Search Results (16)

Soybean meal (SBM) is a foundational protein source, but its industrial application is constrained by a complex matrix of anti-nutritional factors (ANFs). This review provides a critical synthesis of the biochemical transition from raw SBM to fermented SBM (FSBM), focusing on the synergistic mechanisms of fungal and bacterial co-fermentation. We identify that the efficacy of FSBM is primarily driven by the microbial proteolysis of glycinin into low-molecular-weight bioactive peptides (<1000 Da). These peptides serve as the primary drivers for improved intestinal morphology (increased villus height) and the modulation of the gut microbiota, providing a mechanistic basis for reported probiotic effects. Furthermore, we establish that the 5–10% improvement in the feed conversion ratio (FCR) documented for swines mathematically offsets the processing premium of fermentation. However, critical gaps remain in the standardization of solid-state fermentation (SSF) protocols, specifically regarding the selection of fungal (Aspergillus) and bacterial (Bacillus or Lactobacillus) strains, whose distinct metabolic pathways significantly diversify the functional profile of the resulting FSBM. Full article

Valorization of agricultural by-products is a key component of circular strategies aimed at enhancing the sustainability of livestock systems. Almond hulls (AHs), a major residue of the almond-processing industry, are characterized by their high non-fiber carbohydrate (NFC) content, but low crude protein (CP) content and ruminal fermentation. This study evaluated the effects of treating AHs with exogenous fibrolytic enzymes (EFEs) and Saccharomyces cerevisiae (SC) via solid-state fermentation. Treatments were applied individually or in combination (SC + EFEs). The effects on chemical composition and ruminal fermentation were assessed. EFEs reduced the fiber content and increased the NFC content. This accelerated ruminal fermentation and reduced the lag time. However, it did not change the overall fermentation extent. SC increased the CP content and ether extract but reduced the NFC content. This modification promoted the growth of ruminal bacteria. As a result, the ruminal fermentation extent, ruminal degradability and volatile fatty acid (VFA) content improved. However, methane (CH₄) and carbon dioxide (CO₂) emissions relative to the substrate, degraded substrate and total gas emission were not affected. SC + EFEs had synergistic effects. This further increased the CP content and ether extract and reduced the NFC and fiber contents. The treatment modulated ruminal microbiota by decreasing protozoa and increasing bacteria. It also reduced the fermentation lag time and enhanced the fermentation extent, degradability and VFA production favoring propionate formation. Additionally, it reduced CH₄ and CO₂ emissions per unit of degraded substrate and the total gas emission. Overall, the SC + EFEs represent an effective approach to enhance the nutritional value of AHs while partially mitigating greenhouse gas emissions relative to substrate utilization and fermentation pathways. Full article

Acetate esters, synthesized by alcohol acyltransferase (AATases) encoded primarily by the ATF1 gene, are pivotal for the desirable fruity aroma in fermented foods. However, the role and regulatory impact of ATF1 in solid-state fermented meat remain largely unexplored. This study engineered Saccharomyces cerevisiae by knocking out and overexpressing ATF1 to investigate its influence on flavor formation in a sour meat model system. Compared to the wild-type strain, ATF1 overexpression (SCpA group) increased ethyl acetate content by 70.15% and uniquely produced significant levels of isoamyl acetate. Conversely, ATF1 deletion (SCdA group) led to a 61.23% reduction in ethyl acetate. Transcriptomic analysis revealed that ATF1 overexpression triggered a systemic metabolic shift, not only activating the final esterification step but also upregulating key genes in central carbon metabolism (SUC2, ICL1), amino acid biosynthesis, and precursor supply pathways (ACS2, ADH1). This synergistic regulation redirected metabolic flux towards the accumulation of both alcohol and acyl-CoA precursors, thereby amplifying acetate ester synthesis. Our findings demonstrate that ATF1 is a critical engineering target for flavor enhancement in fermented meats and uncover a broader metabolic network it influences, providing a robust strategy for the targeted modulation of food flavor profiles. Full article

Chinese Baijiu distiller’s grains are by-products of the Chinese Baijiu brewing process, characterized by high water content, high acidity, and high fiber content, which make them unsuitable for animal feed, especially for monogastric animals. This study investigated the possibility of increasing the feed value of Nong-flavor Baijiu distiller’s grains (NFBDGs) for monogastric animals via solid-state fermentation by microbial-enzyme synergy. Experiments evaluated microbial growth, pH variation, improvement of crude protein (CP), true protein (TP), and acid-soluble protein (ASP), degradation of crude fiber (CF), acid detergent fiber (ADF), and neutral detergent fiber (NDF). The results indicated that Ligilactobacillus salivarius CRS23, Bacillus subtilis YLZ7, Saccharomyces cerevisiae CJM26, and xylanase were identified for the fermentation of NFBDGs. When the initial moisture content of NFBDGs was 60% and the initial pH was 3.4, under the conditions of aerobic fermentation at 37 °C for 4 days, the pH of NFBDGs increased from 3.49 to 6.04, the contents of CP and TP increased by 33.59% and 31.21%,,, respectively, while the contents of CF, ADF, and NDF decrease by 35.44%, 20.53%, and 25.02% respectively. The nutritional value of NFBDGs was significantly improved after microbial-enzyme synergistic fermentation, providing a new approach for their application as feed. Full article

