초록 |
Two-amino-4-hydroxybutanoic acid (i.e., homoserine), is not only a microbial metabolite but also a valuable building block for synthesis of various chemical compounds. Several by-product pathways were disrupted and several enzymes related to homoserine production were up-regulated in Escherichia coli. By modifying the glucose uptake system, cell growth and glucose consumption could be partially restored in the mutant strain. Furthermore, by up-regulation of phosphoenolpyruvate carboxylase, carbon flux was more diverted to homoserine and acetate production was more reduced. One new mutant strain having mutations in >12 genes could produce 2 g/L homoserine in flask culture. |