A direct comparison of approaches for increasing carbon flow to aromatic biosynthesis in Escherichia coli
A direct comparison of approaches for increasing carbon flow to aromatic biosynthesis in Escherichia coli
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DOI：
10.1007/bf01570148
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发表时间：
1996-07-01
期刊：
影响因子：
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通讯作者：
Berry, A
中科院分区：
文献类型：
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作者：
Gosset, G;YongXiao, J;Berry, A
在大肠杆菌等基因株中比较了增加芳香族氨基酸生物合成碳承诺的不同方法。在具有野生型PEP：葡萄糖磷酸转移酶（PTS）系统的菌株中，编码丙酮酸激酶（pykA和pykF）的基因的失活导致流向芳香族生物合成的碳增加3.4倍。在已经由于tktA基因（编码转酮醇酶）的过表达而增加了向芳烃的碳流的菌株中，pykA和/或pykF突变没有影响。与PTS+对照菌株相比，PTS-葡萄糖（+）突变体显示出向芳烃的碳流增加1.6倍。在PTS-葡萄糖（+）宿主背景中，tktA的过表达引起碳流进一步增加3.7倍，而pykA和pykF的失活引起5.8倍增加。当所有测试的变量（PTS-葡萄糖（+）、pykA、pykF和过表达的tktA）在单个菌株中组合时，实现了芳香族生物合成的碳承诺增加19.9倍。
Different approaches to increasing carbon commitment to aromatic amino acid biosynthesis were compared in isogenic strains of Escherichia coli. In a strain having a wild-type PEP:glucose phosphotransferase (PTS) system, inactivation of the genes encoding pyruvate kinase (pykA and pykF) resulted in a 3.4-fold increase in carbon flow to aromatic biosynthesis. In a strain already having increased carbon flow to aromatics by virtue of overexpression of the tktA gene (encoding transketolase), the pykA and/or pykF mutations had no effect. A PTS- glucose(+) mutant showed a 1.6-fold increase in carbon flow to aromatics compared to the PTS+ control strain. In the PTS- glucose(+) host background, overexpression of tktA caused a further 3.7-fold increase in carbon flow, while inactivation of pykA and pykF caused a 5.8-fold increase. When all of the variables tested (PTS- glucose(+), pykA, pykF, and overexpressed tktA) were combined in a single strain, a 19.9-fold increase in carbon commitment to aromatic biosynthesis was achieved.