Screening of Biosurfactant-producing Bacteria from Symbiotic Microbes with Gastropods in the Persian Gulf

Abstract

Introduction: Biosurfactants or surface-active compounds with amphiphilic molecular structures, including a hydrophilic and a hydrophobic domain, are produced by microorganisms. These compounds increase the biodegradation of hydrocarbons in the environment due to their ability to emulsify hydrocarbon-water mixtures. This study was conducted to isolate and characterize biosurfactant-producing bacteria from the samples of Gastropods. 
 Materials and Methods: The gastropod samples were collected from oil-contaminated sites in the Persian Gulf, Middle East. Biosurfactant-producing strains were isolated from these samples. The biosurfactant production ability was analyzed using Drop Collapse TEST, oil spreading test, emulsification activity test, and BATH test.
 Results: In total, 11 biosurfactant-producing strains were isolated. Two isolates with higher growth rates and biosurfactant production ability were selected for further studies. The best isolates were identified as Halomonas sp. isolate BHA16 and Vibrio alginolyticus isolate BHA 17 based on molecular analysis. Gas chromatography analysis of remaining crude oil confirmed that these strains could degrade to 51.44 % and 67.58% of crude oil, respectively.
 Conclusion: The results of this study indicated the surfactant activity of the bacterial strains isolated from Gastro pods had a good potential for the biodegradation of crude oil and could be used for the cleanup of oil-contaminated marine environments.