Chikezie PC, Chioma Y Ezirim, Kizito M Iheanacho and Ngwu R Nwachukwu
The levels of activities of dehydrogenase, hydrogen peroxidase, catalase and lipase of different soil strata from hydrocarbon polluted site (HCPS), domestic waste polluted site (DWPS) and palm oil mill effluent polluted site (POMEPS) as well as unpolluted site were evaluated. Soil samples, namely, subsoil from 50 cm below soil surface, and topsoil were collected from different locations in Egbema urban area in Ohaji/Egbema local government area of Imo state, Nigeria. Soil enzymes activities were measured using spectrophotometric and titrimetric methods. Dehydrogenase activities of topsoil and subsoil from POMEPS were significantly (p<0.05) higher than those from unpolluted site. Comparative analysis of soil enzyme activity showed that topsoil and subsoil from HCPS gave the highest hydrogen peroxidase activity of 8.48 ± 0.01 × 10-3 U/g and 7.52 ± 0.02 × 10-3 U/g respectively. Topsoil from POMEPS gave the highest lipase activity of 1.90 ± 0.02 U/g and was followed by lipase activity of subsoil from DWPS=1.85 ± 0.02 U/g. Catalase activity of the subsoil was significantly (p<0.05) higher than that of the topsoil from all soil sites. The overall variability in enzymes activities of soil strata from different polluted sites defined the pattern of soil contamination, which could serve as biomarkers for ascertaining level of soil pollution as well as monitorial indices for bioremediation.