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Fermentation, Volume 10, Issue 7 (July 2024) – 28 articles

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32 pages, 3065 KiB  
Article
Optimization of Biodegradation of Common Bean Biomass for Fermentation Using Trichoderma asperellum WNZ-21 and Artificial Neural Networks
by Salma Saleh Alrdahe, Zeiad Moussa, Yasmene F. Alanazi, Haifa Alrdahi, WesamEldin I. A. Saber and Doaa Bahaa Eldin Darwish
Fermentation 2024, 10(7), 354; https://doi.org/10.3390/fermentation10070354 (registering DOI) - 13 Jul 2024
Viewed by 180
Abstract
This study showcases a promising approach to sustainably unlocking plant biomass residues by combining biodegradation with artificial intelligence to optimize the process. Specifically, we utilized the definitive screening design (DSD) and artificial neural networks (ANNs) to optimize the degradation of common bean biomass [...] Read more.
This study showcases a promising approach to sustainably unlocking plant biomass residues by combining biodegradation with artificial intelligence to optimize the process. Specifically, we utilized the definitive screening design (DSD) and artificial neural networks (ANNs) to optimize the degradation of common bean biomass by the endophytic fungus Trichoderma asperellum WNZ-21. The optimized process yielded a fungal hydrolysate rich in 12 essential and non-essential amino acids, totaling 18,298.14 μg/g biomass. GC-MS analysis revealed four potential novel components not previously reported in microbial filtrates or plants and seven components exclusive to plant sources but not reported in microbial filtrates. The hydrolysate contained phenolic, flavonoid, and tannin compounds, as confirmed by FT-IR analysis. High-resolution transmission electron microscopy depicted structures resembling amino acid micelles and potential protein aggregates. The hydrolysate exhibited antioxidant, antibacterial, and anticancer properties and innovatively induced apoptotic modulation in the MCF7 cancer cell line. These findings underscore the potential of ANN-optimized fermentation for various applications, particularly in anticancer medicine due to its unique composition and bioactivities. The integration of the DSD and ANNs presents a novel technique for biomass biodegradation, warranting the valorization of plant biomass and suggesting a further exploration of the new components in the fungal hydrolysate. This approach represents the basic concept for exploring other biomass sources and in vivo studies. Full article
(This article belongs to the Special Issue New Research on Strains Improvement and Microbial Biosynthesis)
17 pages, 3863 KiB  
Article
Analysis of Microbial Community Changes and Their Correlations with Volatile Flavouring Substances during Autonomous Fermentation of Western Sichuan Yi Suancai Based on High-Throughput Sequencing
by Yuli Fang, Minghong Bian, Xuan Wu, Lemei Yuan, Qiang Xu, Weitao Zhou and Baolin Han
Fermentation 2024, 10(7), 353; https://doi.org/10.3390/fermentation10070353 - 12 Jul 2024
Viewed by 272
Abstract
Western Sichuan Yi suancai contains a group of highly functional microorganisms in an alpine and high-altitude ecological environment. Due to its unique salt-free fermentation process, it is nutritious and has a crispy texture. Six periods were established during fermentation: day 0, day 2, [...] Read more.
Western Sichuan Yi suancai contains a group of highly functional microorganisms in an alpine and high-altitude ecological environment. Due to its unique salt-free fermentation process, it is nutritious and has a crispy texture. Six periods were established during fermentation: day 0, day 2, day 5, day 8, day 11, and day 14. The results showed that the antioxidant capacity and organic acid content increased during the fermentation process, while the pH gradually decreased, indicating that suancai from the later periods was better for supplementing the human body with acid substances and eliminating free radicals. Twenty-six flavour compounds were identified, including alcohols, esters, ketones, and acids. Ethyl alcohol, 3-methyl-1-butanol, ethyl methanoate, and acetic acid were the main contributors to the flavour, imparting floral and fruity notes to the suancai. Five dominant bacterial genera (Lactobacillus, Leuconostoc, Weissella, Klebsiella, and unclassified_o__Lactobacillales) were identified via high-throughput sequencing during the fermentation process, and there were nine dominant fungal genera (Dipodascaceae_gen_Incertae_sedis, Mucor, Pichia, unclassified__f__Dipodascaceaet, Cyberlindnera, Diutina, Trichosporon, Saccharomycopsis, and Wickerhamomyces). Correlation analysis showed that the antioxidant capacity was positively correlated with genera such as Lactobacillus, Mucor, and Alternaria, indicating that these microorganisms have important roles in enhancing the antioxidant properties of suancai. Meanwhile, some genera, such as Microbacterium, Herbaspirillum, Mortierella, and Sampaiozyma, promote the synthesis of alcohols, esters, acids, and ketones. This study revealed the interactions between microorganisms and metabolites during the fermentation of western Sichuan Yi suancai and provided a scientific basis for further understanding the fermentation mechanism of traditional suancai and improving the fermentation process. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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13 pages, 2075 KiB  
Article
Optimization of the Process of Chinese Hamster Ovary (CHO) Cell Fed-Batch Culture to Stabilize Monoclonal Antibody Production and Overall Quality: Effect of pH Control Strategies
by Kexue Liang, Hongzhen Luo and Qi Li
Fermentation 2024, 10(7), 352; https://doi.org/10.3390/fermentation10070352 - 12 Jul 2024
Viewed by 241
Abstract
Monoclonal antibodies (mAbs) used in biomedical research and therapeutic applications are primarily produced by Chinese hamster ovary (CHO) cells via fed-batch culture. The growing need for elevated quantities of biologics mandates the continual optimization of the mAb production process. The development of an [...] Read more.
Monoclonal antibodies (mAbs) used in biomedical research and therapeutic applications are primarily produced by Chinese hamster ovary (CHO) cells via fed-batch culture. The growing need for elevated quantities of biologics mandates the continual optimization of the mAb production process. The development of an effective process control method is indispensable for the production of specified mAbs by CHO cells. In this study, the effects of the pH control strategy on CHO cell fed-batch culture to produce an antibody (EA5) were first investigated in a 3 L bioreactor. The results indicate that controlling the culture pH at 7.2 during the fed-batch stage could produce a higher EA5 titer of 6.1 g/L with a lower Man5 ratio of 2.2% by day 14. Based on this, an optimized CHO cell fed-batch culture was conducted in a 15 L bioreactor to verify its effectiveness and stability. In this case, on day 14, an EA5 titer of 6.5 g/L was achieved with productivity of 0.46 g/L/day, which was 1.07-fold higher compared to that of the culture in the 3 L bioreactor. Furthermore, regarding the product quality, a monomer abundance of 96.0%, a main peak of 55.0%, and a Man5 proportion of 2.4% were maintained in the 15 L bioreactor. In addition, different cell clarification processes were evaluated using the CHO cell culture broth from the 3 L and 15 L bioreactors to further improve productivity and economic performance. Overall, this study provides some directions for process intensification and improving the quality of mAbs produced by CHO cells in the biopharmaceutical industry. Full article
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18 pages, 766 KiB  
Review
Starter Cultures for the Production of Fermented Table Olives: Current Status and Future Perspectives
by Marilisa Giavalisco, Emanuela Lavanga, Annamaria Ricciardi and Teresa Zotta
Fermentation 2024, 10(7), 351; https://doi.org/10.3390/fermentation10070351 - 12 Jul 2024
Viewed by 222
Abstract
Table olives are widely produced and consumed in the Mediterranean area. The production of table olives is mainly based on spontaneous fermentations, which may have several drawbacks (e.g., the development of undesirable microorganisms; organoleptic defects) compared to fermentative processes driven by starter cultures [...] Read more.
