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BioMed Research International
Volume 2017, Article ID 5373262, 13 pages
https://doi.org/10.1155/2017/5373262
Research Article

Significance of Heavy-Ion Beam Irradiation-Induced Avermectin B1a Production by Engineered Streptomyces avermitilis

1Institute of Modern Physics, Chinese Academy of Sciences, 509 Nanchang Rd., Lanzhou, Gansu 730000, China
2Lanzhou University, 222 South Tianshui Road, Lanzhou, Gansu 730000, China
3Institute of Veterinary Drug Quality Inspection of Shandong Province, Jinan 250022, China

Correspondence should be addressed to Shu-Yang Wang; nc.ca.sacpmi@ysgnaw

Received 30 June 2016; Revised 9 October 2016; Accepted 23 October 2016; Published 24 January 2017

Academic Editor: Somboon Tanasupawat

Copyright © 2017 Shu-Yang Wang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Heavy-ion irradiation technology has advantages over traditional methods of mutagenesis. Heavy-ion irradiation improves the mutation rate, broadens the mutation spectrum, and shortens the breeding cycle. However, few data are currently available regarding its effect on Streptomyces avermitilis morphology and productivity. In this study, the influence of heavy-ion irradiation on S. avermitilis when cultivated in approximately 10 L stirred-tank bioreactors was investigated. The specific productivity of the avermectin (AVM) B1a-producing mutant S. avermitilis 147-G58 increased notably, from 3885 to 5446 μg/mL, approximately 1.6-fold, compared to the original strain. The mycelial morphology of the mutant fermentation processes was microscopically examined. Additionally, protein and metabolite identification was performed by using SDS-PAGE, 2- and 3-dimensional electrophoresis (2DE and 3DE). The results showed that negative regulation gene deletion of mutants led to metabolic process upregulating expression of protein and improving the productivity of an avermectin B1a. The results showed that the heavy-ion beam irradiation dose that corresponded to optimal production was well over the standard dose, at approximately 80 Gy at 220 AMeV (depending on the strain). This study provides reliable data and a feasible method for increasing AVM productivity in industrial processes.