메탄올자화균 Methylobacterium extorquens AM1의 phaR 유전자 결실을 통한 poly 3-hydroxybutyrate (PHB) 생합성 억제

초록

Methylotrophy is able to use reduced one-carbon compound, such as methanol and methylamine, as a sole carbon source. Methylobacterium extorquens AM1 is the most extensively studied methylotroph utilizing serine-isocitrate lyase cycle. Because the Poly 3-hydroxybutyrate (PHB) synthesis pathway in M. extorquens AM1 is likely to interlink with EMCP (ethylmalonyl-CoA pathway), glyoxylate, and TCA cycles, regulation of PHB production is needed to produce EMCP-derived acid or TCA acids. To adjust carbon flux to PHB production, PhaR, which seems to have function of regulator of PHB synthesis and acetyl-CoA flux, was knocked out in M. extorquens AM1 by using markerless gene deletion methods. As a result, PHB granules were remarkably reduced in the knockout strain ΔphaR compared to parental strain. Although lag phase was extended for 12h, ΔphaR showed similar cell growth and methanol consumption rate compared to wild type.

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