Polish Journal of Microbiology (Sep 2022)

Breeding of High Daptomycin-Producing Strain by Streptomycin Resistance Superposition

  • Chu Shuaibei,
  • Hu Wenting,
  • Zhang Kaihong,
  • Hui Fengli

DOI
https://doi.org/10.33073/pjm-2022-041
Journal volume & issue
Vol. 71, no. 3
pp. 463 – 471

Abstract

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Daptomycin is a cyclolipopeptide antibiotic produced by Streptomyces roseosporus. It is widely used to treat drug-resistant bacterial infections; however, daptomycin yield in wild strains is very low. To improve the daptomycin production by the strain BNCC 342432, a modified method of ribosome engineering with superposition of streptomycin resistance was adopted in this study. The highest-yield mutant strain SR-2620 was obtained by increasing streptomycin resistance of BNCC 342432, and achieved daptomycin production of 38.5 mg/l in shake-flask fermentation, 1.79-fold higher than the parent strain and its heredity stability was stable. The morphological characteristics of the two strains were significantly different, and the 440th base G of the rpsL gene in the mutant strain was deleted, which resulted in a frameshift mutation. Our results demonstrate that gradually increasing strain resistance to streptomycin was an effective breeding method to improve daptomycin yield in S. roseosporus.

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