[Objective]This study aimed to improve the yield of bacteriocins from lactic acid bacteria by optimizing the fermentation process for production of bacteriocins from lactic acid bacteria.[Method]By single-factor analy...[Objective]This study aimed to improve the yield of bacteriocins from lactic acid bacteria by optimizing the fermentation process for production of bacteriocins from lactic acid bacteria.[Method]By single-factor analysis,fermentation temperature,seed age,inoculation volume,fermentation duration and fermentation media p H were optimized to determine the best fermentation process.The inhibitory zone of bacteriocins from lactic acid bacteria was analyzed with oxford cup method,based on which the fermentation process was evaluated.[Result]The optimal fermentation process was optimized：fermentation temperature 37℃,seed age 14 h,inoculation volume 2%,fermentation duration 48 h,fermentation media p H 5.0.[Conclusion]Under the optimized fermentation conditions,the yield of bacteriocins from lactic acid bacteria was improved significantly.展开更多
Summer green tea(SGT)is not favored by consumers due to its strong bitterness and astringency.This study aims to improve the taste of SGT using tea-derived fungi isolated from Liupao tea by solid-state fermentation.Ba...Summer green tea(SGT)is not favored by consumers due to its strong bitterness and astringency.This study aims to improve the taste of SGT using tea-derived fungi isolated from Liupao tea by solid-state fermentation.Based on 19 detected main compounds,principal component analysis(PCA)and hierarchical cluster analysis(HCA)showed Aspergillus sydowii,Penicillium manginii,Aspergillus intermedius,Aspergillus amstelodami,and Aspergillus niger groups were clustered together with significant differences from the control.Additionally,metabolomics analysis showed P.manginii,A.intermedius,and A.amstelodami strains could reduce the chemical components associated with bitter and astringent flavors,such as epicatechin gallate,epicatechin,(+)-gallocatechin,quercetin,kaempferol,myricetin,procyanidin B2,L-phenylalanine and its glycoside derivatives(VIP>1,P<0.05),and increase the contents of theabrownins associated with umami taste(P<0.05).In summary,the taste of SGT can be improved by the above fungi fermentation.展开更多
The effects of natural fermentation and inoculation fermentation on the volatile flavor substances of pickled ginger was studied.High-throughput sequencing and gas chromatographic-mass spectrometry were used to measur...The effects of natural fermentation and inoculation fermentation on the volatile flavor substances of pickled ginger was studied.High-throughput sequencing and gas chromatographic-mass spectrometry were used to measure the bacterial community changes and its flavour compounds during one to six days’fermentation.First,55 and 51 volatile compounds were detected in the natural and the Lactiplantibacillus plantarum-inoculated fermentation samples,respectively.Alkenes,alcohols,aldehydes and esters were the main volatile components of both types of fermented ginger,but their contents were different.Then,40 and 43 bacterial genera were detected in the natural and inoculation fermented gingers,respectively,including 15 major bacterial genera such as Lactobacillus.However,the abundance of bacterial genera in the samples was different.The correlation analysis showed that a total of 43 bacterial genera had medium to high correlations with 49 volatile flavor compounds(|ρ|>0.6),including one aldehyde,two ketones,five esters,nine alcohols and 32 olefins.The comprehensive results showed that,compared with natural fermentation,inoculation fermentation could change the abundance of bacteria in pickled ginger,thereby improving the volatile flavor compounds of this popular product.展开更多
Spontaneous fermentation of young ginger pickles(YGP)involves numerous indigenous microbes from raw materials and the environments,while inoculated fermentation is an ideal strategy for standardizing YGP production an...Spontaneous fermentation of young ginger pickles(YGP)involves numerous indigenous microbes from raw materials and the environments,while inoculated fermentation is an ideal strategy for standardizing YGP production and improving quality.This study investigated the effects of exogenous inoculation with Lactiplantibacillus plantarum ATCC 8014 on the quality characteristics and metabolic profile of YGP.It particularly explored the response of indigenous microbes,focusing on their interactions and metabolic characteristics in relation to exogenously inoculated microbes.The results indicated that L.plantarum inoculation significantly increased organic acid levels,while decreasing nitrite content during YGP fermentation.In addition,L.plantarum-inoculated YGP exhibited increased Lactiplantibacillus abundance and significant alterations in color and texture characteristics when compared to naturally fermented YGP.Beta diversity analysis revealed improved similarity of fermented microbial community structure,while co-occurrence network analysis showed that L.plantarum inoculation increased interaction complexity,the positive correlation ratio,and the number of keystone taxa,particularly strengthening the symbiotic relationships among LAB.Furthermore,a total of 27 volatile and 29 non-volatile differential metabolites were identified between inoculated and uninoculated YGP.These differential metabolites were linked to the degradation of valine,leucine,and isoleucine,as well as pyruvate metabolism and glycolysis/gluconeogenesis pathways.Correlation network analysis suggested that the differential LAB significantly enhanced the quality attributes and metabolic profiles of YGP,likely due to the driving effects of L.plantarum on the symbiotic relationships among indigenous LAB.Overall,these findings provided valuable insights into the management of YGP fermentation and the standardization of its quality.展开更多
基金Supported by Research Project of Sichuan University of Science&Engineering(No.2011RC12,2014KY02)Scientific Research Foundation of the Education Department of Sichuan Province(No.15ZA0222)Research Project of Liquor-marking Biological Technology and Application of Key Laboratory of Sichuan Province(NJ2013-06)
文摘[Objective]This study aimed to improve the yield of bacteriocins from lactic acid bacteria by optimizing the fermentation process for production of bacteriocins from lactic acid bacteria.[Method]By single-factor analysis,fermentation temperature,seed age,inoculation volume,fermentation duration and fermentation media p H were optimized to determine the best fermentation process.The inhibitory zone of bacteriocins from lactic acid bacteria was analyzed with oxford cup method,based on which the fermentation process was evaluated.[Result]The optimal fermentation process was optimized：fermentation temperature 37℃,seed age 14 h,inoculation volume 2%,fermentation duration 48 h,fermentation media p H 5.0.[Conclusion]Under the optimized fermentation conditions,the yield of bacteriocins from lactic acid bacteria was improved significantly.
