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Production and properties of a lipopeptide biosurfactant by B. subtilis subsp. inaquosorum

Thivaharan, Varadavenkatesan and Ramachandra Murty, V (2013) Production and properties of a lipopeptide biosurfactant by B. subtilis subsp. inaquosorum. Journal of Microbiology and Biotechnology Research , 3 (4). pp. 63-73. ISSN 2231-3168

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Abstract

The capability of indigenous bacteria isolated from soil adjoining a petroleum storage depot to produce biosurfactants was investigated in the study. A total of nine bacteria were isolated and a series of preliminary screening tests were conducted. One of the isolates, showing excellent potential for biosurfactant production, was identified as Bacillus subtilissubsp. inaquosorum by 16s rRNA analysis. Shake flask fermentation studies with used engine oil as sole carbon source were performed. After 120 h, the Bacillus was able to produce a maximum of 1.18 g/L of crude biosurfactant. It also reduced the surface tension of the medium to a least value of 31.6 mN/m after 108 h.The extracted biosurfactant was confirmed to havea lipopetidic composition using FTIR spectral data.The stability analysis involved monitoring the surface tension and emulsification index of the cell-free culture broth, exposed to highly reduced/elevated levels of pH (2-12), temperature (4ºC-121ºC) and salinity (0-20% w/v NaCl). It was found that the extracted biosurfactant was rigorous enough to withstand the tougher physical conditions without compromising on the surface tension and emulsification properties.Sand pack studies conducted at ambient and higher temperatures also proved the suitability of the extracted biosurfactant for operations involving reclamationof residual oils.

Item Type: Article
Uncontrolled Keywords: Biosurfactant, B.subtilis, Stability test, Sand pack test, Surface Tension.
Subjects: Engineering > MIT Manipal > Biotechnology
Depositing User: MIT Library
Date Deposited: 07 Nov 2013 11:35
Last Modified: 16 Nov 2013 05:47
URI: http://eprints.manipal.edu/id/eprint/137669

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