초록
<P>Isoprene, as a versatile bulk chemical, has wide industrial applications. Here, we attempted to improve isoprene biosynthesis in <I>Saccharomyces cerevisiae</I> by simultaneous strengthening of precursor supply and conversion <I>via</I> a combination of pathway compartmentation and protein engineering. At first, a superior isoprene synthase mutant ISPSLN was created by saturation mutagenesis, leading to almost 4-fold improvement in isoprene production. Subsequent introduction of ISPSLN to strains with strengthened precursor supply in either cytoplasm or mitochondria implied an imperfect match between the synthesis and conversion of the isopentenyl pyrophosphate (IPP)/dimethylallyl diphosphate (DMAPP) pool. To reconstruct metabolic balance between the upstream and downstream flux, additional copies of diphosphomevalonate decarboxylase gene (<I>MVD1</I>) and isopentenyl-diphosphate delta-isomerase gene (<I>IDI1</I>) were introduced into the cytoplasmic and mitochondrial engineered strains. Finally, the diploid strain created by mating the above haploid strains produced 11.9 g/L of isoprene, the highest ever reported in eukaryotic cells.</P><BR>[FIG OMISSION]</BR>