Critical review on biosurfactant analysis, purification and characterization using rhamnolipid as a model biosurfactant

[Display omitted] •Biosurfactants possess diversity in structural and functional properties.•Screening methodologies play important role to obtain desired biosurfactant producer.•Biosynthesis of rhamnolipid (RL) by Pseudomonas aeruginosa is discussed.•Rhamnolipids have potential application in microbial enhanced oil recovery.•Research should be focused on utilization of renewable substrates for RL production. Surfactants are one of the most versatile group of chemicals used in various industrial processes. Their market is competitive, and manufacturers will have to expand surfactant production in ecofriendly and cost effective manner. Increasing interest in biosurfactants led to an intense research for environment friendly and cost-efficient production of biosurfactant. Structural diversity and functional properties of biosurfactants make them an attractive group of compounds for potential use in wide variety of industrial, environmental and biotechnological applications. Screening methods make task easier to obtain potential biosurfactant producing microorganisms. Variety of purification and analytical methods are available for biosurfactant structural characterization. This review aims to compile information on types and properties of biosurfactant, microbial screening methods as well as biosynthesis, extraction, purification and structural characterization of biosurfactant using rhamnolipid as a model biosurfactant. It also describes factors affecting rhamnolipid production. It gives an overview of oil recovery using biosurfactant from Pseudomonas aeruginosa.