Abstract

The Gram-positive bacterium such as streptomycetes known for its production of a diverse array of biotechnologically important secondary metabolites, have major application in health, nutrition and economics of our society. There are limited studies on the genetics of streptomycetes, especially seaweed associated Streptomyces sp. So, the present study made an attempt to study the genetics of production of antibiotic and other phenotypic properties was demonstrated by plasmid DNA curing analysis. The DNA-intercalating agent ethidium bromide was used to eliminate plasmid DNA from streptomycetes and effects of curing agent (EB) on the antibiotic production and loss of other phenotypic traits such as aerial and substrate mycelial production, biomass production, protein synthesis were studied. The study demonstrates that the ethidium bromide is potent and probably region-specific mutagens that are capable of inducing high rates of plasmid loss (curing), production of antibiotics was not eliminated, but was reduced by 20.2-79.8% and extracellular protein of 26 KDa mol.wt. was unaffected by curing agents. Data suggests that production of antibiotics and other phenotypic traits likely chromosomally encoded in marine Streptomyces species. The study concludes that the new methodologies such as mutasynthesis have contributed substantially to the discovery of additional antibiotics as an added feather to the scope of antibiotic industry.

Key words: Plasmids, genetics of Streptomyces, curing, phenotypic traits, antibiotic production.