TY - JOUR ID - open821 UR - http://dx.doi.org/10.1007/s11743-999-0091-6 IS - 3 A1 - Makkar, R S A1 - Cameotra, Swaranjit Singh N2 - Structural and biochemical characterization of a biosurfactant produced by Bacillus subtilis under thermophilic conditions was performed. Preliminary structural determination of CHCl3/CH3OH (65?15) extracts by thin-layer chromatographic reagents showed it to be identical to surfactin. Also, the infrared, 1H nuclear magnetic resonance, and mass spectroscopy analysis confirmed it to be identical to surfactin. Biochemically, the surfactant was a lipopeptide-containing lipid (17.05%) and protein (13.2%). The surfactant yielded a minimal aqueous surface-tension value of 28 dyne/cm and an interfacial tension value at 0.1% concentration of 0.2 dyne/cm against diesel oil. The critical micelle concentration of the surfactant was 35 mg/L. The biosurfactant exhibited an emulsification value (E 24) of 90 against diesel oil and a sand-pack oil recovery of 62%. It has potential application in microbial-enhanced oil recovery in thermophilic, alkaline, acidic, and halophilic environments VL - 2 TI - Structural characterization of a biosurfactant produced by Bacillus subtilis at 45°C AV - restricted EP - 372 N1 - Copyright of this article belongs to Springer Science. Y1 - 1999/// PB - Springer Science JF - Journal of Surfactants and Detergents KW - Bacillus - biosurfactant - surfactin - thermophilic SN - 1097-3958 SP - 367 ER -