Biodegradation of Hydrocarbons by Bacillus cereus and Enterococcus casseliflavus Isolated from Crude oil Contaminated Seafood

This study aims to determine the biodegradability capacity of Enterococcus casseliflavus and Bacillus isolated from crude oil contaminated seafood. Fresh seafood samples such as crude oil contaminated periwinkle and prawn were obtained. BOD, COD, pH, nitrate, phosphate, heavy metals (Cr, Cd, Pb, Zn), polyaromatic hydrocarbons (PAHs), total petroleum hydrocarbon (TPH} were determined. Standard microbiological methods for total heterotrophic bacterial and Lactobacillus count were determined. The isolates were molecularly identified and were subjected for biodegradability test at day 0, 30 and 60 respectively. Total bacterial count ranged 7.13 to 8.05 log10cfu/g; Lactobacillus count ranged 5.04 to 6.26 log10cfu/g in the crude oil contaminated seafood. The pH level at day zero ranges from 7.1 (neutral) to 5.8 (acidic), Phosphate ranges from 0.032 to 0.133 (mg/l), Nitrogen level ranged from 0.94 to 0.20%, Cadmium (Cd) ranged from 1.8233 to 1.3322, Zinc (Zn) ranged from 2.5334 to 1.8732, Chromium (Cr) ranged from7.5133 to 4.7221, Lead (Pb) ranged from 12.3124 to 8.3421(ppm). PAHs level ranged from 2231.1 to 1211.0 and TPH level ranged from 3342.3 to 2184.2(ppm) at day zero. The pH level at day thirty ranges from 5.8 to 6.4 (acidic), Phosphate level ranged from 0.383 to 0.110 (mg/l), Nitrogen level ranged from 2.11 to 0.50%, Cadmium (Cd) ranged from 0.6332 to 0.2104, Zinc (Zn) ranged from 1.7322 to 0.1043, Chromium (Cr) ranged from 5.2262 to 2.0122, Lead (Pb) ranged from 7.4102 to 4.611(ppm), PAHs ranged from 2238.2 to 1312.8, TPH ranged from 2238.2 to 1312.8(ppm). Whereas at day sixty, the PAHs level ranged from 72.01 to 311.2 and TPH level ranged from 221.6 to 551.2 (ppm). Biodegradation of petroleum hydrocarbons is energetically favorable, therefore indigenous hydrocarbon degrading microorganisms play a significant role in biodegradation process.