sustainable and widely adopted technology for the treatment of organic solid wastes (OSWs). However, AD efficiency varies significantly across different substrates, primarily due to differences in the microbial community and metabolic pathways. This review provides a comprehensive summary of the AD processes for four types of typical OSWs (i.e., sewage sludge, food waste, livestock manure, and straw), with an emphasis on their universal characteristics across global contexts, focusing mainly on the electron transfer mechanisms, essential microbial communities, and key metabolic pathways. Special attention was given to the mechanisms by which substrate-specific structural differences influence anaerobic digestion efficiency, with a focused analysis and discussion on how different components affect microbial communities and metabolic pathways. This study concluded that the hydrogenotrophic methanogenesis pathway, TCA cycle, and the Wood–Ljungdahl pathway serve as critical breakthrough points for enhancing methane production potential. This research not only provides a theoretical foundation for optimizing AD efficiency, but also offers crucial scientific insights for resource recovery and energy utilization of OSWs, making significant contributions to advancing sustainable waste management practices. Full article

(This article belongs to the Special Issue Feature Review Papers in Industrial Fermentation, 2nd Edition)

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22 pages, 1419 KiB

Open AccessArticle

Bioconversion of Olive Pomace: A Solid-State Fermentation Strategy with Aspergillus sp. for Detoxification and Enzyme Production

by Laura A. Rodríguez, María Carla Groff, Sofía Alejandra Garay, María Eugenia Díaz, María Fabiana Sardella and Gustavo Scaglia

Fermentation 2025, 11(8), 456; https://doi.org/10.3390/fermentation11080456 - 6 Aug 2025

Viewed by 215

Abstract

This study aimed to evaluate solid-state fermentation (SSF) as a sustainable approach for the simultaneous detoxification of olive pomace (OP) and the production of industrially relevant enzymes. OP, a semisolid byproduct of olive oil extraction, is rich in lignocellulose and phenolic compounds, which [...] Read more.

This study aimed to evaluate solid-state fermentation (SSF) as a sustainable approach for the simultaneous detoxification of olive pomace (OP) and the production of industrially relevant enzymes. OP, a semisolid byproduct of olive oil extraction, is rich in lignocellulose and phenolic compounds, which limit its direct reuse due to phytotoxicity. A native strain of Aspergillus sp., isolated from OP, was employed as the biological agent, while grape pomace (GP) was added as a co-substrate to enhance substrate structure. Fermentations were conducted at two scales, Petri dishes (20 g) and a fixed-bed bioreactor (FBR, 2 kg), under controlled conditions (25 °C, 7 days). Key parameters monitored included dry and wet weight loss, pH, color, phenolic content, and enzymatic activity. Significant reductions in color and polyphenol content were achieved, reaching 68% in Petri dishes and 88.1% in the FBR, respectively. In the FBR, simultaneous monitoring of dry and wet weight loss enabled the estimation of fungal biotransformation, revealing a hysteresis phenomenon not previously reported in SSF studies. Enzymes such as xylanase, endopolygalacturonase, cellulase, and tannase exhibited peak activities between 150 and 180 h, with maximum values of 424.6 U·g⁻¹, 153.6 U·g⁻¹, 67.43 U·g⁻¹, and 6.72 U·g⁻¹, respectively. The experimental data for weight loss, enzyme production, and phenolic reduction were accurately described by logistic and first-order models. These findings demonstrate the high metabolic efficiency of the fungal isolate under SSF conditions and support the feasibility of scaling up this process. The proposed strategy offers a low-cost and sustainable solution for OP valorization, aligning with circular economy principles by transforming agro-industrial residues into valuable bioproducts. Full article

(This article belongs to the Topic Biomass: Advanced Strategies for Renewable Chemicals and Energy Production)

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2 pages, 960 KiB

Open AccessCorrection

Correction: Mu et al. Mixed Inoculation with Lacticaseibacillus casei and Staphylococcus carnosus Improves Safety, Gel Properties and Flavor of Giant Squid Surimi Without Added Seasonings. Fermentation 2025, 11, 404

by Hongliang Mu, Peifang Weng and Zufang Wu

Fermentation 2025, 11(8), 455; https://doi.org/10.3390/fermentation11080455 - 5 Aug 2025

Viewed by 178

Abstract

In the original publication [...] Full article

(This article belongs to the Special Issue Functional Properties of Microorganisms in Fermented Foods, 2nd Edition)

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20 pages, 753 KiB

Open AccessArticle

Production of Vegan Ice Cream: Enrichment with Fermented Hazelnut Cake

by Levent Yurdaer Aydemir, Hande Demir, Zafer Erbay, Elif Kılıçarslan, Pelin Salum and Melike Beyza Ozdemir

Fermentation 2025, 11(8), 454; https://doi.org/10.3390/fermentation11080454 - 4 Aug 2025

Viewed by 602

Abstract

The growing demand for sustainable plant-based dairy alternatives has spurred interest in valorizing agro-industrial byproducts like hazelnut cake, a protein-rich byproduct of oil extraction. This study developed formulations for vegan ice cream using unfermented (HIC) and Aspergillus oryzae-fermented hazelnut cake (FHIC), comparing [...] Read more.

The growing demand for sustainable plant-based dairy alternatives has spurred interest in valorizing agro-industrial byproducts like hazelnut cake, a protein-rich byproduct of oil extraction. This study developed formulations for vegan ice cream using unfermented (HIC) and Aspergillus oryzae-fermented hazelnut cake (FHIC), comparing their physicochemical, functional, and sensory properties to conventional dairy ice cream (DIC). Solid-state fermentation (72 h, 30 °C) enhanced the cake’s bioactive properties, and ice creams were characterized for composition, texture, rheology, melting behavior, antioxidant activity, and enzyme inhibition pre- and post-in vitro digestion. The results indicate that FHIC had higher protein content (64.64% vs. 58.02% in HIC) and unique volatiles (e.g., benzaldehyde and 3-methyl-1-butanol). While DIC exhibited superior overrun (15.39% vs. 4.01–7.00% in vegan samples) and slower melting, FHIC demonstrated significantly higher post-digestion antioxidant activity (4.73 μmol TE/g DPPH vs. 1.44 in DIC) and angiotensin-converting enzyme (ACE) inhibition (4.85–7.42%). Sensory evaluation ranked DIC highest for overall acceptability, with FHIC perceived as polarizing due to pronounced flavors. Despite textural challenges, HIC and FHIC offered nutritional advantages, including 18–30% lower calories and enhanced bioactive compounds. This study highlights fermentation as a viable strategy to upcycle hazelnut byproducts into functional vegan ice creams, although the optimization of texture and flavor is needed for broader consumer acceptance. Full article

