Fermentation

20 pages, 4850 KB

Open AccessArticle

Green Tea Modulates Temporal Dynamics and Environmental Adaptation of Microbial Communities in Daqu Fermentation

by Liang Zhao, Fangfang Li, Hao Xiao, Tengfei Zhao, Yanxia Zhong, Zhihui Hu, Lu Jiang, Xiangyong Wang and Xinye Wang

Fermentation 2025, 11(9), 511; https://doi.org/10.3390/fermentation11090511 (registering DOI) - 31 Aug 2025

Abstract

This study investigated the impact of green tea addition on microbial community dynamics during Daqu fermentation, a critical process in traditional baijiu production. Four Daqu variants (0%, 10%, 20%, 30% tea) were analyzed across six fermentation periods using 16S rRNA/ITS sequencing, coupled with [...] Read more.

This study investigated the impact of green tea addition on microbial community dynamics during Daqu fermentation, a critical process in traditional baijiu production. Four Daqu variants (0%, 10%, 20%, 30% tea) were analyzed across six fermentation periods using 16S rRNA/ITS sequencing, coupled with STR, TDR, Sloan neutral model, and phylogenetic analyses. Results showed time-dependent increases in bacterial/fungal richness, with 30% tea maximizing species richness. Tea delayed bacterial shifts until day 15 but accelerated fungal reconstruction from day 6, expanding the temporal response window. While stochastic processes dominated initial assembly (77–94% bacteria, 88–99% fungi), deterministic processes intensified with tea concentration, particularly in fungi (1% → 12%). Tea increased bacterial dispersal limitation and reduced phylogenetic conservatism of endogenous factors. This work proposed a framework for rationally engineering fermentation ecosystems by decoding evolutionary-ecological rules of microbial assembly. It revealed how plant-derived additives can strategically adjust niche partitioning and ancestral constraints to reprogram microbiome functionality. These findings provided a theoretical foundation in practical strategies for optimizing industrial baijiu production through targeted ecological interventions. Full article

(This article belongs to the Special Issue Development and Application of Starter Cultures, 2nd Edition)

25 pages, 2237 KB

Open AccessArticle

How Does Methanogenic Inhibition Affect Large-Scale Waste-to-Energy Anaerobic Digestion Processes? Part 1—Techno-Economic Analysis

by Denisse Estefanía Díaz-Castro, Ever Efraín García-Balandrán, Alonso Albalate-Ramírez, Carlos Escamilla-Alvarado, Sugey Ramona Sinagawa-García, Pasiano Rivas-García and Luis Ramiro Miramontes-Martínez

Fermentation 2025, 11(9), 510; https://doi.org/10.3390/fermentation11090510 (registering DOI) - 31 Aug 2025

Abstract

This two-part study assesses the impact of biogas inhibition on large-scale waste-to-energy anaerobic digestion (WtE-AD) plants through techno-economic and life cycle assessment approaches. The first part addresses technical and economic aspects. An anaerobic co-digestion system using vegetable waste (FVW) and meat waste (MW) [...] Read more.

This two-part study assesses the impact of biogas inhibition on large-scale waste-to-energy anaerobic digestion (WtE-AD) plants through techno-economic and life cycle assessment approaches. The first part addresses technical and economic aspects. An anaerobic co-digestion system using vegetable waste (FVW) and meat waste (MW) was operated at laboratory scale in a semi-continuous regime with daily feeding to establish a stable process and induce programmed failures causing methanogenic inhibition, achieved by removing MW from the reactor feed and drastically reducing the protein content. Experimental data, combined with bioprocess scale-up models and cost engineering methods, were then used to evaluate the effect of inhibition periods on the profitability of large-scale WtE-AD processes. In the experimental stage, the stable process achieved a yield of 521.5 ± 21 mL CH₄ g⁻¹ volatile solids (VS) and a biogas productivity of 0.965 ± 0.04 L L⁻¹ d⁻¹ (volume of biogas generated per reactor volume per day), with no failure risk detected, as indicated by the volatile fatty acids/total alkalinity ratio (VFA/TA, mg VFA L⁻¹/mg L⁻¹) and the VFA/productivity ratio (mg VFA L⁻¹/L L⁻¹ d⁻¹), both recognized as effective early warning indicators. However, during the inhibition period, productivity decreased by 64.26 ± 11.81% due to VFA accumulation and gradual TA loss. With the progressive reintroduction of the FVW:MW management and the addition of fresh inoculum to the reaction medium, productivity recovered to 96.7 ± 1.70% of its pre-inhibition level. In WtE-AD plants processing 60 t d⁻¹ of waste, inhibition events can reduce net present value (NPV) by up to 40.2% (from 0.98 M USD to 0.55 M USD) if occurring once per year. Increasing plant capacity (200 t d⁻¹), combined with higher revenues from waste management fees (99.5 USD t⁻¹) and favorable electricity markets allowing higher selling prices (up to 0.23 USD kWh⁻¹), can enhance resilience and offset inhibition impacts without significantly compromising profitability. These findings provide policymakers and industry stakeholders with key insights into the economic drivers influencing the competitiveness and sustainability of WtE-AD systems. Full article

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

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26 pages, 4380 KB

Open AccessReview

Novel Fermentation Techniques for Improving Food Functionality: An Overview

by Precious O. Ajanaku, Ayoyinka O. Olojede, Christiana O. Ajanaku, Godshelp O. Egharevba, Faith O. Agaja, Chikaodi B. Joseph and Remilekun M. Thomas

Fermentation 2025, 11(9), 509; https://doi.org/10.3390/fermentation11090509 (registering DOI) - 31 Aug 2025

Abstract

Fermentation has been a crucial process in the preparation of foods and beverages for consumption, especially for the purpose of adding value to nutrients and bioactive compounds; however, conventional approaches have certain drawbacks such as not being able to fulfill the requirements of [...] Read more.

