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Fermentation
Volume 11
Issue 8
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Fermentation, Volume 11, Issue 8 (August 2025) – 68 articles

Cover Story (view full-size image): Weizmannia ginsengihumi was isolated from sugarcane bagasse for the production of lactic acid by xylose fermentation. Response surface analysis indicated that the optimal concentrations of carbon and nitrogen sources were 32.5 and 3.0 g·L−1, respectively, without the need to add sodium acetate to the culture medium, leading to the production of 20.02 ± 0.19 g·L−1, a productivity of 0.55 g/L/h after 36 h of fermentation, and a residual sugar concentration of 12.59 ± 0.51 g·L−1. The results obtained demonstrate the potential of Weizmannia ginsengihumi in producing lactic acid from biomass, thereby contributing to sustainability. View this paper
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13 pages, 2084 KB  
Article
Effects of Applied Voltage on the Microbial Communities at the Anode and Cathode During Methane Fermentation
by Hikaru Kaneko, Mitsuhiko Koyama and Hiroyuki Daimon
Fermentation 2025, 11(8), 488; https://doi.org/10.3390/fermentation11080488 - 21 Aug 2025
Viewed by 456
Abstract
This study investigated the effects of applied voltage on methane fermentation using separate reactors for the anode and cathode, with activated carbon felt as electrodes and a constant voltage of 0.7 V. Compared to the control, the cathode reactor exhibited approximately 1.2 times [...] Read more.
This study investigated the effects of applied voltage on methane fermentation using separate reactors for the anode and cathode, with activated carbon felt as electrodes and a constant voltage of 0.7 V. Compared to the control, the cathode reactor exhibited approximately 1.2 times higher methane production and 1.3 times higher methane concentration, whereas the anode reactor showed a reduction to about 0.5 times and 0.8 times, respectively. Microbial analysis revealed that the anode reactor created an electron-accepting environment, promoting the growth of Clostridium sensu stricto 1 and Fastidiosipila, both contributing to organic acid (electron) production. Conversely, the cathode reactor established an electron-donating environment, enhancing methane production by hydrogenotrophic methanogens such as Methanoculleus and Methanobacterium. Although similar methanogen levels were found in the anode reactor, methane production was higher in the cathode reactor. These findings indicate that the anode facilitates organic acid production via electron acceptance, while the cathode acts as an electron donor that promotes hydrogenotrophic methanogenesis. This study provides a clear evaluation of the effects of microbial electrochemical technologies on methane fermentation, demonstrating their potential to stimulate microbial activities and enhance methane production. Full article
(This article belongs to the Section Industrial Fermentation)
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16 pages, 1303 KB  
Article
Carotenoid Production by Dunaliella salina with Magnetic Field Application
by Izabela Queiroz Silva, Bruno Roswag Machado, Tamires Machado Ferreira, Júlia de Farias Borges, Cláudia Maria Luz Lapa Teixeira and Lucielen Oliveira Santos
Fermentation 2025, 11(8), 487; https://doi.org/10.3390/fermentation11080487 - 21 Aug 2025
Viewed by 362
Abstract
The use of external triggers in microalgae cultivation has emerged as a promising approach to enhance biomass production and biochemical composition. For instance, magnetic fields (MFs) have had their potential to modulate cellular metabolism and physiological responses explored. This study investigated the effects [...] Read more.
The use of external triggers in microalgae cultivation has emerged as a promising approach to enhance biomass production and biochemical composition. For instance, magnetic fields (MFs) have had their potential to modulate cellular metabolism and physiological responses explored. This study investigated the effects of MF exposure on Dunaliella salina and evaluated its impact on biomass production, pigment synthesis and biochemical composition. The highest biomass concentration (0.59 g L−1) was observed under continuous exposure to 60 mT (MF60-24 h); it represented a 51% increase in comparison with the control. A gradual rise in pH, which reached 10.83, was observed during cultivation. MF exposure also enhanced chlorophyll-a (118%) and carotenoid (95%) concentrations; thus, it improved photosynthetic efficiency and potential oxidative stress responses. The biochemical composition revealed a shift in metabolic pathways after prolonged MF exposure (24 h d−1), decreasing carbohydrate content by 7%, while increasing lipid accumulation by 7%. Scanning electron microscopy (SEM) indicated structural modifications on the cell surface induced by the MF. Therefore, MF applications improve D. salina cultivation and enhance biomass composition for biotechnological applications. Full article
(This article belongs to the Special Issue Cyanobacteria and Eukaryotic Microalgae (2nd Edition))
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13 pages, 2095 KB  
Article
Combination Strategy of Bioenzymes and Sophorolipid Pretreatments Enhance Volatile Fatty Acid Production Based on Co-Fermentation of Waste Activated Sludge and Rubberwood Hydrolysates
by Fen Yin, Wenxuan Bie, Xiaojun Ma, Jianing Li, Yingying Zheng and Dongna Li
Fermentation 2025, 11(8), 486; https://doi.org/10.3390/fermentation11080486 - 21 Aug 2025
Viewed by 422
Abstract
In this study, we developed a combination strategy of bioenzymes and sophorolipid (SL) co-pretreatment to enhance volatile fatty acids (VFAs) in co-fermentation of waste activated sludge (WAS) and rubberwood hydrolysates (RWHs). Among all the pretreatments, SL and laccase co-pretreatment markedly increased soluble bioavailable [...] Read more.
In this study, we developed a combination strategy of bioenzymes and sophorolipid (SL) co-pretreatment to enhance volatile fatty acids (VFAs) in co-fermentation of waste activated sludge (WAS) and rubberwood hydrolysates (RWHs). Among all the pretreatments, SL and laccase co-pretreatment markedly increased soluble bioavailable substrates (carbohydrates and proteins) by inducing EPS catabolism and WAS disintegration, and obtained the highest VFAs yield of 7049.43 mg/L. The proportion of VFA composition can be controlled by modifying the types and amounts of added bioenzymes. Under SL and laccase co-pretreatment conditions, RWHs were more efficiently converted into VFAs due to the higher activity of WAS, resulting in lower cellulose (3.41%) and lignin (0.66%) content in the fermentation broth. Compared with other pretreatments, SL and laccase co-pretreatment enhanced the enrichment of the functional microorganisms, including anaerobic fermentation bacteria (Firmicutes, Bacteroidota, and Proteobacteria) and reducing bacteria (Acinerobacter and Ahniella). Therefore, the combination pretreatments might be a promising solution for strengthening VFA accumulation in the WAS and RWH co-fermentation. Full article
(This article belongs to the Special Issue The Future of Fermentation Technology in the Biorefining Process: 3rd Edition)
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17 pages, 1886 KB  
Article
Volatilomic and Sensorial Profiles of Cabernet Sauvignon Wines Fermented with Different Commercial Yeasts
by Alejandra Chávez-Márquez, Alfonso A. Gardea, Humberto González-Rios, Maria del Refugio Robles-Burgueño and Luz Vázquez-Moreno
Fermentation 2025, 11(8), 485; https://doi.org/10.3390/fermentation11080485 - 21 Aug 2025
Viewed by 584
Abstract
Volatilomic and sensory analyses of wine are excellent tools for enologists and winemakers when selecting commercial yeast based on the production of metabolites related to desirable wine characteristics. Integrating this holistic approach could lead to the terroir description, characterization, and quality control improvement [...] Read more.
