Chromosomal engineering of inducible isopropanol- butanol-ethanol production in .

The use of environmentally damaging petrochemical feedstocks can be displaced by fermentation processes based on engineered microbial chassis that recycle biomass-derived carbon into chemicals and fuels. The stable retention of introduced genes, designed to extend product range and/or increase productivity, is essential. Accordingly, we have created multiply marked auxotrophic strains of that provide distinct loci (, , , ) at which heterologous genes can be rapidly integrated using allele-coupled exchange (ACE).