| Abstract |
Some bacteria with different mechanisms for hydrocarbon
degradation were isolated from oil-contaminated soils in
Korea. Isolate Acinetobacter calcoaceticus SL1 showed
biosurfactant- producing activity in oil-spreading test, and it
exhibited a good emulsifying activity of 43.6 and 54.5% for
diesel oil and n-hexane, respectively. It also has high cell
surface hydrophobicity which can make it easily attaches to
hydrocarbons and degrade them. It degraded 100% of 1,000
mg/L of n-octadecane and naphthalene, respectively in 3 days,
72.3% of 1,000 mg/L diesel oil in 7 days and 78.0% of 10,000
mg/L diesel oil in oil-contaminated soil during 28 days. Isolated
strains Bacillus amyloliquefaciens S10 and B. subtilis GO9 can
produce biosurfactant and formed 6.34 and 2.5 cm diameter of
clear zones, respectively in oil-spreading test. Surface tension
of their culture supernatant reduced from 74.6 to 34.4 and 33.3
mN/m, respectively during incubation, and critical micelle
concentrations of culture supernatants were 2.0 and 5.9%,
respectively. Consortium of A. calcoaceticus SL1 and B.
amyloliquefaciens S10 degraded 77.8% of 10,000 mg/L diesel
oil in 3 days, which indicated more efficient oil degradation
than that by A. calcoaceticus SL1 alone. If these bacteria were
applied together as a consortium to oil-contaminated sites, they
may show a high removal rate of petroleum hydrocarbons. |
