No abstract

The effectiveness of agricultural wastes as bioremediation materials is gaining research attention as a better option in mitigating the issue of crude oil effects in soil environment. In the present study, the growth performance of Telfairia occidentalis and Arachis hypogaea linn in crude oil polluted soil amended with plantain peels (PP) and cocoa pod husks (CPH) were investigated. Eight kilograms (8 kg) each of dried soil samples were collected and weighed into 60 polythene bags. The polythene bags except the pristine control were polluted with 80 ml of crude oil and allowed for 14 days of soil acclimatization. The treatments comprising of CPH and PP were amended after 14 days, using the following concentrations: 0, 100, 150 and 200 g and allowed to acclimatize for 60 days. T. occidentalis and A. hypogaea linn were cultivated immediately after treatment regimen. The pH of the amended and un-amended soil samples were observed to be at a range recommended for effective bioremediation of hydrocarbon polluted soil. The organic carbon content of the CPH amended soils were significantly reduced as compared to the PP amended soil. The phosphorus, nitrogen, potassium and other essential soil parameters evaluated were significantly high (P<0.05) in CPH amended soil than the PP amended soil. Crops grown in the rehabilitated soils possess a high adaptability in CPH amended soil than the PP amended soil. The amendments most preferably cocoa pod husks which tend to be more effective in the reduction of hydrocarbon content of the soil should be utilized in the enhancement of microbial degradation of crude oil product in soils.

Understanding the physiological and molecular characteristics of naturally occurring fungi in glyphosate pesticide-contaminated environment is crucial to managing its contamination. The study was aimed at isolating and characterizing soil fungi for their physiological roles towards glyphosate degradation. Pure cultures of fungi were isolated from soil contaminated with glyphosate at farms in Lagos, Nigeria. The cultures were grown on minimal salt agar media amended with glyphosate. The best isolates exhibiting good tolerance to the glyphosate were characterized using molecular techniques. The BLAST search indicated that the fungi belong to four Aspergillus species (Aspergillus flavus strain JN-YG-3-5, Aspergillus niger strain APBSDSF96, Aspergillus fumigatus strain FJAT-31052 and Aspergillus flavus strain APBSWTPF130, Trichoderma gamsii and Penicillium simplicissimum. The biodegradation study of the glyphosate by the selected fungi species showed the presence of Aminomethylphosphonic Acid (AMPA) except for Aspergillus fumigatus strain FJAT-31052. Annotation analysis of the partial gene sequence showed that the strains possess protein coding gene clusters for glyphosate utilization and other physiological activities. The GhostKOALA output confirmed that CYP2W1 gene (Cytochrome P450, fungi type) was present in Aspergillus fumigatus strain FJAT-31052 which was absent in the genome of other fungi. The physiological and molecular characteristics of Aspergillus fumigatus strain FJAT-31052 clearly show that this fungus is a useful organism for managing contamination by glyphosate pesticide.

In the present study the tolerance potentials of T. cacao in hydrocarbon polluted soil was evaluated. Top soil (0-25 cm depth) was collected from three points, bulked to form composite soil sample. Eight kilograms of the soil sample each were weighed into twenty five (25) perforated bags. The bags were polluted with 0 ml/kg, 50 ml/kg, 100 ml/kg, 150 ml/kg and 200 ml/kg of crude oil respectively with five replicates for each concentration and allowed for 2 weeks before planting. Three seeds of cocoa were sown in each of the polythene bags. Water was applied every three days to keep the soil moist. The results showed that cocoa plants at 8 weeks after planting (WAP) had significantly higher height (P<0.05) than those of 4 weeks after planting (WAP). The plant