Abstract

Petroleum hydrocarbons enter the environment through oil spills, improper waste management, industrial effluent discharge, and other anthropogenic activities, resulting in ecological degradation. Crude oil contamination is a major environmental problem that adversely affects soil quality and microbial diversity. This study investigated the physicochemical and fungal populations associated with crude oil-contaminated soils in Ataba, Andoni, Rivers State, Nigeria. Seven soil samples were collected from different contaminated sites and analyzed using standard microbiological methods. Total heterotrophic fungi (THF) and hydrocarbon-utilizing fungi (HUF) were enumerated using the spread plate technique. Pure fungal cultures were isolated and characterized based on their cultural and microscopic features. The THF counts ranged from 3.3 × 10⁴ to 6.5 × 10⁵ CFU/g, while HUF counts ranged from 1.7 × 10⁵ to 6.7 × 10⁶ CFU/g. The fungal isolates identified included Aspergillus niger, Aspergillus spp., Penicillium spp., Candida spp., Mucor spp., Blastomyces spp., Trichosporon spp ., Fusarium spp., and Rhizopus spp. The physicochemical parameters were low in concentration across the sampling locations. The occurrence of hydrocarbon-utilizing fungi in the contaminated soils demonstrates their adaptation to petroleum-polluted environments and their ability to metabolize hydrocarbon compounds. The findings of this study indicate that crude oil-contaminated soils in Ataba harbor diverse fungal species with biodegradation potential. These indigenous fungi may serve as valuable candidates for bioremediation and the cleanup of crude oil-polluted environments. Their application could contribute to environmentally sustainable management of petroleum-contaminated sites.