Microbial Biosurfactant Screening: Diversity in Assessment Methods

Abstract Biosurfactants are a group of surface-active agents mainly produced by microorganisms and have a wide range of applications in industries as well as agriculture. Global usage of such biologically active compounds as detergents, bioremediation agents, cosmetic products is hugely dependent on their high production. New avenues of research have opened up due to this increased interest, most of which are focused on identifying specialized microorganisms capable of biosurfactant production. Screening methods for selection of biosurfactant producing bacteria are, therefore, of utmost importance in this endeavor. The aim of this review was to discuss various conventional and novel methods that can overcome the hurdles encountered in time effective, economical microbial biosurfactant screening. This review lists several important biosurfactant screening methods based on supernatant, biomass as well as culture media. New methods devised for biosurfactant screening in the last half decade such as surfactant dependent dye solubilization, metagenomic studies etc. are also explained in detail. A thorough grasp of both contemporary and anachronistic screening methodologies will not only lead to discoveries of novel native strains capable of biosurfactant production but also form the basis on which new screening methods can be devised.