Fermentation has been a crucial process in the preparation of foods and beverages for consumption, especially for the purpose of adding value to nutrients and bioactive compounds; however, conventional approaches have certain drawbacks such as not being able to fulfill the requirements of the ever-increasing global population as well as the sustainability goals. This review aims to evaluate how the application of advanced fermentation techniques can transform the food production system to be more effective, nutritious, and environmentally friendly. The techniques discussed include metabolic engineering, synthetic biology, AI-driven fermentation, quorum sensing regulation, and high-pressure processing, with an emphasis on their ability to enhance microbial activity with a view to enhancing product output. Authentic, wide-coverage scientific research search engines were used such as Google Scholar, Research Gate, Science Direct, PubMed, and Frontiers. The literature search was carried out for reports, articles, as well as papers in peer-reviewed journals from 2010 to 2024. A statistical analysis with a graphical representation of publication trends on the main topics was conducted using PubMed data from 2010 to 2024. In this present review, 112 references were used to investigate novel fermentation technologies that fortify the end food products with nutritional and functional value. Images that illustrate the processes involved in novel fermentation technologies were designed using Adobe Photoshop. The findings indicate that, although there are issues regarding costs, the scalability of the process, and the acceptability of the products by the consumers, the technologies provide a way of developing healthy foods and products produced using sustainable systems. This paper thus calls for more research and development as well as for the establishment of a legal frameworks to allow for the integration of these technologies into the food production system and make the food industry future-proof. Full article

(This article belongs to the Special Issue Feature Review Papers in Fermentation for Food and Beverages 2024)

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Graphical abstract

17 pages, 3060 KB

Open AccessArticle

Bacillus subtilis Genome Reduction Improves Surfactin Production

by Vitória Fernanda Bertolazzi Zocca, Fabiane de Oliveira Barban, Guilherme Engelberto Kundlatsch, Leonardo Ferro Tavares, Flávio Pereira Picheli, Adriana Candido da Silva Moura and Danielle Biscaro Pedrolli

Fermentation 2025, 11(9), 508; https://doi.org/10.3390/fermentation11090508 (registering DOI) - 30 Aug 2025

Abstract

Bacillus subtilis ∆6 is a genome-reduced strain derived from the laboratory strain 168 through deletion of six prophages and AT-rich islands. The parental and the genome-reduced strains were edited to restore the capacity to synthesize surfactin. Although the genome deletions are not directly [...] Read more.

Bacillus subtilis ∆6 is a genome-reduced strain derived from the laboratory strain 168 through deletion of six prophages and AT-rich islands. The parental and the genome-reduced strains were edited to restore the capacity to synthesize surfactin. Although the genome deletions are not directly related to surfactin biosynthesis, the ∆6 strain produces more surfactin while building lower biomass compared to the parental strain. Further editions to ∆6, such as srfA promoter replacement, codY deletion, and comA overexpression, were deleterious to surfactin production. The results showcase that the ∆6 is metabolically distinct from its parental strain and other surfactin-producing strains, as the gene editions made have been previously described to increase surfactin production in these strains. The ∆6 produced the highest surfactin titer, rate, and yield in LB medium enriched with glucose, compared to other commonly used media for B. subtilis. This work demonstrates the enhanced capacity of a genome-reduced strain to produce surfactin compared to the parental strain, as well as the metabolic changes resulting from genome engineering. Full article

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

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40 pages, 2044 KB

Open AccessArticle

Physicochemical Exploration of Cocoa Butter During Spontaneous Fermentation: A Comparative Study Across Three Latin American Countries

by César R. Balcázar-Zumaeta, Jorge L. Maicelo-Quintana, Gilson C. A. Chagas Junior, Nelson Rosa Ferreira, Wandson Braamcamp de Souza Pinheiro, Luis Nelson Cardoso e-C. Filho, Alberdan Silva Santos, Angel F. Iliquin-Chávez, Pedro García-Alamilla, Ilse S. Cayo-Colca and Efraín M. Castro-Alayo

Fermentation 2025, 11(9), 507; https://doi.org/10.3390/fermentation11090507 - 29 Aug 2025

Abstract

This study characterized the physicochemical properties of cocoa butter (CB) extracted from cocoa beans of the Criollo Nativo (Peru), Criollo (Mexico), and Forastero (Brazil) varieties subjected to spontaneous fermentation under traditional local conditions in each country. Cocoa samples were collected at 24-h intervals, [...] Read more.