基金supported by the following project funds:1.Liupao tea processing technology optimization supported by Wuzhou Academy of Agricultural Sciences(No.H20496)supported by Wuzhou Tea Industry Development Service Center(No.H220644),Wuzhou 543003,China。
文摘Summer green tea(SGT)is not favored by consumers due to its strong bitterness and astringency.This study aims to improve the taste of SGT using tea-derived fungi isolated from Liupao tea by solid-state fermentation.Based on 19 detected main compounds,principal component analysis(PCA)and hierarchical cluster analysis(HCA)showed Aspergillus sydowii,Penicillium manginii,Aspergillus intermedius,Aspergillus amstelodami,and Aspergillus niger groups were clustered together with significant differences from the control.Additionally,metabolomics analysis showed P.manginii,A.intermedius,and A.amstelodami strains could reduce the chemical components associated with bitter and astringent flavors,such as epicatechin gallate,epicatechin,(+)-gallocatechin,quercetin,kaempferol,myricetin,procyanidin B2,L-phenylalanine and its glycoside derivatives(VIP>1,P<0.05),and increase the contents of theabrownins associated with umami taste(P<0.05).In summary,the taste of SGT can be improved by the above fungi fermentation.
基金supported by the Key R&D projects in Sichuan Province[Grant No.2020YFN0151]the Natural Science Foundation Program of Sichuan Province[Grant No.2022NSFSC1705].
文摘The effects of natural fermentation and inoculation fermentation on the volatile flavor substances of pickled ginger was studied.High-throughput sequencing and gas chromatographic-mass spectrometry were used to measure the bacterial community changes and its flavour compounds during one to six days’fermentation.First,55 and 51 volatile compounds were detected in the natural and the Lactiplantibacillus plantarum-inoculated fermentation samples,respectively.Alkenes,alcohols,aldehydes and esters were the main volatile components of both types of fermented ginger,but their contents were different.Then,40 and 43 bacterial genera were detected in the natural and inoculation fermented gingers,respectively,including 15 major bacterial genera such as Lactobacillus.However,the abundance of bacterial genera in the samples was different.The correlation analysis showed that a total of 43 bacterial genera had medium to high correlations with 49 volatile flavor compounds(|ρ|>0.6),including one aldehyde,two ketones,five esters,nine alcohols and 32 olefins.The comprehensive results showed that,compared with natural fermentation,inoculation fermentation could change the abundance of bacteria in pickled ginger,thereby improving the volatile flavor compounds of this popular product.
基金supported by the’Nan Hai Xin Xing’Science and Technology Innovation Talent Platform Project Funding of Hainan Province(NHXXRCXM202312)Hainan University Scientific Research Start-up Fund Project(Grant No.XJ2300006565).
文摘Spontaneous fermentation of young ginger pickles(YGP)involves numerous indigenous microbes from raw materials and the environments,while inoculated fermentation is an ideal strategy for standardizing YGP production and improving quality.This study investigated the effects of exogenous inoculation with Lactiplantibacillus plantarum ATCC 8014 on the quality characteristics and metabolic profile of YGP.It particularly explored the response of indigenous microbes,focusing on their interactions and metabolic characteristics in relation to exogenously inoculated microbes.The results indicated that L.plantarum inoculation significantly increased organic acid levels,while decreasing nitrite content during YGP fermentation.In addition,L.plantarum-inoculated YGP exhibited increased Lactiplantibacillus abundance and significant alterations in color and texture characteristics when compared to naturally fermented YGP.Beta diversity analysis revealed improved similarity of fermented microbial community structure,while co-occurrence network analysis showed that L.plantarum inoculation increased interaction complexity,the positive correlation ratio,and the number of keystone taxa,particularly strengthening the symbiotic relationships among LAB.Furthermore,a total of 27 volatile and 29 non-volatile differential metabolites were identified between inoculated and uninoculated YGP.These differential metabolites were linked to the degradation of valine,leucine,and isoleucine,as well as pyruvate metabolism and glycolysis/gluconeogenesis pathways.Correlation network analysis suggested that the differential LAB significantly enhanced the quality attributes and metabolic profiles of YGP,likely due to the driving effects of L.plantarum on the symbiotic relationships among indigenous LAB.Overall,these findings provided valuable insights into the management of YGP fermentation and the standardization of its quality.