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

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14 pages, 2011 KiB

Open AccessArticle

Circulating of In Situ Recovered Stream from Fermentation Broth as the Liquor for Lignocellulosic Biobutanol Production

by Changsheng Su, Yunxing Gao, Gege Zhang, Xinyue Zhang, Yating Li, Hongjia Zhang, Hao Wen, Wenqiang Ren, Changwei Zhang and Di Cai

Fermentation 2025, 11(8), 453; https://doi.org/10.3390/fermentation11080453 - 3 Aug 2025

Viewed by 322

Abstract

Developing a more efficient, cleaner, and energy-saving pretreatment process is the primary goal for lignocellulosic biofuels production. This study demonstrated the feasibility of circulating high-concentration acetone–butanol–ethanol (ABE) obtained via in situ product recovery (ISPR) as a pretreatment liquor. Taking ABE solvent separated from [...] Read more.

Developing a more efficient, cleaner, and energy-saving pretreatment process is the primary goal for lignocellulosic biofuels production. This study demonstrated the feasibility of circulating high-concentration acetone–butanol–ethanol (ABE) obtained via in situ product recovery (ISPR) as a pretreatment liquor. Taking ABE solvent separated from pervaporation (PV) and gas stripping (GS) as examples, results indicated that under dilute alkaline (1% NaOH) catalysis, the highly recalcitrant lignocellulosic matrices can be efficiently depolymerized, thereby improving fermentable sugars recovery in saccharification stage and ABE yield in subsequent fermentation stage. Results also revealed delignification of 91.5% (stream from PV) and 94.3% (stream from GS), with total monosaccharides recovery rates of 56.5% and 57.1%, respectively, can be realized when using corn stover as feedstock. Coupled with ABE fermentation, mass balance indicated a maximal 106.6 g of ABE (65.8 g butanol) can be produced from 1 kg of dry corn stover by circulating the GS condensate in pretreatment (the optimized pretreatment conditions were 1% w/v alkali and 160 °C for 1 h). Additionally, technical lignin with low molecular weight and narrow distribution was isolated, which enabled further side-stream valorisation. Therefore, integrating ISPR product circulation with lignocellulosic biobutanol shows strong potential for application under the concept of biorefinery. Full article

(This article belongs to the Special Issue Technological Advances in Lignocellulosic Biomass Conversion to Bioenergy)

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19 pages, 5733 KiB

Open AccessArticle

The Production Optimization of a Thermostable Phytase from Bacillus subtilis SP11 Utilizing Mustard Meal as a Substrate

by Md. Al Muid Khan, Sabina Akhter, Tanjil Arif, Md. Mahmuduzzaman Mian, Md. Arafat Al Mamun, Muhammad Manjurul Karim and Shakila Nargis Khan

Fermentation 2025, 11(8), 452; https://doi.org/10.3390/fermentation11080452 - 3 Aug 2025

Viewed by 395

Abstract

Phytate, an antinutritional molecule in poultry feed, can be degraded by applying phytase, but its use in low- and middle-income countries is often limited due to importation instead of local production. Here, inexpensive raw materials were used to optimize the production of a [...] Read more.

Phytate, an antinutritional molecule in poultry feed, can be degraded by applying phytase, but its use in low- and middle-income countries is often limited due to importation instead of local production. Here, inexpensive raw materials were used to optimize the production of a thermostable phytase from an indigenous strain of Bacillus subtilis SP11 that was isolated from a broiler farm in Dhaka. SP11 was identified using 16s rDNA and the fermentation of phytase was optimized using a Plackett–Burman design and response surface methodology, revealing that three substrates, including the raw material mustard meal (2.21% w/v), caused a maximum phytase production of 436 U/L at 37 °C and 120 rpm for 72 h, resulting in a 3.7-fold increase compared to unoptimized media. The crude enzyme showed thermostability up to 80 °C (may withstand the feed pelleting process) with an optimum pH of 6 (near pH of poultry small-intestine), while retaining 96% activity at 41 °C (the body temperature of the chicken). In vitro dephytinization demonstrated its applicability, releasing 978 µg of inorganic phosphate per g of wheat bran per hour. This phytase has the potential to reduce the burden of phytase importation in Bangladesh by making local production and application possible, contributing to sustainable poultry nutrition. Full article

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

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21 pages, 1458 KiB

Open AccessArticle

Production of a Biosurfactant for Application in the Cosmetics Industry

by Ana Paula Barbosa Cavalcanti, Gleice Paula de Araújo, Káren Gercyane de Oliveira Bezerra, Fabíola Carolina Gomes de Almeida, Maria da Glória Conceição da Silva, Alessandra Sarubbo, Cláudio José Galdino da Silva Júnior, Rita de Cássia Freire Soares da Silva and Leonie Asfora Sarubbo

Fermentation 2025, 11(8), 451; https://doi.org/10.3390/fermentation11080451 - 2 Aug 2025

Viewed by 529

Abstract

The cosmetics industry has been seeking to develop products with renewable natural ingredients to reduce the use of or even replace synthetic substances. Biosurfactants can help meet this demand. These natural compounds are renewable, biodegradable, and non-toxic or have low toxicity, offering minimal [...] Read more.

The cosmetics industry has been seeking to develop products with renewable natural ingredients to reduce the use of or even replace synthetic substances. Biosurfactants can help meet this demand. These natural compounds are renewable, biodegradable, and non-toxic or have low toxicity, offering minimal risk to humans and the environment, which has attracted the interest of an emerging consumer market and, consequently, the cosmetics industry. The aim of the present study was to produce a biosurfactant from the yeast Starmerella bombicola ATCC 22214 cultivated in a mineral medium containing 10% soybean oil and 5% glucose. The biosurfactant reduced the surface tension of water from 72.0 ± 0.1 mN/m to 33.0 ± 0.3 mN/m after eight days of fermentation. The yield was 53.35 ± 0.39 g/L and the critical micelle concentration was 1000 mg/L. The biosurfactant proved to be a good emulsifier of oils used in cosmetic formulations, with emulsification indices ranging from 45.90 ± 1.69% to 68.50 ± 1.10%. The hydrophilic–lipophilic balance index demonstrated the wetting capacity of the biosurfactant and its tendency to form oil-in-water (O/W) emulsions, with 50.0 ± 0.20% foaming capacity. The biosurfactant did not exhibit cytotoxicity in the MTT assay or irritant potential. Additionally, an antioxidant activity of 58.25 ± 0.32% was observed at a concentration of 40 mg/mL. The compound also exhibited antimicrobial activity against various pathogenic microorganisms. The characterisation of the biosurfactant using magnetic nuclear resonance and Fourier transform infrared spectroscopy revealed that the biomolecule is a glycolipid with an anionic nature. The results demonstrate that biosurfactant produced in this work has potential as an active biotechnological ingredient for innovative, eco-friendly cosmetic formulations. Full article

