Phylogenic Analysis of NRPS and PKS Genes Associated with Antagonistic Micromonospora Rc5 and Streptomyces Ru87 Isolates

Aims: To invistigate phylogenic analysis of NRPS and PKS genes. To discover uncommon and novel types of actinomycetes isolated from Egyptian soils.

Study Design: Fifty rare actinomycetes were isolated from Egyptian soils and tested for antimicrobial activities. Phylogenic analysis of NRPS and PKS Genes was invistigated with unique isolates. Fosmid genomic libraries were constructed and integrated with NRPS and PKS genes.

Methodoloy: Isolation was conducted using humic acid vitamin agar media and starch casein agar media. They were tested against some food and blood borne pathogens. Screening studies of NRPS and PKS genes were conduected via NRPS/PKS PCR assays, and phylogenetic analysis, and fosmid libraries with positive hits of NRPS and PKS genes as a preliminary step for manipulation of these genes.

Results: Forty rare actinomycetes showed significant antimicrobial activities. Micromonospora Rc5 and Streptomyces Ru87 isolates reported the highest antimicrobial activities and then revealed positive hits of NPRS and PKS genes. Fosmid genomic libraries were successfully constructed and integrated with NRPS and PKS genes. Adenylation domain of NRPS gene of Micromonospora sp. Rc5 showed high similarity (97%) to Micromonospora haikouensis. Similar domain of Streptomyces sp. Ru87 found identical (100% boost strap) to Streptomyces viridochromogenes, Streptomyces ribosidificus and Streptomyces hygroscopicus. Whereas, NJ phylogenetic tree of PKS gene fragments of both Rc5 and Ru87 isolates were highly distinctive with bootstrap values (70%, 69%, respectively).

Conclusion: These unique isolates harbour phylogenetically divergent PKS gene cluster that is responsible for distinct biochemical pathways of novel antibiotics. To our knowledge, this is first attempt to tackle phylogenic analysis of NRPS and PKS genes and discover uncommon and novel types of actinomycetes isolated from Egyptian soils. These novel isolates may contain unexpected genes, and subsequently, offers a significant contribution for alternative novel antimicrobial compounds in drug discovery.