Volatilomic and sensory analyses of wine are excellent tools for enologists and winemakers when selecting commercial yeast based on the production of metabolites related to desirable wine characteristics. Integrating this holistic approach could lead to the terroir description, characterization, and quality control improvement of the vinification process. Volatilomic and sensory profiles of Cabernet Sauvignon Mexican wines fermented with three commercial yeasts (WLP740, ICVD254, and ICVD80) were obtained using HS-SPME-GC-qTOF/MS and CATA evaluation. A total of 100 volatile compounds were identified, with unique entities per strain. WLP740 wines were rated as high quality, presenting fruity and minty aromas with fewer off-aromas, while ICVD254 wines showed higher levels of compounds associated with off-notes and were rated as low quality. ICVD80 wines were of medium quality, with fruity esters and higher alcohols descriptors. Volatilomic profiles highlighted the role of specific compounds in differentiating strains and sensory attributes, while yeast selection significantly impacts wine aroma and quality. The authors acknowledge the need for further analyses, including an increased sample size, yeast species, diverse vineyards, and vinification processes, which will result in a solid and robust methodology. Full article
(This article belongs to the Special Issue Science and Technology of Winemaking)
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19 pages, 4640 KB  
Article
A Comparative Proteomic Analysis of the Acetification Process of Komagataeibacter europaeus Using Different Substrates
by Daniela Herrera-Rosero, Juan J. Román-Camacho, Juan Carlos García-García, Inés M. Santos-Dueñas, Teresa García-Martínez, Isidoro García-García and Juan Carlos Mauricio
Fermentation 2025, 11(8), 484; https://doi.org/10.3390/fermentation11080484 - 20 Aug 2025
Viewed by 409
Abstract
Although vinegar is technically elaborated by a well-known bioprocess, the behavior and function of the microorganisms responsible for its production still need investigation. In vinegars obtained from raw materials and systems typical of Europe, the acetic acid bacteria species Komagataeibacter europaeus predominates due [...] Read more.
Although vinegar is technically elaborated by a well-known bioprocess, the behavior and function of the microorganisms responsible for its production still need investigation. In vinegars obtained from raw materials and systems typical of Europe, the acetic acid bacteria species Komagataeibacter europaeus predominates due to its particular adaptive metabolism. This work addresses the study of several adaptation mechanisms of K. europaeus during acetic acid fermentation in a submerged semi-continuous production system. The aim is to analyze the molecular response and behavior of this species to increasing acidity gradients, up to 7–8% w/v acetic acid, applying a comparative proteomic approach in three matrices (synthetic alcoholic medium, dark craft beer, and dry fine wine). A total of 1070 proteins are identified, with 174 showing statistically significant changes in abundance (FDR < 0.05), particularly in pathways related to amino acid biosynthesis, fatty acid metabolism, and stress response. The proteomic patterns differ among substrates, with the synthetic alcohol medium inducing stress-related proteins and the dark craft beer enhancing lipid biosynthesis. These observations provide experimental evidence that the fermentation substrate modulates metabolic adaptation in K. europaeus, offering a rational basis for designing fermentation protocols that enhance bacterial resilience, thereby optimizing vinegar production processes. Full article
(This article belongs to the Special Issue Fermentation: 10th Anniversary)
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18 pages, 1441 KB  
Article
Cutinase Production in Komagataella phaffii (Pichia pastoris): Performance Differences Between Host Strains
by Andrea Sabido-Ramos, Montserrat Tagle-Gil, Krystel Estefany León-Montes, José Augusto Castro-Rodríguez and Amelia Farrés
Fermentation 2025, 11(8), 483; https://doi.org/10.3390/fermentation11080483 - 20 Aug 2025
Viewed by 463
Abstract
The Pichia system has been exploited for decades as a host for recombinant protein production, but there is still an information gap regarding problems that may arise with its use. The application of strains based on the methanol-induced alcohol oxidase 1 (AOX1) promoter [...] Read more.
The Pichia system has been exploited for decades as a host for recombinant protein production, but there is still an information gap regarding problems that may arise with its use. The application of strains based on the methanol-induced alcohol oxidase 1 (AOX1) promoter may represent a safety issue, and its performance varies among strains. In this study, the ability of a Komagataella phaffii MutS KM71H strain to produce recombinant cutinases was evaluated and compared to that of the more widely used Mut+ X-33 strain. The effects of the nature of the cutinase (ANCUT1 and ANCUT3, from Aspergillus nidulans), methanol level, and inoculum concentrations were evaluated in shake flasks containing a complex medium. Higher activities and volumetric cutinase productivity were observed at lower induction cell densities (0.5%) for the MutS KM71H aox1::pPICZα-A-ANCUT1 strain, while a higher one (2%) yielded better results in KM71H aox1::pPICZα-A-ANCUT3. The best inoculum and inducer conditions for both strains yielded similar results. The behavior of the different cutinases in the MutS or Mut+ genetic background was opposed: strain KM71H aox1::pPICZα-A-ANCUT3 produced 19% more activity than strain X-33 aox1::pPICZα-A-ANCUT3, while the ANCUT1 containing strain produced significantly higher activity in the X-33 Mut+ strain. These results indicate that MutS strains are viable host options without the complications of rapidly growing methanol strains. The effect of the gene structure being expressed is a phenomenon that needs further exploration. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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14 pages, 2336 KB  
Article
Exploring the Impact of Alginite Mineral on Lactic Acid Bacteria
by Pál Tóth and Áron Németh
Fermentation 2025, 11(8), 482; https://doi.org/10.3390/fermentation11080482 - 20 Aug 2025
Viewed by 392
Abstract
Studying the uses of different organic-mineral rocks is an expanding area of research. Although these materials have primarily been used in forestry and agriculture, other potential applications include cosmetics and nutrition. Alginite is a volcanic substance that resembles loam and is composed of [...] Read more.
Studying the uses of different organic-mineral rocks is an expanding area of research. Although these materials have primarily been used in forestry and agriculture, other potential applications include cosmetics and nutrition. Alginite is a volcanic substance that resembles loam and is composed of clay minerals and extinct unicellular algae. Hungary’s unique and environmentally friendly agricultural utilization of alginite has sparked international interest and prompted further exploration of its potential applications. In recent years, studies have shown that alginate can be useful in agriculture and as a food supplement, the latter only when supplemented with lactic acid-producing bacteria (LAB). On the contrary, our study investigates the application of alginite during the LAB fermentation, expecting higher cell numbers. Our experiments, conducted using small-scale impedimetric high-throughput equipment, revealed that alginite positively influenced total cell biomass regarding at least two of the three tested LAB species, confirming the enhancement hypothesis. We also thoroughly investigated the fermentations in a lab-scale bioreactor to validate these results. The boosting potential of alginite was verified for all tested LAB strains since, depending on the applied strain, alginite resulted in a 27–63% increase in cell dry weight for all tested LAB. Full article
(This article belongs to the Special Issue Lactic Acid Bacteria: Evaluation of Benefits on Human Health and Improvement of Food Safety)
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26 pages, 610 KB  
Review
Enhancing the Nutritional Value of Foods Through Probiotics and Dietary Fiber from Fruit and Berry Pomace
by Jolita Jagelavičiūtė, Loreta Bašinskienė and Dalia Čižeikienė
Fermentation 2025, 11(8), 481; https://doi.org/10.3390/fermentation11080481 - 20 Aug 2025
Viewed by 642
Abstract
The growing demand for health-promoting food products has led to increased efforts to develop formulations enriched with probiotics and dietary fiber (DF). While traditional fermented foods remain widely recognized sources of probiotics, there is a pressing need to innovate novel, nutritious, and high-quality [...] Read more.
The growing demand for health-promoting food products has led to increased efforts to develop formulations enriched with probiotics and dietary fiber (DF). While traditional fermented foods remain widely recognized sources of probiotics, there is a pressing need to innovate novel, nutritious, and high-quality alternatives that also incorporate additional functional ingredients. In the context of sustainable consumption and health-conscious dietary trends, fruit and berry pomace has emerged as a promising source of DF with prebiotic potential, supporting the growth and activity of beneficial gut microorganisms. A growing body of research emphasizes the potential of pomace valorization, showcasing its relevance in the development of value-added food products. This review explores the key features and selection principles for probiotic strains, particularly those from the former group of Lactobacillus species, alongside opportunities for combining probiotics with fruit and berry pomace in functional food matrices. Special attention is given to the physiological and technological attributes of DF derived from pomace, which are critical for their successful application in food systems and their potential synergistic effects with probiotics. Although numerous probiotic-enriched products are currently available, DF remains an underutilized component in many of these formulations. Research has predominantly focused on dairy-based applications; however, the increasing demand for plant-based diets calls for a shift towards non-dairy alternatives. Looking forward, future innovations should prioritize the integration of probiotics and pomace-derived DF as symbiotic systems into plant-based food products, with an emphasis on their dual roles as nutritional enhancers and potential prebiotics. Full article
(This article belongs to the Special Issue Fermentation-Driven Biotechnological Valorization of Bioactive Compounds from Plants)
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21 pages, 8034 KB  
Article
Decoding Forage-Driven Microbial–Metabolite Patterns: A Multi-Omics Comparison of Eight Tropical Silage Crops
by Xianjun Lai, Siqi Liu, Yandan Zhang, Haiyan Wang and Lang Yan
Fermentation 2025, 11(8), 480; https://doi.org/10.3390/fermentation11080480 - 20 Aug 2025
Viewed by 433
Abstract
Tropical forage crops vary widely in biochemical composition, resulting in inconsistent silage quality. Understanding how plant traits shape microbial and metabolic networks during ensiling is crucial for optimizing fermentation outcomes. Eight tropical forages—Sorghum bicolor (sweet sorghum), Sorghum × drummondii (sorghum–Sudangrass hybrid), Sorghum [...] Read more.