(This article belongs to the Special Issue The Industrial Feasibility of Biosurfactants)

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22 pages, 2868 KiB

Open AccessArticle

Impact of Heat Stress on Rumen Fermentation Patterns and Microbiota Diversity and Its Association with Thermotolerance in Indigenous Goats

by Mullakkalparambil Velayudhan Silpa, Veerasamy Sejian, Chinnasamy Devaraj, Artabandhu Sahoo and Raghavendra Bhatta

Fermentation 2025, 11(8), 450; https://doi.org/10.3390/fermentation11080450 - 1 Aug 2025

Viewed by 316

Abstract

Goats are considered to be the ideal climate-resilient animal species in the tropics. Fewer studies are documented assessing the heat stress response of caprine ruminal microbiota, which can also be a crucial indicator of the resilience and/or adaptability of animals. This study was [...] Read more.

Goats are considered to be the ideal climate-resilient animal species in the tropics. Fewer studies are documented assessing the heat stress response of caprine ruminal microbiota, which can also be a crucial indicator of the resilience and/or adaptability of animals. This study was conducted to comparatively assess the heat stress responses of two indigenous goat breeds, Nandidurga and Bidri, based on changes associated with the rumen fermentation pattern and distribution pattern of rumen microbiota. A total of 24 adult animals were randomly allocated into four groups of six animals each, NC (n = 6; Nandidurga control), NHS (n = 6; Nandidurga heat stress), BC (n = 6; Bidri control) and BHS (n = 6; Bidri heat stress). The animals were reared in climate chambers for a duration of 45 days wherein the NC and BC animals were maintained under thermoneutral temperature while the NHS and BHS animals were subjected to simulated heat stress. Heat stress was observed to significantly reduce the rumen ammonia, extracellular CMCase, intracellular carboxy methyl cellulase (CMCase) and total CMCase both in Nandidurga and Bidri goats. In addition to this, a significant reduction in acetate, propionate and total volatile fatty acids (VFAs) was observed in Nandidurga goats. The V3–V4 16s rRNA sequencing further revealed a significant alteration in the rumen microbiota in heat-stressed Nandidurga and Bidri goats. While both the breeds exhibited nearly similar responses in the rumen microbial abundance levels due to heat stress, breed-specific differences were also observed. Furthermore, the LEFSe analysis revealed a significant alteration in the abundances of microbes at the genus level, which were observed to be relatively greater in Bidri goats than Nandidurga goats. Furthermore, these alterations were predicted to impair the functional pathways, especially pathways associated with metabolism. This study therefore provided an insight into the rumen microbial dynamics in heat-stressed goats. Though both the breeds exhibited excellent resilience to the subjected heat stress, there were relatively less ruminal alterations in Nandidurga goats than in Bidri goats. Full article

(This article belongs to the Special Issue Research Progress of Rumen Fermentation)

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17 pages, 1511 KiB

Open AccessArticle

Impact of Selected Starter-Based Sourdough Types on Fermentation Performance and Bio-Preservation of Bread

by Khadija Atfaoui, Sara Lebrazi, Anas Raffak, Youssef Chafai, Karima El Kabous, Mouhcine Fadil and Mohammed Ouhssine

Fermentation 2025, 11(8), 449; https://doi.org/10.3390/fermentation11080449 - 1 Aug 2025

Viewed by 425

Abstract

The aim of this study is to evaluate the effects of different types of sourdough (I to IV), developed with a specific starter culture (including Lactiplantibacillus plantarum, Levilactobacillus brevis, and Candida famata), on bread fermentation performance and shelf-life. Real-time tracking of multiple [...] Read more.

The aim of this study is to evaluate the effects of different types of sourdough (I to IV), developed with a specific starter culture (including Lactiplantibacillus plantarum, Levilactobacillus brevis, and Candida famata), on bread fermentation performance and shelf-life. Real-time tracking of multiple parameters (pH, dough rising, ethanol release, and total titratable acidity) was monitored by a smart fermentation oven. The impact of the different treatments on the lactic acid, acetic acid, and ethanol content of the breads were quantified by high performance liquid chromatography analysis. In addition, the bio-preservation capacity of the breads contaminated with fungi was analyzed. The results show that liquid sourdough (D3: Type 2) and backslopped sourdough (D4: Type 3) increased significantly (p < 0.05) in dough rise, dough acidification (lower pH, higher titratable acidity), production of organic acids (lactic and acetic), and presented the optimal fermentation quotient. These findings were substantiated by chemometric analysis, which successfully clustered the starters based on performance and revealed a strong positive correlation between acetic acid production and dough-rise, highlighting the superior heterofermentative profile of D3 and D4. These types of sourdough also stood out for their antifungal capacity, preventing the visible growth of Aspergillus niger and Penicillium commune for up to 10 days after inoculation. Full article

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

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13 pages, 553 KiB

Open AccessArticle

Biorefinery-Based Energy Recovery from Algae: Comparative Evaluation of Liquid and Gaseous Biofuels

by Panagiotis Fotios Chatzimaliakas, Dimitrios Malamis, Sofia Mai and Elli Maria Barampouti

Fermentation 2025, 11(8), 448; https://doi.org/10.3390/fermentation11080448 - 1 Aug 2025

Viewed by 394

Abstract

In recent years, biofuels and bioenergy derived from algae have gained increasing attention, fueled by the growing demand for renewable energy sources and the urgent need to lower CO₂ emissions. This research examines the generation of bioethanol and biomethane using freshly harvested [...] Read more.