Table olives are widely produced and consumed in the Mediterranean area. The production of table olives is mainly based on spontaneous fermentations, which may have several drawbacks (e.g., the development of undesirable microorganisms; organoleptic defects) compared to fermentative processes driven by starter cultures (typically lactic acid bacteria, yeasts, or their combinations). Studies on the effect of starter cultures have been mainly focused on some technological traits (e.g., acidifying capability, the degradation of phenolic compounds, metabolite production) and, to a lesser extent, on the dynamics of olive microbiota during fermentation. Recently, the application of Amplicon Targeted—High-Throughput Sequencing (AT–HTS) has enabled improvement of the knowledge on the composition and evolution of microbial communities during fermentations, including the role of starter cultures. The AT–HTS approaches used so far, however, have several constraints (e.g., poor investigation of mycobiota and metabolically active microorganisms) that do not allow a full understanding of the complex microbial interactions occurring in fermented olives. The aim of this review is to provide insights into the role of starter cultures in fermented olives and highlight the need to apply, as for other fermented foods, integrated “omics” approaches to predict and exploit their metabolic potential to improve the final properties of products. Full article
(This article belongs to the Special Issue Development and Application of Starter Cultures, 2nd Edition)
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15 pages, 897 KiB  
Review
Unveiling the Impact of Lactic Acid Bacteria on Blood Lipid Regulation for Cardiovascular Health
by Birsen Yilmaz, Neslihan Arslan, Teslime Özge Şahin, Duygu Ağadündüz, Fatih Ozogul and João Miguel F. Rocha
Fermentation 2024, 10(7), 350; https://doi.org/10.3390/fermentation10070350 - 9 Jul 2024
Viewed by 416
Abstract
Lactic acid bacteria (LAB) are a group of microorganisms which are beneficial and well-characterized with respect to the flavor and texture of food products via fermentation. The accumulated literature has suggested that dietary intake of fermented foods rich in LAB is related to [...] Read more.
Lactic acid bacteria (LAB) are a group of microorganisms which are beneficial and well-characterized with respect to the flavor and texture of food products via fermentation. The accumulated literature has suggested that dietary intake of fermented foods rich in LAB is related to different health-promoting benefits; however, in recent years, emerging evidence suggests a contribution of LAB to blood lipid regulation and cardiovascular health via certain mechanisms. Different potential mechanisms for the lipid regulatory effects of LAB may include the interaction of hydroxymethylglutaryl-CoA (HMG-CoA) reductase and bile salt hydrolase activity and bile salt metabolism; gut microbiome modulation; and regulation of mRNA expression of genes related to fat metabolism in animal models and human studies. This review comprehensively aims to answer whether/how LAB influence blood lipids in both animal models and human studies while also uncovering the underlying mechanisms linking LAB to lipid metabolism. Full article
(This article belongs to the Special Issue Recent Trends in Lactobacillus and Fermented Food, 2nd Edition)
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16 pages, 1114 KiB  
Review
Advances and Challenges in Biomanufacturing of Glycosylation of Natural Products
by Shunyang Hu, Bangxu Wang, Liang Pei, Jisheng Wang, Ya Gan, Liangzhen Jiang, Bingliang Liu, Jie Cheng and Wei Li
Fermentation 2024, 10(7), 349; https://doi.org/10.3390/fermentation10070349 - 9 Jul 2024
Viewed by 453
Abstract
Glycosylation is one of the most common and important modifications in natural products (NPs), which can alter the biological activities and properties of NPs, effectively increase structural diversity, and improve pharmacological activities. The biosynthesis of glycosylation in natural products involves multiple complex biological [...] Read more.
Glycosylation is one of the most common and important modifications in natural products (NPs), which can alter the biological activities and properties of NPs, effectively increase structural diversity, and improve pharmacological activities. The biosynthesis of glycosylation in natural products involves multiple complex biological processes, which are coordinated by many enzymes. UDP-glycosyltransferases (UGTs) play a crucial role in glycosylation modification, and have attracted long-term and widespread research attention. UGTs can catalyze the O-, C-, S-, and N-glycosylation of different substrates, producing a variety of glycosides with broad biological activity, while improving the solubility, stability, bioavailability, pharmacological activity, and other functions of NPs. In recent years, the rapid development of synthetic biology and advanced manufacturing technologies, especially the widespread application of artificial intelligence in the field of synthetic biology, has led to a series of new discoveries in the biosynthesis of NP glycosides by UGT. This work summarizes the latest progress and challenges in the field of NP glycosylation, covering the research results and potential applications of glycosylated derivatives of terpenes, flavonoids, polyphenols, aromatic compounds, and other compounds in terms of biogenesis. Looking to the future, research may leverage artificial intelligence-driven synthetic biology techniques to decipher genes related to the synthetic pathway, which is expected to further promote the large-scale synthesis and application of glycosylated NPs, and increase the diversity of NPs in the pharmaceutical, functional food, and cosmetic industries. Full article
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28 pages, 2744 KiB  
Review
Pomegranate Wine Production and Quality: A Comprehensive Review
by Kasiemobi Chiagozie Ezeora, Mathabatha Evodia Setati, Olaniyi Amos Fawole and Umezuruike Linus Opara
Fermentation 2024, 10(7), 348; https://doi.org/10.3390/fermentation10070348 - 4 Jul 2024
Viewed by 616
Abstract
Food and beverages with healthy and functional properties, especially those that prevent chronic diseases, are receiving considerable interest among consumers and researchers. Among the products with enhanced properties, fermented beverages from non-grape wines have a high potential for growth. Pomegranate (Punica granatum [...] Read more.
Food and beverages with healthy and functional properties, especially those that prevent chronic diseases, are receiving considerable interest among consumers and researchers. Among the products with enhanced properties, fermented beverages from non-grape wines have a high potential for growth. Pomegranate (Punica granatum L.) is a super fruit known for its richness in bioactive compounds that have been reported to have several therapeutic properties against non-communicable diseases. Diverse products can be obtained from the valorization of pomegranate fruit, including wines, supplements, dried arils, juices, vinegar, and syrup. There is no literature evidence of the optimization of the fermentation processes of pomegranate juice that explores the relationships between multiple factors and their interactions. This review provides an overview of the composition of pomegranate fruit and the related health benefits for human health. It also discusses the ways in which pomegranate wine fermentation is impacted by pre-fermentation and fermentation factors. Additionally, it highlights the different subjective and objective techniques for analyzing pomegranate wine quality and the advancement of technologies such as sensors to replace traditional methods of sensory evaluation. It provides comprehensive insights into how different fermentation factors interact and can improve the bioprocess, leading to the production of high-quality wine. Full article
(This article belongs to the Special Issue Fermentation and Biotechnology in Wine Making)
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15 pages, 1928 KiB  
Article
Effects of Neolamarckia cadamba Leaf Extract on Dynamic Fermentation Characteristics and Bacterial Community of Stylosanthes guianensis Silage
by Peishan Huang, Mengmeng Chen, Dekui Chen, Meiqi Zang, Weiling Zhang, Xiyue Lin, Hongyan Han and Qing Zhang
Fermentation 2024, 10(7), 347; https://doi.org/10.3390/fermentation10070347 - 2 Jul 2024
Viewed by 478
Abstract
This study focused on exploring the effects of Neolamarckia cadamba leaf extract (NE) on the fermentation process and bacterial community of stylo (Stylosanthes guianensis) silage. Fresh raw materials of stylo were ensiled with 0%, 1%, and 2% NE, and various fermentation [...] Read more.