Tropical forage crops vary widely in biochemical composition, resulting in inconsistent silage quality. Understanding how plant traits shape microbial and metabolic networks during ensiling is crucial for optimizing fermentation outcomes. Eight tropical forages—Sorghum bicolor (sweet sorghum), Sorghum × drummondii (sorghum–Sudangrass hybrid), Sorghum sudanense (Sudangrass), Pennisetum giganteum (giant Napier grass), Pennisetum purpureum cv. Purple (purple elephant grass), Pennisetum sinese (king grass), Leymus chinensis (sheep grass), and Zea mexicana (Mexican teosinte)—were ensiled under uniform conditions. Fermentation quality, bacterial and fungal communities (16S rRNA and ITS sequencing), and metabolite profiles (untargeted liquid chromatography–mass spectrometry, LC-MS) were analyzed after 60 days. Sweet sorghum and giant Napier grass showed optimal fermentation, with high lactic acid levels (111.2 g/kg and 99.4 g/kg, respectively), low NH4+-N (2.4 g/kg and 3.1 g/kg), and dominant Lactiplantibacillus plantarum. In contrast, sheep grass and Mexican teosinte exhibited poor fermentation, with high NH4+-N (6.7 and 6.1 g/kg) and Clostridium dominance. Fungal communities were dominated by Kazachstania humilis (>95%), while spoilage-associated genera such as Cladosporium, Fusarium, and Termitomyces proliferated in poorly fermented silages. Metabolomic analysis identified 15,827 features, with >3000 significantly differential metabolites between silages. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment revealed divergence in flavonoid biosynthesis, lipid metabolism, and amino acid pathways. In the sweet sorghum vs. sheep grass comparison, oxidative stress markers ((±) 9-HODE, Agrimonolide) were elevated in sheep grass, while sweet sorghum accumulated antioxidants like Vitamin D3. Giant Napier grass exhibited higher levels of antimicrobial flavonoids (e.g., Apigenin) than king grass, despite both being dominated by lactic acid bacteria. Sorghum–Sudangrass hybrid silage showed enrichment of lignan and flavonoid derivatives, while Mexican teosinte accumulated hormone-like compounds (Gibberellin A53, Pterostilbene), suggesting microbial dysbiosis. These findings indicate that silage fermentation outcomes are primarily driven by forage-intrinsic traits. A “forage–microbiota–metabolite” framework was proposed to explain how plant-specific properties regulate microbial assembly and metabolic output. These insights can guide forage selection and development of precision inoculant for high-quality tropical silage. Full article
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16 pages, 3508 KB  
Article
Metabolomic Profiling Reveals Dynamic Changes in Organic Acids During Zaolajiao Fermentation: Correlation with Physicochemical Properties and CAZymes
by Ju Chen, Xueya Wang, Wenxin Li, Jianwen He, Yong Yin, Min Lu and Yubing Huang
Fermentation 2025, 11(8), 479; https://doi.org/10.3390/fermentation11080479 - 20 Aug 2025
Viewed by 380
Abstract
Zaolajiao (ZLJ) is a traditional national specialty fermented condiment in Guizhou, and organic acid is one of its main flavor substances. In the study, we used metabolomics and multivariate analysis to identify differential organic acids (DOAs) during ZLJ fermentation and explored their correlations [...] Read more.
Zaolajiao (ZLJ) is a traditional national specialty fermented condiment in Guizhou, and organic acid is one of its main flavor substances. In the study, we used metabolomics and multivariate analysis to identify differential organic acids (DOAs) during ZLJ fermentation and explored their correlations with physicochemical indices and CAZymes. Eight DOAs were detected, with citric acid prominent early and lactic acid dominant late in fermentation. Citric acid exhibited a highly significant negative correlation (p < 0.01, |r| > 0.955) with AA3, GT4, and CE1, while showing significant positive correlation (p < 0.05) with GH1, soluble sugars, and total acids. Lactic acid exhibited a highly significant positive correlation with total acid, AA3, and GT4 (p < 0.05, |r| > 0.955). Conversely, it showed a significant negative correlation with soluble sugar (p < 0.05) and a highly significant negative correlation with GH1 (p < 0.05, |r| > 0.955). The most significant metabolic pathway for DOAs enrichment was the citrate cycle (TCA cycle). Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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15 pages, 2196 KB  
Article
Collagenase Production from Aspergillus serratalhadensis URM 7866 Using Industrial By-Products: Purification and Characterization
by Luiz Henrique Svintiskas Lino, Kethylen Barbara Barbosa Cardoso, Pietra Gícia Oliveira Cosmo da Silva, Raphael Luiz Andrade Silva, Maria Eduarda Luiz Coelho de Miranda, Daniel Charles dos Santos Macêdo, Ana Lúcia Figueiredo Porto, Cristina Maria de Souza Motta, Marcia Nieves Carneiro da Cunha, Thiago Pajéu Nascimento, Carolina de Albuquerque Lima Duarte, Romero Marcos Pedrosa Brandão Costa and Daniela de Araújo Viana Marques
Fermentation 2025, 11(8), 478; https://doi.org/10.3390/fermentation11080478 - 20 Aug 2025
Viewed by 430
Abstract
Collagenases are enzymes with broad biotechnological applications in medicine. This study describes the production and characterization of a collagenase from Aspergillus serratalhadensis URM 7866, isolated from the Caatinga biome. Solid-state fermentations were conducted using wheat bran under varying conditions of pH (6, 7, [...] Read more.
Collagenases are enzymes with broad biotechnological applications in medicine. This study describes the production and characterization of a collagenase from Aspergillus serratalhadensis URM 7866, isolated from the Caatinga biome. Solid-state fermentations were conducted using wheat bran under varying conditions of pH (6, 7, 8), moisture content (50%, 60%, 70%), and substrate concentration (2.5 g, 5 g, 10 g). The optimal condition—10 g of wheat bran at pH 8 and 70% moisture—yielded the highest collagenolytic activity (177.96 U/mL) and a specific activity of 50.55 U/mg. The enzyme was purified via multiple chromatography, with pre-purification and final purification factors of 18.09 and 20.21, respectively, reaching a specific activity of 1021.86 U/mg. The enzyme showed optimal activity at 50 °C and pH 8, with stability from 20 to 40 °C and pH 7–9. PMSF caused >80% inhibition; EDTA caused ~34% inhibition. Activity increased with Na+ and Ca2+ and was inhibited by Zn2+. The enzyme retained full activity in anionic and non-ionic surfactants (1–10%). FTIR confirmed characteristic amide bands, and kinetic analysis revealed a Km of 1.72 mg/mL and Vmax of 6.89 mg/mL/min. These findings support its potential for alkaline and surfactant-rich industrial processes. Full article
(This article belongs to the Special Issue Fungal Biotechnology: Exploring the Potential of Solid State Fermentation for Sustainable Production)
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28 pages, 1337 KB  
Review
Recent Advances in Microbial Bioconversion as an Approach to Boost Hydroxytyrosol Recovery from Olive Mill Wastewater
by Irene Maria Zingale, Anna Elisabetta Maccarronello, Claudia Carbone, Cinzia Lucia Randazzo, Teresa Musumeci and Cinzia Caggia
Fermentation 2025, 11(8), 477; https://doi.org/10.3390/fermentation11080477 - 20 Aug 2025
Viewed by 539
Abstract
Olive mill wastewater (OMWW) is a highly complex matrix derived from olive oil extraction, containing phenolic compounds, lipids, minerals, and organic acids. Hydroxytyrosol (HT), an outstanding antioxidant and health-promoting phenolic compound, has garnered significant interest as a natural preservative and functional ingredient. Enzymatic [...] Read more.
