Bioremediation of heavy metal in crude oil contaminated soil using isolated Indigenous microorganism cultured with E coli DE3 BL21

Oluwamodupe Emmanuel Giwa, Francisca Omolara Ibitoye

Soil contamination from crude oil have often been observed in recent years to increase the heavy metals and some hydrocarbon level in the environment from the soil to the plant and animals from the soil and hence the risk of bioaccumulation of this toxic compounds in the ecosystems which may threaten the human health in the endemic society. Bioremediation potency of individual indigenous bacteria isolated from soil polluted with crude oil was evaluated. Conventional method of identification was used to isolate and identify the indigenous microbes and the following were identified; Bacillus spp, Staphylococcus aureus, Micrococcus sp and Pseudomonas aeruginosa. The microbial accounts of total viable count after bio-augmentation 4.3×108, 2.7×108, 2×107 and 1.6×107 CFU g−1 for Pseudomonas aeruginosa, Bacillus spp, Micrococcus sp and Staphylococcus aureus respectively. Each microbe was bio-amplified in an improvised bioreactor containing nutrient broth and re-inoculated into a 20 gram of sterilized polluted soil with crude oil to ensure mono-bioremediation. The heavy metal analyses were carried out using AS machine in the space of 60 days. There was a significant different at a probability level 0.05 in the degree of bioremediation in all the treatment using t-test, comparing the Bio-Augmented Mechanic Site Sample + PET system and Bio-Augmented Mechanic Site Sample. PET System E. coli DE3 BL21 aided in a synergistic relationship with each selected bacteria to achieve remediation of the polluted soil which may be associated with natural gene sharing and protein amplification by the PET system. Moreover, the gene in each isolated indigenous bacteria encoding bioremediation should be excised and cultured with PET system (E. coli DE3 BL21). The proteins harvested may be used directly to study its bioremediation potentials.