title: Enhanced production of 2,3-butanediol by engineered Bacillus subtilis.
abstract: Production of 2,3-butanediol by Bacillus subtilis takes place in late-log or stationary phase, depending on the expression of bdhA gene encoding acetoin reductase, which converts acetoin to 2,3-butanediol. The present work focuses on the development of a strain of B. subtilis for enhanced production of 2,3-butanediol in early log phase of growth cycle. For this, the bdhA gene was expressed under the control of P( alsSD ) promoter of AlsSD operon for acetoin fermentation which served the substrate for 2,3-butanediol production. Addition of acetic acid in the medium induced the production of 2,3-butanediol by 2-fold. Two-step aerobic-anaerobic fermentation further enhanced 2,3-butanediol production by 4-fold in comparison to the control parental strain. Thus, addition of acetic acid and low dissolved oxygen in the medium are involved in activation of bdhA gene expression from P( alsSD ) promoter in early log phase. Under the conditions tested in this work, the maximum production of 2,3-butanediol, 2.1 g/l from 10 g/l glucose, was obtained at 24 h. Furthermore, under the optimized microaerophilic condition, the production of 2,3-butanediol improved up to 6.1 g/l and overall productivity increased by 6.7-fold to 0.4 g/l h in the engineered strain compared to that in the parental control.
authors.affiliation: Organization of Advance Science and Technology, Kobe University, Kobe 657-8501, Japan.
authors.forename: Ranjita
authors.initials: R
authors.lastname: Biswas
authors.forename: Masaru
authors.initials: M
authors.lastname: Yamaoka
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakayama
authors.forename: Takashi
authors.initials: T
authors.lastname: Kondo
authors.forename: Ken-ichi
authors.initials: K
authors.lastname: Yoshida
authors.forename: Virendra S
authors.initials: VS
authors.lastname: Bisaria
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kondo
mesh_terms: D019342:Acetic Acid / Q000378:metabolism; D000093:Acetoin / Q000378:metabolism; D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000378:metabolism; D001412:Bacillus subtilis / Q000235:genetics* / Q000378:metabolism*; D002072:Butylene Glycols / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D015870:Gene Expression; D060847:Metabolic Engineering / Q000379:methods*; D053858:Metabolic Networks and Pathways / Q000235:genetics*; D010100:Oxygen / Q000378:metabolism; D011401:Promoter Regions, Genetic
chemical_list: D002072:Butylene Glycols; D003470:Culture Media; C026978:2,3-butylene glycol; D000093:Acetoin; D000429:Alcohol Oxidoreductases; C019801:butanediol dehydrogenase; D019342:Acetic Acid; D010100:Oxygen