Olive mill wastewater (OMWW) is a highly complex matrix derived from olive oil extraction, containing phenolic compounds, lipids, minerals, and organic acids. Hydroxytyrosol (HT), an outstanding antioxidant and health-promoting phenolic compound, has garnered significant interest as a natural preservative and functional ingredient. Enzymatic hydrolysis, utilizing purified enzymes to cleave glycosidic or ester bonds, and microbial bioconversion, employing whole microorganisms with their intrinsic enzymes and metabolic pathways, are effective biotechnological strategies for fostering the release of HT from its conjugated forms. These approaches offer great potential for the sustainable recovery of HT from OMWW, contributing to the valorization of this environmentally impactful agro-industrial by-product. Processed OMWW can lead to clean-label HT-enriched foods and beverages, capitalizing on by-product valorization and improving food safety and quality. In this review, the most important aspects of the chemistry, technology, and microbiology of OMWW were explored in depth. Recent trends and findings in terms of both enzymatic and microbial bioconversion processes are critically discussed, including spontaneous and driven fermentation, using selected microbial strains. These approaches are presented as economically viable options for obtaining HT-enriched OMWW for applications in the food and nutraceutical sectors. The selected topics aim to provide the reader with a solid background while inspiring and facilitating future research and innovation. Full article
(This article belongs to the Special Issue Microbial Upcycling of Organic Waste to Biofuels and Biochemicals)
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17 pages, 3945 KB  
Article
Banana Pseudostem By-Product: A Sustainable Source of Prebiotics and Protection for Probiotic Lactic Acid Bacteria Under Gastrointestinal Conditions
by Márcia Maria de Souza Moretti, Tais Fernanda Borgonovi, Svetoslav Dimitrov Todorov and Ana Lúcia Barretto Penna
Fermentation 2025, 11(8), 476; https://doi.org/10.3390/fermentation11080476 - 20 Aug 2025
Viewed by 468
Abstract
Agricultural by-products, such as banana pseudostems (BPS), present a sustainable solution for waste reduction and the recovery of valuable metabolites with biotechnological applications. This study investigated the potential of BPS as a substrate for bio-fermentation, specifically for the cultivation of lactic acid bacteria [...] Read more.
Agricultural by-products, such as banana pseudostems (BPS), present a sustainable solution for waste reduction and the recovery of valuable metabolites with biotechnological applications. This study investigated the potential of BPS as a substrate for bio-fermentation, specifically for the cultivation of lactic acid bacteria (LAB). Maçã cultivar BPSs (MBPS) and Nanica cultivar BPSs (NBPS) flour samples showed differences in carbohydrate composition, especially in resistant starch (16.7 and 2.7%), cellulose (27.0 and 52.4%), and hemicellulose (25.4 and 33.8%), respectively. Phenolic compound content in NBPS was higher than in MBPS (193.9 and 153.5 GAE/100 g, respectively). The BPS starches and flour were well assimilated by the probiotic LAB cultures. Limosilactobacillus fermentum SJRP30 and SJRP43 showed significant growth in media with gelatinized Maçã flour (GMF) and non-gelatinized Nanica flour (NGNF) BPS by-products (Log 9.18 and 9.75 CFU/mL, respectively), while Lacticaseibacillus rhamnosus GG exhibited the highest growth (Log 11.31 CFU/mL) in the medium with NGNF BPS by-products. The probiotic Lbs. casei SJRP146 and Lmb. fermentum SJRP30 and SJRP43 presented high enzymatic activity and the ability to assimilate D-xylose. Only Lactobacillus delbrueckii subsp. bulgaricus SJRP57 and SJRP49 were able to assimilate starch. Their prebiotic potential under in vitro gastrointestinal digestion was evidenced by promoting the selected probiotic bacteria’s protection and maintaining their viable cells after challenging conditions, likely associated with the BPS composition. Lab. delbrueckii subsp. bulgaricus SJRP57, Lacticaseibacillus casei SJRP145, and Lmb. fermentum SJRP43 performed similarly to the commercial strain Lbs. rhamnosus GG. These results demonstrate the feasibility of using cost-effective and abundant agricultural waste as a promising sustainable ingredient with potential prebiotic activity, via eco-friendly production methods that do not require chemical or enzymatic extraction. Full article
(This article belongs to the Special Issue Fermentation of Organic Waste for High-Value-Added Product Production)
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15 pages, 1813 KB  
Article
Impacts of Sonication on Fermentation Process and Physicochemical, Microbiological and Sensorial Characteristics of Fermented Black Carrot Juice
by Muhammet Ercan, Mehmet Akbulut, Hacer Çoklar and Talha Demirci
Fermentation 2025, 11(8), 475; https://doi.org/10.3390/fermentation11080475 - 19 Aug 2025
Viewed by 360
Abstract
In recent years, ultrasound has been integrated into fermentation technology due to its activating effect on microorganisms, and the possible effects of ultrasound-assisted fermentation on the fermentation process, yield and quality of the final product have also attracted attention. This study aimed to [...] Read more.
In recent years, ultrasound has been integrated into fermentation technology due to its activating effect on microorganisms, and the possible effects of ultrasound-assisted fermentation on the fermentation process, yield and quality of the final product have also attracted attention. This study aimed to reveal the effects of sonication applied before the fermentation on the fermentation process and the quality of fermented black carrot juice. The samples were sonicated at a frequency of 35 kHz and an amplitude of 60% for 0, 5, 15 or 30 min before the fermentation. During the fermentation, the pH, acidity, organic acid profile, ethanol and soluble solid content (SSC), color, turbidity, total lactic acid bacteria (LAB), total mesophilic aerobic bacteria (TMAB) and yeast counts were determined. The amount of SSC in the samples increased at the beginning of fermentation as the sonication time increased. Lactic, acetic and propionic acids were detected in the samples. The amount of lactic acid in all the samples treated with ultrasound was higher than in the control sample and the amounts of acetic acid, propionic acid and ethanol were lower. Ultrasound application caused an increase in the TMAB and yeast counts. A five-minute ultrasound application caused a decrease in the number of LAB, while 15- and 30-min applications caused an increase. Thirty minutes of ultrasound treatment resulted in the reddest fermented black carrot juices with the highest level of color saturation. The most appreciated sample in terms of taste, aroma and general acceptability was the sample subjected to a five-minute ultrasound application. As a result, ultrasound application before fermentation positively supports different quality parameters of fermented black carrot juice and the use of sonication in production can be recommended. 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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20 pages, 1655 KB  
Article
Probiotic Potential of Some Lactic Acid Bacteria Isolated from Blue Maize Atole Agrio from Veracruz, México
by Margarita Torres-Gregorio, Rosa María Ribas-Aparicio, María Guadalupe Aguilera-Arreola, Gustavo F. Gutiérrez-López and Humberto Hernández-Sánchez
Fermentation 2025, 11(8), 474; https://doi.org/10.3390/fermentation11080474 - 19 Aug 2025
Viewed by 358
Abstract
Mexican culture offers a great variety of traditional maize-based fermented foods that are beneficial for human health. Atole agrio (sour atole), prepared from blue maize (Zea mays) in the state of Veracruz, has been scarcely studied as a potential functional food. [...] Read more.
