Comparative Activities of Soil Enzymes from Polluted Sites in Egbema, Imo State, Nigeria

Chioma Y Ezirim,Paul C Chikezie,Ngwu R Nwachukwu,Kizito M Iheanacho

doi:10.4172/2375-4397.1000185

Chioma Y Ezirim, Paul C Chikezie + Show 2 more

Open Access

https://doi.org/10.4172/2375-4397.1000185

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Abstract

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.

Highlights

Soil is an important component of all terrestrial ecosystems as well as a main source of production in agriculture and forestry
The present study provided comparative assessments on variations in activities of different soil enzymes such as dehydrogenase, hydrogen peroxidase, catalase and lipase in soil samples exposed to different pollutants
Soil dehydrogenase activity varied within the range of 7.47 ± 0.04-0.1 ± 0.01 U/g, of which topsoil from palm oil mill effluent polluted site (POMEPS) gave the highest enzyme activity (7.47 ± 0.04 U/g) followed by topsoil from domestic waste polluted site (DWPS) (4.32 ± 0.02 U/g), topsoil from hydrocarbon polluted site (HCPS) (3.43 ± 0.02 U/g) and topsoil from CONTROL site (0.10 ± 0.001 U/g) (Figure 1)

Summary

Introduction

Soil is an important component of all terrestrial ecosystems as well as a main source of production in agriculture and forestry. Soil ecosystem is an extremely heterogeneous microenvironment where physical, chemical and biological processes occur simultaneously among numerous inorganic and organic components and living organisms. Among this variety of soil components, soil enzymes exert predominant influence on the ecosystem because they (a) catalyze all the biochemical transformations occurring in soil (b) guarantee the exchange of materials among the biotic and abiotic portions and the soil ecosystem (c) allow the growth, survival and activity of soil living organisms [2]. Soil contamination or soil pollution is caused by the presence of xenobiotics or organic matters that can alter natural soil environmental indices It is typically caused by industrial activity [3], agricultural chemicals [4], or improper disposal of waste. The response of different enzyme to the same pollutant may vary greatly and the same enzyme may respond differently to different pollutant [7]

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Conclusion