【摘 要】
：
以一株L-亮氨酸生产菌谷氨酸棒杆菌(Corynebacterium glutamicum)CP为研究对象,研究高活性磷酸转酮酶(PKT,fxpk编码)的表达对其产酸的影响.首先研究过表达PKT对C.glutamicum CP产酸的影响,副产物L-丙氨酸的积累减少.通过删除ltbR(leucine and tryptophan biosynthesis regulator),插入Ptuf-fxpk表达盒,弱化gltA(编码柠檬酸合酶)的表达,获得菌株C.glutamicum CPΔltbR∷Ptuf-fxp
【机 构】
：
天津科技大学生物工程学院,天津300457;代谢控制发酵技术国家地方联合工程实验室,天津300457;天津科技大学生物工程学院,天津300457
论文部分内容阅读
以一株L-亮氨酸生产菌谷氨酸棒杆菌(Corynebacterium glutamicum)CP为研究对象,研究高活性磷酸转酮酶(PKT,fxpk编码)的表达对其产酸的影响.首先研究过表达PKT对C.glutamicum CP产酸的影响,副产物L-丙氨酸的积累减少.通过删除ltbR(leucine and tryptophan biosynthesis regulator),插入Ptuf-fxpk表达盒,弱化gltA(编码柠檬酸合酶)的表达,获得菌株C.glutamicum CPΔltbR∷Ptuf-fxpkΔPgltA∷PdapA,其生长速率下降,L-亮氨酸的产量(53.0 g/L)提高10.0％,同时副产物L-丙氨酸减少33.3％,转化率提高23.5％.本研究获得L-亮氨酸的工程菌,较出发菌具有一定优势.
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