Production and structural elucidation of trehalose tetraesters (biosurfactants) from a novel alkanothrophic Rhodococcus wratislaviensis strain

Abstract

To isolate a biosurfactant-producing bacterial strain and to identify and characterize the chemical structure and properties of its biosurfactants. The bacterium Rhodococcus wratislaviensis BN38, isolated from soil, was found to produce glycolipid biosurfactants when grown on 2%n-hexadecane. The glycolipids were isolated by chromatography on silica gel columns and their structures elucidated using a combination of multidimensional NMR and ESI-MS/MS techniques. The main product was identified as 2,3,4,2'-trehalose tetraester with molecular mass of 876 g mol(-1). It was also noted that the biosurfactant was produced under nitrogen-limiting conditions and could not be synthesized from water-soluble substrates. The purified product showed extremely high surface-active properties. The glycolipid biosurfactant produced by the alkanothrophic strain R. wratislaviensis BN38 was characterized to be 2,3,4,2'-trehalose tetraester which exhibited high surfactant activities. Strain BN38 of R. wratislaviensis is a potential candidate for use in bioremediation applications or in biosurfactant exploration.