Adaptation of lactic acid bacteria to butanol

Butanol can be produced biologically through fermentation of various substrates by Gram-positive Clostridium species. However, to profitably produce butanol at industrial scales, new microbial biocatalysts with increased tolerance to butanol are needed. In this study we report the isolation and selection of microbes to butanol. Ten strains, including Lactobacillus mucosae strains BR0605-3, BR0605-B15, BR0713-18, BR0713-20, BR0713-30, BR0713-33, Lactobacillus amylovorus strain NE-L 0206-19, Pediococcus parvulus NE-L 0206-31, Lactobacillus crispatus NE-L 0206-47, and Weissella confusa BR0216-18 were found capable of growth in 3–4% butanol after long term adaptation. These strains can be used to study tolerance mechanisms as well as identifying specific butanol stress response genes for development of butanol tolerant microbes.