This study characterized the physicochemical properties of cocoa butter (CB) extracted from cocoa beans of the Criollo Nativo (Peru), Criollo (Mexico), and Forastero (Brazil) varieties subjected to spontaneous fermentation under traditional local conditions in each country. Cocoa samples were collected at 24-h intervals, and CB was extracted to evaluate its lipid composition through fatty acid profiling and spectroscopic techniques (FT-IR and NMR). Also, the thermal and structural properties via differential scanning calorimetry (DSC), including melting and crystallization profiles, crystallization kinetics, and polymorphism, were determined. The results revealed that stearic, oleic, and palmitic acids were predominant in all varieties, while trace levels of myristic and pentadecanoic acids contributed to molecular packing. FT-IR identified bands associated with glycerol chain formation in TAGs, which were confirmed by NMR through chemical shifts linked to the distribution of POS, SOS, and POP species. CB exhibited melting temperatures between 19.6 and 20.5 °C, favoring polymorphic transitions toward more stable forms. Form I (γ) predominated during early fermentation, while Forms II (α) and III (β′₂) were subsequently identified, particularly in Criollo varieties. These findings demonstrate that fermentation time significantly influences the chemical composition, oxidative stability, and crystalline structure of CB, providing valuable insights for optimizing cocoa processing and the development of high-quality chocolate products. Full article

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

16 pages, 1875 KB

Open AccessArticle

Evaluation of Biomass, Lipid and Chlorophyll Production of a Microalgal Consortium Cultured in Dairy Wastewater

by Christian Ariel Cabrera-Capetillo, Omar Surisadai Castillo-Baltazar, Vicente Peña-Caballero, Moisés Abraham Petriz-Prieto, Adriana Guzmán-López, Esveidi Montserrat Valdovinos-García and Micael Gerardo Bravo-Sánchez

Fermentation 2025, 11(9), 506; https://doi.org/10.3390/fermentation11090506 - 29 Aug 2025

Abstract

Currently, microalgae cultivation requires strategies to improve yield and reduce production costs for biotechnological purposes. Dual-purpose systems are one of the most widely used strategies for these purposes, using culture media supplemented with wastewater. This study evaluated the growth of a microalgal consortium [...] Read more.

Currently, microalgae cultivation requires strategies to improve yield and reduce production costs for biotechnological purposes. Dual-purpose systems are one of the most widely used strategies for these purposes, using culture media supplemented with wastewater. This study evaluated the growth of a microalgal consortium in three treatments with different proportions of dairy wastewater (WWDI) and synthetic BBM-3N medium (Bold Basal Medium), with the aim of optimizing biomass, chlorophyll, and lipid production. The treatment with 60% BBM-3N medium and 40% WWDI (Case 3) showed the best performance under experimental conditions, reaching a biomass concentration of 0.7543 g/L, a chlorophyll production of 10.6890 µg/mL, and a lipid content of 14.63%. These results exceeded those obtained in the cases with 100% BBM-3N or 100% WWDI. In addition, a techno-economic evaluation was carried out via SuperPro Designer simulation, which allowed the annual operating costs for each treatment to be estimated. Case 3 stood out as the most viable option, combining good biological performance with lower operating costs compared to the raw material, demonstrating the potential of using wastewater as a partial source of nutrients in microalgal cultures intended for the production of value-added products. Full article

(This article belongs to the Special Issue Cyanobacteria and Eukaryotic Microalgae (2nd Edition))

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19 pages, 9448 KB

Open AccessArticle

Optimization of Monascus purpureus Culture Conditions in Rice Bran for Enhanced Monascus Pigment Biosynthesis

by Di Chen, Yanping Xu, Han Li and Xuemin Zhu

Fermentation 2025, 11(9), 505; https://doi.org/10.3390/fermentation11090505 - 28 Aug 2025

Abstract

Monascus pigments (MPs) are the most valuable secondary metabolites of Monascus. To improve the production of MPs is of great importance to food processing. Currently, studies using rice bran as the substrate to produce MPs are rare. In this study, rice bran [...] Read more.

Monascus pigments (MPs) are the most valuable secondary metabolites of Monascus. To improve the production of MPs is of great importance to food processing. Currently, studies using rice bran as the substrate to produce MPs are rare. In this study, rice bran with different carbon sources and cellulase hydrolysis conditions were explored in Monascus purpureus M9 in this study. Through single-factor experiments and Box–Behnken response surface optimization, we demonstrated that mannitol supplementation combined with cellulase treatment of substrate significantly enhanced the yields of MPs. The optimal conditions (4.00% mannitol, cellulase hydrolysis at 60 °C for 2 h) achieved a maximum color value of 3538 U/g. Furthermore, comparative evaluation under different culture conditions, including only rice bran (RB), cellulase hydrolysis of rice bran (Cel), rice bran supplemented with mannitol (Man), mannitol supplementation combined with cellulase pretreatment of substrate (Opti), and only rice (Rice), confirmed the effectiveness of the optimized treatment. The color value of the Opti group was 27.95 times more than that of the RB group and reached 80.96% of the counterpart of the Rice group. The Opti group also significantly enhanced the yields of two orange pigments (Monascorubrin and Rubropunctatin), induced more sexual spore formation, and exhibited the maximum biomass and colony diameter among different groups. The hyphae of the Man and Opti groups were full, intact, and tubular. The citrinin content in the Opti group was under the limit standard of China. The data provides a theoretical basis reference for improving the yields of MPs with RB as the substrate. Full article

