Assessment of the Population and Species Diversity of Fungi in Diesel ContaminatedSoil

Petroleum contamination is a known environmental challenge in the South-South regionof Nigeria. This study investigated the fungal population and diversity of diesel contaminatedsoil close to a petroleum dispensing station in Port Harcourt. Four composite soil samples werecollected equidistance from the polluted site and designated as A, B, C and D. An unpollutedsoil sample designated E served as control. The cultivation and isolation of fungi fromthesoil samples were carried out by plating aliquot of serially diluted samples onto sterile SabouraudDextrose Agar in Petri dishes. Cultured plates were incubated at room temperature for 3to5days for the growth of fungi. Colonies which developed were counted and identified throughmacroscopic and microscopic methods. Fungal population were found to decrease in the diesel oil polluted samples (A, B, C, and D) and increased in the unpolluted soil sample E. This showsthat the diesel oil has a decreasing ef ect on soil fungi population as depicted in the dropof themean count spore forming units (SFU) from 620 x10 5 SFU/gt to 2.15 x 10 5 SFU/g withthecontrol recording the highest count of fungi. Some fungi isolated from the soils and identifiedwere: Penicillium chrysogenum, Aspergillus niger, Rhizopus oligiosporus, Fusariumsolani, Thrichoderma sp., Alternaria sp., Pichia sp. And other species of Aspergillus. Amongst theisolates, Aspergillus niver and Penicillum chrysogenum were predominant and showedfast growth rates and are suggestive for utilization and biodegradation of diesel hydrocarboninthepolluted soils.