Mexican culture offers a great variety of traditional maize-based fermented foods that are beneficial for human health. Atole agrio (sour atole), prepared from blue maize (Zea mays) in the state of Veracruz, has been scarcely studied as a potential functional food. The purpose of this study was to select endogenous potentially probiotic lactic acid bacteria (LAB) from freshly fermented blue maize atole agrio. Samples of spontaneously fermented atole agrio were used for the isolation of LAB on MRS agar. The abilities to tolerate acidic pH, bile salts, and sodium chloride, as well as surface hydrophobicity and aggregation capabilities, were used as criteria for probiotic potential. Selected LAB were identified using MALDI-TOF-MS. Finally, safety-related characterizations, such as hemolytic activity and antibiotic susceptibility, were performed. In the initial stages of fermentation, the presence of fungi, yeasts, coliform organisms, and LAB were detected, and in the final fermentation process, where the blue atole agrio reached a pH of 4, 49 isolates of LAB were obtained. Sixteen isolates showed high tolerance to pH 2, and seven of them showed tolerance to 3% bile salts and 4% sodium chloride. The seven isolates were identified as Pediococcus pentosaceus. Although the seven isolates showed low hydrophobicity to hexadecane and chloroform, they had medium autoaggregation and coaggregation with pathogens. The seven isolates showed notable antibacterial properties against Staphylococcus aureus, Salmonella enterica serovar Typhimurium, Escherichia coli, and Listeria monocytogenes, as well as good amylolytic capacity. All the P. pentosaceus strains were non-hemolytic, sensible to clindamycin and resistant to the other 11 antibiotics tested. Only subtle differences were found among the seven isolates, which can be considered potential candidates for probiotics. The freshly fermented blue maize atole agrio can be considered a functional food containing potentially probiotic LAB and the antioxidant phenolic compounds present in blue maize. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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19 pages, 329 KB  
Article
The Effect of Ruminal Fluid Adaptation to a Direct Fed Microbial: In Vitro Methane Production and Fermentation Characteristics
by Sreemol Suthan Nair, S. Richard O. Williams, Aodán S. ó Neachtain, Renata Tognelli, Subhash Chandra, Pablo S. Alvarez-Hess, Long Cheng, Khageswor Giri and Joe L. Jacobs
Fermentation 2025, 11(8), 473; https://doi.org/10.3390/fermentation11080473 - 19 Aug 2025
Viewed by 395
Abstract
Direct-fed microbials (DFM) have emerged as a promising dietary strategy for enteric methane abatement. However, it is unclear whether in vitro studies trialing DFM should use ruminal fluid previously adapted to the DFM of interest or if the DFM can be directly added [...] Read more.
Direct-fed microbials (DFM) have emerged as a promising dietary strategy for enteric methane abatement. However, it is unclear whether in vitro studies trialing DFM should use ruminal fluid previously adapted to the DFM of interest or if the DFM can be directly added to an unadapted inoculum. Ten lactating, multiparous, rumen cannulated Holstein-Friesian cows were randomly allocated to one of two groups: 1) adapted, basal diet plus 4 g/d of a blend of Bacillus subtilis and Bacillus licheniformis (1.6 × 109 CFU/g each), delivered via the rumen canula; and 2) naive, basal diet only. Ruminal fluid from both groups was incubated in an in vitro 24-h batch culture system with two rates of Bacillus spp. and three feed substrates (hay, pasture, cereal grain), resulting in 12 treatments. Methane production was 16% greater, and total volatile fatty acid concentration was 7% greater in incubations using adapted ruminal fluid compared to those using naive ruminal fluid; however, neither parameter was affected when Bacillus spp. was added to the batch incubation system. Future in vitro studies evaluating DFM should consider including a period of in vivo adaptation to mimic their potential impact under in vivo feeding conditions. Full article
15 pages, 1407 KB  
Article
Chromium-Driven Changes in Heavy Metal Resistance Genes During Pig Manure Composting
by Guoqiang Zhao, Peng Li, Yao Feng and Yuanwang Liu
Fermentation 2025, 11(8), 472; https://doi.org/10.3390/fermentation11080472 - 18 Aug 2025
Viewed by 377
Abstract
Composting is an effective method for stabilizing and valorizing pig manure, which is rich in nutrients but also contains heavy metals such as chromium (Cr). These heavy metals can promote the development of heavy metal resistance genes (MRGs) during composting, posing environmental and [...] Read more.
Composting is an effective method for stabilizing and valorizing pig manure, which is rich in nutrients but also contains heavy metals such as chromium (Cr). These heavy metals can promote the development of heavy metal resistance genes (MRGs) during composting, posing environmental and health risks. In this study, pig manure composting supplemented with pyridine carboxylate chromium was applied to investigate its effects on heavy metal speciation and MRG abundance and explore the influence factors of the dynamics of MRGs during composting. The results showed that the addition of Cr significantly influenced the composting process, including temperature fluctuations and nutrient dynamics. Specifically, the addition of Cr weakened the impact of water addition on temperature, as evidenced by the failure of the Cr-amended treatment to re-enter the thermophilic phase after water addition. The speciation of Cr changed during composting, with a significant reduction in high-bioavailable Cr forms (e.g., a 54.56% reduction in high-bioavailable Cr in the Cr-amended treatment) and an increase in low-bioavailable forms. The abundance of MRGs, particularly copper resistance genes, increased over time, with more pronounced fluctuations in the Cr-amended treatment. The primary factors influencing the dynamics of these MRGs during composting were identified as heavy metal speciation, microbial community structure, and specific physicochemical properties such as pH, electrical conductivity, and dissolved organic carbon. The present study offers valuable insights into the complex interactions between heavy metals and microbial communities during composting and provides inspiration for managing heavy metals to minimize the spread of MRGs. Full article
(This article belongs to the Special Issue Turning Organic Solid Waste into Soil Nutrients Using Biological Technology)
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16 pages, 931 KB  
Article
Production and Characterization of a Novel Glycolipid Biosurfactant from Bradyrhizobium sp.
by Marcos André Moura Dias, Eduardo Luiz Rossini, Douglas de Britto and Marcia Nitschke
Fermentation 2025, 11(8), 471; https://doi.org/10.3390/fermentation11080471 - 15 Aug 2025
Viewed by 530
Abstract
Biosurfactants (BS) are surface-active compounds synthesized by microorganisms with broad industrial applications. Although BS-producing strains are widely reported, little is known about their production by diazotrophic bacteria. This study investigated, for the first time, the BS produced by Bradyrhizobium sp. ESA 81, a [...] Read more.
Biosurfactants (BS) are surface-active compounds synthesized by microorganisms with broad industrial applications. Although BS-producing strains are widely reported, little is known about their production by diazotrophic bacteria. This study investigated, for the first time, the BS produced by Bradyrhizobium sp. ESA 81, a diazotrophic bacterium isolated from the Brazilian semiarid region. The strain was cultivated in the mineral medium using sunflower oil and ammonium nitrate as carbon and nitrogen sources. The compound was chemically characterized using TLC, FAME, FTIR, and mass spectrometry (MALDI-TOF). The results revealed a mixture of glycolipids composed of trehalose linked to fatty acid chains ranging from C9 to C18. The BS exhibited a surface tension of 31.8 mN/m, a critical micelle concentration of 61.2 mg/L, and an interfacial tension of 22.1 mN/m. The BS also showed an emulsification index (EI24) of 55.0%. High stability was observed under extreme conditions of temperature (−20 to 121 °C), pH (2–12), NaCl (5–20%), and sucrose (1–5%). These findings indicate that the trehalolipid BS produced by Bradyrhizobium sp. ESA 81 is a stable and efficient surface-active agent, with promising potential for use in biotechnological and industrial processes. Full article
(This article belongs to the Special Issue The Industrial Feasibility of Biosurfactants)
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14 pages, 2495 KB  
Article
Optimization of Culture Conditions for Bacteriocin Production by Pediococcus Acidilactici CCFM18 and Characterization of Its Biological Properties
by Xiaojing Guo, Xinyan Bai, Zhenjia Zheng, Zhichang Qiu, Xuguang Qiao and Yiteng Qiao
Fermentation 2025, 11(8), 470; https://doi.org/10.3390/fermentation11080470 - 15 Aug 2025
Viewed by 498
Abstract
Bacteriocins are ribosomal synthesized antimicrobial peptides produced by bacteria, but their low yields limit industrial applications as food preservatives. This study aimed to optimize the culture conditions of Pediococcus acidilactici CCFM18 and investigate the biological properties of the bacteriocin. The culture temperature, initial [...] Read more.
