title: Development of butanol-tolerant Bacillus subtilis strain GRSW2-B1 as a potential bioproduction host.
abstract: As alternative microbial hosts for butanol production with organic-solvent tolerant trait are in high demands, a butanol-tolerant bacterium, Bacillus subtilis GRSW2-B1, was thus isolated. Its tolerance covered a range of organic solvents at high concentration (5%v/v), with remarkable tolerance in particular to butanol and alcohol groups. It was susceptible for butanol acclimatization, which resulted in significant tolerance improvement. It has versatility for application in a variety of fermentation process because it has superior tolerance when cells were exposed to butanol either as high-density, late-exponential grown cells (up to 5%v/v) or under growing conditions (up to 2.25%v/v). Genetic transformation procedure was optimized, yielding the highest efficiency at 5.17 × 103 colony forming unit (μg DNA)-1. Gene expression could be effectively driven by several promoters with different levels, where as the highest expression was observed with a xylose promoter. The constructed vector was stably maintained in the transformants, in the presence or absence of butanol stress. Adverse effect of efflux-mediated tetracycline resistance determinant (TetL) to bacterial organic-solvent tolerance property was unexpectedly observed and thus discussed. Overall results indicate that B. subtilis GRSW2-B1 has potential to be engineered and further established as a genetic host for bioproduction of butanol.
authors: Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand. alisa.v@chula.ac.th.
authors: Naoya
authors: N
authors: Kataoka
authors: Takahisa
authors: T
authors: Tajima
authors: Junichi
authors: J
authors: Kato
authors: Wanitcha
authors: W
authors: Rachadech
authors: Alisa S
authors: AS
authors: Vangnai