In recent years, biofuels and bioenergy derived from algae have gained increasing attention, fueled by the growing demand for renewable energy sources and the urgent need to lower CO₂ emissions. This research examines the generation of bioethanol and biomethane using freshly harvested and sedimented algal biomass. Employing a factorial experimental design, various trials were conducted, with ethanol yield as the primary optimization target. The findings indicated that the sodium hydroxide concentration during pretreatment and the amylase dosage in enzymatic hydrolysis were key parameters influencing the ethanol production efficiency. Under optimized conditions—using 0.3 M NaOH, 25 μL/g starch, and 250 μL/g cellulose—fermentation yielded ethanol concentrations as high as 2.75 ± 0.18 g/L (45.13 ± 2.90%), underscoring the significance of both enzyme loading and alkali treatment. Biomethane potential tests on the residues of fermentation revealed reduced methane yields in comparison with the raw algal feedstock, with a peak value of 198.50 ± 25.57 mL/g volatile solids. The integrated process resulted in a total energy recovery of up to 809.58 kWh per tonne of algal biomass, with biomethane accounting for 87.16% of the total energy output. However, the energy recovered from unprocessed biomass alone was nearly double, indicating a trade-off between sequential valorization steps. A comparison between fresh and dried feedstocks also demonstrated marked differences, largely due to variations in moisture content and biomass composition. Overall, this study highlights the promise of integrated algal biomass utilization as a viable and energy-efficient route for sustainable biofuel production. Full article

(This article belongs to the Special Issue Algae Biotechnology for Biofuel Production and Bioremediation)

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16 pages, 1130 KiB

Open AccessArticle

Biotechnological Potential of Weizmannia ginsengihumi in the Conversion of Xylose into Lactic Acid: A Sustainable Strategy

by Larissa Provasi Santos, Ingrid Yoshimura, Fernanda Batista de Andrade and Jonas Contiero

Fermentation 2025, 11(8), 447; https://doi.org/10.3390/fermentation11080447 - 31 Jul 2025

Viewed by 352

Abstract

The aim of this study was to isolate Weizmannia spp. that produce lactic acid from xylose and use an experimental design to optimize the production of the metabolite. After isolation, the experiments were conducted in xylose-yeast extract-peptone medium. The identification of isolates was [...] Read more.

The aim of this study was to isolate Weizmannia spp. that produce lactic acid from xylose and use an experimental design to optimize the production of the metabolite. After isolation, the experiments were conducted in xylose-yeast extract-peptone medium. The identification of isolates was performed using the 16S rDNA PCR technique, followed by sequencing. A central composite rotatable design (CCRD) was used to optimize the concentrations of the carbon source (xylose), nitrogen source (yeast extract and peptone), and sodium acetate. Two strains were considered promising for lactic acid production, with W. coagulans BLMI achieving greater lactic acid production under anaerobic conditions (21.93 ± 0.9 g·L⁻¹) and a yield of 69.18%, while the strain W. ginsengihumi BMI was able to produce 19.79 ± 0.8 g·L⁻¹, with a yield of 70.46%. CCRD was used with the W. ginsengihumi strain due to the lack of records in the literature on its use for lactic acid production. The carbon and nitrogen sources influenced the response, but the interactions of the variables were nonsignificant (p < 0.05). The response surface analysis indicated that the optimal concentrations of carbon and nitrogen sources were 32.5 and 3.0 g·L⁻¹, respectively, without the need to add sodium acetate to the culture medium, leading to the production of 20.02 ± 0.19 g·L⁻¹, productivity of 0.55 g/L/h after 36 h of fermentation, and a residual sugar concentration of 12.59 ± 0.51 g·L⁻¹. These results demonstrate the potential of W. ginsengihumi BMI for the production of lactic acid by xylose fermentation since it is carried out at 50 °C, indicating a path for future studies Full article

(This article belongs to the Special Issue New Research on Strains Improvement and Microbial Biosynthesis, 2nd Edition)

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20 pages, 1664 KiB

Open AccessArticle

Phenolic Evolution During Industrial Red Wine Fermentations with Different Sequential Air Injection Regimes

by Paula A. Peña-Martínez, Alvaro Peña-Neira and V. Felipe Laurie

Fermentation 2025, 11(8), 446; https://doi.org/10.3390/fermentation11080446 - 31 Jul 2025

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Abstract

During red wine production, managing the pomace cap is key for a successful fermentation, allowing the extraction of phenolics and other metabolites and providing the necessary oxygen for yeast activity. In recent years, automatic cap management systems based on the injection of gases [...] Read more.

During red wine production, managing the pomace cap is key for a successful fermentation, allowing the extraction of phenolics and other metabolites and providing the necessary oxygen for yeast activity. In recent years, automatic cap management systems based on the injection of gases have gained popularity, despite the limited scientific information regarding the outcomes of their use. This trial aimed to evaluate the composition of wine during industrial red wine fermentations using an automatic sequential air injection system (i.e., AirMixing MI^TM). Fourteen lots of Cabernet Sauvignon grapes were fermented using four air injection regimes, where the intensity and daily frequency of air injections were set to either low or high. As expected, the treatment combining high-intensity and high-frequency air injection produced the largest dissolved oxygen peaks reaching up to 1.9 mg L⁻¹ per cycle, compared to 0.1 mg L⁻¹ in the low-intensity and low-frequency treatment. Yet, in all cases, little to no accumulation of oxygen overtime was observed. Regarding phenolics, the highest intensity and frequency of air injections led to the fastest increase in total phenolics, anthocyanins, short polymeric pigments, and tannin concentration, although compositional differences among treatments equilibrate by the end of fermentation. The main differences in phenolic compounds observed during fermentation were mediated by temperature variation among wine tanks. Based on these findings, it is advisable to keep the characterizing kinetics of phenolic extraction and expand the study to the aroma evolution of wines fermented with this technology. Full article

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

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15 pages, 1919 KiB

Open AccessArticle

Degradation of Microplastics in an In Vitro Ruminal Environment

by Sonia Tassone, Rabeb Issaoui, Valentina Balestra, Salvatore Barbera, Marta Fadda, Hatsumi Kaihara, Sara Glorio Patrucco, Stefania Pragliola, Vincenzo Venditto and Khalil Abid

Fermentation 2025, 11(8), 445; https://doi.org/10.3390/fermentation11080445 - 31 Jul 2025

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Abstract

Microplastic (MP) pollution is an emerging concern in ruminant production, as animals are exposed to MPs through air, water, and feeds. Ruminants play a key role in MP transmission to humans via animal products and contribute to MP return to agricultural soil through [...] Read more.