This study focused on exploring the effects of Neolamarckia cadamba leaf extract (NE) on the fermentation process and bacterial community of stylo (Stylosanthes guianensis) silage. Fresh raw materials of stylo were ensiled with 0%, 1%, and 2% NE, and various fermentation parameters, nitrogen components, and microbial compositions were analyzed at different time points (days 3, 7, 14, and 30) during the ensiling process. The experiment showed that, in comparison to the control group, incorporating NE into the ensiling process resulted in improved fermentation parameters, including increased lactic acid and acetic acid levels, as well as decreased pH, coliform population, and ammonia nitrogen concentration. Moreover, the relative abundances of Lactobacillus and Pediococcus were augmented, while the growth of Enterobacter was inhibited by the NE addition. These results suggest that NE has potential as a novel additive for silage, promoting a reduction in harmful bacteria and enhancements in the nutritional quality and fermentation characteristics of stylo silage. Full article
(This article belongs to the Section Industrial Fermentation)
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15 pages, 4552 KiB  
Article
Online Monitoring of the Temperature and Relative Humidity of Recycled Bedding for Dairy Cows on Dairy Farms
by Yong Wei, Kun Liu, Yaao Li, Zhixing Li, Tianyu Zhao, Pengfei Zhao, Yayin Qi, Meiying Li and Zongyuan Wang
Fermentation 2024, 10(7), 346; https://doi.org/10.3390/fermentation10070346 - 1 Jul 2024
Viewed by 496
Abstract
In large-scale dairy farming, the use of high-temperature-fermented dairy manure bedding instead of rice husk-based bedding and other commercial types of bedding is widely favored. Strip-stacking aerobic fermentation is the main production method of dairy manure bedding, but it has problems including unstable [...] Read more.
In large-scale dairy farming, the use of high-temperature-fermented dairy manure bedding instead of rice husk-based bedding and other commercial types of bedding is widely favored. Strip-stacking aerobic fermentation is the main production method of dairy manure bedding, but it has problems including unstable fermentation and the secondary breeding of pathogens. In this work, a multi-probe, integrated, online monitoring system for temperature and relative humidity was used for fermentation process optimization. The effects of the temporal and spatial distribution of fermentation temperature and relative humidity on the nutrient content curve and the moisture and ash content of manure bedding materials were systematically studied. The effect of the fermentation process on the retention rate of effective bedding materials (cellulose, hemicellulose, and lignin) was analyzed. The experiments proved that high-quality bedding material can be obtained through reasonable stacking fermentation. The fabricated bedding material has a total dry base content consisting of cellulose, hemicellulose, and lignin of 78%, an ash content of 6%, and a nutrient content of 17%. The obtained bedding material was produced to increase the bed rest rate and continuously inhibit the bedding bacteria content, keeping it at a low level for 5 days. This study proves that temperature and humidity monitoring can guide the optimization of the strip-stacking fermentation process of dairy manure and that it can be applied to large-scale farms to improve fermentation parameters. Full article
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13 pages, 2534 KiB  
Article
Microbial Consortium of Jeju Traditional Fermented Foods and Their Cosmetic Ingredient Potential
by Sung-Eun Bae, Sungmin Bae, Sung Jin Park, Pomjoo Lee and Chang-Gu Hyun
Fermentation 2024, 10(7), 345; https://doi.org/10.3390/fermentation10070345 - 1 Jul 2024
Viewed by 444
Abstract
In this study, we analyzed the microbial community of traditional fermented foods of Jeju Island to identify the distribution of useful microorganisms and confirm their anti-inflammatory and anti-melanogenic effects to determine their potential use as cosmetic ingredients. Firstly, we examined the microbial communities [...] Read more.
In this study, we analyzed the microbial community of traditional fermented foods of Jeju Island to identify the distribution of useful microorganisms and confirm their anti-inflammatory and anti-melanogenic effects to determine their potential use as cosmetic ingredients. Firstly, we examined the microbial communities of Omphalius rusticus Jeotgal (OR), Spratelloides gracilis Jeotgal (SG), Chromis notata Jeotgal (CN), Turbo cornutus Jeotgal (TC), Trichiurus lepturus intestine Jeotgal (TL), Branchiostegus japonicus Sweet Rice Punch (BJ), Salted Anchovy Sauce (SA), Jeju Soy Sauce (JSS), and Jeju Soybean Paste (JSP). We found that Latilactobacillus sakei (87.2%), Tetragenococcus halophilus (37.7%), T. halophilus (96.8%), Bacillus subtilis (23.4%), T. halophilus (71.3%), L. sakei (53.7%), Lentibacillus sp. (42.9%), Enterococcus durans (14.6%), and E. durans (32.8%) were the dominant species. Secondly, to study the nine Jeju fermented foods’ anti-inflammatory and anti-melanogenic effects, we employed RAW 264.7 and B16F10 cells, classic cell models for inflammation and melanogenesis studies. Ethyl acetate extracts of the nine Jeju fermented foods all inhibited nitric oxide (NO) and melanin production in a concentration-dependent manner. Thirdly, to test the applicability of the nine Jeju fermented foods to human skin, we used the MTT assay to assess their cytotoxic effects on human keratinocytes (HaCaT cells). Finally, the topical applicability of the nine Jeju fermented foods was tested through primary skin irritation, and it was found that they did not cause any adverse effects. Therefore, extracts from the nine Jeju fermented foods have potential applications as ingredients in anti-inflammatory and anti-melanogenic products and can be used in the cosmetic industry. Full article
(This article belongs to the Special Issue Probiotic Fermented Foods: An Overview)
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26 pages, 3714 KiB  
Article
Evaluating the Performance of Yarrowia lipolytica 2.2ab in Solid-State Fermentation under Bench-Scale Conditions in a Packed-Tray Bioreactor
by Alejandro Barrios-Nolasco, Carlos Omar Castillo-Araiza, Sergio Huerta-Ochoa, María Isabel Reyes-Arreozola, José Juan Buenrostro-Figueroa and Lilia Arely Prado-Barragán
Fermentation 2024, 10(7), 344; https://doi.org/10.3390/fermentation10070344 - 29 Jun 2024
Viewed by 395
Abstract
Solid-State Fermentation (SSF) offers a valuable process for converting agri-food by-products (AFBP) into high-value metabolites, with Yarrowia lipolytica 2.2ab (Yl2.2ab) showing significant potential under laboratory-scale controlled conditions; however, its assessment in larger-scale bioreactor scenarios is needed. This work evaluates Yl2.2ab’s [...] Read more.
Solid-State Fermentation (SSF) offers a valuable process for converting agri-food by-products (AFBP) into high-value metabolites, with Yarrowia lipolytica 2.2ab (Yl2.2ab) showing significant potential under laboratory-scale controlled conditions; however, its assessment in larger-scale bioreactor scenarios is needed. This work evaluates Yl2.2ab’s performance in a bench-scale custom-designed packed-tray bioreactor. Key features of this bioreactor design include a short packing length, a wall-cooling system, and forced aeration, enhancing hydrodynamics and heat and mass transfer within the tray. Preliminary studies under both abiotic and biotic conditions assessed Yl2.2ab’s adaptability to extreme temperature variations. The results indicated effective oxygen transport but poor heat transfer within the tray bed, with Yl2.2ab leading to a maximum growth rate of 28.15 mgx gssdb−1 h−1 and maximum production of proteases of 40.10 U gssdb−1 h−1, even when temperatures at the packed-tray outlet were around 49 °C. Hybrid-based modeling, incorporating Computational Fluid Dynamics (CFD) and Pseudo-Continuous Simulations (PCSs), elucidated that the forced-aeration system successfully maintained necessary oxygen levels in the bed. However, the low thermal conductivity of AFBP posed challenges for heat transfer. The bioreactor design presents promising avenues for scaling up SSF to valorize AFBP using Yl2.2ab’s extremophilic capabilities. Full article
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14 pages, 1030 KiB  
Article
Exploring the Impact of Extended Maceration on the Volatile Compounds and Sensory Profile of Monastrell Red Wine
by Alejandro Martínez-Moreno, Rosa Toledo-Gil, Ana Belén Bautista-Ortin, Encarna Gómez-Plaza, José Enrique Yuste and Fernando Vallejo
Fermentation 2024, 10(7), 343; https://doi.org/10.3390/fermentation10070343 - 29 Jun 2024
Viewed by 416
Abstract
Volatile organic compounds (VOCs) are crucial to the wine’s overall quality since they define the aromatic profile. The aim of this study was to investigate whether a 146-day extended maceration (EM) treatment positively affects the aromatic and sensory properties of Monastrell red wine. [...] Read more.
