title: Optimization of neutral protease production from Bacillus subtilis: using agroindustrial residues as substrates and response surface methodology.
abstract: Statistically based experimental designs were applied to optimize the fermentation medium and cultural conditions for the maximization of neutral protease using three agroindustrial residues (cassava pulp, soybean meal, and wheat bran) and Bacillus subtilis DES-59. The Plackett-Burman design was used to evaluate the effects of variables such as the concentration of substrates, initial pH, shaker's rotating speed, temperature, inoculum size, and incubation time. Among the eight parameters, three significant variables (cassava pulp, soybean meal, and inoculum size) were selected for the optimization study, in which a central composite design was used to optimize the concentrations of cassava pulp and soybean meal and inoculum size and investigate the interactive effects of the three variables. The optimal parameters obtained from response surface methodology are 37.78 g/L of cassava pulp, 15 g/L of soybean meal, and 6.5% (v/v) of inoculum size, respectively, resulting in a maximum neutral protease activity of 4107 ± 122 U/mL.
authors: School of Bioscience and Bioengineering, South China University of Technology, Guangzhou Higher Education Mega Center, Panyu, Guangzhou, PR China. mjzhu@scut.edu.cn
authors: Ming-Jun
authors: MJ
authors: Zhu
authors: Jing-Rong
authors: JR
authors: Cheng
authors: Hong-Tu
authors: HT
authors: Chen
authors: Mao-Cheng
authors: MC
authors: Deng
authors: Wen-Hua
authors: WH
authors: Xie
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology* / Q000378:metabolism*; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods; D003470:Culture Media / Q000378:metabolism*; D005285:Fermentation / Q000502:physiology; D006863:Hydrogen-Ion Concentration; D008666:Metalloendopeptidases / Q000096:biosynthesis* / Q000378:metabolism*; D013025:Glycine max / Q000378:metabolism; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D008666:Metalloendopeptidases; C071298:bacillolysin