Microplastic (MP) pollution is an emerging concern in ruminant production, as animals are exposed to MPs through air, water, and feeds. Ruminants play a key role in MP transmission to humans via animal products and contribute to MP return to agricultural soil through excreta. Identifying effective strategies to mitigate MP pollution in the ruminant sector is crucial. A promising yet understudied approach involves the potential ability of rumen microbiota to degrade MPs. This study investigated the in vitro ruminal degradation of three widely distributed MPs—low-density polyethylene (LDPE), polyethylene terephthalate (PET), and polyamide (PA)—over 24, 48, and 72 h. PET MP exhibited the highest degradation rates (24 h: 0.50 ± 0.070%; 48 h: 0.73 ± 0.057%; and 72 h: 0.96 ± 0.082%), followed by LDPE MP (24 h: 0.03 ± 0.020%; 48 h: 0.25 ± 0.053%; and 72 h: 0.56 ± 0.066%) and PA MP (24 h: 0.10 ± 0.045%; 48 h: 0.02 ± 0.015%; and 72 h: 0.14 ± 0.067%). These findings suggest that the ruminal environment could serve as a promising tool for LDPE, PET, and PA MPs degradation. Further research is needed to elucidate the mechanisms involved, potentially enhancing ruminants’ natural capacity to degrade MPs. Full article

(This article belongs to the Special Issue Ruminal Fermentation: 2nd Edition)

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16 pages, 2259 KiB

Open AccessArticle

Probiotic Potential and Characterization of Enterococcus faecium Strains Isolated from Camel Milk: Implications for Animal Health and Dairy Products

by Imen Fguiri, Manel Ziadi, Samira Arroum, Touhami Khorchani and Hammadi Mohamed

Fermentation 2025, 11(8), 444; https://doi.org/10.3390/fermentation11080444 - 31 Jul 2025

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Abstract

In this study, 62 lactic acid bacteria (LAB) strains were isolated from raw camel milk and evaluated for their probiotic potential. The strains exhibited significant variability in their ability to withstand simulated gastrointestinal conditions. Of the isolates, only 26 survived exposure to pH [...] Read more.

In this study, 62 lactic acid bacteria (LAB) strains were isolated from raw camel milk and evaluated for their probiotic potential. The strains exhibited significant variability in their ability to withstand simulated gastrointestinal conditions. Of the isolates, only 26 survived exposure to pH 2, and just 10 were tolerant to 0.3% bile salts. Partial sequencing of the 16S rRNA gene identified all the strains as belonging to the species Enterococcus faecium. Several probiotic traits were assessed, including adhesion to gastric mucin and STC-1 intestinal epithelial cells, as well as auto-aggregation and co-aggregation capacities. Although adhesion to hydrophobic solvents such as chloroform and ethyl acetate was generally low to moderate, all the strains demonstrated strong adhesion to gastric mucin, exceeding 60% at all the growth stages. Notably, two strains—SCC1-33 and SLch6—showed particularly high adhesion to STC-1 cells, with values of 7.8 × 10³ and 4.2 × 10³ CFU/mL, respectively. The strains also exhibited promising aggregation properties, with auto-aggregation and co-aggregation ranging between 33.10% and 63.10%. Furthermore, all the isolates displayed antagonistic activity against Listeria innocua, Micrococcus luteus, and Escherichia coli. Cytotoxicity assays confirmed that none of the tested strains had harmful effects on STC-1 cells, indicating their safety and supporting their potential application as probiotics. Full article

(This article belongs to the Special Issue Probiotics, Prebiotics and Their Use as Innovative Ingredients in Food Technology, 2nd Edition)

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14 pages, 4298 KiB

Open AccessArticle

Construction of Synthetic Microbial Communities for Fermentation of Mung Bean Sour Pulp and Analysis of Nutritional Components

by Yanfang Zhang, Luwei Cao, Haining Yang, Peng Li and Dahong Wang

Fermentation 2025, 11(8), 443; https://doi.org/10.3390/fermentation11080443 - 31 Jul 2025

Viewed by 413

Abstract

To explore an industrial fermentation approach for traditional mung bean sour pulp, this study isolated core microorganisms including lactic acid bacteria and yeasts from naturally fermented samples and constructed a synthetic microbial community. The optimized community consisted of Lactiplantibacillus pentosus, Lactococcus garvieae [...] Read more.

To explore an industrial fermentation approach for traditional mung bean sour pulp, this study isolated core microorganisms including lactic acid bacteria and yeasts from naturally fermented samples and constructed a synthetic microbial community. The optimized community consisted of Lactiplantibacillus pentosus, Lactococcus garvieae, and Cyberlindnera jadinii at a ratio of 7:3:0.1 and was used to ferment cooked mung bean pulp with a material-to-water ratio of 1:8 and 1% sucrose addition. Under these conditions, the final product exhibited significantly higher levels of protein (4.55 mg/mL), flavonoids (0.10 mg/mL), polyphenols (0.11 mg/mL), and vitamin C (7.75 μg/mL) than traditionally fermented mung bean sour pulp, along with enhanced antioxidant activity. The analysis of organic acids, free amino acids, and volatile compounds showed that lactic acid was the main acid component, the bitter amino acid content was reduced, the volatile flavor compounds were more abundant, and the level of harmful compound dimethyl sulfide was significantly decreased. These results indicate that fermentation using a synthetic microbial community effectively improved the nutritional quality, flavor, and safety of mung bean sour pulp. Full article

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19 pages, 2442 KiB

Open AccessArticle

Monitoring C. vulgaris Cultivations Grown on Winery Wastewater Using Flow Cytometry

by Teresa Lopes da Silva, Thiago Abrantes Silva, Bruna Thomazinho França, Belina Ribeiro and Alberto Reis

Fermentation 2025, 11(8), 442; https://doi.org/10.3390/fermentation11080442 - 31 Jul 2025

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Abstract

Winery wastewater (WWW), if released untreated, poses a serious environmental threat due to its high organic load. In this study, Chlorella vulgaris was cultivated in diluted WWW to assess its suitability as a culture medium. Two outdoor cultivation systems—a 270 L raceway and [...] Read more.

