脱脂乳中苏氨酸的浓度对嗜热链球菌乙醛产量及glyA基因表达的影响  

Expression analysis of the glyA gene encoding serine hydroxymethyltransferase(SHMT) with threonine aldolase activity in Streptococcus thermophilus S13-6

作　　者：丹彤[1] 张和平[1] 

机构地区：[1]内蒙古农业大学乳品生物技术与工程教育部重点实验室,呼和浩特010018

出　　处：《中国乳品工业》2013年第2期4-6,共3页China Dairy Industry

基　　金：内蒙古自然科学基金开放课题(20102010)

摘　　要：这项研究以在酸奶发酵过程中产生良好风味Streptococcus thermophilus S13-6为实验菌株,考察了脱脂乳中苏氨酸的浓度对乙醛产量及glyA基因(编码丝氨酸羟甲基转移酶)表达的影响。结果表明,随着脱脂乳中苏氨酸浓度的增加,S13-6菌株的乙醛的产量和glyA基因的表达量明显增加。说明丝氨酸羟甲基转移酶在S13-6菌株的乙醛代谢过程中发挥着重要作用。In this study, Streptococcus thermophilus $13-6 strains with good flavor-enhancing property were investigated to evaluate the acetalde- hyde production as well as the expression ofglyA gene. The results showed that acetaldehyde production was linear with increasing L-threo- nine levels in the fermented milk. Further, quantitative real-time PCR analysis showed that the glyA gene was upregulated in the fermented milk in the presence of L-threonine. Understanding the degradation pathway from threonine to glycine and acetaldehyde can be applied to control and improve acetaldehyde production in fermented products with S. thermophilus as the starter culture.

关 键 词：乙醛 嗜热链球菌 GLYA 基因表达 

分 类 号：Q93-33[生物学—微生物学]