Isolation and Screening of Biosurfactant producing Bacteria, their characterization and their potential applications

Biosurfactants, are amphiphilic substances generated on the cell membrane that have a tendency to lower surface tension, to lower the toxicity and to increase the biodegradability. This study focused on isolation, screening and identification of biosurfactant producing bacteria, their extraction and potential applications in enhancing plant growth and their antimicrobial activity. The bacteria were isolated from the soil polluted with old motor oil. The ability to produce biosurfactants was examined using series of tests including the emulsification index test, drop collapse assay, blood hemolysis, oil spread assay and microplate assay. The effective isolate was identified as Pseudomonas citronellolis by 16s rRNA sequencing. Further the extraction and characterization of rhamnolipid were carried out. The characterization report from FTIR matches with the functional groups of rhamnolipid. Thus, the extracted rhamnolipid were explored for exhibiting their interest towards various biotechnological approaches. The antimicrobial activity of the extract was assessed against the selected pathogens and their applications in the plant growth showing enhanced growth compared to the control. This study can be further used to formulate rhamnolipid in large scale as plant growth promoter and oil cleanser in the future.