Abstract:
The aim of the study was to study the efficiency for biodegradation of diesel,
gasoline, used lubricating oil and crude oil under aerobic and anaerobic conditions by 3
bacterial strains including Bacillus subtilis strain SE1, SD4 and Bacillus siamensis strain
SJ1#1 which were able to produce lipopeptide biosurfactant. The results showed that all 3
strains of bacteria can grow and degrade 4 types of oil under aerobic condition more than
anaerobic condition. When considering growth, physical characteristics of oil, spectrogram
of degradation oil and total gas production indicated that B. subtilis strain SE1 showed the
efficiency of diesel, gasoline, used lubricating oil and crude oil degradation under aerobic
and anaerobic conditions while B. subtilis strain SD4 and B. siamensis strain SJ1#1 show
less efficiency, respectively. Then the study of 4 types of oil degradation by B. subtilis strain
SE1 under aerobic condition analysed using GC-MS. The study found that B. subtilis strain
SE1 demonstrated completely degraded gasoline and its metabolites in 35 days. While the
other types of oil can partially degrade as of following order gasoline diesel, used lubricant
oil and crude oil, respectively. Therefore B. subtilis strain SE1 could be applied for
bioremediation of the environment is contaminanted with petroluem oil in the future.