Winery wastewater (WWW), if released untreated, poses a serious environmental threat due to its high organic load. In this study, Chlorella vulgaris was cultivated in diluted WWW to assess its suitability as a culture medium. Two outdoor cultivation systems—a 270 L raceway and a 40 L bubble column—were operated over 33 days using synthetic medium (control) and WWW. A flow cytometry (FC) protocol was implemented to monitor key physiological parameters in near-real time, including cell concentration, membrane integrity, chlorophyll content, cell size, and internal complexity. At the end of cultivation, the bubble column yielded the highest cell concentrations: 2.85 × 10⁶ cells/mL (control) and 2.30 × 10⁶ cells/mL (WWW), though with lower proportions of intact cells (25% and 31%, respectively). Raceway cultures showed lower cell concentrations: 1.64 × 10⁶ (control) and 1.54 × 10⁶ cells/mL (WWW), but higher membrane integrity (76% and 36% for control and WWW cultures, respectively). On average, cells grown in the bubble column had a 22% larger radius than those in the raceway, favouring sedimentation. Heterotrophic cells were more abundant in WWW cultures, due to the presence of organic carbon, indicating its potential for use as animal feed. This study demonstrates that FC is a powerful, real-time tool for monitoring microalgae physiology and optimising cultivation in complex effluents like WWW. Full article

(This article belongs to the Special Issue Strategies for Optimal Fermentation by Using Modern Tools and Methods, 2nd Edition)

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18 pages, 4971 KiB

Open AccessArticle

Sustainable Production of Bacterial Cellulose in a Rotary Disk Bioreactor: Grape Pomace as a Replacement for the Carbon Source

by Rodrigo Cáceres, Patricio Oyarzún, Juan Pablo Vargas, Francisca Cuevas, Kelly Torres, Elizabeth Elgueta, Irene Martínez and Dariela Núñez

Fermentation 2025, 11(8), 441; https://doi.org/10.3390/fermentation11080441 - 31 Jul 2025

Viewed by 403

Abstract

Bacterial nanocellulose (BNC) is a highly pure biopolymer with promising applications in the biomedical, food, and textile industries. However, the high production costs and low yields obtained in static conditions limit its scalability and industrial applications. This study addresses the sustainable production of [...] Read more.

Bacterial nanocellulose (BNC) is a highly pure biopolymer with promising applications in the biomedical, food, and textile industries. However, the high production costs and low yields obtained in static conditions limit its scalability and industrial applications. This study addresses the sustainable production of BNC using a rotary disk bioreactor (RDB) and explores the use of grape pomace extract as an alternative carbon source for BNC production. Parameters such as the BNC production and biomass yield were evaluated using Komagataeibacter xylinus ATCC 53524 under different operational conditions (disk surface, rotation speed, and number of disks). The results showed that cellulose production increased using silicone-coated disks at 7–9 rpm (up to 2.72 g L⁻¹), while higher yields (5.23 g L⁻¹) were achieved when using grape pomace extract as the culture medium in comparison with conventional HS medium. FTIR and TGA characterizations confirmed that BNC obtained with grape pomace extract presents the same thermal and chemical characteristics than BNC produced with HS medium. This work provides insight into the feasibility of upscaling BNC production using a bioprocessing strategy, combining production in the RDB system and the use of an agro-industrial waste as a sustainable and cost-effective alternative. Full article

(This article belongs to the Section Fermentation Process Design)

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17 pages, 1710 KiB

Open AccessArticle

Physiological, Genetic, and Fermentative Traits of Oenococcus oeni Isolates from Spontaneous Malolactic Fermentation in Koshu Wine

by Misa Otoguro, Sayaka Inui, Taichi Aoyanagi, Ayana Misawa, Hiromi Nakano, Yoshimi Shimazu and Shigekazu Misawa

Fermentation 2025, 11(8), 440; https://doi.org/10.3390/fermentation11080440 - 31 Jul 2025

Viewed by 335

Abstract

Koshu wine, produced from the indigenous Japanese grape Vitis vinifera L. cv. Koshu exhibits a lower pH than other white wines, hindering malolactic fermentation (MLF) by lactic acid bacteria (LAB). Here, we aimed to isolate LAB strains capable of performing MLF under these [...] Read more.

Koshu wine, produced from the indigenous Japanese grape Vitis vinifera L. cv. Koshu exhibits a lower pH than other white wines, hindering malolactic fermentation (MLF) by lactic acid bacteria (LAB). Here, we aimed to isolate LAB strains capable of performing MLF under these challenging conditions to improve wine quality. Sixty-four Oenococcus oeni and one Lactobacillus hilgardii strain were isolated from Koshu grapes and wines that had undergone spontaneous MLF. MLF activity was assessed under varying pH, SO₂, and ethanol conditions in modified basal medium (BM) and Koshu model wine media. Expression of stress-related genes was analyzed using real-time PCR. Carbon source utilization was evaluated via API 50CH assays. All isolates degraded malic acid and produced lactic acid at 15 °C and pH 3.2 in BM without reducing sugars. Seven strains, all identified as O. oeni, demonstrated MLF activity at pH 3.0 in modified BM lacking added reducing sugars or tomato juice. Six wine-derived strains tolerated up to 12% ethanol, whereas the grape-derived strain was inhibited at 10%. In a synthetic Koshu wine model (13% ethanol, pH 3.0), wine-derived isolates exhibited higher MLF activity than commercial starter strains. In high-performing strains, mleA was upregulated, and most isolates preferred fructose, arabinose, and ribose over glucose. These findings suggest that indigenous O. oeni strains from Koshu wine possess unique stress tolerance and metabolic traits, making them promising candidates for region-specific MLF starter cultures that could enhance Koshu wine quality and terroir expression. Full article

(This article belongs to the Special Issue Fermentation and Biotechnology in Wine Making)

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23 pages, 11314 KiB

Open AccessArticle

Transcriptomic Analysis Reveals Opposing Roles of CEL1B in Sophorose- and Lactose-Induced Cellulase Expression in Trichoderma reesei Rut C30

by Lu Wang, Junping Fan, Xiao He, Jian Cheng, Xinyan Zhang, Tian Tian and Yonghao Li

Fermentation 2025, 11(8), 439; https://doi.org/10.3390/fermentation11080439 - 31 Jul 2025

Viewed by 364

Abstract

The β-glucosidase CEL1B has been linked to regulating cellulase expression in Trichoderma reesei, yet its inducer-specific functions and broader regulatory roles remain poorly characterized. In this study, CRISPR-Cas9-mediated gene knockout was applied in the industrial high-producing T. reesei Rut C30 to investigate [...] Read more.

