Production and characterization of biosurfactant produced by a novel Pseudomonas sp. 2B
No Thumbnail Available
Date
2012
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Biosurfactant-producing bacteria were isolated from terrestrial samples collected in areas contaminated with petroleum compounds. Isolates were screened for biosurfactant production using Cetyl Tri Ammonium Bromide (CTAB)-Methylene blue agar selection medium and the qualitative drop-collapse test. An efficient bacterial strain was selected based on rapid drop collapse activity and highest biosurfactant production. The biochemical characteristics and partial sequenced 16S rRNA gene of isolate, 2B, identified the bacterium as Pseudomonas sp. Five different low cost carbon substrates were evaluated for their effect on biosurfactant production. The maximum biosurfactant synthesis (4.97g/L) occurred at 96h when the cells were grown on modified PPGAS medium containing 1% (v/v) molasses at 30°C and 150rpm. The cell free broth containing the biosurfactant could reduce the surface tension to 30.14mN/m. The surface active compound showed emulsifying activity against a variety of hydrocarbons and achieved a maximum emulsion index of 84% for sunflower oil. Compositional analysis of the biosurfactant reveals that the extracted biosurfactant was a glycolipid type, which was composed of high percentages of lipid (~65%, w/w) and carbohydrate (~32%, w/w). Fourier transform infrared (FT-IR) spectrum of extracted biosurfactant indicates the presence of carboxyl, hydroxyl and methoxyl functional groups. The mass spectra (MS) shows that dirhamnolipid (l-rhamnopyranosyl-l-rhamnopyranosyl-3-hydroxydecanoyl-3-hydroxydecanoate, Rha-Rha-C <inf>10</inf>-C <inf>10</inf>) was detected in abundance with the predominant congener monorhamnolipid (l-rhamnopyranosyl-?-hydroxydecanoyl-?-hydroxydecanoate, Rha-C <inf>10</inf>-C <inf>10</inf>). The crude oil recovery studies using the biosurfactant produced by Pseudomonas sp. 2B suggested its potential application in microbial enhanced oil recovery and bioremediation. © 2012 Elsevier B.V..
Description
Keywords
16S rRNA gene, Ammonium bromides, Bacterial strains, Bio surfactant, Biochemical characteristics, Biosurfactant production, Carbon substrates, Cell-free, Compositional analysis, Dirhamnolipid, Drop-collapse, Emulsifying activity, Enhanced oil recovery, Fourier transform infrared, Glyco lipids, Low costs, Mass spectra, Methylene Blue, Monorhamnolipid, Oil recoveries, Petroleum compounds, Potential applications, Pseudomonas sp, Sunflower oil, Surface-active compounds, Ammonium compounds, Aromatic compounds, Bacteria, Biomolecules, Bioremediation, Bromine compounds, Carbohydrates, Characterization, Convergence of numerical methods, Crude oil, Drops, Emulsification, Functional groups, Genes, Hydrocarbons, Mass spectrometry, RNA, Surface active agents, Surface tension, Vegetable oils, Enhanced recovery, biosurfactant, carbohydrate, cetrimide, glycolipid, hydrocarbon, lipid, methylene blue, molasses, petroleum derivative, rhamnolipid, article, bacterial growth, bacterial strain, bacterium identification, bacterium isolation, bioremediation, biosynthesis, carbon source, chemical composition, critical micelle concentration, emulsion, enzyme specificity, infrared spectroscopy, mass spectrometry, nonhuman, nucleotide sequence, pH, priority journal, Pseudomonas, RNA gene, salinity, surface tension, temperature, Micelles, Surface-Active Agents, Bacteria (microorganisms), Helianthus, Pseudomonas sp., Pseudomonas sp. 2
Citation
Colloids and Surfaces B: Biointerfaces, 2012, 95, , pp. 23-29