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Table 2 Demulsification percentage of motor oil emulsions in distilled water and in sea water after addition of biosurfactants

From: Yeasts and bacterial biosurfactants as demulsifiers for petroleum derivative in seawater emulsions

Microorganisms Biosurfactant concentration Demulsification of motor oil (%)a
Oil-in-water (O/W) emulsions
Distilled water Sea water
C. sphaerica Cell-free broth 39.0 ± 0.9 40.6 ± 0.5
½ CMC 35.0 ± 0.9 38.2 ± 0.6
CMC 36.9 ± 0.7 38.4 ± 0.7
2 × CMC 37.0 ± 0.9 39.4 ± 0.8
C. lipolytica (a) Cell-free broth 30.0 ± 0.9 36.0 ± 0.9
½ CMC 37.9 ± 0.4 37.0 ± 0.9
CMC 37.0 ± 0.9 42.4 ± 0.8
2 × CMC 35.7 ± 0.3 43.0 ± 0.9
C. lipolytica (b) Cell-free broth 27.3 ± 0.7 26.9 ± 0.9
½ CMC 27.0 ± 0.6 27.0 ± 0.9
CMC 27.0 ± 0.9 26.7 ± 0.6
2 × CMC 27.0 ± 0.5 27.3 ± 0.5
C. guilliermondii Cell-free broth 31.7 ± 0.9 44.9 ± 0.9
½ CMC 40.0 ± 0.7 40.7 ± 0.4
CMC 42.6 ± 0.3 44.6 ± 0.9
2 × CMC 42.1 ± 0.9 41.0 ± 0.9
P. cepacia Cell-free broth 30.6 ± 0.7 39.0 ± 0.9
½ CMC 34.0 ± 0.9 45.0 ± 0.9
CMC 43.3 ± 0.7 37.5 ± 0.5
2 × CMC 43.8 ± 0.5 65.0 ± 0.9
Bacillus sp. Cell-free broth 42.0 ± 0.9 37.0 ± 0.9
½ CMC 46.6 ± 0.9 40.0 ± 0.8
CMC 47.0 ± 0.9 54.4 ± 0.9
2 × CMC 60.1 ± 0.8 66.0 ± 0.9
P. aeruginosa Cell-free broth 44.0 ± 0.5 50.0 ± 0.6
½ CMC 21.2 ± 0.4 29.1 ± 0.8
CMC 48.0 ± 0.9 50.0 ± 0.9
2 × CMC 62.0 ± 0.9 65.7 ± 0.6
  1. Results are expressed as mean ± pure error
  2. aControl values for the demulsification in the absence of biosurfactants were less than 5%