Generation and initial characterization of a collection of spontaneous Streptomyces albus J1074 mutants resistant to rifampicin
Faktori eksperimentalʹnoï evolûcìï organìzmìv
Aim. Streptomyces albus J1074 is one of the most popular streptomycete chassis for heterologous expression of natural product (NP) biosynthetic gene clusters (BGCs). There is keen interest in further improvement of the strain to provide increased yields of corresponding NPs. Introduction of certain types of antibiotic resistance mutations is a proven way to improve Streptomyces strains. For example, selection for increased resistance to rifampicin is known to lead to increased antibiotic
... d antibiotic activity. Here we used available lineages of antibiotic-resistant mutants of S. albus to raise rifampicin-resistant variants (Rifr) and to study their properties. Methods. Microbiological and molecular genetic approaches were combined to generate Rifr mutants and to study their properties. Results. By plating S. albus onto GYM agar supplemented with 10 mcg/mL of rifampicin, we isolated 85 stable Rifr colonies, whose resistance level was within 10-200 mcg/mL range. Sequencing revealed wide spectrum of missense mutations within rpoB gene. Bioassays demonstrated dramatically increased endogenous antibiotic activity of certain Rifr mutants. Conclusions. Selection for rifampicin resistance is a viable way to increase the yields of NPs in S. albus. Keywords: Streptomyces albus J1074, antibiotic resistance, rifampicin.