Chromosomal integration of the pSOL1 megaplasmid of Clostridium acetobutylicum for continuous and stable advanced biofuels production

Biofuel production by Clostridium acetobutylicum is compromised by strain degeneration due to loss of its pSOL1 megaplasmid. Here we used engineering biology to stably integrate pSOL1 into the chromosome together with a synthetic isopropanol pathway. In a membrane bioreactor continuously fed with glucose mineral medium, the final strain produced advanced biofuels, n -butanol and isopropanol, at high yield (0.31 g g −1 ), titre (15.4 g l −1 ) and productivity (15.5 g l −1 h −1 ) without degeneration. The stable integration of a 192 kb plasmid into the chromosome of Clostridium acetobutylicum by a synthetic biology approach enables continuous production of n -butanol.