Volatile organic compounds (VOCs) are crucial to the wine’s overall quality since they define the aromatic profile. The aim of this study was to investigate whether a 146-day extended maceration (EM) treatment positively affects the aromatic and sensory properties of Monastrell red wine. A total of 43 aromatic compounds belonging to different chemical classes were identified using solid-phase microextraction combined with gas chromatography–mass spectrometry (SPME/GC-MS). In general, EM treatment decreased both the number and total relative concentration of VOCs. Specifically, EM decreased the concentration of alcohols, terpenes and sulphur compounds compared to control wines. However certain compounds such as 2-ethyl-1-hexanol, phenylethyl and ethyl decanoate significantly increased with prolonged maceration. Conversely, EM treatment did not significantly affect the total relative concentrations of esters and ketones. From sensorial point of view, the triangular test showed a positive identification of wines (10/18) with a significant preference for EM wines. Moreover, descriptive analysis revealed that EM wines scored lower values in appearance, aroma and taste. Future research should aim to optimize maceration time to enhance the content of VOCs without compromising the sensory quality of the wine. Full article
(This article belongs to the Special Issue Wine Aromas: 2nd Edition)
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20 pages, 1143 KiB  
Article
A Semi-Continuous Fermentation Process for Pulque Production Using Microfiltration-Sterilized Aguamiel and Aseptic Conditions to Standardize the Overall Quality of the Beverage
by Concepción Calderón-García, Paula Cecilia Guadarrama-Mendoza, Edith Ponce-Alquicira, Adelfo Escalante, Yesica Ruiz-Ramírez and Rogelio Valadez-Blanco
Fermentation 2024, 10(7), 342; https://doi.org/10.3390/fermentation10070342 - 28 Jun 2024
Viewed by 423
Abstract
Despite the current appreciation of pulque as a probiotic fermented beverage, pulque has been also regarded as a poor-quality product, particularly due to the lack of sanitary control during its elaboration. To address this problem, a semi-continuous fermentation system was established, emulating the [...] Read more.
Despite the current appreciation of pulque as a probiotic fermented beverage, pulque has been also regarded as a poor-quality product, particularly due to the lack of sanitary control during its elaboration. To address this problem, a semi-continuous fermentation system was established, emulating the artisanal production process. Microfiltration-sterilized aguamiel was employed as the substrate, whereas a good-quality pulque was used as the fermentation inoculum. During the fermentation, the physicochemical, microbiological (lactic acid and Leuconostoc-type bacteria and yeasts) and sensory characteristics of the must were monitored. The isolated microorganisms were identified by molecular biology and MALDI-MS techniques. The sterilization of aguamiel by microfiltration did not negatively affect its physicochemical attributes. After 6–8 days of operation of the semi-continuous bioreactor, the fermentation reached a quasi-stationary state considering most of the parameters monitored during the experiment. The final fermentation product presented similar physicochemical, microbial and sensory properties to those of the pulque inoculum. The genera identified were Leuconostoc, Lentilactobacillus, Lactobacillus, Liquorilactobacillus, Fructilactobacillus and Saccharomyces. The strains Lentilactobacillus diolivorans and Liquorilactobacillus capillatus and uvarum have not been previously isolated from pulque. In conclusion, the fermentation system developed in this work was effective to standardize the quality of pulque while preserving the positive attributes of the artisanal process, thus harnessing the probiotic properties of pulque. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
46 pages, 897 KiB  
Review
Antimicrobial and Ecological Potential of Chlorellaceae and Scenedesmaceae with a Focus on Wastewater Treatment and Industry
by Yana Ilieva, Maya Margaritova Zaharieva, Alexander Dimitrov Kroumov and Hristo Najdenski
Fermentation 2024, 10(7), 341; https://doi.org/10.3390/fermentation10070341 - 28 Jun 2024
Viewed by 854
Abstract
A complex evaluation of antimicrobial activities of microalgae, including those relevant to wastewater treatment (WWT), in light of the integrated biorefinery concept, is performed. An example of this concept is linking a commercial microalgal system to plants, factories, or farms that emit polluted [...] Read more.
A complex evaluation of antimicrobial activities of microalgae, including those relevant to wastewater treatment (WWT), in light of the integrated biorefinery concept, is performed. An example of this concept is linking a commercial microalgal system to plants, factories, or farms that emit polluted wastewater (WW). The microalgae would not only metabolize the pollutants—such as nitrogen (N) and phosphorus (P)—from the WW, thus fueling their biomass, but they would exert an antibacterial effect against the pathogenic bacteria there. The biomass then could be harvested and used for biofertilizers, biofuels, and bioplastics and might possibly be utilized as animal feed, antimicrobial and other pharmaceutical agents. A large amount of the research on the antimicrobial activity and WWT potential focuses on the families Chlorellaceae and Scenedesmaceae, which are also some of the most commercially used strains of microalgae. For that reason, they are the species chosen for the current review. Furthermore, the increasing antimicrobial resistance necessitates the search for antibiotic alternatives, and the antibacterial and antifungal activity of Chlorellaceae and Scenedesmaceae is very promising. Microalgae are rich in antibacterial compounds like polyunsaturated fatty acids (PUFAs), polysaccharides, carotenoids, proteins, etc., and for that reason, their extracts possess antimicrobial effects. The in vitro antimicrobial activity of Chlorellaceae and Scenedesmaceae families has varied in a broad range from low to strong activity or no effect. Several strains have fulfilled the criteria for outstanding and high activity, especially C. vulgaris and other Chlorellaceae spp., with an effect equal to or better than the control antibiotics. There were several strains with minimum inhibitory concentrations (MIC) below 80 µg/mL and even 10 and 1.5 µg/mL; some species also had inhibition zones (IZ) over 30 mm, even as high as 48 mm. In vivo results are also promising but scarce, and all this warrants further in vivo and in situ studies—from animal models to clinical and environmental trials. Altogether, important data in the light of the circle economy, the urgent necessity to decrease CO2 emissions to fight climate change, and to curb the harmful influence of future pandemics are presented. This review paves the way for further utilizing the total potential of a microalgal system. Full article
(This article belongs to the Special Issue Cyanobacteria and Eukaryotic Microalgae)
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16 pages, 2337 KiB  
Article
Development of Foam-Free Biosurfactant Production Processes Using Bacillus licheniformis
by Eduardo Leal, José A. Teixeira and Eduardo J. Gudiña
Fermentation 2024, 10(7), 340; https://doi.org/10.3390/fermentation10070340 - 28 Jun 2024
Viewed by 445
Abstract
Microbial biosurfactants are considered environmentally friendly alternatives to synthetic surfactants in numerous applications. One of the main bottlenecks to their widespread use is the lack of effective processes for their production on an industrial scale. Biosurfactant production using conventional aerated bioreactors results in [...] Read more.