Background: Sunflower meal (SFM), a promising feed material, is constrained by its high content of crude fiber (CF) and chlorogenic acid (CGA). Methods: This study utilized a synergistic solid-state fermentation process involving the Bacillus subtilis strain B3 and the enzyme β-glucanase to enhance SFM’s application potential. Results: The synergistic treatment notably reduced CF by 12.7% and CGA by 99.77%, while simultaneously increasing acid-soluble protein and reducing sugar by 111.3% and 283.1%, respectively. Positive impacts on its physical structure, characterized by a looser network with visible pores, and on its microbial community, evidenced by an enriched abundance of fungal species such as Cyberlindnera and Aspergillus, were also observed. In vitro assays indicated improved digestibility of dry matter, neutral detergent fiber, and crude protein, along with a non-significant reduction in methane production. Conclusions: These results demonstrate that microbial-enzymatic synergy effectively enhances SFM’s nutritional profile. Full article

The non-medicinal parts of Polygonatum sibiricum (P. sibiricum) and Gentiana scabra (G. scabra) are abundant but underutilized in Liaoning Province, China, creating an environmental burden. Solid-state fermentation (SSF) offers a strategy to enhance their bioactivity, yet triple microbial co-fermentation remains underexplored. This study applied a triple microbiota—featuring Aspergillus niger (A. niger), Bacillus subtilis (B. subtilis), and Saccharomyces cerevisiae (S. cerevisiae)—to ferment the stems and leaves of both plants. Antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) was assessed via the Kirby–Bauer test, while Liquid Chromatography–Tandem Mass Spectrometry (LC–MS/MS)-based non-targeted metabolomics identified differential metabolites and enriched pathways. Co-fermentation significantly increased the inhibition zones to 17.4 ± 0.8 mm for E. coli and 17.7 ± 0.3 mm for S. aureus, a 1.8-fold improvement over the unfermented controls (p < 0.001). Among the 2976 metabolites detected, 1236 were differentially expressed, with Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis highlighting activation of aminoacyl-tRNA biosynthesis, ABC transporter, and phenylalanine–tyrosine–tryptophan pathways. Differential abundance analysis indicated that the aminoacyl-tRNA pathway (DA score > 0.9) is critical for antimicrobial peptide synthesis. Phenylalanine derivatives, including 4-hydroxybenzaldehyde, which increased over 430-fold (Log₂ FC = 8.78), contributed to membrane-disruptive antibacterial effects. Mechanistically, A. niger hydrolyzes cellulose to release precursors, B. subtilis synthesizes antimicrobial peptides, and S. cerevisiae enhances metabolite solubility and excretion, collectively boosting antibacterial activity by 80%, suggesting a potent synergistic interaction among the triple microbiota. This cascade mechanism provides a scalable approach for valorizing approximately 55 million tons of traditional Chinese medicine (TCM) waste annually. Full article

As the core of the solid-state fermentation system, the quality of pit mud is directly determined by the synergistic effects of volatile flavor compounds, microbial communities, and abiotic physicochemical factors. However, pit mud lacks systematic knowledge, especially concerning the dynamic association mechanism and threshold effect of its three components. This results in blind spots within the pit mud metabolism regulation network, which has become a bottleneck in precise pit mud quality regulation. Focusing on the volatile flavor compounds of pit mud is crucial to exploring their association with the core microbial community and physicochemical factors of pit mud, in order to cultivate high-quality pit mud. Although a large number of studies have revealed the formation mechanism of high-quality pit mud based on the three factors and cultivated artificial pit mud through microbial enhancement or synthetic flora to improve the quality. However, anaerobic fermentation is a complex system, and the complexity and dynamics of microorganisms make it difficult for biofortification and synthetic flora to effectively regulate the quality of pit mud. Therefore, this paper reviews the research progress on flavor compounds, microbial communities and abiotic factors associated with pit mud quality, deepens the understanding of their influence on pit mud quality, and proposes a precise environmental control strategy to alter the composition and content of the microbial community in the pit mud. The key to this scheme lies in constructing a correlation network through multi-omics integration to identify the physical and chemical factors related to the quality of the pit mud. During the fermentation process, intervention measures are taken on environmental parameters, ultimately effectively changing the physical and chemical factors, thereby achieving the assumption of precise control of the quality of the pit mud. This provides necessary references and inspirations for improving the quality of pit mud, cultivating artificial cellar mud, and enhancing the quality of Baijiu. Full article

