Isolation and characterization of high level butanol producing bacterium Clostridium beijerinckii AC2

Biobutanol is a type of biofuel that can be used as a direct substitute for gasoline. Therefore, development in biobutanol production is ongoing, focusing on improving the efficiency of microbial strains. Naturally occurring strains often have low butanol yields. In this study, a novel bacterium was discovered to produce high titers of butanol for sustainable biofuel. The isolate, identified as Clostridium beijerinkii strain AC2, showed significantly higher butanol production compared to well-known wild-type strains C. beijerinkii ATCC 10132 and C. acetobutylicum ATCC 824. The maximum butanol production from C. beijerinkii AC2 was 30.21±2.32 g/L, significantly different at p ≤ 0.05 from C. beijerinkii ATCC 10132 and C. acetobutylicum ATCC 824, which produced 17.13±2.65 g/L and 16.56±2.54 g/L, respectively, using 100 g/L glucose under pH 7.0 and 37°C for 7 days. Moreover, C. beijerinkii AC2 showed a higher level of butanol tolerance at 50 g/L compared to 25 g/L and 20 g/L for C. beijerinkii ATCC 10132 and C. acetobutylicum ATCC 824, respectively. Enhancing butanol production in strain AC2 is possible. Therefore, the significance and impact of the study suggest that C. beijerinkii AC2 may be capable of producing elevated levels of butanol under suitable conditions.