Microbial biosurfactants are considered environmentally friendly alternatives to synthetic surfactants in numerous applications. One of the main bottlenecks to their widespread use is the lack of effective processes for their production on an industrial scale. Biosurfactant production using conventional aerated bioreactors results in excessive foaming due to the combination of air injection and their tensioactive properties. A not widely explored approach to overcome this problem is the development of foam-free production processes, which require the identification and characterization of appropriate microorganisms. Bacillus licheniformis EL3 was evaluated for biosurfactant production under oxygen-limiting conditions in a bioreactor, using a mineral medium containing glucose as a carbon source and NaNO3 and NH4Cl as nitrogen sources. After optimizing the operational conditions, glucose concentration, and inoculum strategy, B. licheniformis EL3 produced 75 ± 3 mg biosurfactant/L in 43 h. The purified biosurfactant exhibited exceptional surface active properties, with minimum surface tension values (29 mN/m) and a critical micelle concentration (27 mg/L) similar to those achieved with commercial surfactin. Furthermore, biosurfactant yield per substrate (YP/S = 0.007 g biosurfactant/g glucose) was similar to the figures reported for Bacillus subtilis strains grown in similar conditions, whereas biosurfactant yield per biomass (YP/X = 0.755 g biosurfactant/g biomass) and specific biosurfactant productivity (qBS = 0.018 g biosurfactant/(g biomass × h)) were almost three times higher when compared to previous reports. The results obtained indicate that B. licheniformis EL3 is a promising candidate for the development of foam-free biosurfactant production processes at an industrial scale. Full article
(This article belongs to the Special Issue Fermentation: 10th Anniversary)
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11 pages, 617 KiB  
Article
Exopolysaccharides from Lactiplantibacillus plantarum C7 Exhibited Antibacterial, Antioxidant, Anti-Enzymatic, and Prebiotic Activities
by Taroub Bouzaiene, Mariem Mohamedhen Vall, Manel Ziadi, Ines Ben Rejeb, Islem Yangui, Abdelkarim Aydi, Imene Ouzari and Hamdi Moktar
Fermentation 2024, 10(7), 339; https://doi.org/10.3390/fermentation10070339 - 28 Jun 2024
Viewed by 440
Abstract
Previously, the exopolysaccharides produced by Lactiplantibacillus plantarum C7 isolated from the broiler intestine have been shown to possess probiotic potential. In this study, we highlighted the capacity of this strain to produce exopolysaccharide (EPS) endowed with several biological activities. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and [...] Read more.
Previously, the exopolysaccharides produced by Lactiplantibacillus plantarum C7 isolated from the broiler intestine have been shown to possess probiotic potential. In this study, we highlighted the capacity of this strain to produce exopolysaccharide (EPS) endowed with several biological activities. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) free radical scavenging activities of EPS were found to be 30.4% and 68.165%, respectively, at 100 mg/mL. The ferrous reducing potential of EPS was measured to be 25.26%. Furthermore, EPS exhibited antibacterial effects against both Gram-negative and Gram-positive pathogens, including Escherichia coli ATCC 10536 and Bacillus cereus ATCC 11778, with inhibition zones of 22.5 ± 0.70 mm and 20 ± 1.41, respectively. On the other hand, the exopolysaccharide also exhibited excellent inhibitory activity against butyrylcholinesterase (BChE), achieving 70.99% inhibition at a concentration of 10 mg/mL. FTIR spectra were used to characterize functional groups in EPS. Our findings proved that EPS from Lactiplantibacillus plantarum C7 could be explored for various applications, particularly in the health and functional food sectors. Full article
(This article belongs to the Special Issue Application of Bacillus in Fermented Food)
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13 pages, 1470 KiB  
Article
Biological Activity and Phenolic Content of Kombucha Beverages under the Influence of Different Tea Extract Substrates
by Raluca A. Mihai, Nelson S. Cubi-Insuaste and Rodica D. Catana
Fermentation 2024, 10(7), 338; https://doi.org/10.3390/fermentation10070338 - 28 Jun 2024
Viewed by 413
Abstract
In this study, the influence of different tea extract substrates on the biological activities of kombucha beverages was investigated. The variations in bioactive compounds such as polyphenols and flavonoids and their potential health-promoting properties represented by antioxidant activity were analyzed. Our findings shed [...] Read more.
In this study, the influence of different tea extract substrates on the biological activities of kombucha beverages was investigated. The variations in bioactive compounds such as polyphenols and flavonoids and their potential health-promoting properties represented by antioxidant activity were analyzed. Our findings shed light on the diverse effects of tea substrates on the production of bioactive compounds and their subsequent impact on the biological activities of kombucha, providing valuable insights for optimizing kombucha production and its potential health benefits. The new tea substrate for kombucha, called horchata, an Ecuadorian tea, shows a similar trend but with a low content of phenolics (4.511 ± 0.111 mg gallic acid equivalent (GAE)/g dry weight (DW)) and flavonoids (1.902 ± 0.0455 mg quercetin equivalent (QE)/g DW), and antioxidant activity (DPPH—33.569 ± 1.377 µmol TROLOX/g DW, ABTS—20.898 ± 2.709 µmol TROLOX/g DW, FRAP—34.456 ± 2.0618 Fe2+ mM/100 g DW compared to black and green tea as substrates for kombucha. Through HPLC-DAD, several polyphenols were registered, and homovanillic acid showed the highest concentration (74.45 mg/100 g). Horchata kombucha scored the highest in sweetness and smell, reflecting its popularity among the tasters, making it a valuable candidate as a kombucha substrate. Full article
(This article belongs to the Special Issue Flavor and Aroma in the Fermented Food)
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13 pages, 1746 KiB  
Article
Pectinase Production from Cocoa Pod Husk in Submerged Fermentation and Its Application in the Clarification of Apple Juice
by Anderson Steyner Rozendo, Luciana Porto de Souza Vandenberghe, Patricia Beatriz Gruening de Mattos, Hervé Louis Ghislain Rogez and Carlos Ricardo Soccol
Fermentation 2024, 10(7), 337; https://doi.org/10.3390/fermentation10070337 - 28 Jun 2024
Viewed by 433
Abstract
The present work aimed to use cocoa pod husk (CPH) and its extracted pectin as a potential substrate for the production of pectinase and to test the enzyme produced in the clarification process of apple juice. CPH with a particle size of <0.84 [...] Read more.
The present work aimed to use cocoa pod husk (CPH) and its extracted pectin as a potential substrate for the production of pectinase and to test the enzyme produced in the clarification process of apple juice. CPH with a particle size of <0.84 mm was employed for pectinase production by a selected strain of Aspergillus niger NRRL 2270. The optimization of the physicochemical conditions of the production medium led to an enzymatic activity of 602.03 U/g dry CPH, which was obtained under the following conditions: 110.25 g/L of CPH, 5% w/v pectin extract, 0.05 g/L of yeast extract, incubation at 28 °C, and pH 4, representing a 176% increase in enzymatic activity under the evaluated conditions. The production kinetics of pectinase showed maximum enzymatic activity at 96 h. Subsequently, the enzymatic extract was precipitated, microfiltered, and ultrafiltrated, resulting in 4852.50 U/mg of specific activity. The enzymatic activity after recovery and purification processes corresponded to 819 U/g dry CPH. Finally, a clarification stage of apple juice was carried out, in which the produced pectinase (CauPec) showed turbidity of 448.89 NTU compared to 417.89 NTU for the commercial enzyme and a viscosity of 1.86 cP, CauPec, and 1.19 cP, commercial pectinase, as well as soluble solids of 8.0 for commercial pectinase and 8.73 for CauPec. Therefore, it can be concluded that CPH and its pectin extract were excellent substrates for the production of pectinases, whose formulation is highly stable and can be applied in the clarification of apple juice. Full article
(This article belongs to the Special Issue Fermentation: 10th Anniversary)
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13 pages, 1399 KiB  
Article
Impact of a Biopreservative Derived from Lactic Fermentation on Quality after Food Processing: A Case Study on Sliced Cooked Ham
by André Fioravante Guerra, Angela Gava Barreto, Isabella Rodrigues Viviani, Lucas Marques Costa, Carlos Alberto Guerra, Viviana Corich, Alessio Giacomini and Wilson José Fernandes Lemos Junior
Fermentation 2024, 10(7), 336; https://doi.org/10.3390/fermentation10070336 - 27 Jun 2024
Viewed by 366
Abstract
This study presents an innovative approach to enhancing the shelf life and maintaining the quality of sliced cooked ham through the application of a natural biopreservative derived from lactic fermentation. The biopreservative, at concentrations ranging from 1% to 3.5%, demonstrated substantial efficacy in [...] Read more.
