초록
<P><B>Abstract</B></P><P><B>Aims</B></P><P>To establish the biotechnology platforms for production of bio‐based chemicals in various micro‐organisms is considered as a promising target to improve renewable production of isoprene.</P><P><B>Methods and Results</B></P><P>In this study, we heterologously expressed the mevalonate (MVA) isoprene biosynthesis pathway, and explored three strategies of increasing isoprene production in <I>Escherichia coli</I>. We first manipulated the expression levels of the MVA pathway genes through changing the gene cassettes and promoters. To introduce cofactor engineering, we then overexpressed NADP‐dependent glyceraldehyde‐3‐phosphate dehydrogenase gene from <I>Clostridium acetobutylicum</I> to supply available NADPH. To reduce the inhibitory by‐product accumulation, we finally knocked out acetate‐producing genes, phosphate acetyl transferase and pyruvate oxidase B in <I>E. coli</I>JM109 (DE3), decreasing acetate accumulation 89% and increasing isoprene production 39%. The strategies described here finally increased the isoprene titre to 92 mg l<SUP>−1</SUP> in two‐gene deletion strain JMAB‐4T7P1Trc, increasing 2·6‐fold comparing to strain JM7T7.</P><P><B>Conclusion</B></P><P>The multimodularly engineering approaches including promoter engineering, cofactor engineering and by‐product reducing could be used to improve isoprene production in <I>E. coli</I>.</P><P><B>Significance and Impact of the Study</B></P><P>The metabolic strategies in this study show us directions for further studies to promote transformation of renewable sources to isoprene.</P>