title: Enhanced acarbose production by Streptomyces M37 using a two-stage fermentation strategy.
abstract: In this work, we investigated the effect of pH on Streptomyces M37 growth and its acarbose biosynthesis ability. We observed that low pH was beneficial for cell growth, whereas high pH favored acarbose synthesis. Moreover, addition of glucose and maltose to the fermentation medium after 72 h of cultivation promoted acarbose production. Based on these results, a two-stage fermentation strategy was developed to improve acarbose production. Accordingly, pH was kept at 7.0 during the first 72 h and switched to 8.0 after that. At the same time, glucose and maltose were fed to increase acarbose accumulation. With this strategy, we achieved an acarbose titer of 6210 mg/L, representing an 85.7% increase over traditional batch fermentation without pH control. Finally, we determined that the increased acarbose production was related to the high activity of glutamate dehydrogenase and glucose 6-phosphate dehydrogenase.
authors.affiliation: School of Life Science and Technology, Southwest University of Science and Technology, Mianyang, Sichuan, China.|State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China.|Engineering Research Center for Biomass Resource Utillization and Modification of Sichuan Province, Mianyang, Sichuan, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Ren
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China.
authors.forename: Long
authors.initials: L
authors.lastname: Chen
authors.affiliation: Engineering Research Center for Biomass Resource Utillization and Modification of Sichuan Province, Mianyang, Sichuan, China.
authors.forename: Shuangli
authors.initials: S
authors.lastname: Xiong
authors.affiliation: State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, Jiangsu, China.
authors.forename: Qunyi
authors.initials: Q
authors.lastname: Tong
mesh_terms: D020909:Acarbose / Q000737:chemistry / Q000378:metabolism*; D005285:Fermentation; D005954:Glucosephosphate Dehydrogenase / Q000737:chemistry; D005969:Glutamate Dehydrogenase / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D013302:Streptomyces / Q000378:metabolism*
chemical_list: D005954:Glucosephosphate Dehydrogenase; D005969:Glutamate Dehydrogenase; D020909:Acarbose