Bacteriocins are ribosomal synthesized antimicrobial peptides produced by bacteria, but their low yields limit industrial applications as food preservatives. This study aimed to optimize the culture conditions of Pediococcus acidilactici CCFM18 and investigate the biological properties of the bacteriocin. The culture temperature, initial pH, and culture time significantly affected the growth of P. acidilactici CCFM18 and bacteriocin production. The optimal culture conditions determined through response surface methodology (RSM) were a culture temperature of 35 °C, an initial pH of 7.0, and a growth time of 16 h. Under these conditions, bacteriocin production reached 1454.61 AU/mL, representing a 1.8-fold increase compared to pre-optimization levels. Biological characterization revealed that the bacteriocin exhibited strong thermal stability (up to 100 °C for 30 min) and pH stability (pH 2–9), but was sensitive to proteolytic enzymes, including pepsin, trypsin, papain, and protease K. The bacteriocin demonstrated antimicrobial activity against both Gram-positive and Gram-negative bacteria, including Enterococcus faecalis and Escherichia coli. These findings provide a theoretical basis for the industrial production and application of the bacteriocin. Full article
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21 pages, 3369 KB  
Article
Digestate-Based Liquid Growth Medium for Production of Microbial Chitosan
by Silvia Crognale, Cristina Russo, Eleonora Carota, Ilaria Armentano, Federico Di Gregorio, Alessandro D’Annibale, Alessio Cimini and Maurizio Petruccioli
Fermentation 2025, 11(8), 469; https://doi.org/10.3390/fermentation11080469 - 15 Aug 2025
Viewed by 421
Abstract
This study investigated the feasibility of using both the solid and the liquid fractions of waste from the anaerobic digestion process—the digestate—as a possible liquid growth medium for fungal production of chitosan. An enriched liquid phase (ELP), combining both fractions, and derived from [...] Read more.
This study investigated the feasibility of using both the solid and the liquid fractions of waste from the anaerobic digestion process—the digestate—as a possible liquid growth medium for fungal production of chitosan. An enriched liquid phase (ELP), combining both fractions, and derived from mild acid hydrolysis treatment at 120 °C with 6% H2SO4 (w/v) for 70 min, was screened for its ability to support biomass and chitosan production by 17 fungal strains. The best results were obtained with Absidia blakesleeana NRRL 2696 and Rhizopus oryzae NRRL 1510 cultures, which yielded chitosan volumetric productions of 444 and 324 mg L−1, respectively. The chitosan preparations of the former and the latter strain, characterized by infrared spectroscopy, elemental analysis, viscosimetry and thermogravimetric analysis, showed deacetylation degrees of 79% and 84.2%, respectively, and average viscosimetric molecular weights of around 20 and 5.4 kDa, respectively. Moreover, both fungal chitosan samples exerted significant antibacterial activity towards Gram-negative (i.e., Pseudomonas syringae and Escherichia coli) and Gram-positive (i.e., Bacillus subtilis) species. Full article
(This article belongs to the Special Issue Fungal Secondary Metabolism: Discovery and Characterization of Biologically Active Compounds)
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14 pages, 461 KB  
Article
Modulating Fermentation in Total Mixed Ration Silages Using Lasalocid Sodium and Essential Oils
by Isabele Paola de Oliveira Amaral, Mariany Felex de Oliveira, Marco Antonio Previdelli Orrico Junior, Marciana Retore, Tatiane Fernandes, Yara América da Silva, Ana Carolina Amorim Orrico, Ronnie Coêlho de Andrade and Giuliano Reis Pereira Muglia
Fermentation 2025, 11(8), 468; https://doi.org/10.3390/fermentation11080468 - 15 Aug 2025
Viewed by 444
Abstract
This study evaluated the effects of lasalocid sodium (LASA) and essential oils on the fermentation and nutritional quality of total mixed ration (TMR) silages. A 4 × 2 factorial design tested four additives—a control (distilled water), LASA (375 mg/kg DM), limonene essential oil [...] Read more.
This study evaluated the effects of lasalocid sodium (LASA) and essential oils on the fermentation and nutritional quality of total mixed ration (TMR) silages. A 4 × 2 factorial design tested four additives—a control (distilled water), LASA (375 mg/kg DM), limonene essential oil (LEO), and a blend of cinnamaldehyde and carvacrol (EOB), both at 400 mg/kg DM—during summer and autumn. The TMRs were formulated to meet the nutritional requirements of lactating cows producing 20 kg of milk per day. After 110 days of ensiling, silages were analyzed for fermentation losses, pH, short-chain fatty acids, ammoniacal nitrogen (NH3-N), aerobic stability (AS), and chemical composition. The additives significantly improved dry matter recovery (DMR), especially LASA and EOB in autumn. EOB showed the lowest effluent losses and highest AS, with higher acetic acid and lower NH3-N contents. LEO and EOB increased lactic acid, while LASA reduced ethanol and butyric acid levels in summer. Crude protein increased with LEO in autumn, and LASA and LEO improved total digestible nutrients (TDNs) in summer. EOB-treated silages had higher fiber fractions in autumn, without compromising feed value. Therefore, LASA, LEO, and particularly EOB enhanced silage fermentation and nutrient preservation, with EOB showing the most consistent results across seasons. Full article
(This article belongs to the Special Issue Fermentation Strategies to Enhance Feed Nutritional Value and Optimize Industry Resources)
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15 pages, 1143 KB  
Article
Development and Characterization of Pistachio Yogurt Analog: A Healthy, Sustainable, and Innovative Plant-Based Alternative
by Inés M. Ramos, Samuel Rodríguez García and Justa M. Poveda
Fermentation 2025, 11(8), 467; https://doi.org/10.3390/fermentation11080467 - 15 Aug 2025
Viewed by 564
Abstract
Plant-based yogurts are increasingly recognized as sustainable and health-conscious alternatives to dairy-based products, driven by environmental, ethical, and nutritional motivations. Pistachio milk, derived from an efficient and resilient crop, emerges as a promising raw material for yogurt production, offering unique sensory qualities and [...] Read more.
Plant-based yogurts are increasingly recognized as sustainable and health-conscious alternatives to dairy-based products, driven by environmental, ethical, and nutritional motivations. Pistachio milk, derived from an efficient and resilient crop, emerges as a promising raw material for yogurt production, offering unique sensory qualities and a dense nutritional profile. Rich in unsaturated fatty acids, bioactive compounds, and essential nutrients, pistachios are ideal for fermentation with lactic acid bacteria (LAB). In this study, a novel pistachio-based yogurt analog (PBYA) was developed using lactic acid fermentation, with a yogurt commercial starter, of pistachio milk. The production process was optimized to create an additive-free, clean-label formulation without the use of stabilizers or thickeners. The physicochemical, microbiological, and sensory properties of the PBYA were evaluated over refrigerated storage. The final product exhibited high levels of protein (5.6%), fat (5.4–6.8%), and total solids (20.5–21.4%), along with desirable texture and flavor characteristics. Notably, PBYA presented significantly higher concentrations of total free amino acids (754 mg/L) compared to commercial soy (557 mg/L) and cow’s milk yogurts (390 mg/L), particularly in essential amino acids such as lysine, methionine, and tryptophan. This enhanced free amino acid profile contributes to the product’s functional and nutritional value. Sensory analysis revealed good acceptance of the product, with improvements in viscosity and firmness over time, likely due to microbial exopolysaccharide production. Overall, the findings highlight the feasibility and commercial potential of PBYA as a clean-label, plant-based fermented product that meets current consumer demands for sustainability, nutrition, and sensory 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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15 pages, 1303 KB  
Article
Acidification Kinetics, Culture Viability, Physicochemical and Antioxidant Characteristics of Yogurt Fortified with Apple Pulp
by Dimitra Dimitrellou and Panagiotis Kandylis
Fermentation 2025, 11(8), 466; https://doi.org/10.3390/fermentation11080466 - 13 Aug 2025
Viewed by 540
Abstract
Nowadays, there is interest in yogurts and fermented milks with incorporated fruits to fulfill the growing demand for healthier, nutritional, and functional foods. In the present study, the potential of apple pulp incorporation into yogurts was evaluated. Apple pulps from five cultivars (Gala, [...] Read more.