This study presents an innovative approach to enhancing the shelf life and maintaining the quality of sliced cooked ham through the application of a natural biopreservative derived from lactic fermentation. The biopreservative, at concentrations ranging from 1% to 3.5%, demonstrated substantial efficacy in microbial inhibition, keeping the microbial density low and relatively constant over time (p < 0.05). Remarkably, even at the lower concentration of 1%, the microbial growth rates were significantly reduced, with the treated samples showing notable stability over 24 days at both 7 °C and 25 °C. The microbial count in the treated with biopreservative group was significantly lower (3.19 log cfu/g) compared to the blank (4.59 log cfu/g) and control (5.01 log cfu/g) over 4 days at 7 °C. The shelf life of the ham was 24 days for the blank, 20 days for the control, and 101 days for the treated group at 7 °C. Moreover, colorimetric analysis revealed that the treated samples maintained better color stability, experiencing less variation in the hue angle and chroma, suggesting a protective effect against quality degradation over time. The successful application of the biopreservative aligns with the growing consumer demand for natural food additives and underscores the movement toward sustainable, health-conscious food preservation practices. The findings of this study indicate a promising avenue for the food industry to adopt environmentally friendly alternatives to synthetic additives, which could significantly influence future standards in food processing and preservation. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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10 pages, 668 KiB  
Article
Evaluation of Essential Oils and Their Blends on the Fermentative Profile, Microbial Count, and Aerobic Stability of Sorghum Silage
by Elon S. Aniceto, Tadeu S. Oliveira, José R. Meirelles, Jr., Ismael N. Silva, Elvanio J. L. Mozelli Filho, Raphael S. Gomes, Juliana P. Arévalo and Patrícia R. Moraes
Fermentation 2024, 10(7), 335; https://doi.org/10.3390/fermentation10070335 - 27 Jun 2024
Viewed by 343
Abstract
This study aims to evaluate the effect of these essential oils and their blends on the fermentative profile, losses by gases and effluents, nutritional value, microbial count, and aerobic stability of sorghum silage. A completely randomized design was used with eight treatments and [...] Read more.
This study aims to evaluate the effect of these essential oils and their blends on the fermentative profile, losses by gases and effluents, nutritional value, microbial count, and aerobic stability of sorghum silage. A completely randomized design was used with eight treatments and four repetitions. The evaluated treatments were the following: control (CON), without any essential oil; rosemary (Ros); tea tree (TT); citronella (Cit); Ros + TT (50% + 50%); Ros + Cit (50% + 50%); TT + Cit (50% + 50%); and Ros + TT + Cit (33% + 33% + 33%). A 1000 mg/kg dose of ensiled mass (as-fed basis) was used for each of the treatments. The addition of essential oils and their blends had a significant impact (p < 0.05) on the chemical composition of sorghum silage. Crude protein content increased (p < 0.001) with the use of essential oils and their blends. The Ros affected (p < 0.05) the fibrous fraction of sorghum silage. Neutral detergent fiber in vitro degradability was reduced (p = 0.003) when we used the blend TT + Cit compared to Ros and TT. We observed that only Ros did not reduce acetic acid concentration (p = 0.031) compared to the CON. The essential oils and their blends did not affect losses (p > 0.05). Lactic acid bacteria population increased (p = 0.039) when using the blend Ros + TT + Cit compared to the CON. However, the populations of entero-bacteria and fungi were not affected (p > 0.05) by the essential oils or their blends. For aerobic stability, we observed that Ros increased (p < 0.001) the air exposure time of the sorghum silage. Furthermore, the essential oils impacted the sorghum silage’s pH, which affected (p = 0.003) its aerobic stability. In conclusion, the essential oils did not reduce sorghum silage losses. However, the Ros improved the nutritional quality and aerobic stability of sorghum silage, while the blend Ros + TT + Cit increased the lactic acid bacteria count in the silage. More in-depth studies are needed to elucidate the action of essential oils as silage additives. Full article
(This article belongs to the Special Issue Application of Fermentation Technology in Animal Nutrition)
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12 pages, 1160 KiB  
Article
Coffee-Flavoured Kombucha: Development, Physicochemical Characterisation, and Sensory Analysis
by Morena Senna Saito, Wilton Amaral dos Santos and Maria Eugênia de Oliveira Mamede
Fermentation 2024, 10(7), 334; https://doi.org/10.3390/fermentation10070334 - 27 Jun 2024
Viewed by 388
Abstract
Considering the health benefits of kombucha, already widely studied, the objective of this study was to develop kombucha beverages with the addition of an infusion of specialty arabica coffee from the first fermentation, varying the proportion of specialty coffee (2% to 13%), and [...] Read more.
Considering the health benefits of kombucha, already widely studied, the objective of this study was to develop kombucha beverages with the addition of an infusion of specialty arabica coffee from the first fermentation, varying the proportion of specialty coffee (2% to 13%), and evaluate their pH, volatile acidity, degree of alcohol, centesimal composition, sodium contents, and colour parameters to determine the acceptability of the beverages. Concerning the pH, all of the formulations conformed with the kombucha identity standard, but K3 (11% coffee) and K4 (13% coffee) were below the established minimum for volatile acidity. Except for K4, all of the other formulations were classified as alcoholic kombuchas, although their values were very close to the limit for non-alcoholic beverages. The formulations presented low sugar and sodium contents, which corroborated their low caloric value. Therefore, coffee-flavoured kombucha fermented for 18 days becomes an option for consumers looking for low-calorie, refreshing, and healthy drinks. The luminosity of the beverages decreased as the proportion of coffee increased, and consequently, the values for a* and b* increased, indicating a strong tendency for a yellowish-red colour. Sensorially, the formulations K4 and K3 were the most well accepted in all respects and can therefore be considered formulations with high commercialisation potential. Full article
(This article belongs to the Special Issue Analysis of Quality and Sensory Characteristics of Fermented Products)
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19 pages, 1590 KiB  
Article
Correlation between Microorganisms and Volatile Compounds during Spontaneous Fermentation of Sour Bamboo Shoots
by Xinyuan Zhang, Qiong Wang, Yuanhong Xie, Hongxing Zhang, Junhua Jin, Yong Xiong, Xiaona Pang and Frank Vriesekoop
Fermentation 2024, 10(7), 333; https://doi.org/10.3390/fermentation10070333 - 26 Jun 2024
Viewed by 831
Abstract
Chinese sour bamboo shoot is a traditionally, spontaneous fermented food that is particularly popular due to its complex and distinctive flavor. The volatile compounds of sour bamboo shoot originate mainly from the raw materials and the microbial fermentation. To reveal the correlation between [...] Read more.