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

The solid-state fermentation (SSF) of agro-industrial by-products such as okara, pomegranate peel, and cranberry pomace presents a sustainable approach to enhance the release of bioactive compounds. This study investigated the effects of different microbial cultures—Rhizopus oligosporus, Aspergillus oryzae, Streptococcus thermophilus, and a co-culture of R. oligosporus and S. thermophilus—on the bioconversion of bioactive compounds in 100% okara, okara with 2% pomegranate peel, and okara with 1% cranberry pomace. The objective was to assess whether co-culture fermentation with molds and S. thermophilus augments the release of bioactive compounds in okara-based fermentations through synergistic enzymatic activity. Over a period of 72 h, isoflavone transformation (daidzin, daidzein, genistin, and genistein), pH evolution, and water activity were assessed. The co-culture system exhibited improved bioconversion, leading to significant (p < 0.01) increases in daidzein and genistein in pure okara compared to the starting material. The highest polyphenol content (0.908 mg/g) and antioxidant capacity (24.9 mg Trolox eq/g) were recorded in 100% okara. However, pomegranate peel inhibited β-glucosidase activity, delaying the release of isoflavone aglycones. These findings confirm that co-culture fermentation is an effective strategy for enhancing the bioactive properties of okara-based fermentations. This facilitates the release of bioactive aglycones and supports the upcycling of agro-industrial by-products into functional food ingredients. Future research should focus on optimizing fermentation parameters to further enhance the release of bioactive compounds. Full article

Marine microplastics (MPs) represent a novel ecological niche, populated by fungi with high potential for pharmaceutical discovery. This study explores the bioactivity of fungal strains isolated from MPs in Mediterranean sediments, focusing on their osteogenic and antiviral activities. Crude extracts prepared via solid-state and submerged-state fermentation were tested for their effects on extracellular matrix mineralization in vitro and bone growth in zebrafish larvae, and for their activity against the respiratory syncytial virus (RSV) and herpes simplex virus type 2 (HSV-2). Several extracts exhibited significant mineralogenic and osteogenic activities, with Aspergillus jensenii MUT6581 and Cladosporium halotolerans MUT6558 being the most performing ones. Antiviral assays identified extracts from A. jensenii MUT6581 and Bjerkandera adusta MUT6589 as effective against RSV and HSV-2 at different extents, with no cytotoxic effect. Although chemical profiling of A. jensenii MUT6581 extract led to the isolation of decumbenones A and B, they did not reproduce the observed bioactivities, suggesting the involvement of other active compounds or synergistic effects. These results highlight the plastisphere as a valuable resource for novel bioactive compounds and suggest the need for further fractionation and characterization to identify the molecules responsible for these promising activities. Full article

Solid-state fermentation represents a sustainable approach for the conversion of agro-industrial wastes into high-added-value feed ingredients. The present study aimed to evaluate the effects of the dietary addition of a solid-state-fermented mixture of olive mill stone waste (OMSW) and Lathyrus clymenum husks (LP) on the antioxidant blood parameters of weaned piglets. Two hundred 35-day-old weaned piglets were allotted into two groups and fed either a control (C) diet or a diet containing 50 g of OMSW-LP per kg (OMSW-LP) for 40 days. Blood samples were collected at 35 and 75 days of age to assess the free radical scavenging activity (FRSA), reduced glutathione (GSH) levels, catalase activity (CAT), protein carbonyls (CARBs), and thiobarbituric acid reactive species (TBARS). The OMSW-LP diet reduced the TBARS (p = 0.049) and CARB contents (p = 0.012) and increased the levels of FRSA (p = 0.005), GSH (p = 0.040), and CAT activity (p = 0.012) in the piglets’ blood, likely due to the synergistic action of the antioxidants and bioactive compounds present in the OMSW-LP mixture. Overall, the dietary inclusion of solid-state-fermented OMSW-LP at 50 g/kg could potentially serve a bio-functional purpose since it enhanced the antioxidant blood parameters in this study, a crucial factor for the health and growth of piglets post-weaning. Full article