Nowadays, there is interest in yogurts and fermented milks with incorporated fruits to fulfill the growing demand for healthier, nutritional, and functional foods. In the present study, the potential of apple pulp incorporation into yogurts was evaluated. Apple pulps from five cultivars (Gala, Starking, Jonagold, Golden, and Granny Smith) were characterized for their antioxidant activity and total phenolic content, with Granny Smith pulp selected for further application due to its superior functional properties. Apple pulp (0–15% w/w) significantly influenced the acidification kinetics by lowering the initial pH and reducing fermentation time. The viability of yogurt starters remained above 108 CFU/g throughout 28 days, fulfilling FAO/WHO criteria, although in yogurts with apple pulp, it was found to significantly decrease in a concentration-dependent manner compared to the control. Quality analyses revealed that apple pulp improved water-holding capacity and reduced syneresis. The antioxidant activity and total phenolic content of yogurts increased proportionally with apple pulp concentration, showing strong positive correlations. Yogurts containing 10–15% w/w apple pulp exhibited the most pronounced functional enhancements. These findings suggest that apple pulp serves as a promising sustainable natural ingredient for producing functional yogurts with improved health-promoting properties due to the antioxidant potential of apple-derived phenolics. Full article
(This article belongs to the Section Fermentation for Food and Beverages)
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13 pages, 868 KB  
Article
Isolation and Characterization of Low-Temperature and High-Salinity Amylase from Halomonas sp. KS41843
by Jin A Kim, Min Ju Kim, Joung Han Yim, Il-Chan Kim, Jae-Sung Rhee and Se Jong Han
Fermentation 2025, 11(8), 465; https://doi.org/10.3390/fermentation11080465 - 13 Aug 2025
Viewed by 434
Abstract
The polar regions harbor uniquely diverse organisms adapted to low temperatures. Strains obtained from these regions are likely to produce enzymes that are industrially useful at low temperatures. In this study, a Halomonas sp. strain isolated from the Antarctic Sea was cultured at [...] Read more.
The polar regions harbor uniquely diverse organisms adapted to low temperatures. Strains obtained from these regions are likely to produce enzymes that are industrially useful at low temperatures. In this study, a Halomonas sp. strain isolated from the Antarctic Sea was cultured at 15 °C to obtain partially purified α-amylase. This enzyme exhibited maximum activity at 30 °C and pH 5.0, retaining over 80% of its maximum activity even at 5 °C. Its activity was >1.5-fold in the presence of Co2+, Mn2+, Mg2+, Fe2+, and Na+, indicating enhancement by most metal ions. Halophilic strain-derived enzyme maintained up to 95% of its maximum activity even at 4 M NaCl, highlighting its potential for industrial applications and possible cost savings. In this study, the low-temperature and high-salinity active amylase produced by Antarctic Halomonas sp. KS41843 was identified as a promising candidate for future biotechnology applications. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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17 pages, 3054 KB  
Article
Synthesis of 3,4-Dihydroxybenzoic Acid in E. coli and C. glutamicum Using Dehydroshikimate Dehydratase of Different Types
by Ekaterina Shmonova, Arina Kruglova, Nikita Nikandrov, Nataliya Stoynova and Vera Doroshenko
Fermentation 2025, 11(8), 464; https://doi.org/10.3390/fermentation11080464 - 12 Aug 2025
Viewed by 409
Abstract
Dehydroshikimate (DHS) dehydratase (DSD) catalyzes the conversion of DHS into 3,4-dihydroxybenzoic acid (3,4-DHBA), a compound with promising applications across various industries. The DSD from Podospora anserina (DSDPa) was characterized and its catalytic properties were compared with those of previously investigated enzymes, [...] Read more.
Dehydroshikimate (DHS) dehydratase (DSD) catalyzes the conversion of DHS into 3,4-dihydroxybenzoic acid (3,4-DHBA), a compound with promising applications across various industries. The DSD from Podospora anserina (DSDPa) was characterized and its catalytic properties were compared with those of previously investigated enzymes, AsbF (Bacillus thuringiensis), Qa-4 (Neurospora crassa), and QsuB (Corynebacterium glutamicum), both in vitro and in vivo using tube fermentation. Escherichia coli and C. glutamicum were used as platforms to construct model 3,4-DHBA producers. To increase DHS availability in both hosts, shikimate dehydrogenase AroE was inactivated, and the plasmid pVS7-aroG4, encoding 3-deoxy-D-arabinoheptulosonate 7-phosphate synthase (E. coli), was introduced. In E. coli, heterologous 3,4-DHBA synthesis was achieved through chromosomal integration of dsd genes. The fungal genes were codon-optimized for this bacterium. The same genes were cloned into the pVK9 vector and introduced into C. glutamicum, where 3,4-DHBA degradation was disrupted (ΔpcaHG). AsbF (kcat ~ 1 s−1) showed poor 3,4-DHBA accumulation in both hosts (1–1.5 g/L). The enzymes with better catalytic characteristics, QsuB (kcat ~ 60 s−1), DSDPa (kcat ~ 125 s−1), and Qa-4 (kcat ~ 220 s−1), provided 5 g/L 3,4-DHBA in E. coli and 3 g/L 3,4-DHBA in C. glutamicum, except for Qa-4. The low production (~1.5 g/L) observed for Qa-4 in C. glutamicum might be attributed to a non-optimal nucleotide sequence rich in codons rare for C. glutamicum. Full article
(This article belongs to the Section Microbial Metabolism, Physiology & Genetics)
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24 pages, 1647 KB  
Review
Exploring Exopolysaccharides Produced in Indigenous Mexican Fermented Beverages and Their Biotechnological Applications
by Julián Fernando Oviedo-León, Abril Ramírez Higuera, Jorge Yáñez-Fernández, Humberto Hernández-Sánchez and Diana C. Castro-Rodríguez
Fermentation 2025, 11(8), 463; https://doi.org/10.3390/fermentation11080463 - 12 Aug 2025
Viewed by 708
Abstract
Indigenous Mexican fermented beverages, such as pulque, colonche, tepache, and water kefir, are pillars of the country’s cultural and gastronomic heritage. Their sensory attributes and health-promoting properties arise from complex microbial consortia, in which lactic acid bacteria (LAB), mainly Lactobacillus and Leuconostoc, [...] Read more.
Indigenous Mexican fermented beverages, such as pulque, colonche, tepache, and water kefir, are pillars of the country’s cultural and gastronomic heritage. Their sensory attributes and health-promoting properties arise from complex microbial consortia, in which lactic acid bacteria (LAB), mainly Lactobacillus and Leuconostoc, acetic acid bacteria (AAB), primarily Acetobacter, and yeasts such as Saccharomyces and Candida interact and secrete exopolysaccharides (EPSs). Dextran, levan, and heteropolysaccharides rich in glucose, galactose, and rhamnose have been consistently isolated from these beverages. EPSs produced by LAB enhance the viscosity and mouthfeel, extend the shelf life, and exhibit prebiotic, antioxidant, and immunomodulatory activities that support gut and immune health. Beyond food, certain EPSs promote plant growth, function as biocontrol agents against phytopathogens, and facilitate biofilm-based bioremediation, underscoring their biotechnological potential. This review integrates recent advances in the composition, biosynthetic pathways, and functional properties of microbial EPSs from Mexican fermented beverages. We compare reported titers, outline key enzymes, including dextransucrase, levansucrase, and glycosyltransferases, and examine how fermentation variables (the substrate, pH, and temperature) influence the polymer yield and structure. Finally, we highlight emerging applications that position these naturally occurring biopolymers as sustainable ingredients for food and agricultural innovation. Full article
(This article belongs to the Special Issue The Health-Boosting Power of Fermented Foods and Their By-Products)
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18 pages, 2013 KB  
Article
Enhancing Nutritional Value and Sensory Quality of Spirulina (Arthrospira platensis) Through Preharvest Co-Cultivation with Yeast Saccharomyces cerevisiae
by Yue Zhao, Jikang Sui, Yuxuan Cui, Mingyong Zeng, Haohao Wu, Guangxin Feng and Xiangning Lu
Fermentation 2025, 11(8), 462; https://doi.org/10.3390/fermentation11080462 - 11 Aug 2025
Viewed by 592
Abstract
Spirulina’s (Arthrospira platensis) use in food applications is limited by its dark color and sulfurous odor. This study aimed to develop a preharvest bioprocessing strategy using Saccharomyces cerevisiae co-cultivation to address these limitations. At a yeast/microalgae biomass ratio of 10:1000 with [...] Read more.
