The bacterial strains namely Pseudomonas aeruginosa ZK and Bacillus subtilis S1X were isolated and cultured in the minimal salt medium (MSM) by following the procedure as described elsewhere . To determine the hydrophobicity of these bacterial strains, bacterial adhesion to hydrocarbons (BATH) and salt aggregation (SA) tests were conducted by following the test protocols as described elsewhere . All the tests were conducted in triplicate to ensure reproducibility. Briefly, during the BATH test, the bacterial cultures were centrifuged at 5500 rpm overnight at a constant temperature of 4 °C. The supernatant was discarded and the pellet was resuspended in phosphate/urea/Mg (PUM) buffer solution after washing two times with the same buffer solution. The optical density (OD) of the suspension was determined at 600nm and set to 1.0 (A0) by using a spectrophotometer (Shimadzu UV-Vis). This suspension (500 ml) was vortexed with 500 µl of hexadecane and the mixture was allowed to separate for 10-15 minutes. In this mixture, the optical density of the aqueous phase (A1) was measured at 600 nm and the degree of hydrophobicity (Dh) was calculated by using equation 1.