Screening for Surface-active Agent Producing Bacteria in Used Engine Oil Contaminated Soil Samples

Biosurfactant producing bacteria were isolated from engine oil contaminated soils from auto mechanic workshops in Pudukkottai, Tamilnadu, South India. Haemolytic activity, emulsification activity, drop collapsing test as well as oil displacement test were used to determine biosurfactant producing activity of isolated bacterial strains. Among 25 different strains,5 strains exhibited clear zone on blood agar plates. Five strains named PDKT1-PDKT5 were identified by 16S rRNA Sequencing as a Serratia marcescens (99%homology); a Pseudomonas aerugenosa (99%homology);a Pseudomonas sp (98% homology);a Bacillus subtilus (99 %homology) and a Bacillus licheniformis (99% homology) strain, respectively. Strain PDKT-2 showed the highest activity for oil displacement test and emulsification test. In the present study an attempt on the significant role of bacteria in the production of biosufactant was made.