MICROBIAL AND HEAVY METAL ANALYSIS OF GARDEN SOILS CLOSE TO DUMPSITES.

ABSTRACT

The African culture has always been one which practices agriculture on a subsistence scale. This results in the use of many improvised means to supply plant nutrients, such as the use of locally made fertilizers and compost. Samples used for this study were obtained from the topsoil from various locations within Benin City, Edo state, namely; Okunmagiagiemwen community, Agor-orior community, Amagada community, Ekosodin and The University of Benin. The sample collection was done with the aid of a hand trowel pre cleaned with concentrated ethanol to prevent microbial contamination. The samples were taken to the laboratory and analysed straight away. The samples were analysed for pathogenic bacterial and fungal agents using standard microbiological techniques. The samples were also analysed for their heavy metal contents using atomic absorption spectroscopy. The mean bacterial counts for the soil samples ranged from 6.4 x 10⁴ - 1.1x 10⁴ cfu/g for the soil sourced from all the dumpsites. The mean fungal counts ­­varied from 3.16 x10⁵ - 1.67x10⁵cfu/g for the control soil. Seven bacterial and nine fungal isolates were characterized and identified from the various dumpsite and control soils. The bacterial isolates were; Bacillus sp., Bacillus cereus, Pseudomonas sp., Proteus sp., Staphylococcus aureus, Citrobacter freudii and Yersinia sp. While the fungal isolates were; Aspergillus niger, Penicillum sp., Rhizopus sp., Mucor sp., Fusarium sp., Aspergillus fumigatus, Aspergillus flavus, Trichoderma sp. and Saccharomyces sp.