Table 4.

Demulsification performance on W/O (Tween–kerosene) and O/W (Span–Tween–kerosene) model emulsions by the crude biosurfactants (cell-free broth)

Biosurfactant producers	Model emulsions demulsification (%)a
	W/O	O/W
C. sphaerica	90.0 ± 0.9	94.7 ± 0.4
C. lipolytica (a)	38.2 ± 0.9	35.7 ± 0.4
C. lipolytica (b)	44.0 ± 0.9	45.2 ± 0.9
C. guilliermondii	30.0 ± 0.9	32.0 ± 0.9
P. cepacia	30.0 ± 0.9	33.4 ± 0.8
Bacillus sp.	37.0 ± 0.9	41.0 ± 0.9
P. aeruginosa	35.0 ± 0.9	38.2 ± 0.5

Results are expressed as mean ± pure error

^aControl values for the demulsification in the absence of biosurfactants were less than 5%