ISOLATION AND CHARACTERIZATION OF SOIL MICROBIAL FLORA THAT DEGRADES DEISEL OIL

ABSTRACT Crude oil is a mixture of a thousand of various compounds, organic and inorganic, including aliphatic and aromatic hydrocarbons. Diesel is produced from the fractional distillation of crude oil. The purpose of the research work is to study and determine diesel degradation potential of soil bacteria from farmlands or agricultural soils. McConkay and Potato Dextrose Agar were the culture media used for the isolation of bacteria and fungi from the diesel soaked cotton wool buried in the soil sample. The microbial load for a period of eight weeks was observed and enumerated. A total number of twenty-five isolates were obtained, fifteen bacterial isolates and ten fungal isolates. Bacillus species which was the dominant bacteria species was introduced into mineral salt broth and its absorbance for five days interval was measured with Spectrophotometer at wavelength 540nm. The increasing turbidity in the mineral salt broth shows that Bacillus species which is an indigenous bacteria from the soil sample obtained from farm soil is capable of degrading diesel.