Genome-based analysis of biosynthetic potential from antimycotic Streptomyces rochei strain A144

Streptomyces rochei is a species of Streptomyces with a diverse range of biological activities. Streptomyces rochei strain A144 was isolated from desert soils and exhibits antagonistic activity against several plant pathogenic fungi. The genome of S. rochei A144 was sequenced and revealed the presence of one linear chromosome and one plasmid. The chromosome length was found to be 8 085 429 bp, with a GC content of 72.62%, while the Plas1 length was 177 399 bp, with a GC content (proportion of guanine and cytosine in DNA sequences) of 69.08%. Comparative genomics was employed to analyse the S. rochei group. There is a high degree of collinearity between the genomes of S. rochei strains. Based on pan-genome analysis, S. rochei has 10 315 gene families, including 4051 core and 2322 unique genes. AntiSMASH was used to identify the gene clusters for secondary metabolites, identifying 33 secondary metabolite genes on the A144 genome. Among them, 18 clusters were found to be >70% identical to known biosynthetic gene clusters (BGCs), indicating that A144 has the potential to synthesize secondary metabolites. The majority of the BGCs were found to be conserved within the S. rochei group, including those encoding polyketide synthases, terpenes, non-ribosomal peptide synthetases, other ribosomally synthesized and post-translationally modified peptides, nicotianamine-iron transporters, lanthipeptides, and a few other types. The S. rochei group can be a potential genetic source of useful secondary metabolites with applications in medicine and biotechnology.