Zhao Q, Xie H, Peng Y, Wang X, Bai L. Improving acarbose production and eliminating the by-product component C with an efficient genetic manipulation system of
Actinoplanes sp. SE50/110.
Synth Syst Biotechnol 2017;
2:302-309. [PMID:
29552655 PMCID:
PMC5851932 DOI:
10.1016/j.synbio.2017.11.005]
[Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2017] [Revised: 11/23/2017] [Accepted: 11/23/2017] [Indexed: 01/31/2023] Open
Abstract
The α-glucosidase inhibitor acarbose is commercially produced by Actinoplanes sp. and used as a potent drug in the treatment of type-2 diabetes. In order to improve the yield of acarbose, an efficient genetic manipulation system for Actinoplanes sp. was established. The conjugation system between E. coli carrying ØC31-derived integrative plasmids and the mycelia of Actinoplanes sp. SE50/110 was optimized by adjusting the parameters of incubation time of mixed culture (mycelia and E. coli), quantity of recipient cells, donor-to-recipient ratio and the concentration of MgCl2, which resulted in a high conjugation efficiency of 29.4%. Using this integrative system, a cloned acarbose biosynthetic gene cluster was introduced into SE50/110, resulting in a 35% increase of acarbose titer from 2.35 to 3.18 g/L. Alternatively, a pIJ101-derived replicating plasmid combined with the counter-selection system CodA(sm) was constructed for gene inactivation, which has a conjugation frequency as high as 0.52%. Meanwhile, almost all 5-flucytosine-resistant colonies were sensitive to apramycin, among which 75% harbored the successful deletion of targeted genes. Using this replicating vector, the maltooligosyltrehalose synthase gene treY responsible for the accumulation of component C was inactivated, and component C was eliminated as detected by LC-MS. Based on an efficient genetic manipulation system, improved acarbose production and the elimination of component C in our work paved a way for future rational engineering of the acarbose-producing strains.
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