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Evaluation of screening methods for demulsifying bacteria and characterization of lipopeptide bio-demulsifier produced by Alcaligenes sp.
- Source :
-
Bioresource technology [Bioresour Technol] 2009 Feb; Vol. 100 (3), pp. 1358-65. Date of Electronic Publication: 2008 Sep 16. - Publication Year :
- 2009
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Abstract
- In this paper, surface tension measurement, oil-spreading test and blood-plate hemolysis test were attempted in the screening of demulsifying bacteria. After the comparison to the screening results obtained in demulsification test, 50 mN/m of surface tension of culture was proposed as a preliminary screening standard for potential demulsifying bacteria. For the identification of efficient demulsifying strains, surface tension level was set at 40 mN/m. The detected strains were further verified in demulsification test. Compared to using demulsification test alone as screening method, the proposed screening protocol would be more efficient. From the screening, a highly efficient demulsifying stain, S-XJ-1, was isolated from petroleum-contaminated soil and identified as Alcaligenes sp. by 16S rRNA gene and physiological test. It achieved 96.5% and 49.8% of emulsion breaking ratio in W/O and O/W kerosene emulsion within 24h, respectively, and also showed 95% of water separation ratio in oilfield petroleum emulsion within 2h. The bio-demulsifier was found to be cell-wall combined. After soxhlet extraction and purification through silicon-gel column, the bio-demulsifier was then identified as lipopeptide biosurfactant by TLC and FT-IR.
Details
- Language :
- English
- ISSN :
- 1873-2976
- Volume :
- 100
- Issue :
- 3
- Database :
- MEDLINE
- Journal :
- Bioresource technology
- Publication Type :
- Academic Journal
- Accession number :
- 18799309
- Full Text :
- https://doi.org/10.1016/j.biortech.2008.08.004