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

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15 pages, 1363 KB

Open AccessArticle

Photofermentative Hydrogen Production from Real Dark Fermentation Effluents: A Sequential Valorization of Orange Peel Waste

by Brenda Nelly López-Hernández, Carlos Escamilla-Alvarado, Alonso Albalate-Ramírez, Pasiano Rivas-García, Héctor Javier Amézquita-García, Santiago Rodríguez-Valderrama and María Guadalupe Paredes

Fermentation 2025, 11(9), 504; https://doi.org/10.3390/fermentation11090504 - 28 Aug 2025

Abstract

This study explores the sequential valorization of orange peel waste (OPW) through photo-fermentation using real dark fermentation effluents (DFE) as substrates for hydrogen production using Rhodobacter capsulatus B10. Three DFE types—differing in prior biocompound extraction method—and their concentrations at three levels (25, 35, [...] Read more.

This study explores the sequential valorization of orange peel waste (OPW) through photo-fermentation using real dark fermentation effluents (DFE) as substrates for hydrogen production using Rhodobacter capsulatus B10. Three DFE types—differing in prior biocompound extraction method—and their concentrations at three levels (25, 35, and 45%) were evaluated. The highest hydrogen yield (126.5 mL H₂ g⁻¹ VFA) was achieved with DFE derived from essential oil-extracted OPW at a concentration of 25%. The highest DFE concentration reduced the hydrogen yield due to intensified medium opacity and potential substrate inhibition. Kinetic modeling revealed that the Modified Gompertz and T_i-Gompertz models best described hydrogen production dynamics. This study presents the first evidence of hydrogen production via photo-fermentation using real effluents derived from OPW processing, demonstrating a novel route for citrus waste reuse within a biorefinery framework. These findings underscore the innovation and relevance of integrating waste valorization with clean energy production, while also identifying key operational challenges to be addressed. Full article

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

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13 pages, 1716 KB

Open AccessArticle

Towards Higher Energy Conversion Efficiency by Bio-Hydrogen and Bio-Methane Co-Production: Effect of Enzyme Loading and Initial pH

by Xueting Zhang, Zhipeng Song, Danping Jiang, Chenxi Xia, Zejie Li, Wenzhe Li and Quanguo Zhang

Fermentation 2025, 11(9), 503; https://doi.org/10.3390/fermentation11090503 - 28 Aug 2025

Abstract

Bio-hydrogen and bio-methane co-production was a promising way to enhance the energy conversion efficiency, and enzyme loading and pH are key factors influencing anaerobic fermentation processes. Therefore, in this study, the co-production process of bio-hydrogen and bio-methane was evaluated based on the effect [...] Read more.

Bio-hydrogen and bio-methane co-production was a promising way to enhance the energy conversion efficiency, and enzyme loading and pH are key factors influencing anaerobic fermentation processes. Therefore, in this study, the co-production process of bio-hydrogen and bio-methane was evaluated based on the effect of enzyme loading (20%, 30%, and 40%) combined with initial pH (6.0, 7.0, 8.0, and 9.0). The results indicated that, compared with other conditions, 30% enzyme loading with an initial pH of 8.0 was more feasible for bio-hydrogen and bio-methane co-production from duckweed, achieving a bio-hydrogen yield of 114.56 mL/g total solid (TS) and a bio-methane yield of 260.32 mL/g TS. Under optimum condition, the energy conversion efficiency was 71.4%, which was 6-fold and 4.8-fold higher than that of the single bio-hydrogen production stage (pH 8, 40% and 10.2%) and single methane production stage (control group with 12.30%), respectively. Full article

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19 pages, 1137 KB

Open AccessArticle

Effects of Stinging nettle Powder on Probiotics Survival, Physiochemical Properties, and Nutritional Value of Kefir

by Said Ajlouni, Jiheng Wu, Eliana Tang and Tingyu Liu

Fermentation 2025, 11(9), 502; https://doi.org/10.3390/fermentation11090502 - 27 Aug 2025

Abstract

Kefir is a historic dairy-fermented beverage produced using lactic acid bacteria and yeast as a starter culture and is considered nutritious with a good taste. Many studies have been conducted to incorporate various possible functional materials into kefir to enhance its nutritional value. [...] Read more.

