摘要
乙偶姻是枯草芽孢杆菌的主要代谢产物,它作为一种食用香精,广泛应用于食品、烟草、化妆品、清洁剂、酒类等行业。本研究首先在不产芽孢的枯草芽孢杆菌(BSD1,阻断了芽孢的合成途径)中敲除了2,3-丁二醇脱氢酶(BDH)的编码基因bdh A、乳酸脱氢酶(LDH)的编码基因ldh和乙酸激酶的编码基因(ACK)ack A,随后克隆了来自菌株B.subtilis168的α-乙酰乳酸合成酶(ALS)和α-乙酰乳酸脱羧酶(ALDC)基因als S和als D,并将其在上述敲除菌中过量表达,结果表明阻断副产物合成途径和加强乙偶姻合成途径关键酶的表达,会显著提高乙偶姻的产量,最终乙偶姻产量达到38.08 g/L,产率为0.45 g·L^(-1)·h^(-1),产率提高了约87.5%。
Acetoin,a major extracellular catabolic product of Bacillus subtilis,has been extensively applied in varied fields such as food,alcohol,detergent,tobacco and cosmetic industries,and so on.In this study we inactivated 2,3-butanediol dehydrogenase（BDH）,lactate dehydrogenase（LDH）and acetate kinase（ACK）in sporulation-deficient B.subtilis strain（BSD1,in which spore synthetic pathway was blocked）firstly,then cloned alsS and alsD from the enzymesα-acetolactate synthetase（ALS） and α-acetolactate decearboxylase（ALDC）,both encoded by alsSD operon,which were over-expressed in the recombinant strain.The results illustrated that it was an effective way to enhance acetion yield by eliminating byproducts and overexpressing key enzymes of acetoin biosynthetic pathway.Finally,by shake flask fermentation,the recombinant B.subtilis produced 38.08 g/L acetoin,with a productivity of 0.45 g·L-1·h-1,which increased by 87.5% compared to control.
出处
《基因组学与应用生物学》
CAS
CSCD
北大核心
2017年第12期5159-5166,共8页
Genomics and Applied Biology
基金
国家自然科学基金(31500065
31400082)
国家高技术研究发展计划(863计划)(2015AA021004)
江苏省青年自然科学基金(BK20150142)
中国博士后科学基金资助项目(2015M570407
2016T90421)
江苏高校优势学科建设工程资助项目共同资助
