Biodegradation Potentials of Fungi Isolated from Hydrocarbon-Polluted Soil of Umungede, Owaza in Ukwa West Local Government, Abia State, Nigeria

Petroleum hydrocarbon contamination from the oil and gas industry's operations, including oil spills, tank leaks, lubrication, petroleum extraction, transportation, and services, is one of the major environmental issues affecting the world today. The bioremediation and degradation of hydrocarbon pollutants from the environment have been accomplished using various methods, including mechanical and chemical procedures; however, some of these processes are typically costly and may have negative environmental impacts. This research is designed to isolate, characterise, identify and determine the ability of fungi to degrade hydrocarbons present in crude oil while quantifying their degree of effectiveness. The Soil sample used in this research was aseptically collected from Umungede, Igiriukwu, in Owaza village of Ukwa West LGA, Abia State, and sent to the research laboratory. Growth and degradation studies were conducted over a time course using standard methods, including the gravimetric method of estimation and gas chromatography-mass spectrometry (GC-MS) analysis. The biodegradation studies were conducted over a 15-day period, and the initial and final total petroleum hydrocarbon concentrations in the various setups, which contained the isolated fungi, crude oil, and growth media, were calculated. The results of the screening revealed that the yeast Pichia kudriavzevii/Issatchenkia orientalis, more commonly known as Candida krusei, had the highest percentage of degradability potential, at 98.23%. The Aspergillus niger closely followed these strains, XM_MG659649.1, MW_186673.1, and MT_729936.1, which also showed a very high degradation potential of 96.56%, 91.66%, and 94.26%, respectively. Aspergillus terreus also demonstrated a good degradation ability, but it was the least effective among the organisms studied in this research setup. Based on this study, it can be summarised that fungi are highly effective and efficient at removing hydrocarbon pollutants from sediments, oil, and water. However, since the potential of fungus has not yet been fully realised, further research is advised, particularly in the contemporary proteomic and genomic era.