The β-glucosidase CEL1B has been linked to regulating cellulase expression in Trichoderma reesei, yet its inducer-specific functions and broader regulatory roles remain poorly characterized. In this study, CRISPR-Cas9-mediated gene knockout was applied in the industrial high-producing T. reesei Rut C30 to investigate CEL1B function without the confounding effects of KU70 deletion. Unlike previous studies focused solely on cellulose or lactose induction, transcriptomic analysis of the CEL1B knockout strain revealed its regulatory roles under both lactose- and sophorose-rich conditions, with sophorose representing the most potent natural inducer of cellulase expression. Under lactose induction, CEL1B deletion resulted in a 52.4% increase in cellulase activity (p < 0.05), accompanied by transcriptome-wide upregulation of β-glucosidase genes (CEL3A: 729%, CEL3D: 666.8%, CEL3C: 110.9%), cellulose-sensing receptors (CRT1: 203.0%, CRT2: 105.8%), and key transcription factors (XYR1: 2.7-fold, ACE3: 2.8-fold, VIB1: 2.1-fold). Expression of ER proteostasis genes was significantly upregulated (BIP1: 3.3-fold, HSP70: 6.2-fold), contributing to enhanced enzyme secretion. Conversely, under sophorose induction, CEL1B deletion reduced cellulase activity by 25.7% (p < 0.05), which was associated with transcriptome profiling showing significant downregulation of β-glucosidase CEL3H (66.6%) and cellodextrin transporters (TrireC30_91594: 79.3%, TrireC30_127980: 76.3%), leading to reduced cellobiohydrolase expression (CEL7A: 57.8%, CEL6A: 67.8%). This first transcriptomic characterization of the CEL1B knockout strain reveals its dual opposing roles in modulating cellulase expression in response to lactose versus sophorose, providing new strategies for optimizing inducer-specific enzyme production in T. reesei. Full article

(This article belongs to the Special Issue Fungal Secondary Metabolism: Discovery and Characterization of Biologically Active Compounds)

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21 pages, 719 KiB

Open AccessArticle

Changes in Ruminal Dynamics and Microbial Populations Derived from Supplementation with a Protein Concentrate for Cattle with the Inclusion of Non-Conventional Feeding Sources

by Diana Sofía Torres-Velázquez, Daniel Francisco Ramos-Rosales, Manuel Murillo-Ortiz, Jesús Bernardo Páez-Lerma, Juan Antonio Rojas-Contreras, Karina Aide Araiza-Ponce and Damián Reyes-Jáquez

Fermentation 2025, 11(8), 438; https://doi.org/10.3390/fermentation11080438 - 30 Jul 2025

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Abstract

Feed supplementation strategies are essential for optimizing cattle productivity, and the incorporation of non-conventional feed resources may reduce both production costs and environmental impact. This study evaluated the effects of pelletized protein concentrates (including Acacia farnesiana, A. schaffneri, and Agave duranguensis [...] Read more.

Feed supplementation strategies are essential for optimizing cattle productivity, and the incorporation of non-conventional feed resources may reduce both production costs and environmental impact. This study evaluated the effects of pelletized protein concentrates (including Acacia farnesiana, A. schaffneri, and Agave duranguensis bagasse) on rumen fermentation parameters, microbial communities, and gas emissions. Fistulated bullocks received the concentrate daily, and ruminal contents were collected and filtered before and after supplementation to assess in vitro gas and methane production, pH, and microbial composition using high-throughput sequencing of 16S rRNA and mcrA amplicons. In addition, in situ degradability was evaluated during and after the supplementation period. Supplementation led to a significant (p < 0.05) reduction in degradability parameters and methane production, along with a marked decrease in the abundance of Methanobrevibacter and an increase in succinate-producing taxa. These effects were attributed to the enhanced levels of non-fiber carbohydrates, hemicellulose, crude protein, and the presence of bioactive secondary metabolites and methanol. Rumen microbiota composition was consistent with previously described core communities, and mcrA-based sequencing proved to be a valuable tool for targeted methanogen detection. Overall, the inclusion of non-conventional ingredients in protein concentrates may improve ruminal fermentation efficiency and contribute to methane mitigation in ruminants, although further in vivo trials on a larger scale are recommended. Full article

(This article belongs to the Special Issue Exploring Fermentation Strategies for the Valorization of Food By-Products and Their Bioactive Potential)

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18 pages, 14875 KiB

Open AccessArticle

Comparison of Lactic Acid Production from Different Agro-Industrial Waste Materials

by Greta Naydenova, Lili Dobreva, Svetla Danova, Petya Popova-Krumova and Dragomir Yankov

Fermentation 2025, 11(8), 437; https://doi.org/10.3390/fermentation11080437 - 30 Jul 2025

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Abstract

In recent years, great attention has been paid to second-generation (from agricultural and industrial wastes) lactic acid (LA) production. In the present study, the possibility of two Lactiplantibacillus plantarum strains, namely 53 and 2HS, to produce LA from waste materials was investigated. Distiller’s [...] Read more.

In recent years, great attention has been paid to second-generation (from agricultural and industrial wastes) lactic acid (LA) production. In the present study, the possibility of two Lactiplantibacillus plantarum strains, namely 53 and 2HS, to produce LA from waste materials was investigated. Distiller’s dried grains with solubles (DDGS), spent coffee grounds (SCG), wood chips, and cheese whey were used as substrates after pretreatment, and the results were compared with those with lactose as a carbon source. Both strains were capable of assimilating sugars from all waste materials. Nearly 20 g/L LA from 23 g/L reducing sugars (RS) obtained from DDGS, 22 g/L LA from 21 g/L RS from SCG, and 22 g/L LA from 21 g/L whey lactose were produced compared to 22 g/L LA obtained from 22 g/L lactose monohydrate in the fermentation broth. The wood chip hydrolysate (WH) contains only 10 g/L RS, and its fermentation resulted in the production of 5 g/L LA. This amount is twice as low as that produced from 11 g/L lactose monohydrate. A mathematical model was constructed based on the Compertz and Luedeking–Piret equations. Full article

(This article belongs to the Special Issue Fermentative Production of Valuable Chemicals from Lignocellulosic Biomass)

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16 pages, 1739 KiB

Open AccessArticle

Impact of the Thermovinification Practice Combined with the Use of Autochthonous Yeasts on the Fermentation Kinetics of Red Wines

by Islaine Santos Silva, Ana Paula André Barros, Marcos dos Santos Lima, Bruna Carla Agustini, Carolina Oliveira de Souza and Aline Camarão Telles Biasoto

Fermentation 2025, 11(8), 436; https://doi.org/10.3390/fermentation11080436 - 29 Jul 2025

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Abstract

Thermovinification has emerged as a rising alternative method in red wine production, gaining popularity among winemakers. The use of autochthonous yeasts isolated from grapes is also an interesting practice that contributes to the creation of wine with a distinctive regional character. This research [...] Read more.

