BACTERIOLOGICAL AND MINERAL STUDIES OF ROAD SIDE SOIL SAMPLES IN ADO-EKITI METROPOLIS, NIGERIA

Abstract

The bacteriological and heavy metal analyses of road side soil samples in Ado-Ekiti metropolis, Nigeria were investigated. Bacterial population of the soil samples were analyzed using serial dilution procedure and pour plate method for the isolation of organisms. Biochemical tests like catalase, citrate were used to identify the isolated organisms. Atomic absorption spectrophotometry method was used to analyze the heavy metal contents in the soil samples. The mean total bacterial count ranged between 1.60 x 102 CFU.g-1 and 14.5 x 103 CFU.g-1; while the mean total coliform count ranged between 0.3 x102 CFU.g-1 and 2.0 x 102 CFU.g-1. There was significant difference at 0.05 level between the mean total bacteria and total coliform counts of the soil samples at 40meters distance to the major road. There were significant difference within the group of total bacteria and coliform counts at 0.05 level. Staphylococcus spp have the highest frequency of occurrence of 41.5% while Proteus spp have the least frequency of occurrence of 1%. The heavy metal contents of the road side soil samples ranged as follows: zinc (8.45 - 325.22 mg.kg-1), lead (0.25 - 174.21 mg.kg-1), copper (1.56 - 40.33 mg.kg-1), cobalt (0.37 - 140.33 mg.kg-1), and mercury (0.01 - 4.52 mg.kg-1). Conclusively, heavy metals contents had negative effect on the organisms in the soil and also on the environment.