Lichenysins G, a novel family of lipopeptide biosurfactants from Bacillus licheniformis IM 1307: Production, isolation and structural evaluation by NMR and mass spectrometry

Abstract

A series of 9 lactonic lipopeptide biosurfactants was isolated from Bacillus licheniformis IM 1307 as representatives of the lichenysin group and we propose to name them lichenysins G. They were recovered from the culture medium as complex mixtures of molecules having different peptide sequences and different structures of β-hydroxy fatty acids. Their separation was achieved by a reversed-phase HPLC method leading to eight well-separated compounds. The complete structure of individual isoforms was proposed following the results of amino acid and fatty acid analysis, LSI-MS and 2D NMR spectroscopies. Compared to surfactin, lichenysins G are at least 10 fold more efficient biosurfactants.