Efficacy Of Indigenous Microbes for Removal of Oil Contaminated Soil by Producing Biosurfactant

Abstract

Bacteria with ability to produce biosurfactants have potential applications in environmental protection. They are surface active chemicals that can lower the surface tension between two liquids or a solid and a liquid. Microorganisms of several types manufacture them. Objective: To isolate, optimize, screen, and describe bacteria that produce biosurfactants from petroleum-contaminated soil. Methods: Isolates were named as ZMS1 and ZMS2, which were gram positive rods with mucoidy colonies and off white or colorless appearance, respectively. The isolation was carried out using initial screening methods including blood hemolytic assay, foaming activity, emulsification assay and oil spreading technique in kerosene supplemented media at culture conditions of pH7 and temperature 37ºC. Results: The results of these different tests showed the production of biosurfactant by bacteria. Stain removal efficiency of bacterial supernatant considered as a biosurfactant, was also tested following previously described method. Both isolates, ZMS1 and ZMS2 were producing biosurfactants with the capacity remove stains of blood and tea. Furthermore, to get the biosurfactant production using cheaper carbon source, potato peel extract and molasses extract were used as a carbon source in synthetic medium for the growth of ZMS1 and ZMS2. Despite the fact that the isolates produced biosurfactant, they were not purified or eluted. However, both the isolates ZMS1 and ZMS2 shown their significance in several biotechnological and industrial domains. Conclusions: Present study will be helpful in future and these microbes can be utilized for the remediation of oil polluted soil, which in turn can be proven in the improvement of soil fertility.