Abstract
Biosurfactants are non-toxic, biodegradable surface-active compounds produced by microorganisms. These natural surfactants serve as substitute for chemical surfactants that are toxic and hazardous to the environment. Biosurfactants are gaining much interest because of their industrial and economical value but due to their surface activities biosurfactant producing bacteria can be pathogenic in nature. This study is based on isolation, purification and screening of non-pathogenic biosurfactant producing bacteria from Karachi coast of Arabian Sea. Out of 89 isolates, strain no DGHE2, DGHE6, DGHE10, DGHE12, DGHE32, DGHE52, DGHE55, DGHE56, DGHE62, DGHE71, DGHE85, DGHE86 and DGHE87 were found to be negative for hemolytic activity and showed above 30% emulsification index for at least one of the tested hydrocarbons. The same strains gave high values for BATH assay with hexane and xylene. In the present study we have successfully isolated 13 non-pathogenic bacterial strains capable of producing biosurfactant. Production of such eco-friendly strains would benefit the industries and environment to great extent in the production of biosurfactants.