Chinese sour bamboo shoot is a traditionally, spontaneous fermented food that is particularly popular due to its complex and distinctive flavor. The volatile compounds of sour bamboo shoot originate mainly from the raw materials and the microbial fermentation. To reveal the correlation between microorganisms and flavor, third-generation sequencing and Gas Chromatography-Ion Mobility Spectrometry were applied to analyze the dynamics of microbial communities at the species level and volatile compounds during sour bamboo shoot fermentation. The abundance of Lactobacillus acetotolerans and Lactobacillus fermentum increased during the fermentation, while Lactobacillus amyloliquefaciens decreased at first but then began to rise. At the end of fermentation, Lactobacillus amyloliquefaciens and Lactobacillus acetotolerans became the predominant species. A total of sixty-seven volatile compounds, which included twenty-three esters, nineteen alcohols, eight ketones, six aldehydes, six aromatic hydrocarbons, four acids and one ether, were identified. These compounds constituted the primary flavor of sour bamboo, which created a complex flavor of sour bamboo shoot. Among them, the contents of acetic acid, propionic acid, and isoamyl alcohol gradually increased during the fermentation process, and they became the main volatile compounds. Furthermore, the correlation between microorganisms and volatile compounds was investigated through two-way Orthogonal Partial Least Squares (O2PLS), which revealed a positive correlation between Lactobacillus amylolyticus and ethyl propanoate. Additionally, the abundance of Lactobacillus acetotolerans and Lactobacillus fermentum was found to be positively correlated with 2-heptenal. These findings provide a theoretical basis for understanding the formation mechanism of sour bamboo shoot flavor and the standardized production of high-quality sour bamboo shoots. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
19 pages, 3912 KiB  
Article
The Formulation of a Natural Detergent with a Biosurfactant Cultivated in a Low-Cost Medium for Use in Coastal Environmental Remediation
by Ivison A. da Silva, Fabíola Carolina G. de Almeida, Romulo N. Alves, Maristela C. C. Cunha, Jéssica Cristina M. de Oliveira, Mucio Luiz B. Fernandes and Leonie A. Sarubbo
Fermentation 2024, 10(7), 332; https://doi.org/10.3390/fermentation10070332 - 26 Jun 2024
Viewed by 768
Abstract
Green surfactants have significant potential for improving environmental remediation methods. The aim of the present study was to formulate a green natural detergent containing the biosurfactant produced by Starmerella bombicola ATCC 22214 grown in 1.2% canola oil, 10% sucrose, and 0.5% corn steep [...] Read more.
Green surfactants have significant potential for improving environmental remediation methods. The aim of the present study was to formulate a green natural detergent containing the biosurfactant produced by Starmerella bombicola ATCC 22214 grown in 1.2% canola oil, 10% sucrose, and 0.5% corn steep liquor. The biosurfactant reduced surface tension to 31.84 mN/m and was produced at a yield of 22 g/L. Twelve formulations were proposed using cottonseed oil as the natural solvent and different stabilisers (vegetable wax, hydroxyethyl cellulose, and sodium alginate). The detergent was evaluated for its emulsifying capacity and stability over a 10-day period. Ecotoxicity was investigated using the marine recruitment test on metal plates covered with paint into which the biosurfactant was incorporated as well as tests with a microcrustacean and vegetable seeds. The formulation designated H, consisting of 1% biosurfactant, 40% cottonseed oil, and 2% hydroxyethyl cellulose, achieved the best results. The formulation exhibited both stability and emulsifying capacity (100% of petroleum). The ecotoxicity tests revealed the safety of the natural detergent. The detergent achieved satisfactory oil dispersion and solubilised 98% of the oil impregnated on the rock. The results indicate that the natural detergent holds promise for efficiently cleaning up environmental areas contaminated with oil and petroleum products. Full article
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12 pages, 1829 KiB  
Article
Inhibitor Tolerance Capacity of Pichia kudriavzevii NBRC1279 and NBRC1664
by Hironaga Akita and Akinori Matsushika
Fermentation 2024, 10(7), 331; https://doi.org/10.3390/fermentation10070331 - 25 Jun 2024
Viewed by 563
Abstract
The thermotolerant yeast Pichia kudriavzevii (previously known as Issatchenkia orientalis), can produce ethanol from a variety of carbon sources and grows at around 45 °C. Thus, this yeast is considered a useful biocatalyst for producing ethanol from lignocellulose through simultaneous saccharification and [...] Read more.
The thermotolerant yeast Pichia kudriavzevii (previously known as Issatchenkia orientalis), can produce ethanol from a variety of carbon sources and grows at around 45 °C. Thus, this yeast is considered a useful biocatalyst for producing ethanol from lignocellulose through simultaneous saccharification and fermentation (SSF). SSF has several advantages, such as a simplified manufacturing process, ease of operation and reduced energy input. Using P. kudriavzevii NBRC1279 and NBRC1664, we previously succeeded in producing ethanol through SSF; however, the extent to which inhibitors by-produced from lignocellulose hydrolysis affect the growth and ethanol productivity of the two strains remains to be investigated. In this study, to better understand the inhibitor tolerance capacity of the two strains, spot assay, growth experiment, real-time quantitative PCR (RT-qPCR) analysis and multiple sequence alignment analysis were carried out. When P. kudriavzevii NBRC1279 and NBRC1664, as well as Saccharomyces cerevisiae BY4742 as a control, were cultured on SCD plates containing 17% ethanol, 42 mM furfural, 56 mM 5-hydroxymethylfurfural (HMF) or 10 mM vanillin, only P. kudriavzevii NBRC1664 was able to grow under all conditions. Moreover, the inhibitor tolerance capacity of P. kudriavzevii NBRC1664 was greater than those of other strains using SCD medium containing the same concentrations of various inhibitors. When an RT-qPCR analysis of seven gene sequences from aldehyde dehydrogenase and the aldehyde dehydrogenase family protein (ADHF) was performed using P. kudriavzevii NBRC1664 cultivated in the presence of 56 mM HMF, ADHF1 and ADHF2 were up-regulated in the early logarithmic growth phase. Moreover, a multiple sequence alignment of the amino acid sequences of ADHF1, ADHF2 and the known ADH suggested that ADHF1 and ADHF2 may catalyze the reversible NAD+-dependent oxidation of HMF. Our data may be useful for future studies on the metabolic engineering of more useful strains for ethanol production from lignocellulose. Full article
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16 pages, 3248 KiB  
Article
Human Health Benefits and Microbial Consortium of Stevia Fermented with Barley Nuruk
by Hyun-Ju Han, Min Nyeong Ko, Chan Seong Shin and Chang-Gu Hyun
Fermentation 2024, 10(7), 330; https://doi.org/10.3390/fermentation10070330 - 25 Jun 2024
Viewed by 750
Abstract
In this study, the microbial community present during the barley yeast fermentation of stevia leaves and its correlation with antioxidant, anti-obesity, and anti-inflammatory properties, as well as metabolites, were investigated using UPLC-Q-TOF-MS. Stevia was fermented using commercial TSB media (TSB 1, TSB 3, [...] Read more.
