Biofilm formation of functional microorganisms in fermented foods can serve as a strategy to cope with environmental stress.Tetragenococcus halophilus,a key functional microorganism in traditional fermented foods,form...Biofilm formation of functional microorganisms in fermented foods can serve as a strategy to cope with environmental stress.Tetragenococcus halophilus,a key functional microorganism in traditional fermented foods,forms biofilms that aid in adapting to extreme conditions,thereby improving fermentation efficiency and product flavor.However,the regulation and molecular mechanisms of T.halophilus biofilms remain poorly studied.Hence,we investigated T.halophilus JY1 biofilms via dynamic monitoring,SEM,FT-IR,and transcriptomics,while verifying related targets in detail to determine the formation mechanism and stress response.Biofilm formation is a cyclical process with dynamic changes,and the demand for its remodelling is increased under high salinity conditions.Compared to planktonic state,T.halophilus JY1 biofilm cells showed enhanced extracellular polymer abundance and maintained intact cellular morphology with 2.5 M NaCl.Regarding gene expression,biofilm cells boosted glycolysis for energy accumulation and regulated carbon metabolic flow.Up-regulated expression of the dhaKLM gene cluster led to accumulated glucose,a precursor of extracellular polysaccharides,facilitating biofilm formation.This study addresses biofilm regulation from the viewpoint of extracellular polysaccharides and provides scientific evidence for resistance mechanisms in fermentation-functional microorganisms.展开更多
This study employed metagenomics and metabolomics to evaluate the impact of Tetragenococcus halophilus and Zygosaccharomyces rouxii on microbiota composition and metabolite profiles in secondary fortified fermented so...This study employed metagenomics and metabolomics to evaluate the impact of Tetragenococcus halophilus and Zygosaccharomyces rouxii on microbiota composition and metabolite profiles in secondary fortified fermented soy sauce.The Co-culturing of T.halophilus T10 and Z.rouxii QH-1(T1Z)enriched microbial diversity and promoted the proliferation of functional species,thereby enhancing biomarker species.Annotations matched from EggNOG,KEGG,and CAZy databases underscored the significance of carbohydrate and amino acid metabolism in moromi.Sample T1Z enhanced the metabolism by increasing the abundance and catalytic efficiency of the relevant enzymes,resulting in increases of 3.94%,2.69%,and 11.14%,respectively,with total nitrogen,amino acid nitrogen,and free amino acids.It introduced 11 volatile compounds and increased the alcohol content by 13.65%,and the aldehyde content by 49.28%,while also suppressing the accumulation of ammonium nitrogen and biogenic amines.Metabolic pathway analysis identified Staphylococcus gallinarum,Mammaliicoccus sciuri,and certain Bacillus species,especially B.parathracis,B.velezensis,and B.subtilis,as principal contributors to car-bohydrate and amino acid metabolism.These findings offer insight into microbial strain selection for industrial fermentation and provide a foundation for optimizing the process through co-culture bioaugmentation to enhance and underscore the potential of modern microbial techniques in traditional practices.展开更多
Biogenic amines(BAs),a class of toxic nitrogen-containing compounds,are commonly found in high-protein fermented foods.This study investigated whether,what and how the fermentation parameters influence the BAs accumul...Biogenic amines(BAs),a class of toxic nitrogen-containing compounds,are commonly found in high-protein fermented foods.This study investigated whether,what and how the fermentation parameters influence the BAs accumulation in spontaneous soy sauce fermentation.The results showed that BAs accumulation in soy sauce fermentation throughout the year showed significant seasonal differences,which were closely related to temperature and pH value.Furthermore,different microbial communities were found in high-and low-BAs groups,indicating that seasonal fermentation factors affect BAs accumulation by influencing the microbial population.Following bioinformatic analysis,single-microorganism culture analysis,and simulated fermentation,it was found that lower temperature or higher NaCl concentration can reduce BAs accumulation,most likely by suppressing the proliferation of BAs-producing bacteria.This is a comprehensive study of the impact of fermentation parameters on BAs production,and will serve as a foundation for future research on BAs management.展开更多
基金was supported by Natural Science Foundation of Guangdong Province,China(2024A1515012719).
