Assessment of mycological profile and heavy metals concentration of Orogodo River in Delta State, Nigeria

Abstract

Fungal and heavy metals pollution of rivers are of public health concerns. The mycological and heavy metal characteristics of surface water from Orogodo River in Delta State, Nigeria, were assessed during a single sampling period (February, 2025), across three sampling stations namely; Mbiri, Owa Nta and Agbor, using standard analytical methods including culture-based fungal enumeration, morphological identification and atomic absorption spectrophotometry (AAS) for the determination of metals. Fungal colony forming units (CFUs) were recorded as 10.44 ± 2.14×10³ CFU/mL, 10.44 ± 2.26×10³ CFU/mL, and 9.88 ± 1.99×10³ CFU/mL for Site I (Mbiri), Site II (Owa Nta), and Site III (Agbor), with identified aquatic fungi; Saccharomyces sp., Aspergillus niger, Fusarium oxysporum, Penicillum chrysogenum and Rhizopus sp. Species distribution analysis revealed Saccharomyces sp. as the most prevalent isolate, present in the respective stations surveyed while Penicillium chrysogenum, Rhizopus sp., and Fusarium oxysporum were among the least common. Heavy metal analysis of the river’s surface water showed elevated concentrations of iron (0.76 mg/L) and cadmium (0.05 mg/L), both of which exceeded the World Health Organization and Nigeria Standards for Drinking Water Quality permissible limits (0.3 mg/L and 0.003 mg/L). These results suggest localized fungal and metal contamination and warrant broader seasonal monitoring.