title: Characterization of Biosurfactant Produced by Bacillus licheniformis TT42 Having Potential for Enhanced Oil Recovery.
abstract: Bacillus licheniformis TT42 produced a low-molecular weight anionic biosurfactant that reduced the surface tension of water from 72 to 27 mN/m and the interfacial tension from 12 to 0.05 mN/m against crude oil. We have earlier reported significant enhancement in oil recovery in laboratory sand pack columns and core flood studies, by biosurfactant-TT42 compared to standard strain, Bacillus mojavensis JF2. In the context of this application of the biosurfactant-TT42, its characterization was deemed important. In the preliminary studies, the biosurfactant-TT42 was found to be functionally stable at under conditions of temperature, pH, and salinity generally prevalent in oil reservoirs. Furthermore, the purified biosurfactant-TT42 was found to have a CMC of 22 mg/l. A newly developed activity staining TLC method was used for the purification of biosurfactant-TT42. Structural characterization of biosurfactant-TT42 using TLC, Fourier transform infrared spectroscopy (FTIR), GC-MS, and matrix-assisted laser desorption ionization time of flight (MALDI-TOF)/TOF suggested that it was a mixture of lipopeptide species, all having a common hydrophilic cyclic heptapeptide head with the sequence, Gln-Leu/Ileu-Leu/Ileu-Val-Asp-Leu/Ileu-Leu/Ileu linked to hydrophobic tails of different lengths of 3β-OH-fatty acids bearing 1043, 1057 and 1071 Da molecular weight, where 3β-OH-C19 fatty acid was predominant. This is the longest chain length of fatty acids reported in a lipopeptide.
authors.affiliation: Department of Microbiology and Biotechnology Centre, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390002, India.|Department of Post Harvest Technology, ASPEE College of Horticulture and Forestry, Navsari Agricultural University, Navsari, 396450, Gujarat, India.
authors.forename: Harish
authors.initials: H
authors.lastname: Suthar
authors.affiliation: Department of Microbiology and Biotechnology Centre, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara, Gujarat, 390002, India. anuner26@yahoo.com.
authors.forename: Anuradha
authors.initials: A
authors.lastname: Nerurkar
mesh_terms: D000069976:Bacillus licheniformis / Q000378:metabolism*; D002855:Chromatography, Thin Layer; D008823:Micelles; D010578:Petroleum / Q000382:microbiology*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000378:metabolism*; D013696:Temperature
chemical_list: D008823:Micelles; D010578:Petroleum; D013501:Surface-Active Agents
keywords: Biosurfactant; Lichenysin; Lipopeptide; Structural characterization