文摘Biofilm formation of functional microorganisms in fermented foods can serve as a strategy to cope with environmental stress.Tetragenococcus halophilus,a key functional microorganism in traditional fermented foods,forms biofilms that aid in adapting to extreme conditions,thereby improving fermentation efficiency and product flavor.However,the regulation and molecular mechanisms of T.halophilus biofilms remain poorly studied.Hence,we investigated T.halophilus JY1 biofilms via dynamic monitoring,SEM,FT-IR,and transcriptomics,while verifying related targets in detail to determine the formation mechanism and stress response.Biofilm formation is a cyclical process with dynamic changes,and the demand for its remodelling is increased under high salinity conditions.Compared to planktonic state,T.halophilus JY1 biofilm cells showed enhanced extracellular polymer abundance and maintained intact cellular morphology with 2.5 M NaCl.Regarding gene expression,biofilm cells boosted glycolysis for energy accumulation and regulated carbon metabolic flow.Up-regulated expression of the dhaKLM gene cluster led to accumulated glucose,a precursor of extracellular polysaccharides,facilitating biofilm formation.This study addresses biofilm regulation from the viewpoint of extracellular polysaccharides and provides scientific evidence for resistance mechanisms in fermentation-functional microorganisms.
基金supported by the Science and Technology Department of Sichuan Province of China(No:23JYC0056).
文摘This study employed metagenomics and metabolomics to evaluate the impact of Tetragenococcus halophilus and Zygosaccharomyces rouxii on microbiota composition and metabolite profiles in secondary fortified fermented soy sauce.The Co-culturing of T.halophilus T10 and Z.rouxii QH-1(T1Z)enriched microbial diversity and promoted the proliferation of functional species,thereby enhancing biomarker species.Annotations matched from EggNOG,KEGG,and CAZy databases underscored the significance of carbohydrate and amino acid metabolism in moromi.Sample T1Z enhanced the metabolism by increasing the abundance and catalytic efficiency of the relevant enzymes,resulting in increases of 3.94%,2.69%,and 11.14%,respectively,with total nitrogen,amino acid nitrogen,and free amino acids.It introduced 11 volatile compounds and increased the alcohol content by 13.65%,and the aldehyde content by 49.28%,while also suppressing the accumulation of ammonium nitrogen and biogenic amines.Metabolic pathway analysis identified Staphylococcus gallinarum,Mammaliicoccus sciuri,and certain Bacillus species,especially B.parathracis,B.velezensis,and B.subtilis,as principal contributors to car-bohydrate and amino acid metabolism.These findings offer insight into microbial strain selection for industrial fermentation and provide a foundation for optimizing the process through co-culture bioaugmentation to enhance and underscore the potential of modern microbial techniques in traditional practices.
基金This work was financially supported by National Key R&D Program of China(2018YFC1604100).
文摘Biogenic amines(BAs),a class of toxic nitrogen-containing compounds,are commonly found in high-protein fermented foods.This study investigated whether,what and how the fermentation parameters influence the BAs accumulation in spontaneous soy sauce fermentation.The results showed that BAs accumulation in soy sauce fermentation throughout the year showed significant seasonal differences,which were closely related to temperature and pH value.Furthermore,different microbial communities were found in high-and low-BAs groups,indicating that seasonal fermentation factors affect BAs accumulation by influencing the microbial population.Following bioinformatic analysis,single-microorganism culture analysis,and simulated fermentation,it was found that lower temperature or higher NaCl concentration can reduce BAs accumulation,most likely by suppressing the proliferation of BAs-producing bacteria.This is a comprehensive study of the impact of fermentation parameters on BAs production,and will serve as a foundation for future research on BAs management.
