酿酒酵母芳香族氨基酸合成途径相关基因对细胞SDS耐受性的影响

Effects of Aromatic Amino Acid Biosynthesis Pathway Related Genes on SDS Tolerance in Saccharomyces cerevisiae

酿酒酵母中芳香族氨基酸合成途径对于生产多种芳香族精细化学品至关重要,其中间产物如扁桃酸和4-羟基扁桃酸是重要的精细化学品,在食品、医药、饮料和化妆品等领域具有广泛应用。为了探索酿酒酵母中芳香族氨基酸合成途径及其基因调控机制和中间产物的合成途径,作者总结了从葡萄糖到芳香族氨基酸的完整合成路径及分支,并归纳了参与此过程的14个基因及其在细胞内的功能。在对其中12个基因的单基因缺失菌株进行十二烷基硫酸钠(sodium dodecyl sulfate,SDS)表型检测时,发现aro2/aro2、aro1/aro1、aro7/aro7、trp1/trp1和trp5/trp5这5个缺失菌株对质量分数0.03%的SDS表现出明显的敏感表型。对这几个敏感菌株进行了细胞内活性氧(reactive oxygen species,ROS)测定,发现与野生型相比,aro1/aro1、aro7/aro7和trp1/trp1菌株的细胞内ROS水平显著升高。酿酒酵母中整个芳香族氨基酸合成途径及其分支受到严格的基因调控,对这些基因功能的系统研究,为提高芳香族精细化学品的生物合成产量和酿酒酵母基因组学研究提供理论基础。

The aromatic amino acid synthesis pathway in Saccharomyces cerevisiae is very important for the production of many aromatic fine chemicals.Mandelic acid and 4-hydroxymandelic acid like intermediates are vital fine chemicals,which are widely used in foods,medicines,beverages and cosmetics.In order to explore the gene regulation mechanism in aromatic amino acid synthesis pathway in S.cerevisiae to explore the synthesis pathway of aromatic intermediates,this study summarized the whole aromatic amino acid synthesis pathway and its branches from glucose in S.cerevisiae,it also lists 14 genes and intracellular functions involved in the whole process.The phenotypes of 12 single gene deletion strains were detected in sodium dodecyl sulfate(SDS),while 5 deletion strains,including aro2/aro2,aro1/aro1,aro7/aro7,trp1/trp1 and trp5/trp5,showed obvious sensitive phenotypes to 0.03%SDS.Moreover,the intracellular reactive oxygen species(ROS)levels of five sensitive strains were measured.Results showed that the intracellular ROS levels of aro1/aro1,aro7/aro7 and trp1/trp1 strains were significantly increased,compared with the wild-type strain.The whole aromatic amino acid synthesis pathway and its branches in S.cerevisiae were strictly regulated by genes.A systematic study of these genes functions will provide a theoretical basis for a high-yield biosynthesis of aromatic fine chemicals and genomics of S.cerevisiae.