In this study, the microbial community present during the barley yeast fermentation of stevia leaves and its correlation with antioxidant, anti-obesity, and anti-inflammatory properties, as well as metabolites, were investigated using UPLC-Q-TOF-MS. Stevia was fermented using commercial TSB media (TSB 1, TSB 3, and TSB 5) and sucrose (Sucrose 1, Sucrose 3, and Sucrose 5) for 1, 3, and 5 days, respectively. Stevia ferments showed higher DPPH and ABTS radical scavenging capacity compared to samples incubated with sucrose for 5 days, and all six ferments inhibited nitric oxide production in a concentration-dependent manner in LPS-induced mouse macrophages. Furthermore, UPLC-QTOF-MS analysis identified 23 related substances, including 10 terpenoids (including rubusoside, steviolbioside, and rebadioside derivatives), dulcoside A, and phlomisoside II, which are indicators of stevia, as well as five flavonoids, four phenolic acids, and four fatty acids. We also identified the microbial community during fermentation via the next-generation sequencing of the 16S rRNA gene for bacteria and the internal transcribed spacer (ITS) gene for fungi. The results showed that TSB 1 and Sucrose 1 ferments were dominated by the pathogens Enterococcus hirae (58.93%) and Cronobacter sakazakii (80.92%), while samples fermented for more than 3 days were pathogen-free and dominated by lactic acid bacteria such as Pediococcus stilesii (73.37%). Microbial community analysis using the ITS region showed that Saccharomycopsis fibuligera, classified as a yeast rather than a mold, dominated the stevia fermentation regardless of the fermentation duration. In particular, the microbial community of the fermentation with a sucrose solution was dominated by S. fibuligera by more than 99% throughout the fermentation periods of 1, 3, and 5 days. Finally, to apply the stevia ferments topically to human skin, skin irritation tests were performed on 30 volunteers. The results showed that the highly concentrated extracts (1 mg/mL) of all six stevia ferments were hypoallergenic. Taken together, these findings suggest that barley nuruk fermented from stevia leaves with a sucrose solution offers promise as a natural ingredient for use in functional foods and cosmetics. Full article
(This article belongs to the Special Issue Functional Properties of Microorganisms in Fermented Foods)
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13 pages, 1289 KiB  
Article
Study on the Kinetic Model of Mixed Fermentation by Adding Glutathione-Enriched Inactive Dry Yeast
by Liming Xie, Kangjie Yu, Xiongjun Xiao, Ziyun Wei, Rong Xiong, Yong Du, Yajun Li and Yi Ma
Fermentation 2024, 10(7), 329; https://doi.org/10.3390/fermentation10070329 - 25 Jun 2024
Viewed by 465
Abstract
In order to investigate the impact of glutathione-enriched inactive dry yeast (g-IDY) on the co-fermentation process of Torulaspora delbrueckii and Saccharomyces cerevisiae, different contents of g-IDY (0, 20, 40, and 100 mg/L) were added to the simulated liquid for fermentation. The yeast [...] Read more.
In order to investigate the impact of glutathione-enriched inactive dry yeast (g-IDY) on the co-fermentation process of Torulaspora delbrueckii and Saccharomyces cerevisiae, different contents of g-IDY (0, 20, 40, and 100 mg/L) were added to the simulated liquid for fermentation. The yeast quantity, reducing sugar content, and ethanol volume fraction in the fermentation system were determined every 24 h. Nonlinear fitting of the measured values was carried out using classical Logistic, SGompertz, Boltzmann, and DoseResp models. Additionally, the aroma components of the wine were analyzed by GC-MS. The results indicate that the Logistic model performs best in terms of yeast growth kinetics, whereas the DoseResp and Boltzmann models exhibit the same fitting performance for reducing sugar consumption, both superior to the Logistic model, and the Boltzmann model shows the best-fitting performance for ethanol production. All optimal models have fitting coefficients (R2 values) above 0.99, demonstrating that different contents of g-IDY can effectively complete fermentation. Furthermore, all three fitting models can effectively describe the fermentation process using g-IDY. The use of g-IDY can increase the content of ethyl phenylacetate and phenylethanol, which can be employed to enhance the aroma of wine. Full article
(This article belongs to the Section Fermentation Process Design)
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27 pages, 6172 KiB  
Article
Research on the Composting Technology of Cattle and Sheep Manure Based on Intelligent and Efficient Composting Equipment and the Evaluation Standard of Decomposition Degree
by Lide Su, Kailin Ren, Yong Zhang and Longfei Zhang
Fermentation 2024, 10(7), 328; https://doi.org/10.3390/fermentation10070328 - 22 Jun 2024
Viewed by 399
Abstract
The Inner Mongolia Autonomous Region is a crucial area in China with a significant advantage in animal husbandry, particularly in cattle and sheep farming. However, the disposal of the large quantities of manure produced during farming has severely impacted the industry’s healthy development. [...] Read more.
The Inner Mongolia Autonomous Region is a crucial area in China with a significant advantage in animal husbandry, particularly in cattle and sheep farming. However, the disposal of the large quantities of manure produced during farming has severely impacted the industry’s healthy development. Proper treatment of the manure can convert it into organic fertilizer beneficial to farmland; otherwise, it will cause substantial environmental pollution. This study focuses on existing composting equipment and addresses the issues of cattle and sheep manure mixture ratios and compost maturity evaluation. Through experiments on the mixture of cattle and sheep manure, the optimal ratio for converting cattle and sheep manure into organic fertilizer was determined. Additionally, a fuzzy mathematical evaluation model was employed, along with experimental data, to establish a comprehensive evaluation system for aerobic compost maturity based on multiple indicators, revealing the variation patterns of maturity levels under different mixture ratios. The test results revealed that the composting equipment effectively controls the composting process, shortens the composting cycle, ensures the complete decomposition of organic matter, and meets national standards for livestock and poultry manure treatment. Regarding temperature and humidity, oxygen concentration, seed germination rate, pH value, electrical conductivity (EC), nitrogen, phosphorus, potassium content, and carbon-to-nitrogen ratio, the mixed compost of cattle and sheep manure in various ratios met the relevant standards for agricultural application. Various ratios of organic fertilizers containing cattle and sheep manure significantly promoted the growth of maize, wheat, and mung bean crops. Specifically, the compost decomposition cycle was shortest when sheep and cattle dung were mixed at a ratio of 2:1, while it was longest for all cattle dung. Finally, a fuzzy mathematical comprehensive evaluation model was established by selecting four indicators: water content, carbon-to-nitrogen ratio, apparent score, and germination index. The study demonstrates that the equipment and method offer significant advantages in efficiently treating cattle and sheep manure and producing organic fertilizer, thereby providing strong support for the sustainable development of animal husbandry. Full article
(This article belongs to the Section Industrial Fermentation)
16 pages, 312 KiB  
Article
Functional Properties of Microorganisms Isolated from Formulated Sourdough, Coconut Water Kefir, and Kefir
by Mansi Jayantikumar Limbad, Noemi Gutierrez Maddox, Nazimah Hamid and Kevin Kantono
Fermentation 2024, 10(7), 327; https://doi.org/10.3390/fermentation10070327 - 21 Jun 2024
Viewed by 484
Abstract
Recently, there has been a renewed interest in the fermentation of kefir grains using fruit-based substrates, such as coconut water. Kefir grains contain a mixture of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast, which have important probiotic capacity and play [...] Read more.
Recently, there has been a renewed interest in the fermentation of kefir grains using fruit-based substrates, such as coconut water. Kefir grains contain a mixture of lactic acid bacteria (LAB), acetic acid bacteria (AAB), and yeast, which have important probiotic capacity and play a vital role in improving the nutritional and functional properties of the new product being developed. The principal objective of this study was to determine the functional properties of the microorganisms identified and characterized from kefir, CWK, and sourdough fermented with coconut water kefir (CWKS), such as Limosilactobacillus fermentum, Lactiplantibacillus plantarum, L. fusant, L. reuteri, L. kunkeei, Acetobacter aceti, A. lovaniensis, A. pasteurianus, Candida kefyr, Rhodotorula mucilaginosa, Saccharomyces cerevisiae, C. guilliermondii, and C. colliculosa. In addition to identifying functional properties, such as glutamic acid production, phytase production, phytic acid degradation, and exopolysaccharide production, from this study, it was found that significantly high quantities of glutamic acid, exopolysaccharide, and phytase enzyme were detected in two LAB isolates, Limosilactobacillus fermentum and Lactiplantibacillus plantarum. Full article
(This article belongs to the Special Issue Application of Lactic Acid Bacteria in Fermented Food)
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