Screening for Biodegradative Activity of Diesel Oil by Microorganisms Isolated from Petroleum Polluted Soil of a Mechanic Workshop at AKAD Community, Akure, Nigeria

The present study explored the use of anatomical characters of Sataria barbata and Brachiaria deflexia as indicators of waste engine oil pollution. Four (4) kg of air dried soil was measured into perforated plastic buckets and treated with waste engine oil to obtain different concentrations [0% (control), 2%, 4%, 7% and 10%] on volume to weight basis.The experiment was set up in 3 replicates. The soil samples were allowed to stand for seven days before seedlings were planted. The plants were harvested after 8 weeks of transplanting. Anatomical investigations of the leaves, stems and roots and the epidermal peel of the leaves were carried out. There was reduction in cell size, increase in cell shape irregularity,increased thickness of cell walls of the parenchyma tissues and breakdown of vascular bundles as oil concentration increased in stem anatomy. There was reduction in root cell size, increase in cell shape irregularity and increased thickness of cell wall of the parenchyma tissues and break down of cortex region as oil concentration increased. The leaves epidermal cells showed that both grass species exhibited irregular epidermal cell shape and sinuous cell walls. Waste engine oil contaminated soil had adverse effect on the grass species studied. The effect was significantly different at (p<0.05).