Kogure Takahisa, Wakisaka Naoki, Takaku Hiroaki, Takagi Masamichi
Faculty of Applied Life Sciences, Niigata University of Pharmacy and Applied Life Sciences, Higashijima 265-1, Niitsu, Niigata 956-8603, Japan.
J Biotechnol. 2007 May 1;129(3):502-9. doi: 10.1016/j.jbiotec.2007.01.016. Epub 2007 Jan 30.
2-Deoxy-scyllo-inosose (DOI) is a six-membered carbocycle formed from d-glucose-6-phosphate catalyzed by 2-deoxy-scyllo-inosose synthase (DOIS), a key enzyme in the biosynthesis of 2-deoxystreptamine-containing aminocyclitol antibiotics. DOI is valuable as a starting material for the benzene-free synthesis of catechol and other benzenoids. We constructed a series of metabolically engineered Escherichia coli strains by introducing a DOIS gene (btrC) from Bacillus circulans and disrupting genes for phosphoglucose isomerase, d-glucose-6-phosphate dehydrogenase, and phosphoglucomutase (pgi, zwf and pgm, respectively). It was found that deletion of the pgi gene, pgi and zwf genes, pgi and pgm genes, or all pgi, zwf and pgm genes significantly improved DOI production by recombinant E. coli in 2YTG medium (3% glucose) up to 7.4, 6.1, 11.6, and 8.4 g l(-1), respectively, compared with that achieved by wild-type recombinant E. coli (1.5 g l(-1)). Moreover, E. coli mutants with disrupted pgi, zwf and pgm genes showed strongly enhanced DOI productivity of up to 29.5 g l(-1) (99% yield) in the presence of mannitol as a supplemental carbon source. These results demonstrated that DOI production by metabolically engineered recombinant E. coli may provide a novel, efficient approach to the production of benzenoids from renewable d-glucose.
2-脱氧-scyllo-肌醇(DOI)是一种六元碳环,由2-脱氧-scyllo-肌醇合酶(DOIS)催化d-葡萄糖-6-磷酸形成,DOIS是含2-脱氧链霉胺的氨基环醇抗生素生物合成中的关键酶。DOI作为无苯合成儿茶酚和其他苯类化合物的起始原料具有重要价值。我们通过引入来自环状芽孢杆菌的DOIS基因(btrC)并破坏磷酸葡萄糖异构酶、d-葡萄糖-6-磷酸脱氢酶和磷酸葡萄糖变位酶(分别为pgi、zwf和pgm)的基因,构建了一系列代谢工程改造的大肠杆菌菌株。结果发现,与野生型重组大肠杆菌(1.5 g l⁻¹)相比,缺失pgi基因、pgi和zwf基因、pgi和pgm基因或所有pgi、zwf和pgm基因,可使重组大肠杆菌在2YTG培养基(3%葡萄糖)中DOI产量显著提高,分别达到7.4、6.1、11.6和8.4 g l⁻¹。此外,在以甘露醇作为补充碳源的情况下,pgi、zwf和pgm基因被破坏的大肠杆菌突变体显示出高达29.5 g l⁻¹(99%产率)的DOI生产力显著增强。这些结果表明,通过代谢工程改造的重组大肠杆菌生产DOI可能为从可再生的d-葡萄糖生产苯类化合物提供一种新颖、高效的方法。