Kefir is a historic dairy-fermented beverage produced using lactic acid bacteria and yeast as a starter culture and is considered nutritious with a good taste. Many studies have been conducted to incorporate various possible functional materials into kefir to enhance its nutritional value. This study aims to enrich kefir with 0.25% and 0.5% of Stinging nettle (Sn) powder before fermentation to improve its nutritional value. Stinging nettle (Urtica dioica) is a nutritious and multifunctional herb with a variety of healthful components such as fibers and polyphenols; it has significant potential as a useful food functional ingredient. The physicochemical, microbial, and nutritional properties of kefir fortified with Sn were examined weekly during refrigerated storage for 21 days. The results showed that adding Stinging nettle significantly (p < 0.05) increased the probiotic counts from 7.90 ± 0.22 log to 8.46 ± 0.19 log CFU/g, antioxidant activity (4%), and total polyphenol contents (5%) in kefir yogurt after 12 days of refrigerated storage. The addition of Sn also had a positive effect on the acidity of kefir and increased the viscosity and the syneresis to a certain extent. Furthermore, adding Sn increased lactic acid bacteria counts and the production of short-chain fatty acids after in vitro digestion and colonic fermentation. The results of this study indicated the potential use of Sn powder as a functional ingredient in kefir yogurt and other similar products. Full article

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

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17 pages, 5562 KB

Open AccessArticle

Identification of Dominant Microbes and Their Successions During Solid-State Fermentation of Luzhou-Flavour Liquor Based on High-Throughput Sequencing Following Culture

by Jiangang Yang, Zaibin Xie, Xiao Dou, Yu Zhang, Xiaohui Zhou and Shunchang Pu

Fermentation 2025, 11(9), 501; https://doi.org/10.3390/fermentation11090501 - 27 Aug 2025

Abstract

Microorganisms are crucial for the liquor brewing process and substantially impact liquor flavour and quality; therefore, understanding microbial succession is necessary. Most studies use a single-method approach and fail to provide an in-depth analysis. We aimed to combine traditional culture method with high-throughput [...] Read more.

Microorganisms are crucial for the liquor brewing process and substantially impact liquor flavour and quality; therefore, understanding microbial succession is necessary. Most studies use a single-method approach and fail to provide an in-depth analysis. We aimed to combine traditional culture method with high-throughput sequencing (HTS) to identify the microbial diversity and succession in Luzhou-flavour fermentation. HTS revealed 932 bacterial and 980 fungal operational taxonomic units. 16S rDNA, 26S D1/D2 rDNA, and ITS v4/v5 isolated and identified 256 bacterial and 130 yeast strains. Population succession analysis showed that the dominant populations were yeasts, Lactobacillus, and Bacillus (early stage), and yeasts and Lactobacillus (late stage). Lactobacillus, Pichia, Bacillus, and Candida were abundant among all three layers of fermented grains. However, C. ethanolica, Saccharomycetes sp., and an unidentified Saccharomyces cerevisiae were more abundant in the lower layer than in the middle and upper layers, while L. parabuchneri, Oceanobacillus oncorhynchi, and Thermoactinomyces sp. were present only in the lower layer. Correlations among enzyme activity, volatile production, and dominant microbes during fermentation indicated that P. fermentans, L. suebicus, L. acetotolerans, P. kudriavzevii, P. exigua, and B. tequilensis were significantly affected during brewing. Our results lay a foundation for elucidating the microbial fermentation mechanism of Luzhou-flavour liquor and will assist in improving traditional liquor brewing quality and efficiency. Full article

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

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18 pages, 4311 KB

Open AccessArticle

Mycomaterials from Agave Bagasse: A Valorization Strategy for Sustainable Tequila Packaging

by Flavio A. de Anda-Rodríguez, Mariana R. Corona-Ramírez, Carlos D. Patiño-Arévalo, Marco A. Zárate-Navarro, Ana I. Zárate-Guzmán and Luis A. Romero-Cano

Fermentation 2025, 11(9), 500; https://doi.org/10.3390/fermentation11090500 - 26 Aug 2025

Abstract

A sustainable strategy is proposed for the valorization of solid waste from the Tequila industry through the development of bio-packaging for Tequila bottles using mycelium from Ganoderma lucidum. The fungus was isolated from Bosque de la Primavera (Jalisco, Mexico) and cultivated on [...] Read more.

A sustainable strategy is proposed for the valorization of solid waste from the Tequila industry through the development of bio-packaging for Tequila bottles using mycelium from Ganoderma lucidum. The fungus was isolated from Bosque de la Primavera (Jalisco, Mexico) and cultivated on lignocellulosic substrates: agave bagasse and corn stover. These agricultural residues were dried, ground, and pasteurized to optimize their performance as growth media. Their structural integration before and after fermentation was evaluated using optical microscopy. The high cellulose and hemicellulose content of both substrates supported robust mycelial development, enabling the formation of moldable materials through solid-state fermentation. After growth, the mycelium colonized the substrate, forming a functional mold adapted to the geometry of a Tequila bottle prototype. The molded parts were dried to halt fungal activity, prevent fruiting, and stabilize the structure. Physical and mechanical characterization showed competitive performance with regard to bulk density (0.11 ± 0.1 g cm⁻³), water absorption (78.1 ± 4.2%), and high impact resistance (evaluated via Solidworks simulation). A life cycle assessment revealed that mycelium packaging has a significantly lower environmental impact than expanded polystyrene. The material supports circular economy principles within the Tequila production chain. Full article

(This article belongs to the Special Issue Application of Fungi in Bioconversions and Mycoremediation)

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28 pages, 6593 KB

Open AccessReview

Technological Prospects of Saccharomyces eubayanus: Breakthroughs and Brewing Industry Applications

by Sofía Inés Giorgetti, Julieta Amalia Burini, Juan Ignacio Eizaguirre and Diego Libkind

Fermentation 2025, 11(9), 499; https://doi.org/10.3390/fermentation11090499 - 26 Aug 2025

Abstract

This review explores the accumulated research and technological potential of Saccharomyces eubayanus, a cold-tolerant wild yeast first isolated in 1997 from the Andean-Patagonian forests of Argentina but formally described in 2011. S. eubayanus has garnered attention since it was identified as the [...] Read more.

