Consolidated processing of biobutanol production from food wastes by solventogenic Clostridium sp. strain HN4

In this study, biobutanol production from glucose, starch and food waste by newly identified Clostridium sp. strain HN4 was comprehensively investigated, which is capable of secreting amylase indigenously for the following acetone-butanol-ethanol fermentation. With pH adjustment, strain HN4 could produce 5.23 g/L of butanol from 60 g/L of starch with secretion of 1.95 U/mL amylase through consolidated bioprocessing. Further supplementation of 3 g/L of CaCO3 and 0.5% non-ionic surfactant of Tween 80 could stimulate both amylase activities and the final butanol titer, leading to 17.64 g/L of butanol with yield of 0.15 g/g. Fed batch fermentation integrated with in situ removal could further improve the butanol titer to 35.63 g/L with yield of , representing the highest butanol production and yield from food waste. These unique features of Clostridium sp. strain HN4 could open the door to the possibility of cost-effective biobutanol production from food waste on a large scale.