Production of fumaric acid by simultaneous saccharification and fermentation of starchy materials with 2-deoxyglucose-resistant mutant strains of Rhizopus oryzae.
A mutant strain with high glucoamylase activity and insensitive to catabolite repression was developed to produce fumaric acid by simultaneous saccharification and fermentation (SSF) of starch without additional commercial glucoamylase supplementation. A series of mutant strains resistant to the non-metabolizable and toxic glucose analog 2-deoxyglucose (2-DG) were obtained by implanting nitrogen ion (N(+)) into Rhizopus oryzae ME-F12. Among them, the best mutant strain DG-3 produced 39.80 g/L fumaric acid, which is 1.28-fold of that produced by ME-F12, and exhibited higher glucoamylase activity during SSF. Higher fumaric acid production (44.10 g/L) was achieved when the initial total sugar concentration of cornstarch was 100g/L. During SSF of cheap, raw bioresource-degermed corn powder (100g/L total sugar) by DG-3, the maximum fumaric acid concentration and productivity were 32.18 g/L and 0.44 g/(Lh), respectively.
State Key Laboratory of Material-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, No. 5 Xinmofan Road, Nanjing 210009, PR China.
Yuefang
Y
Deng
Shuang
S
Li
Qing
Q
Xu
Min
M
Gao
He
H
Huang
D050260:Carbohydrate Metabolism; D003847:Deoxyglucose / Q000494:pharmacology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D005285:Fermentation; D005650:Fumarates / Q000378:metabolism*; D009154:Mutation; D012233:Rhizopus / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*
D005650:Fumarates; C032005:fumaric acid; D003847:Deoxyglucose