Spirulina’s (Arthrospira platensis) use in food applications is limited by its dark color and sulfurous odor. This study aimed to develop a preharvest bioprocessing strategy using Saccharomyces cerevisiae co-cultivation to address these limitations. At a yeast/microalgae biomass ratio of 10:1000 with 5 g/L of glucose supplementation, co-cultivation for 24 h induced a rapid color transition from dark blue–green to light green and imparted “floral–fruity” aromas. Major bioactive compounds, including β-carotene, linoleic acid, and γ-linolenic acid, increased significantly, while volatile sulfur compounds were eliminated. Chlorophyll a and carotenoid contents rose by over two fold, reflecting enhanced photosynthetic efficiency. Mechanistic analyses revealed that yeast-derived acetic acid upregulated genes involved in flavor precursor biosynthesis and promoted biomass accumulation. This strategy integrates sensory improvement with nutritional enhancement, providing a sustainable approach for developing spirulina-based functional foods. Full article
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13 pages, 1712 KB  
Article
The Role of Quorum Sensing in Enhancing Lovastatin and Pigment Production in Monascus purpureus C322
by Sirisha Yerramalli, Stephen J. Getting, Godfrey Kyazze and Tajalli Keshavarz
Fermentation 2025, 11(8), 461; https://doi.org/10.3390/fermentation11080461 - 11 Aug 2025
Viewed by 483
Abstract
Monascus purpureus is a filamentous fungus known for producing pharmaceutically valuable secondary metabolites, including azaphilone pigments and lovastatin. Lovastatin is an HMG-CoA reductase inhibitor widely used to manage hypercholesterolaemia, while Monascus pigments serve as natural colourants with antioxidant and antimicrobial properties. This study [...] Read more.
Monascus purpureus is a filamentous fungus known for producing pharmaceutically valuable secondary metabolites, including azaphilone pigments and lovastatin. Lovastatin is an HMG-CoA reductase inhibitor widely used to manage hypercholesterolaemia, while Monascus pigments serve as natural colourants with antioxidant and antimicrobial properties. This study evaluated the impact of quorum-sensing molecules (QSMs)—tyrosol (0.3 mM), farnesol (0.2 mM) and linoleic acid (0.4 mM)—on pigment and lovastatin yields in shake flasks and 2.5 L stirred-tank bioreactors. QSMs were introduced 48 h post-inoculation in shake flasks and 24 h in bioreactors. All QSMs increased yellow (OD400), orange (OD470), and red (OD510) pigments and lovastatin concentration relative to the control, with scale-up further enhancing yields. Farnesol produced the most pronounced effect: in flasks, OD400 7.10 (1.86-fold), OD470 8.00 (2.12-fold), OD510 7.80 (2.08-fold), and 74.6 mg/L lovastatin (2.05-fold); in bioreactors, OD400 11.9 (2.06-fold), OD470 15.1 (2.71-fold), OD510 13.7 (2.47-fold), and 97.2 mg/L lovastatin (2.48-fold). This was followed by tyrosol treatment and then linoleic acid. These findings demonstrate that QSMs—particularly farnesol—significantly (p < 0.01) stimulate pigment and lovastatin biosynthesis in M. purpureus. Quorum sensing modulation represents a promising, scalable strategy to optimise fungal fermentation for industrial metabolite production. Full article
(This article belongs to the Special Issue Scale-Up Challenges in Microbial Fermentation)
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14 pages, 2312 KB  
Article
Isolation and Characterization of Bacteriocin-like-Producing Companilactobacillus farciminis YLR-1 and the Inhibitory Activity of Bacteriocin Against Staphylococcus aureus
by Lirong Yang, Hui Su, Jiayue Wang, Sijia Sun, Sibo Liu, Baishuang Yin, Wenlong Dong and Guojiang Li
Fermentation 2025, 11(8), 460; https://doi.org/10.3390/fermentation11080460 - 11 Aug 2025
Viewed by 527
Abstract
This study aimed to identify a probiotic bacterium with antagonistic activity against the foodborne pathogen Staphylococcus aureus (S. aureus) and investigate the mechanism of its antibacterial components. Growth kinetics were analyzed to assess bacterial proliferation. Acid and bile salt tolerance are [...] Read more.
This study aimed to identify a probiotic bacterium with antagonistic activity against the foodborne pathogen Staphylococcus aureus (S. aureus) and investigate the mechanism of its antibacterial components. Growth kinetics were analyzed to assess bacterial proliferation. Acid and bile salt tolerance are vital indicators for evaluating probiotic survival in the gastrointestinal tract. The results indicated that Companilactobacillus farciminis (C. farciminis) YLR-1 not only had high tolerance to salt conditions (0.03%, 0.3%, and 0.5%) but also has a high survival rate at pH 3–4. The bacteriocin-like inhibitory substance (BLIS) isolated from C. farciminis YLR-1 was dialyzed using a membrane with a molecular weight cut-off (MWCO) of 500 Da, followed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. The results indicate that the BLIS produced by C. farciminis YLR-1 is a small-molecule peptide. BLIS displayed pH tolerance within acidic and neutral environments (4–8) and exhibited thermostability. When treated with proteinase K, the antibacterial action of BLIS was found to be inactivated. Membrane disruption mechanisms were examined using fluorescence imaging and scanning electron microscopy (SEM). SEM and fluorescence imaging revealed that BLIS-induced membrane damage in S. aureus ATCC 25923 causes cytoplasmic leakage and cell death. Full article
(This article belongs to the Section Probiotic Strains and Fermentation)
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18 pages, 2191 KB  
Article
Neuroprotective Properties of Fermented Malted Rice Obtained Under Different Processing Conditions
by Micaela Albarracín, Franco Van de Velde, Raúl E. Cian and Silvina R. Drago
Fermentation 2025, 11(8), 459; https://doi.org/10.3390/fermentation11080459 - 10 Aug 2025
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Abstract
Two products fermented with lactic acid bacteria (LAB) were obtained using malted rice (FR) and mashed malted rice (FMR). Peptide, phenolic acids, and γ-aminobutyric acid (GABA) contents and neuroprotective activities were evaluated before and after simulated gastrointestinal digestion. GABA contents of fermented products [...] Read more.
Two products fermented with lactic acid bacteria (LAB) were obtained using malted rice (FR) and mashed malted rice (FMR). Peptide, phenolic acids, and γ-aminobutyric acid (GABA) contents and neuroprotective activities were evaluated before and after simulated gastrointestinal digestion. GABA contents of fermented products were 45 and 51 mg 100 g−1, with a bioaccessibility of 51 and 45% for FR and FMR, respectively. Both fermented malted rice products exhibited inhibitory effects against tyrosinase, acetylcholinesterase, and prolyl oligopeptidase, with FR demonstrating the highest inhibitory activity. The neuroprotective properties were increased after digestion and could potentially be attributed to bioactive peptides generated by germination, fermentation, and digestion, as well as free phenolic acids. These findings suggest that fermented malted rice possesses promising biofunctional properties and may serve as suitable dietary options for individuals with gluten and lactose intolerance, offering additional neuroprotective benefits. Full article
(This article belongs to the Special Issue Recent Trends in Lactobacillus and Fermented Food, 3rd Edition)
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