Isolation and screening of high efficiency biosurfactant-producing bacteria Pseudomonas sp.

Abstract

Biosurfactants are becoming an important alternative to chemical surfactants in almost every sector in the modern industry because of their improved properties compared to their chemical counterparts. The aim of this study is to isolate and identify bacterial strain from different environment conditions with the capacity to produce rhamnolipid-biosurfactants when grown on blue agar plate (BAP) selective medium. Five strains were screened out using the combination of modified drop-collapse test, oil spreading and emulsification index (E24) test. A strain with an outstanding performance and demonstrated good activity in all the above screening methods was successfully isolated and had shown comparable results against Triton-X 100, a chemical surfactant. The emulsifying capacity of this strain was evaluated by the emulsification index (E24) and it ranged from 54.7% - 62.1%. Using the morphological and BiologGen III MicroPlate analysis, the strain was identified as Pseudomonas aeruginosa. In this study, an efficient and simple protocol to screen out rhamnolipid-biosurfactants producing bacteria was used and this finding will also help to add novel members to the biosurfactants group as well as expanded its current knowledge regarding the diversity and productive capability biosurfactants from a single specific strain. Therefore, this strain might be useful as an alternative to chemical surfactants for a wide range of potential applications.