ABSTRACT

 The microorganisms capable of degrading crude oil are present in any conceivable environment. This study was aimed at ascertaining the microbial and physicochemical properties of soil contaminated with used petroleum product. Soil sample were collected randomly from mechanic workshop, filling station, motorcycle workshop and generating plant. Soil sample contaminated with used petroleum product were analyzed for Total heterotrophic bacterial counts (THBC), hydrocarbon utilizing bacteria (HYCUB), total heterotrophic fungi (THF), and hydrocarbon utilizing fungi (HUF). The result showed that total heterotrophic bacterial count ranged from 2.2 x iü — 1.90 x 108 cfu/g while total fungi count was in the range of 8 x 106 -iü x cfu/g and Hydrocarbon utilizing bacteria was in the range of 1.4 x 106 — 7.8 x 106 cfu/g and hydrocarbon utilizing fungi was in the range of 4 x 106 7.8 x 106 cfu/g. Bacteria of diverse species were isolated from contaminated soils at the end of the study. The following physico-chemical properties were analyzed; Temperature, pH, Ca2 ,Mg2 , K4, Na4, No34No2, Po4, Fe ,Zn,So oil and grease and organic carbon. The results are as follows. Temperature value was ranged from 29 °C- 30°C pH values ranged from pH 5.85 — pH 6.94. The mean values for Ca24, Mg2and K' was ranged from 17.31 - 64.29mg/kg ,0.60 -3.55mg/kg and 0.69 -3.55mg/kg while the mean values for Na4 ,Fe, Zn, organic carbon and oil and grease were 85.81 — 206.76mg/kg ,0.82- 2.15mg/kg, 1.74 -5.74mg/kg, 4..81 -7.47%, and 6.76 - 16 .74mg/kg. Similarly the mean values for, s5o4No3, Po4, and No2was ranged from 11.93-63.7lmg/kg,9.56 - 33.66mg/kg,0.64 -3.54mg/kg and 5.39 -53.79mg/kg. The result of the study has revealed that used petroleum product have an increasing effect on soil physicochemical characteristics and that some of these physico-chemical characteristics may have effect on microbial counts.