Microbial dynamics and physico-chemical properties of artisanal refinery polluted environment in Niger Delta

Artisanal refining of crude oil is a common practice in the Niger Delta region of Nigeria and this has continuously posed serious environmental and health risks. This was designed to investigate the microbial dynamics and physico-chemical properties of environmental (water, sediment and soil) matrix of impacted by artisanal refining activities. Three sampling locations (Bolo, River’s state; Ekpemu, Delta state; and Twon-Brass, Bayelsa state) were studied. Finding revealed that the total heterotrophic bacterial (THB) load of the recipient water from Twon-Brass had the least count of 2.0 ±0.2 x 104cfu/ml, followed by Ekpemu (2.1 ±0.3 x 103cfu/ml), then Bolo (2.35±0.6 x 104cfu/ml). In the contrary, recipient water body in Ekpemu had the least HUB load (1.8 ±0.1 x 103cfu/ml) followed by Bolo (2.0 ±0.3 x 104cfu/ml), and Twon-Brass (2.0 ±0.8 x 104cfu/ml). The bacterial load of the un-impacted aquatic matrix revealed a higher heterotrophic bacterial load (5.8+ 0.30 x 105cfu/ml) and low HUB load (0.2+ 0.21 x 103cfu/ml). In the sediment, Bodo had the least THB load of 2.1 ±0.2 x 105cfu/g, followed by Twon-Brass (2.3 ±0.6 x 105cfu/g), and Ekpemu (2.9 ±0.3 x 105cfu/g).Bolo and Twon-Brass soil were also highly impacted with hydrocarbons with a pollution index close to 1 (HUB/THB ratio = 0.9) while Ekpemu had a pollution index of 0.7. Bacterial species associated with the samples were Bacillus subtilis, Pseudomonas putida, and Pseudomonas aeruginosa were predominant in all the sample locations. Similarly, the artisanal refining activities also altered the physico-chemical properties of the various environmental matrix studied. Based on the finding of this study, it can be predicted that bioremediation various environmental matrix by natural attenuation is ongoing as most of the organisms isolated are hydrocarbon degraders. However, it is recommended that artisanal refining activities should be discouraged.