Biosurfactant production by bacteria retrieved from hydrocarbon polluted environment

Abstract

Bacterial isolates retrieved from stagnant water and hydrocarbon polluted soil using enrichment culture technique were studied for biosurfactant production. Sixteen isolates, showing blood agar haemolysis, were screened for biosurfactant production. Highest oil displacement was generated by isolate BK68 (0.0623 m) followed by 0.0248m, 0.0223m and 0.0206m by isolates BK23, BK34 and BK48, respectively. Highest E24 index was given by isolate BK66 (19.5%) followed by BK68, BK58 and BK23 (19.0%, each) after 4 days of incubation. Surface tension reduction equivalent to 0.071 Nm-1, was shown by isolate BK68, followed by BK23 (0.037 Nm-1) and BK66 (0.036 Nm-1). Promising biosurfactant producers were subjected to identification to genus level. Gram positive and endospore forming isolates BK23, BK58 and BK68 were probably Bacillus spp, while catalase positive coccus bacteria BK66 could be classified as Staphylococcus. Gram negative, oxidase positive and non-glucose fermenting rods of isolates BK34 and BK48 were probably belong to genus Pseudomonas.