天津科技大学学报2017，Vol.32Issue(6)：15-20,25,7.DOI:10.13364/j.issn.1672-6510.20160152
乙酸激酶编码基因缺失的L–色氨酸生产菌株的理性构建
Rational Construction of Mutants without Acetate Kinase for L-Tryptophan Production
摘要
Abstract
To deal with the high concentration of acetate accumulated inL-tryptophan production by usingEscherichia coli TRTH,genes encoded with acetate kinase were analyzed with genomic methods and the results induicate that the complete sequence ofackA or/andtdcD existed inE.coli TRTH.Three mutants TRTHA(TRTH,ΔackA),TRTHT(TRTH,ΔtdcD)and TRTHAT(TRTH,ΔackA ΔtdcD)were constructed by deletingackA or/andtdcD,and the effect ofackA or/and tdcD deletion onL-tryptophan fermentation was investigated.The results indicate that the deletion ofackA or/andtdcDde-creased the accumulation of acetate,increased the biomass and the production ofL-tryptophan,but increased the concentra-tion of glutamate.The biomass and production ofL-tryptophan obtained with TRTHA were higher than those with TRTHT.Compared with TRTH,the highest biomass(47.48,g/L),the production ofL-tryptophan(40.52,g/L)and the glucose conversion rate(15.44%,)of TRTHAT increased by 6.03%,,7.94%, and 7.82%, respectively;the accumulation of ace-tate(1.41,g/L)and glutamate(8.58,g/L)decreased by 10.19%, and increased by 12.15%, respectively.Analysis of metabolic flux distribution of TRTH and TRTHAT indicates that the flux of acetate in TRTHAT was decreased by 72.78%, and the flux of glutamate in TRTHAT was increased by 13.13%, compared with TRTH,and the flux of tryptophan biosynthesis of TRTHAT was 1.74-times of that of TRTH.关键词
大肠杆菌/L–色氨酸/基因组学/乙酸激酶/代谢流分析Key words
Escherichia coli/L-tryptophan/genomics/acetate kinase/analysis of metabolic flux分类
生物科学引用本文复制引用
赵春光,徐庆阳,张成林,陈宁..乙酸激酶编码基因缺失的L–色氨酸生产菌株的理性构建[J].天津科技大学学报,2017,32(6):15-20,25,7.基金项目
国家高技术研究发展计划(863计划)资助项目(2012AA02A703) （863计划）