This review explores the accumulated research and technological potential of Saccharomyces eubayanus, a cold-tolerant wild yeast first isolated in 1997 from the Andean-Patagonian forests of Argentina but formally described in 2011. S. eubayanus has garnered attention since it was identified as the missing parent of the lager-beer yeast S. pastorianus and because it demonstrated valuable fermentative skills and an unexpected large intraspecific genetic diversity. The article recapitulates the characterization of the fermentative capacity of the type strain, as well as its ability to produce distinctive aromatic profiles compared to conventional lager yeasts. We discuss how these features have driven the development of improved strains through experimental evolution and the generation of interspecific hybrids with S. cerevisiae exhibiting appropriate fermentation performance and a broad aromatic diversity. We also aim to address the applications of S. eubayanus in commercial brewing, especially in the craft beer industry, and highlight its potential to add value and/or regional identity to beer through novel flavor profiles. Finally, the review outlines the main challenges limiting large-scale implementation, emphasizing the importance of continued research into strain development and brewing strategies to fully harness the potential of this wild yeast species. Full article

(This article belongs to the Special Issue Alcoholic Fermentation)

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26 pages, 6306 KB

Open AccessArticle

Screening Sourdough Starter Cultures from Yeast and Lactic Acid Bacteria Isolated from Mexican Cocoa Mucilage and Coffee Pulp for Bread Quality Improvement

by Natali Hernández-Parada, Hugo Gabriel Gutiérrez-Ríos, Patricia Rayas-Duarte, Oscar González-Ríos, Mirna Leonor Suárez-Quiroz, Zorba Josué Hernández-Estrada, María Cruz Figueroa-Espinoza and Claudia Yuritzi Figueroa-Hernández

Fermentation 2025, 11(9), 498; https://doi.org/10.3390/fermentation11090498 - 26 Aug 2025

Abstract

This study aimed to identify and evaluate yeasts and lactic acid bacteria (LAB) isolated from Mexican cocoa mucilage (Theobroma cacao) and coffee pulp (Coffea arabica) for their potential use as sourdough starter co-cultures to improve bread quality. Functional screens [...] Read more.

This study aimed to identify and evaluate yeasts and lactic acid bacteria (LAB) isolated from Mexican cocoa mucilage (Theobroma cacao) and coffee pulp (Coffea arabica) for their potential use as sourdough starter co-cultures to improve bread quality. Functional screens included assessments of amylolytic, proteolytic, and phytase activities, CO₂ production, acidification capacity, and exopolysaccharide (EPS) synthesis. Saccharomyces cerevisiae YCTA13 exhibited the highest fermentative performance, surpassing commercial baker’s yeast by 52.24%. Leuconostoc mesenteroides LABCTA3 showed a high acidification capacity and EPS production, while Lactiplantibacillus plantarum 20B3HB had the highest phytase activity. Six yeast–LAB combinations were formulated as mixed starter co-cultures and evaluated in sourdough breadmaking. The B3Y14 co-culture (LABCTA3 + YCTA14) significantly improved the bread volume and height by 35.61% and 17.18%, respectively, compared to the commercial sourdough starter, and reduced crumb firmness by 59.66%. Image analysis of the bread crumb revealed that B3Y14 enhanced the crumb structure, resulting in greater alveolar uniformity and a balanced gas cell geometry. Specifically, B3Y14 showed low alveolar regularity (1.16 ± 0.03) and circularity (0.40 ± 0.01), indicating a fine and homogeneous crumb structure. These findings highlight the synergistic potential of selected allochthonous yeast and LAB strains in optimizing sourdough performance, positively impacting bread texture, structure, and quality. Full article

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

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16 pages, 3118 KB

Open AccessArticle

Functional Investigation of Mutant Vespa tropica Hyaluronidase Produced in Pichia pastoris: In Silico Studies and Potential Applications

by Piyapon Janpan, Bernhard Schmelzer, Anuwatchakij Klamrak, Jaran Nabnueangsap, Yutthakan Saengkun, Shaikh Shahinur Rahman, Prapenpuksiri Rungsa, Diethard Mattanovich and Sakda Daduang

Fermentation 2025, 11(9), 497; https://doi.org/10.3390/fermentation11090497 - 25 Aug 2025

Abstract

The hyaluronidase enzyme derived from Vespa tropica (VesT2a) venom contains two putative catalytic residues. Herein, a double mutation was introduced into VesT2a at its catalytic sites by substituting Asp107 and Glu109 with Asn and Gln, respectively, to assess their essential roles in enzymatic [...] Read more.

