Structure characterization of a methylated ester biosurfactant produced by a newly isolated Dietzia cinnamea KA1

摘要

Biosurfactans are amphiphilic compounds synthesized by a wide group of microorganisms and tend to interact with surfaces of different polarities. In the present study we purified and characterized a biosurfactant produced by Dietzia cinnamea KA-1 when cultured by n-hexadecane as sole carbon source. The crude biosurfactant was extracted with ethyl acetate and purified by freezing at-20A degrees C and then silica Gel column chromatography. The purified biosurfactant applied for more characterization using Elemental analysis (CHNS), Fourier Transform Infrared Spectroscopy (FTIR), Mass Spectroscopy (MS) and Nuclear Magnetic Resonance (H-1 and C-13-NMR) analysis. CHNS analysis showed the presence of C (74.92%) and H (11.63%) but not N or S. Functional groups of OH, CH2, CH3, C=O and aliphatic C-O revealed by FTIR analysis. The presence and position of these groups were confirmed by NMR analysis, and molecular mass of biosurfactant calculated using MS analysis. Finally, the product characterized as a methylated ester compound with molecular formula of C21H42O4. This is the first report of biosurfactant of species D. cinnamea identified as ester, furthermore the ester was found to be in the methylated form.