title: A novel biotransformation process of 4'-demethylepipodophyllotoxin to 4'-demethylepipodophyllic acid by Bacillus fusiformis CICC 20463, Part II: process optimization.
abstract: This work optimized the novel biotransformation process of 4'-demethylepipodophyllotoxin (DMEP) into 4'-demethylepipodophyllic acid (DMEPA) by Bacillus fusiformis CICC 20463. Firstly, the biotransformation process was significantly affected by medium composition. 5 g/L of yeast extract and 10 g/L of peptone were optimal for DMEPA production (i.e., 2.81 + or - 0.21 mg/L), while not beneficial for the cell growth of B. fusiformis. This indicated that the biosynthesis of DMEPA was not corresponded well to the cell growth of B. fusiformis. 40 g/L of sucrose was optimal for DMEPA production (i.e., 2.94 + or - 0.17 mg/L), and 3 g/L of NaCl was the best for DMEPA production (i.e., 4.10 + or - 0.18 mg/L). Secondly, the production of DMEPA was significantly enhanced by the control of substrate concentration and culture pH. 100 mg/L of substrate was optimal for DMEPA production (i.e., 6.47 + or - 0.35 mg/L), and DMEPA concentration was enhanced to 38.78 mg/L by controlling culture pH at 9.0 in the stirred-tank bioreactors. The fundamental information obtained in this study provides a simple and efficient way to produce DMEPA by biotransformation.
authors.affiliation: Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Provincial Key Laboratory of Industrial Microbiology, College of Bioengineering, Hubei University of Technology, 430068 Wuhan, China. yajietang@hotmail.com
authors.forename: Ya-Jie
authors.initials: YJ
authors.lastname: Tang
authors.forename: Xiao-Ling
authors.initials: XL
authors.lastname: Xu
authors.forename: Jian-Jiang
authors.initials: JJ
authors.lastname: Zhong
mesh_terms: D001407:Bacillus / Q000378:metabolism*; D019149:Bioreactors; D001709:Biotechnology / Q000379:methods*; D001711:Biotransformation; D006863:Hydrogen-Ion Concentration; D007218:Industrial Microbiology / Q000379:methods*; D007700:Kinetics; D008956:Models, Chemical; D015233:Models, Statistical; D009584:Nitrogen / Q000737:chemistry; D011034:Podophyllotoxin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000378:metabolism; D012965:Sodium Chloride / Q000737:chemistry; D013395:Sucrose / Q000737:chemistry; D013499:Surface Properties
chemical_list: C548304:4'-demethylepipodophyllic acid; D012965:Sodium Chloride; D013395:Sucrose; D011034:Podophyllotoxin; D009584:Nitrogen; C072088:4'-demethylepipodophyllotoxin