This study investigated the effects of enzyme-assisted low-temperature cold fermentation on sufu’s microbial diversity, biogenic amine (BA) formation, and physicochemical properties. The results showed that the enzyme-assisted fermentations for both room- and low-temperature groups (RTEF30 and LTEF20, respectively) significantly increased total acid (TA), amino nitrogen (NH3-N), and enzyme activity compared to the non-enzyme fermentation at room-temperature post-fermentation (RTNF30). This indicated that enzyme-assisted fermentation effectively overcame challenges associated with low-temperature fermentation of sufu. BA analysis revealed that the LTEF20 group had the highest total BA (3.7 mg/g) and putrescine (1.8 mg/g) levels compared to other groups. Microbial analysis showed that the LTEF20 group exhibited higher microbial diversity compared to the RTEF30 group. They had the highest levels of Enterobacteriaceae (0.4131) and lactic acid bacteria in the early and late phases (0.5556) among the groups. Correlation analysis revealed significant links between sufu’s physicochemical properties and microbial communities. Notably, putrescine positively correlated with Bifidobacterium, while TA negatively correlated with Enterococcus. These findings suggest that microbial activity alterations, caused by low-temperature cold fermentation, influences sufu’s fermentation process and quality, guiding further studies on the regulation of biogenic amine formation.

Caffeic acid phenethyl ester (CAPE) is identified to be an efficacious bioactive polyphenol in propolis for ameliorating glucose and lipid metabolism disorders and inflammation. In this study, an alcohol-induced zebrafish inflammation model was established. CAPE treatments at different concentrations (0.04, 0.2, and 1.0 μg/mL) were administered to alcohol-exposed zebrafish to investigate the underlying mechanisms of alleviating alcohol-induced liver inflammation using transcriptomic analysis and 16S rRNA gene sequencing methods. The results indicated that CAPE decreased the expressions of TNF-α and IL-1β and significantly increased the expression of IL-10 (p < 0.0001). Based on the KEGG enrichment analysis of transcriptomic sequencing, CAPE effectively alleviated the inflammation in zebrafish mainly through pancreatic secretion, complement and coagulation cascades, and protein digestion and absorption. Molecular docking supported the potential of CAPE in targeting cholecystokinin (CCK) A Receptor (CCKAR) and mediating the regulation of pancreatic secretion and related inflammation pathways. Moreover, intestinal microbiota analysis demonstrated that CAPE could improve the alcohol-induced microbiota disorder. Additionally, there was a significant correlation between the key genes related to lipid and sterol metabolism among the KEGG-enriched pathways and the specific intestinal microbial communities in zebrafish. Flavobacterium from Bacteroidota was significantly positively correlated with CEL1, CEL2, and LPIN (p < 0.01), which suggested that the anti-inflammatory function of CAPE was closely associated with the intestinal microbiota improvement. In conclusion, our findings demonstrated that CAPE could ameliorate liver inflammation in alcohol-induced zebrafish, which was mainly associated with the regulation of pancreatic secretion and intestinal microbiota disorder. This study emphasized the anti-inflammatory mechanisms of CAPE based on targeting the pancreatic secretion pathway, which will broaden the application of natural antioxidants in improving metabolic and inflammatory problems.

This study investigated microbial community dynamics and their links to fermentation traits in solid-state fermentation of walnut -based soy sauce (WSS) using walnut meal-soybean meal mixtures. Via 16S rRNA sequencing and molecular docking, it analyzed the effects of three distinct starter culture treatments—Aspergillus oryzae (AO), Aspergillus niger (AN), and mixed starter culture (A. oryzae + A. niger, ON)—as well as fermentation duration on microbial diversity and physicochemical properties, aiming to clarify microbial-driven quality mechanisms. Physicochemical analysis demonstrated superior fermentation performance in the AO group, showing significantly higher amino nitrogen (NH₃-N) accumulation (0.23 g/100 mL) and protease activity (30.5 U/mL) compared to the AN group, with the mixed inoculation group (ON) exhibiting intermediate results, indicating A. oryzae’s dominant role in mixed fermentation. Via PCA and Shannon index, microbial diversity analyses revealed starter cultures shaped microbial community structure: Enterococcus and Staphylococcaceae were enriched by AO starter, and Klebsiella dominated in AN group. Additionally, temporal succession of the microbiota occurred during post-fermentation of WSS, with Lactobacillales, Staphylococcus, and special flavor-producing functional flora dominating early, middle, and later stages, respectively. Staphylococcus positively correlated with protease activity and amino nitrogen, critical for quality. Molecular docking showed major walnut polyphenols significantly affected protease activity, aiding process optimization. This research provides theoretical foundations for improving WSS production and enriches understanding of solid-state fermentation microbial ecology.

Heat stress is prevalent in industrial biomanufacturing processes including Baijiu brewing and bioethanol production. It disrupts the membrane structure an

Sea buckthorn juice (SBJ) is nutritionally valuable, but its high malic acid content contributes to excessive sourness that limits consumer acceptance. In this study, the deacidification phenotypes of two lactic acid bacterial isolates, Lactiplantibacillus plantarum S4 and Lacticaseibacillus paracasei YJ2, were compared using fermentation phenotyping, sensory evaluation, enzyme assays, untargeted metabolomics, transcriptomics, and molecular docking. After 96 h of fermentation, S4 degraded 91.98% of malic acid, compared with 69.50% for YJ2, and exhibited higher viable-cell counts and overall sensory acceptability under the tested conditions. S4 also showed higher crude-extract malate-conversion activity under MLE-favoring conditions. Molecular docking predicted more favorable interactions of malate with S4-derived MleP and MleS than with the corresponding YJ2 proteins; however, these analyses did not directly measure MleP-mediated transport or MleS-specific catalytic flux. Metabolomic profiling showed lower abundance of malic acid and several other organic acids in S4-fermented SBJ, together with increased abundance of succinic acid, 2-oxoglutaric acid, phenyllactic acid-related metabolites, D-octopine, and N-lactoyl-phenylalanine. Transcriptomic analysis revealed differences between S4 and YJ2 in carbohydrate metabolism, glycolysis, pyruvate metabolism, energy generation, and late-stage cellular maintenance. Integration of these datasets supports a working model in which malate-associated conversion, central-carbon redistribution, organic-acid remodeling, and acid-stress adaptation may contribute to the greater malate-removal phenotype of S4. Because only one isolate of each species was examined, the observed differences should be interpreted as differences between S4 and YJ2 rather than as species-level effects.