Isolation and Characterization of Biosurfactant Producing Bacteria from Caspian Sea

• Published in: Biotechnology (Faisalābād, Pakistan) Vol. 9; no. 3; pp. 378 - 382
• Main Authors: Safary, A., Ardakani, M. Roayayi, Suraki, A. Abolhasani, Khiavi, M. Akbarzade, Motamedi, H.
• Format: Journal Article
• Language: English
• Published: 01.09.2010
• Subjects: ISW, Iran; Eurasia, Caspian Sea
• ISSN: 1682-296X
• DOI: 10.3923/biotech.2010.378.382

Marine biosurfactants produced by some marine microorganisms have been paid more attention, particularly for the bioremediation of the sea polluted by crude oil. The goal of this study was isolation and characterization of biosurfactant producing bacteria from Caspian Sea water. Ten morphologically distinct microbial colonies were isolated and screened for biosurfactant production. From the results, two strains isolated from Caspian Sea in Iran, which were able to grow on crude oil as sole carbon sources and to produce biosurfactants. Primary screening of biosurfactant-producing colonies was performed using the qualitative drop-collapse test, oil displacement test and hemolytic test. Among two strains CpAl completely emulsified crude oil in MSM medium within 48 h of cultivation. This strain exhibited the highest activity for oil displacement test toward crude oil (3.14 cm super(2)) and emulsification activity. In second screening, the surface tension of culture supernatants for CpAl isolate grown under identical conditions was measured by Captive Drop Cell instrument. This strain reduced the growth medium surface tension below 40 mN m super(-1) and selected as a best biosurfactant producer in this study.