Thermovinification has emerged as a rising alternative method in red wine production, gaining popularity among winemakers. The use of autochthonous yeasts isolated from grapes is also an interesting practice that contributes to the creation of wine with a distinctive regional character. This research investigated how combining thermovinification with autochthonous yeast strains influences the fermentation dynamics of Syrah wine. Six treatments were conducted, combining the use of commercial and two autochthonous yeasts with traditional vinification (7-day maceration) and thermovinification (65 °C for 2 h) processes. Sugars and alcohols were quantified during alcoholic fermentation by high-performance liquid chromatography with refractive index detection. Cell viability and kinetic parameters, such as ethanol formation rate and sugar consumption, were also evaluated. The Syrah wine’s composition was characterized by classical wine analyses (OIV procedures). The results showed that cell viability was unaffected by thermovinification. Thermovinification associated with autochthonous yeasts improved the efficiency of alcoholic fermentation. Thermovinified wines also yielded a higher alcohol content (13.9%). Future studies should investigate how thermovinification associated with autochthonous yeasts affects the metabolomic and flavoromic properties of Syrah wine and product acceptability. Full article

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

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16 pages, 2615 KiB

Open AccessArticle

The Prebiotic Potential of Porphyra-Derived Polysaccharides and Their Utilization by Lactic Acid Bacteria Fermentation

by Yu-Jyun Wei, Hong-Ting Victor Lin, Chorng-Liang Pan and Chung-Hsiung Huang

Fermentation 2025, 11(8), 435; https://doi.org/10.3390/fermentation11080435 - 29 Jul 2025

Viewed by 445

Abstract

Porphyra-derived polysaccharides (PPs) are promising prebiotic candidates due to their capacity to modulate gut microbiota and promote host health. However, their interactions with and utilization by probiotic microorganisms remain unclear. In this study, the fermentability of PPs by murine-derived lactic acid bacteria [...] Read more.

Porphyra-derived polysaccharides (PPs) are promising prebiotic candidates due to their capacity to modulate gut microbiota and promote host health. However, their interactions with and utilization by probiotic microorganisms remain unclear. In this study, the fermentability of PPs by murine-derived lactic acid bacteria (LAB) strains was investigated, with particular attention to strain-specific metabolic activity, carbohydrate utilization, and potential exopolysaccharide (EPS) production. All tested strains were capable of utilizing PPs to varying extents, with strain A10 exhibiting the highest level of carbohydrate consumption. Notably, strain A5 showed increased mannose concentrations following fermentation, suggesting the biosynthesis of mannose-rich EPSs. HPLC analysis confirmed the presence of high-molecular-weight polysaccharides ranging from 2.6 to 8.1 × 10⁵ Da, indicative of EPS production. FT-IR spectroscopy further revealed spectral features consistent with EPS structures. The antibacterial activity of postbiotic compounds produced by LAB strains fermenting PPs against Escherichia coli and Staphylococcus aureus was observed. These findings demonstrate distinct metabolic adaptations of LAB strains to PPs and emphasize their potential as prebiotic substrates. Full article

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

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18 pages, 2062 KiB

Open AccessReview

Living Cultures in a Glass: The Health Promise of Probiotic Bacteria in Kombucha

by Tara Budimac, Aleksandra Ranitović, Olja Šovljanski, Dragoljub Cvetković and Ana Tomić

Fermentation 2025, 11(8), 434; https://doi.org/10.3390/fermentation11080434 - 29 Jul 2025

Viewed by 467

Abstract

Kombucha is a fermented tea beverage of Asian origin, widely consumed due to its functional properties; yet, it typically lacks sufficient levels of probiotic micro-organisms to be classified as a probiotic product. This review analyzes the occurrence of lactic acid bacteria (LAB) in [...] Read more.

Kombucha is a fermented tea beverage of Asian origin, widely consumed due to its functional properties; yet, it typically lacks sufficient levels of probiotic micro-organisms to be classified as a probiotic product. This review analyzes the occurrence of lactic acid bacteria (LAB) in kombucha, reporting that concentrations rarely exceed 4–5 log CFU/mL and often decline during fermentation or storage. Strategies to enhance probiotic viability, including the use of robust LAB strains and encapsulation technologies, are critically evaluated. Notably, encapsulation using pea and whey protein has been shown to sustain LAB levels above 6 log CFU/mL during fermentation and up to 21 days under refrigerated storage for whey protein. Fortified kombucha beverages with probiotic strains have also been shown to possess enhanced functional and health-promoting benefits compared to traditional control samples. Despite promising approaches, inconsistencies in microbial survival and regulatory constraints remain key challenges. Future research should focus on the optimization of delivery systems for probiotic cultures, identification of kombucha-compatible LAB strains and standardized protocols to validate probiotic efficacy in real-world beverage conditions. Full article

(This article belongs to the Special Issue Fermentation and Bioactive Potential of Kombucha and Bee-Derived Compounds for Health and Wellness)

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13 pages, 1010 KiB

Open AccessArticle

Valorization of Flourensia cernua Foliage Through a Multiproduct Fungal Solid-State Bioprocess and Its Effect on In Vitro Digestibility

by Juan López-Trujillo, Juan Alberto Ascacio-Valdés, Miguel Mellado-Bosque, Cristóbal N. Aguilar, Antonio Francisco Aguilera-Carbó and Miguel Á. Medina-Morales

Fermentation 2025, 11(8), 433; https://doi.org/10.3390/fermentation11080433 - 29 Jul 2025

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Abstract

Biotechnological valorization of Flourensia cernua foliage was carried out using fungal solid-state fermentation; several outcomes of this bioprocess were identified which added value to the plant material. F. cernua leaves placed in aluminum trays were inoculated with Aspergillus niger; extracts of this [...] Read more.

Biotechnological valorization of Flourensia cernua foliage was carried out using fungal solid-state fermentation; several outcomes of this bioprocess were identified which added value to the plant material. F. cernua leaves placed in aluminum trays were inoculated with Aspergillus niger; extracts of this plant were evaluated and the foliage was tested for in vitro digestibility. The solid bioprocess was carried out at 75% humidity for 120 h and after the fermentation, β-glucosidase activity; phenolics and in vitro digestibility were quantified and measured. Two high β-glucosidase production levels were detected at 42 and 84 h with 3192 and 4092 U/L, respectively. Several phenolics of industrial importance were detected with a HPLC-ESI-MS, such as glycosides of luteolin and apigenin. The other outcome was a substantial improvement in anaerobic digestibility. The unfermented sample registered a 30% in vitro degradability, whereas samples subjected to 84 h of fungal fermentation increased degradability by up to 51%. This bioprocess was designed to detect more than one product, which can contribute to an increase in the added value of F. cernua foliage. Full article

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