Physicochemical characterization of biosurfactant and its potential to remove oil from soil and cotton cloth

Abstract

An alkaliphilic bacterium, Klebsiella sp. strain RJ-03, produced a biosurfactant, which showed low viscosity with pseudoplastic rheological behavior and exhibited emulsification activity with oils and hydrocarbons. The biosurfactant has excellent oil removing efficiency as compared to chemical surfactants. The isolated biosurfactant has compatibility with detergents and enhanced oil removing efficiency from soil and cotton cloths. It comprised of sugar, uronic acid, protein and sulfate. GC-MS analysis confirmed the presence of six monosaccharides (w/w), glucose (6.65%), galactose (23.98%), rhamnose (14.94%), mannose (17.54%), fucose (9.47%) and 6-O-Me-galactose (1.4%). It is a high molecular weight, thermostable biopolymer showing degradation above 300 °C. Positive ion reflector mode of MALDI TOF-TOF MS analysis revealed series of low and mid range mass peaks (m/z) corresponding to mono-, di-, tri- and oligo-saccharides content. The NMR, FT-IR, EDX-SEM, AFM and PSD analysis confirmed the presence of functional groups, bonds, elements and particle size respectively.