Synergistic Metabolism of Hydrocarbons by Bacteria from Soil

ABSTRACT
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This work was aimed at isolating and identifying hydrocarbon utilizing
bacteria from waste engine oil polluted soil and assessing their synergistic
metabolism ability using spectrophotometry analysis. Soil sample obtained
from waste engine oil polluted soil in a mechanic workshop in Uyo Akwa
Ibom State was serially diluted upto 10-4and plated out on nutrient agar
medium. Total bacterial count was 4.5×105cfu/g. Bacterial isolates identified
were Bacillussp. and Micrococcussp. The ability for hydrocarbon metabolism
of the bacterial cultures was determined in mineral salt medium containing
1% waste engine oil ,and utilization determined by measuring pH, turbidity of
the medium and total bacterial count at 3 days intervals for 9 days.Result
revealed bacterial count of (CFU/ml) C(0.2×10, 0.5×10, 0.9×10,1.1×10),
C1(3.8×109, 2.3×109, 1.2×1010, 1.8×1010), C2(5.3×109, 3.7×1010, 2.8×1010,
3.1×1010), S1(2.6×109, 3.3×109, 4.8×109, 5.6×109) and S2(4.2×109, 5.7×109,
6.3×109, 7.8×109) for total bacterial count. C(6.72, 6.67, 6.67, 6.61), C1(6.70,
6.70, 6.68, 6.66), C2(6.73, 6.70, 6.70, 6.67), S1(6.68, 6.60, 6.60, 6.55)and
S2(6.68, 6.64, 6.64, 6.60) for pH changes and C(1.600, 1.548, 1.289, 1.310),
C1(1.525, 1.670, 1.194, 1.032), C2(1.720, 1.877, 1.028, 1.330), S1(1.940,
2.097, 2.171, 2.197) and S2(2.103, 2.131, 2.153, 2.172) for turbidity
change.Degradation by mixed isolates (Bacillus and Micrococcussp) resulted
in increased bacterial count (CFU/ml) (8.6×109, 9.3×109, 1.08×1010 and
1.33×1011) at Days 1-9 respectively.Turbidity;(2.097, 2.138, 2.161 and 2.181
respectively. pH;(6.71, 6.64, 6.62 and 6.58) respectively. Thus, bacterial
consortia S1/2 showed appreciable degree of metabolizing hydrocarbon than
the individual isolates. It could therefore be concluded that synergistic
metabolism of hydrocarbons could be achieved using indigenous hydrocarbon
utilizers obtained from waste engine oil polluted soil.