Bacteriological and Physicochemical Assessment of Top Soils Collected from a Commercial Oil Palm Plantation and an Open Dumpsite

Standard bacteriological methods and physico-chemical procedures were utilized in the determination of the isolation and enumeration of the culturable heterotrophic bacterial flora, MCPA utilizing bacteria and physico-chemical profile of top soils collected from a variety of edaphic sites under varying anthropogenic usages. The mean heterotrophic bacterial count ranged from 3.5 × 104 - 1.15 × 105 cfu/g. No MCPA-utilizing bacterial counts were recorded for all the soils after seven days. The observed differences in the mean counts were not significant (P>0.05). Seven (7) tentatively identified bacterial isolates were characterized and they include Bacillus alvei, Bacillus licheniformis, Bacillus polymxa, Achromobacter xylosoxidans, Aeromonas hydrophila, Klebsiella oxytoca and Pseudomonas mendocina. A. xylosoxidans had the highest percentage frequency of occurrence while P mendocina was the least isolated soil borne bacterial specie. All the soils were both acidic and sandy. The ammonia-nitrogen and phosphate data varied from 6.12 - 17.80 mg/kg and 19.09 - 56.23 mg/kg respectively. The non-isolation of MCPA utilizing bacterial species from the soils using MCPA-MSA was reflective of the unsuitability of the culture medium in the preliminary recovery of this unique group of herbicide degrading bacteria.