Identification of genetic variations associated with epsilon-poly-lysine biosynthesis in Streptomyces albulus ZPM by genome sequencing

Sci Rep. 2015 Mar 17:5:9201. doi: 10.1038/srep09201.

Abstract

The biosynthesis of the antibiotic epsilon-poly-lysine (ε-PL) in Streptomyces albulus is performed by polylysine synthase (pls); however, the regulatory mechanism of this process is still unknown. Here, we first obtained the complete genome sequence of S. albulus ZPM, which consists of 9,784,577 bp and has a GC content of 72.2%. The genome houses 44 gene clusters for secondary metabolite biosynthesis, in which 20 gene clusters are involved in the biosynthesis of polyketides and nonribosomally synthesized peptides. High-throughput sequencing was further performed, and genetic variants were identified from pooled libraries consisting of the 30 highest-yield mutants or 30 lowest-yield mutants. More than 350 genetic variants associated with ε-PL yield have been identified. One hundred sixty-two affected proteins, from important metabolic enzymes to novel transcriptional regulators, were identified as being related to ε-PL synthesis. HrdD, one of the affected genes, is a sigma factor that shows the most sensitive response to pH change and contains a non-synonymous mutation (A132V) in mutant strains with lower ε-PL yields. Electrophoretic mobility shift assays showed that the pls gene is likely regulated by transcriptional activator HrdD. The data obtained in this study will facilitate future studies on ε-PL yield improvement and industrial bioprocess optimization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Basal Metabolism / genetics
  • Chromosome Mapping
  • Chromosomes, Bacterial
  • Genes, Bacterial
  • Genetic Variation*
  • Genome, Bacterial*
  • High-Throughput Nucleotide Sequencing
  • Multigene Family
  • Polylysine / biosynthesis*
  • Promoter Regions, Genetic
  • Secondary Metabolism / genetics
  • Streptomyces / genetics*
  • Streptomyces / metabolism*
  • Transcription Factors

Substances

  • Transcription Factors
  • Polylysine