酸奶后酸化中保加利亚乳杆菌关键基因表达分析
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摘要
酸奶中的乳酸菌能将大分子蛋白质分解成人体易吸收的小分子营养物质,这对人体具有很重要的保健功能,然而酸奶的后酸化问题不仅严重影响风味,还大大缩短了酸奶的货架期,阻碍了我国酸奶行业的发展。研究证明,控制保加利亚乳杆菌在酸奶发酵后期的生长代谢,是解决酸奶后酸化的关键。本文在研究模式菌株保加利亚乳杆菌ATCC 11842在复原脱脂乳培养基中生长和产酸特性的基础上,利用半定量RT-PCR技术,分析酸奶后酸化中保加利亚乳杆菌不同时期关键基因表达的差异,选取后酸化过程中表达变化明显的丙糖异构酶基因,通过对该基因的过量表达,探究该基因在酸奶后酸化过程中的功能。结果表明,大多数关键基因受到后酸化的影响而上调或下调,其中丙糖异构酶基因过量表达后影响菌株产酸和生长。
The proteins can be enzymatic hydrolysis into small molecules of nutrients which are easy absorbed by human by lactic acid bacteria in yoghurt. However the post-acidification of yogurt not only seriously affects the flavor,also greatly shortens the shelf life, which hinders the development of the yogurt industry in China. Previous studies indicated that controlling the growth of Lactobacillus delbrueckii subsp. bulgaricus in the late fermentation stage is the key to solve this problem. In this study, we detected the growth and characteristics of acid-producing of the model strain Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842 cultivating in RSM. When the strain fermented in skim milk,the expression of the key genes in different fermentation periods was analyzed by the semi-quantitative RT-PCR technology. The tpi A gene was selected which expression level is significantly different and through over-expression of the gene,its function related to yogurt postacidification was explored. The results showed that most of the key genes were up-regulated or down-regulated by the effect of post-acidification, and over-expression of the tpi A gene affected the acid production and growth of the strain.
The proteins can be enzymatic hydrolysis into small molecules of nutrients which are easy absorbed by human by lactic acid bacteria in yoghurt. However the post-acidification of yogurt not only seriously affects the flavor,also greatly shortens the shelf life, which hinders the development of the yogurt industry in China. Previous studies indicated that controlling the growth of Lactobacillus delbrueckii subsp. bulgaricus in the late fermentation stage is the key to solve this problem. In this study, we detected the growth and characteristics of acid-producing of the model strain Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842 cultivating in RSM. When the strain fermented in skim milk,the expression of the key genes in different fermentation periods was analyzed by the semi-quantitative RT-PCR technology. The tpi A gene was selected which expression level is significantly different and through over-expression of the gene,its function related to yogurt postacidification was explored. The results showed that most of the key genes were up-regulated or down-regulated by the effect of post-acidification, and over-expression of the tpi A gene affected the acid production and growth of the strain.
引文
[1]戚晨晨,古丽奴尔·吐拉西.乳酸菌纯种发酵制备发酵型泡菜的研究进展[J].农产品加工,2013,322(7):50-51.
[2]PLESSAS S,ALEXOPOULOS A,MANTZOURANI I,et al.Application of novel starter cultures for sourdough bread production[J].Anaerobe,2011,17(6):486-489.
[3]ZHU Y,ZHANG Y,LI Y.Understanding the industrial application potential of lactic acid bacteria through genomics[J].Applied Microbiology and Biotechnology,2009,83(4):597-610.
[4]单晓丽,程敏,孙涛,等.货架期内搅拌型酸奶中乳酸菌的检测及其质量分析[J].食品与发酵科技,2010,46(4):82-84.
[5]WANG J,ZHANG W,ZHONG Z,et al.Gene expression profile of probiotic Lactobacillus casei Zhang during the late stage of milk fermentation[J].Food Control,2012,25(1):321-327.
[6]CASAROTTI S N,MONTEIRO D A,MORETTI M M S,et al.Influence of the combination of probiotic cultures during fermentation and storage of fermented milk[J].Food Research International,2014,59:67-75.
[7]孟令帅,徐鑫,刘倩颖,等.市售酸奶在贮存期间品质变化分析[J].食品与发酵工业,2014,40(7):161-165.