Cost and contamination are the bottleneck problems for the replacement of antibiotics with fermented feed. A strain of lactic acid bacteria was isolated and screened from acidified apple juice and identified as Pediococcus acidilactici using morphological, physiological, and biochemical tests and 16S rDNA sequence analysis. The strain was combined with Bacillus subtilis and Saccharomyces cerevisiae to ferment raw corn–soybean meal, and the two-stage fermentation process was optimized with a single-factor test, orthogonal test, and response surface methodology. Compared with unfermented raw material, the protein content of fermented feed was increased by 5.21 percentage points (p < 0.05) and the total amino acids were increased by 3.7 percentage points (p < 0.05), making it rich in amino acids essential for pigs. The high-throughput sequencing results showed that, at the species level, the highest relative abundances of bacteria in the fermentation system were those of Pediococcus acidilactici and Bacillus subtilis, and the most abundant fungi was Saccharomyces cerevisiae. No pathogenic bacteria, such as Salmonella, were detected in the fermentation system. This paper provides a feasible scheme for cheap preparation of an alternative to antibiotics, fermented feed, with uncooked raw materials. It has positive significance for promoting high-value utilization of agricultural and sideline products and improving feed cost-effectiveness. Full article

Naturally occurring phytochemicals from plants or grains are crucial in reducing various metabolic disorders. Bioactive phytonutrients are abundant in the Asian dietary staple, brown rice. This research evaluated the impact of lactic acid bacteria (LABs) bioconversion and fermentation on antioxidant and antiobesity activities and ferulic acid content in brown rice. The combination of bioconversion with Pediococcus acidilactici MNL5 among all LABs used showed a synergistic impact with 24 h of solid-state brown rice fermentation. The 24-h MNL5 fermented brown rice (FBR) demonstrated the most potent pancreatic lipase inhibitory activity (85.5 ± 1.25%) compared to raw brown rice (RBR) (54.4 ± 0.86%). The antioxidant potential of MNL5-FBR was also found to be highest in the DPPH assay (124.40 ± 2.40 mg Trolox Equiv./100 g, DW), ABTS assay (130.52 ± 2.32 mg Trolox Equiv./100 g, DW), and FRAP assay (116.16 ± 2.42 mg Trolox Equiv./100 g, DW). Based on higher antioxidant and antiobesity activities, samples were quantified for ferulic acid content using the HPLC-MS/MS approach. Furthermore, C. elegans supplementation with FBR showed enhanced life span and lipid reduction in fluorescence microscope analysis compared to the control. Our results indicate that the expression study using the C. elegans model (N2 and Daf-2 models) fat gene was conducted, showing a lowering of obesity ability in FBR-fed worms. Our study indicates that FBR has improved antioxidant and antiobesity actions, especially in MNL5-FBR, and can be employed to develop functional foods that combat obesity. Full article

Okara is a major by-product of soymilk and tofu production. Despite retaining abundant nutrients after the process, okara is often under-utilized. In this study, solid-state fermentation (SSF) of okara was carried out using a koji starter (containing both Aspergillus oryzae and Aspergillus sojae) with the intention of releasing its untapped nutrients. Its effects on lipid metabolism in diet-induced obesity (DIO) were observed. The nutritional profile of fermented okara was elucidated using the following parameters: total phenolic content (TPC), pH, protein content, dietary fiber, amino acid content, and free sugar content. In vivo experiments were conducted using high-fat diets supplemented with unfermented okara and fermented okara over three weeks. Supplementation with fermented okara reduced body weight gain, adipose tissue weight, the serum triglyceride profile, and lipid accumulation in the liver, and altered the mRNA expression levels related to lipid metabolism; however, it did not affect pH and short-chain fatty acid (SCFA) production in this study. In conclusion, high-fat diets supplemented using okara fermented with Aspergillus spp. improved the lipid metabolism in mice, due to their high nutritional value, such as TPC, soy protein, and amino acids, and their synergistic effects without altering the gut microbiota. Full article

An efficient processing of organic solid residues will be pivotal in the development of the circular bioeconomy. Due to their composition, such residues comprise a great biochemical conversion potential through fermentations. Generally, the carbohydrates and proteins present in the organic wastes cannot be directly metabolized by microorganisms. Thus, before fermentation, enzymes are used in a hydrolysis step to release digestible sugars and nitrogen. Although enzymes can be efficiently produced from organic solid residues in solid-state fermentations (SsF), challenges in the development and scale-up of SsF technologies, especially bioreactors, have hindered a wider application of such systems. Therefore, most of the commercial enzymes are produced in submerged-liquid fermentations (SmF) from expensive simple sugars. Instead of independently evaluating SsF and SmF, the review covers the option of combining them in a sequential process in which, enzymes are firstly produced in SsF and then used for hydrolysis, yielding a suitable medium for SmF. The article reviews experimental work that has demonstrated the feasibility of the process and underlines the benefits that such combination has. Finally, a discussion is included which highlights that, unlike typically perceived, SsF should not be considered a counterpart of SmF but, in contrast, the main advantages of each type of fermentation are accentuated in a synergistic sequential SsF-SmF. Full article