Genetic Diversity and Functional Potential of Streptomyces spp. Isolated from Pachmarhi Biosphere Reserve, India

Streptomyces is a diverse genus, well known for producing a wide array of metabolites that have significant industrial utilization. The present study investigates the genetic and functional diversity of Streptomyces spp. isolated from the Pachmarhi Biosphere Reserve (PBR), India, an unexplored site. The 16S rRNA gene sequencing and analysis revealed 96 isolates belonging to 40 different species indicating a substantial phylogenetic diversity. The strains were clustered into two groups: a major cluster with 94 strains and a small cluster with two strains. BOX- PCR analyses revealed an incredible genetic diversity existing among the strains of Streptomyces spp. in PBR. The analyses revealed the intra-species diversity and inter-species closeness within the genus Streptomyces in the study area. Qualitative screening for enzyme production has shown that 53, 42, 41, 11, and 54 strains tested positive for CMCase, xylanase, amylase, pectinase, and beta-glucosidase, respectively. Additionally, 54 strains tested positive for PHB production. The strains were assayed quantitatively for the production of CMCase, xylanase, amylase, and pectinase. Streptomyces sp. MP9-2, Streptomyces sp. MP10-11, Streptomyces sp. MP10-18, and Streptomyces sp. MP10-6 recorded maximum CMCase (0.604 U/mL), xylanase (0.553 U/mL), amylase (1.714 U/mL), and pectinase (13.15 U/mL) activities, respectively. Furthermore, several strains demonstrated plant growth-promoting traits, viz. zinc and phosphate solubilization and production of ammonia, HCN (hydrogen cyanide), and IAA (Indole acetic acid), and nitrogen fixation. Fifty strains showed antifungal activity against Fusarium oxysporum f. sp. lycopersici with inhibitions ranging from 7.5 to 47.5%. Current findings underscore the ecological and biotechnological significance of Streptomyces spp. in the unexplored habitat of PBR.