[8]CUI Y,LIU W,QU X,et al.A two component system is involved in acid adaptation of Lactobacillus delbrueckii subsp.bulgaricus[J].Microbiological Research,2012,167(5):253-261.
[9]曲晓军,崔艳华.德氏乳杆菌保加利亚亚种耐酸机制[J].中国乳品工业,2012,40(6):50-52.
[10]FERNANDEZ A,OGAWA J,PENAUD S,et al.Rerouting of pyruvate metabolism during acid adaptation in Lactobacillus bulgaricus[J].Proteomics,2008,8(15):3154-3163.
[11]ZHAI Z,DOUILLARD F P,AN H,et al.Proteomic characterization of the acid tolerance response in Lactobacillus delbrueckii subsp.bulgaricus CAUH1 and functional identification of a novel acid stress-related transcriptional regulator Ldb0677[J].Environmental Microbiology,2014,16(6):1524-1537.
[12]PENAUD S,FERNANDEZ A,BOUDEBBOUZE S,et al.Induction of Heavy-Metal-Transporting CPX-Type ATPases during acid adaptation in Lactobacillus bulgaricus[J].Applied and Environmental Microbiology,2006,72(12):7445-7454.
[13]DARYAEI H,COVENTRY J,VERSTEEG C,et al.Effects of high pressure treatment on glycolytic enzymes of Lactococcus lactis subsp.lactis,Streptococcus thermophilus and Lactobacillus acidophilus[J].Innovative Food Science&Emerging Technologies,2010,11(2):245-249.
[2]PLESSAS S,ALEXOPOULOS A,MANTZOURANI I,et al.Application of novel starter cultures for sourdough bread production[J].Anaerobe,2011,17(6):486-489.
[3]ZHU Y,ZHANG Y,LI Y.Understanding the industrial application potential of lactic acid bacteria through genomics[J].Applied Microbiology and Biotechnology,2009,83(4):597-610.
[4]单晓丽,程敏,孙涛,等.货架期内搅拌型酸奶中乳酸菌的检测及其质量分析[J].食品与发酵科技,2010,46(4):82-84.
[5]WANG J,ZHANG W,ZHONG Z,et al.Gene expression profile of probiotic Lactobacillus casei Zhang during the late stage of milk fermentation[J].Food Control,2012,25(1):321-327.
[6]CASAROTTI S N,MONTEIRO D A,MORETTI M M S,et al.Influence of the combination of probiotic cultures during fermentation and storage of fermented milk[J].Food Research International,2014,59:67-75.
[7]孟令帅,徐鑫,刘倩颖,等.市售酸奶在贮存期间品质变化分析[J].食品与发酵工业,2014,40(7):161-165.
[8]CUI Y,LIU W,QU X,et al.A two component system is involved in acid adaptation of Lactobacillus delbrueckii subsp.bulgaricus[J].Microbiological Research,2012,167(5):253-261.
[9]曲晓军,崔艳华.德氏乳杆菌保加利亚亚种耐酸机制[J].中国乳品工业,2012,40(6):50-52.
[10]FERNANDEZ A,OGAWA J,PENAUD S,et al.Rerouting of pyruvate metabolism during acid adaptation in Lactobacillus bulgaricus[J].Proteomics,2008,8(15):3154-3163.
[11]ZHAI Z,DOUILLARD F P,AN H,et al.Proteomic characterization of the acid tolerance response in Lactobacillus delbrueckii subsp.bulgaricus CAUH1 and functional identification of a novel acid stress-related transcriptional regulator Ldb0677[J].Environmental Microbiology,2014,16(6):1524-1537.
[12]PENAUD S,FERNANDEZ A,BOUDEBBOUZE S,et al.Induction of Heavy-Metal-Transporting CPX-Type ATPases during acid adaptation in Lactobacillus bulgaricus[J].Applied and Environmental Microbiology,2006,72(12):7445-7454.
[13]DARYAEI H,COVENTRY J,VERSTEEG C,et al.Effects of high pressure treatment on glycolytic enzymes of Lactococcus lactis subsp.lactis,Streptococcus thermophilus and Lactobacillus acidophilus[J].Innovative Food Science&Emerging Technologies,2010,11(2):245-249.