The Effective Emulsifying Property of Biosurfactant–Producing Marinobacter hydrocarbonoclasticus ST1 Obtained from Palm Oil Contaminated Sites

The Marinobacter hydrocarbonoclasticus ST1, isolated from soil contaminated with palm oil from palm oil mill factories in southern Thailand, was evaluated as a potential biosurfactant with effective emulsifying property. This strain was able to produce biosurfactant with the maximum emulsification activity of 81% and emulsification index of 60% after 60 h of cultivation under the optimized cultivation conditions. The yield of biosurfactant obtained by chloroform:methanol (2 : 1, vol/vol) extraction was 1.85 g/L. The stability of the biosurfactant was effective over a wide range of pH, temperature and salinity. The high thermostability of the biosurfactant was assessed by simultaneous thermal analyzer. In addition, a preliminary chemical characterization using FT-IR, 1H-NMR and 13C-NMR indicated that it is glycolipid biosurfactant. The features of this biosurfactant make it a promising product for many industrial applications involving to extreme conditions.