Microbiology and Heavy Metal Content of Wetlands Impacted by Crude Oil Pollution in Rivers State, Southern Nigeria

Abstract

Wetland soils constitute vast, under-exploited and sometimes undiscovered ecologies in many countries of the World, including Nigeria. A total of 54 wetland soil samples including surface and subsurface soil at depths of 0-15 cm and 15-30 cm were collected using a sterile hand auger for a period of three months between August and October and subjected to standard and analytical microbiological procedures. The wetland soil samples were further subjected to atomic absorption spectroscopy (AAS) to check for presence and concentration of heavy metals. Results obtained showed that apart from heterotrophic bacterial and fungal counts, hydrocarbon utilizing bacteria (HUB) counts were higher in the surface soil ranging from 12.06±3.43bX107 cfu/g at Iwofe to 6.19±2.67aX107 cfu/g at Chokocho while subsurface soil had HUB ranging from 8.91±6.67aX103 cfu/g at Eagle Island to 4.93±3.95aX103cfu/g at Chokocho. Heavy metals such as Fe, Pb, Cd and Ni were recorded in concentrations above FEPA permissible limit in the surface and subsurface soil across the three wetlands. The heavy metal concentration in each wetland however, decreased with an increase in soil depth. According to literatures, elevated levels of heavy metals in soils decrease microbial population, diversity and activities. However, the microbial population in this study increased with increasing heavy metal concentration which indicates that the microbes can tolerate or utilize heavy metals in their systems; as such can be used for bioremediation of heavy metal polluted soils.

Microbiology and Physicochemical Characteristics of Surface Water from a Local Refinery Site in Port Harcourt, Nigeria

“…The diversity of microbial groups observed upstream and downstream in this study may have been favoured by the interplay of the various ecological factors and anthropogenic activities. Such plethora of microorganisms have also been reported by other researchers [9,11];…”

“…The morphological characteristics and biochemical reactions of the bacterial isolates revealed the presence of microorganisms such as Hafnia alvei, Staphylococcus aureus, Escherichia coli and Brenneria species in the surface water. Some of the fungal species isolated from the water samples were Aspergillus species, Penicillium species and Fusarium species which are known hydrocarbon utilizing organisms [11] (Table 3). In the MPN test for detection of coliforms, Table 4 shows that all the tubes produced acid and gas in each dilution after incubation.…”

“…Other microorganisms such as Anabaena and Nostoc species have been successfully used in the remediation of oil-polluted aquatic ecosystems [8]. Among the isolates were Penicillium and Aspergillus species which have been said to have hydrocarbon utilizing abilities [11].…”

Molecular Characterisation and Plasmid Profiling of Hydrocarbon Utilizing Bacteria Isolates from Wetlands in Rivers State, Southern Nigeria

“…The presence of microbial activity was determined by the enumeration and isolation of total heterotrophic and hydrocarbon utilizing bacteria carried out and presented in previous work of Chibuike et al [29].…”

Seasonal Influence on the Microbiology and Physicochemistry of Crude Oil Polluted Wetlands

“…[26] Moisture Content [27] Chlorine (Hanna Multipurpose Meter) [28] Bromine (Hanna Multipurpose Meter) [28] Nitrogen (Hanna Multipurpose Meter) [28] Phosphorous (Hanna Multipurpose Meter) [28] Potassium (Hanna Multipurpose Meter) [28]…”