Influence of pleiotropic regulatory genes absB, relA, afsS on siomycin production by Streptomyces sioyaensis Lv81

T. Gren, B. Ostash, Y. Hrubskyy, M. Lopatniuk, V. Fedorenko

Ivan Franko National University of Lviv
4, Hrushevskyi St., Lviv 79005, Ukraine

Streptomyces sioyaensis Lv81 (=NRRL-B5408) produces thiopeptide antibiotic siomycin A (SiA). Use of wild type SiA producer is restricted because of low SiA titers. In this work we explored the utility of three heterologous pleiotropic regulatory genes for enhancement of SiA production. These genes under investigation are absB (codes for RNAse III), relA (for (p)ppGpp synthetase) and afsS (for 67-aminoacid peptide with chaperone-like activity). Gene absB was amplified from S. ghanaensis genome, genes relA and afsS from the genome of S. coelicolor. Constructs containing abovementioned genes were transferred into S. sioyaensis cells. Significant increase in SiA titers was detected in case of absB and afsS genes. Thus, both genes appear to be involved in the positive regulation of SiA production. No increase in SiA titers were detected in case of relA overexpression. Our results suggest that pleiotropic regulatory genes are useful tools for siomycin production improvement.

Keywords: secondary metabolism, thiopeptide antibiotics, siomycin, pathway-specific regulators, pleiotropic regulators

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