The hyaluronidase enzyme derived from Vespa tropica (VesT2a) venom contains two putative catalytic residues. Herein, a double mutation was introduced into VesT2a at its catalytic sites by substituting Asp107 and Glu109 with Asn and Gln, respectively, to assess their essential roles in enzymatic function. We used Pichia pastoris to produce the mutated version of the VesT2a (mVesT2a) protein, and the process was more efficient when employing the methanol-inducible promoter (P_AOX1) compared to the constitutive promoter (P_GAP). In bioreactor scale-up, P. pastoris harboring the pAOX1-αMF-mVesT2a plasmid secreted 34.03 ± 2.31 mg/L of mVesT2a, with an apparent molecular mass of 46.6 kDa, retaining only 2.9% of hyaluronidase activity, thus indicating successful mutation. The newly developed indirect ELISA-based method using mVesT2a demonstrated its potential as an alternative approach for measuring hyaluronic acid (HA) at low concentrations and was also used to confirm HA-binding capacity. In silico docking and molecular dynamics simulations further supported the stable interaction of the mVesT2a–HA complex while suggested other surrounded acidic amino acid residues, which may play a minor role in HA degradation, supporting the remaining activity observed in the in vitro experiments. Full article

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

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13 pages, 513 KB

Open AccessArticle

A Novel Approach for Enhancing the Terpenoid Content in Wine Using Starmerella bacillaris

by María Belén Listur, Valentina Martín, Karina Medina, Francisco Carrau, Eduardo Boido, Eduardo Dellacassa and Laura Fariña

Fermentation 2025, 11(9), 496; https://doi.org/10.3390/fermentation11090496 - 25 Aug 2025

Abstract

In this study, we investigated the impact of two native strains of Starmerella bacillaris, used both in pure culture and in a co-inoculation with Saccharomyces cerevisiae, on the volatile profile of a chemically defined fermented model must. The focus of this [...] Read more.

In this study, we investigated the impact of two native strains of Starmerella bacillaris, used both in pure culture and in a co-inoculation with Saccharomyces cerevisiae, on the volatile profile of a chemically defined fermented model must. The focus of this study was the production of monoterpenes and sesquiterpenes and their potential sensory contributions. Geraniol and linalool were detected in all fermentations with Starmerella bacillaris, in ranges of 26.7–43.9 µg/L and 34.3–41.3 µg/L, respectively, independent of the inoculation strategy used. Both strains produced concentrations above their respective odour thresholds of 20 µg/L and 25.5 µg/L. Odour activity value (OAV) analysis confirmed that fermentations with Starmerella bacillaris, particularly under co-inoculation conditions, generated the highest OAVs for these monoterpenes. Citronellol was only detected in mixed fermentations, while nerolidol and farnesol isomers were produced in variable amounts, depending on the strain and inoculation strategy, at concentrations below the odour threshold. These findings demonstrate the ability of Starmerella bacillaris to facilitate de novo biosynthesis of linalool, geraniol, and sesquiterpenes during alcoholic fermentation—in the case of linalool and geraniol, at concentrations exceeding their respective odour thresholds—highlighting the biotechnological potential of these native strains to enhance aroma in wines, particularly those made from neutral grape varieties. Full article

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

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14 pages, 284 KB

Open AccessArticle

Use of a Blend of Exogenous Enzymes in the Diet of Lactating Jersey Cows: Ruminal Fermentation In Vivo and In Vitro, and Its Effects on Productive Performance, Milk Quality, and Animal Health

by Maksuel Gatto de Vitt, Andrei Lucas Rebelatto Brunetto, Karoline Wagner Leal, Guilherme Luiz Deolindo, Natalia Gemelli Corrêa, Luiz Eduardo Lobo e Silva, Roger Wagner, Maria Eduarda Pieniz Hamerski, Gilberto Vilmar Kozloski, Melânia de Jesus da Silva, Amanda Regina Cagliari, Pedro Del Bianco Benedeti and Aleksandro Schafer da Silva

Fermentation 2025, 11(9), 495; https://doi.org/10.3390/fermentation11090495 - 25 Aug 2025

Abstract

The use of exogenous enzymes in the nutrition of dairy cows is an innovative and efficient strategy to maximize productivity and milk quality, with positive applications in the economic and environmental aspects of dairy farming. Therefore, the objective of this study was to [...] Read more.

