Table 1.

Diameter (mm) of clearing zones on the oil surface obtained from oil spreading assay with different concentrations of crude biosurfactant

Sample	PBS	Surfactin	Crude biosurfactant	Crude biosurfactant
			L. rhamnosus	L. jensenii
50 mg/ml	0.0	15.0 ± 1.0	6.8 ± 0.5	7.6 ± 0.5
25 mg/ml	0.0	15.0 ± 1.0	6.0 ± 1.4	6.0 ± 1.7
12.5 mg/ml	0.0	14.6 ± 0.5	5.3 ± 0.5	5.6 ± 1.1
6.25 mg/ml	0.0	13.0 ± 0.5	4.1 ± 0.1	3.8 ± 0.2

PBS was used as a negative control with a clearing zone diameter of 0.0 mm. Surfactin was used as a positive control. Results shown are the average of ± SD of three experiments performed in triplicate.