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.
Highlights
Acarbose is a competitive α-glucosidase inhibitor [1] widely used in the treatment of non-insulin-dependent diabetes mellitus (NIDDM) [2,3]
We investigated the effect of feeding glucose and maltose to promote acarbose production
Our results indicated that pH played an important role in cell growth and acarbose biosynthesis during the fermentation process
Summary
Acarbose (acarviosyl-1,4-maltose) is a competitive α-glucosidase inhibitor [1] widely used in the treatment of non-insulin-dependent diabetes mellitus (NIDDM) [2,3]. Acarbose is a complex oligosaccharide known to reduce and slow down the intestinal absorption of glucose. As a result, it lowers the postprandial increase in blood glucose levels in NIDDM patients. Its medical effect is based on a decreased release of glucose from starch- and sucrose-containing foods in the human intestine, which leads to reduced levels of blood glucose and serum insulin [4]. Acarbose was identified in strains of the genera Actinoplanes and Streptomyces [5,6]. It was reported to belong to a mixed-growth-associated type of secondary metabolites; its biosynthesis being independent of cell growth [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
