title: Statistical optimization of medium components for enhanced acetoin production from molasses and soybean meal hydrolysate.
abstract: The nutritional requirements for acetoin production by Bacillus subtilis CICC 10025 were optimized statistically in shake flask experiments using indigenous agroindustrial by-products. The medium components considered for initial screening in a Plackett-Burman design comprised a-molasses (molasses submitted to acidification pretreatment), soybean meal hydrolysate (SMH), KH(2)PO(4).3H(2)O, sodium acetate, MgSO(4).7H(2)O, FeCl(2), and MnCl(2), in which the first two were identified as significantly (at the 99% significant level) influencing acetoin production. Response surface methodology was applied to determine the mutual interactions between these two components and optimal levels for acetoin production. In flask fermentations, 37.9 g l(-1) acetoin was repeatedly achieved using the optimized concentrations of a-molasses and SMH [22.0% (v/v) and 27.8% (v/v), respectively]. a-Molasses and SMH were demonstrated to be more productive than pure sucrose and yeast extract plus peptone, respectively, in acetoin fermentation. In a 5-l fermenter, 35.4 g l(-1) of acetoin could be obtained after 56.4 h of cultivation. To our knowledge, these results, i.e., acetoin yields in flask or fermenter fermentations, were new records on acetoin fermentation by B. subtilis.
authors.affiliation: State Key Laboratory of Microbial Technology, Shandong University, Jinan, 250100, People's Republic of China.
authors.forename: Z J
authors.initials: ZJ
authors.lastname: Xiao
authors.forename: P H
authors.initials: PH
authors.lastname: Liu
authors.forename: J Y
authors.initials: JY
authors.lastname: Qin
authors.forename: P
authors.initials: P
authors.lastname: Xu
mesh_terms: D000093:Acetoin / Q000378:metabolism*; D001412:Bacillus subtilis / Q000254:growth & development* / Q000378:metabolism; D001709:Biotechnology / Q000379:methods*; D003470:Culture Media / Q000737:chemistry*; D005285:Fermentation; D008954:Models, Biological; D008965:Molasses; D011492:Protein Hydrolysates / Q000378:metabolism*; D012107:Research Design; D013025:Glycine max / Q000378:metabolism*
chemical_list: D003470:Culture Media; D011492:Protein Hydrolysates; D000093:Acetoin