ABSTRACT
The objectives of this experiment were to isolate halotolerant bacteria capable of degrading petroleum hydrocarbons and to determine the optimum conditions for their oil-degrading activity. Bacterial strain DM-1 could utilize oil as a sole carbon and energy source and efficiently degrade petroleum hydrocarbon. Based on its morphological and physiochemical characteristics as well as on Biolog analysis, strain DM-1 was identified as Bacillus subtilis. Strain DM-1 grew well at NaCl concentrations ranging from 5 to 70 g/L, and thus was classified as moderately halotolerant. Environmental conditions significantly influenced the oil-degrading ability of DM-1. A single factor experiment showed that the optimum degradation conditions for strain DM-1 were an initial pH of 7.5, a temperature of 30°C, a salt concentration of 5 g/L, and an inoculation amount of 10%. Under these conditions, strain DM-1 could degrade 66.94% of the petroleum hydrocarbon in 7 days.