The use of exogenous enzymes in the nutrition of dairy cows is an innovative and efficient strategy to maximize productivity and milk quality, with positive applications in the economic and environmental aspects of dairy farming. Therefore, the objective of this study was to evaluate whether the addition of a blend of exogenous enzymes to the diet of lactating Jersey cows has a positive effect on productive performance, milk quality, animal health, ruminal environment, and digestibility. Twenty-one primiparous Jersey cows, with 210 days in lactation (DL), were used. The exogenous enzymes used were blends containing mainly protease, in addition to cellulase, xylanase, and beta-glucanase. The animals were divided into three groups with seven replicates per group (each animal being the experimental unit), as follows: Control (T-0), basal diet without enzyme addition; Treatment (T-80), animals fed enzymes in the diet at a daily dose of 80 mg per kg of dry matter (DM); Treatment (T-160), animals fed enzymes in the diet at a daily dose of 160 mg per kg of DM. The study lasted 84 days, during which higher milk production was observed in the treated groups (T-80 and T-160) compared to the control group (p = 0.04). When calculating feed efficiency from days 1 to 84, greater efficiency was observed in both groups that received the blend compared to the control (p = 0.05). In the centesimal composition of the milk, it was observed that the percentage of protein in the milk of the T-160 group was higher compared to the control group (p = 0.03). The effect of the enzymes was verified for butyric (p = 0.05) and palmitic (p = 0.05) fatty acids. We also observed the effect of the enzyme blend on the amount of volatile fatty acids (VFAs), which were higher in the ruminal fluid of cows that received the enzymes (p = 0.01). Cows that consumed enzymes showed a higher apparent digestibility coefficient of crude protein (p = 0.01). In vitro, the main result is related to lower gas production in 24 and 48 h at T-160. We concluded that the use of a blend of exogenous enzymes in the diet of lactating Jersey cows was able to increase milk production in these animals, resulting in greater feed efficiency and also an increase in milk protein content, positively modulating the fatty acid profile in the rumen and improving the apparent digestibility of nutrients. Full article

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

18 pages, 3536 KB

Open AccessArticle

Preliminary Genetic and Physiological Characterization of Starmerella magnoliae from Spontaneous Mead Fermentation in Patagonia

by Victoria Kleinjan, Melisa González Flores, María Eugenia Rodriguez and Christian Ariel Lopes

Fermentation 2025, 11(9), 494; https://doi.org/10.3390/fermentation11090494 - 24 Aug 2025

Abstract

Honey possesses unique properties, characterized by its high sugar concentration and the synergistic interaction among nectar, pollen, bees, and yeasts. These features render it an exceptional substrate for exploring microbial diversity for bioprospecting purposes. In this study, we characterized fermentative yeast populations from [...] Read more.

Honey possesses unique properties, characterized by its high sugar concentration and the synergistic interaction among nectar, pollen, bees, and yeasts. These features render it an exceptional substrate for exploring microbial diversity for bioprospecting purposes. In this study, we characterized fermentative yeast populations from 19 honey samples collected in Northern Patagonia, Argentina. A total of 380 yeast isolates were obtained, identifying eight yeast species. Starmerella magnoliae emerged as the dominant species, found in 76% of samples and representing 63% of total isolates. Intraspecific diversity analysis, using mtDNA-RFLP and sequencing of nuclear genes (FSY1 and FFZ1), revealed the presence of two distinct phylogeographic populations. Phenotypic assays indicated that most S. magnoliae strains tolerate high sulfite and ethanol concentrations, alongside exhibiting broad temperature tolerance, with some strains thriving even at 37 °C. Despite the fact that none of the strains completed the fermentation, microfermentation trials confirmed the fructophilic nature of this species and highlighted intraspecific variability in glycerol and acetic acid production. These findings underscore S. magnoliae as a promising non-Saccharomyces yeast for the fermented beverage industry. Full article

(This article belongs to the Special Issue Yeast Fermentation, 2nd Edition)

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26 pages, 5286 KB

Open AccessArticle

Optimization of Anaerobic Co-Digestion Parameters for Vinegar Residue and Cattle Manure via Orthogonal Experimental Design

by Yuan Lu, Gaoyuan Huang, Jiaxing Zhang, Tingting Han, Peiyu Tian, Guoxue Li and Yangyang Li

Fermentation 2025, 11(9), 493; https://doi.org/10.3390/fermentation11090493 - 23 Aug 2025

Abstract

The anaerobic co-digestion of agricultural residues emerges as a promising strategy for energy recovery and nutrient recycling within circular agricultural systems. This study aimed to optimize co-digestion parameters for vinegar residue (VR) and cattle manure (CM) using an orthogonal experimental design. Three key [...] Read more.

The anaerobic co-digestion of agricultural residues emerges as a promising strategy for energy recovery and nutrient recycling within circular agricultural systems. This study aimed to optimize co-digestion parameters for vinegar residue (VR) and cattle manure (CM) using an orthogonal experimental design. Three key variables were investigated which are the co-substrate ratio (VR to CM), feedstock-to-inoculum (F/I) ratio, and total solids (TS) content. Nine experimental combinations were tested to evaluate methane yield, feedstock degradation, and digestate characteristics. Results showed that the optimal condition for methane yield comprised a 2:3 co-substrate ratio, 1:2 F/I ratio, and 20% TS, achieving the highest methane yield of 267.84 mL/g volatile solids (VS) and a vs. degradation rate of 58.65%. Digestate analysis indicated this condition generated the most nutrient-rich liquid digestate and solid digestate, featuring elevated N, P, and K concentrations, acceptable seed germination indices (GI), and moderate humification levels. While total nutrient content did not meet commercial organic fertilizer standards, the digestate is suitable for direct land application in rural settings. This study underscores the need to balance energy recovery and fertilizer quality in anaerobic co-digestion systems, providing practical guidance for decentralized biogas plants seeking to integrate waste treatment with agricultural productivity. Full article

(This article belongs to the Section Industrial Fermentation)

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