Sophorolipids (SL) belong to a class of glycolipidic biosurfactants suitable for a wide range of applications. The structural diversity in SL gives rise to variation in physicochemical and biological properties. To achieve the less explored head group diversity in sophorolipid structure, a new xylose fermenting yeast Pichia caribbica has been employed for biosurfactant production. The media and fermentation parameters have been optimized to achieve maximum yield of 7.48 g/L. The physicochemical properties of the xylolipid biosurfactant have been assessed. It reduced the surface tension of distilled water from 70 to 35.9 mN/m with the low critical micellar concentration (CMC) 1.0 mg/L as compared to typical SL (reported CMC range 40–100 mg/L). Structural characterization was done using FTIR and HR-MS to identify the structure. 17-L-[(β-D-xylopyranosyl)-oxy]-Δ9-heptadecanoic acid correlated to m/z 415 majorly constituted the product. Control experiment was performed in which glucose was provided as the hydrophilic carbon. This product was also subjected to HR-MS analysis to determine its chemical nature and found to be different from xylolipid. Presence of xylose as head group was anticipated to give altered physicochemical and biological activities and indeed a low CMC value and better inhibitory action was demonstrated against Staphylococcus aureus.
sophorolipid, critical micelle concentration, antibacterial action, Pichia caribbica, xylolipid
Publication DOI: 10.1002/ejlt.201300363Journal NLM ID: 100961908Publisher: Weinheim, Germany: Wiley-VCH
Correspondence: Prabhune AA
Institutions: Biochemical Sciences Division, National Chemical Laboratory, Pune, India, Physical, Material Chemistry Division, National Chemical Laboratory, Pune, India
Methods: antibacterial assay, HRMS, FT-IR
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