Effect of Fungi Contamination of Two Varieties of Cowpea Sold in Port Harcourt Metropolis

Abstract

The microbial contamination of two cowpea varieties sold in Port Harcourt was investigated. The fungi associated with the grains were isolated by placing the cowpea seeds in sterile Petri dishes containing sizeable cotton wool dampened with 5ml sterile distilled water for seven days to allow for the growth of fungi. Proliferated fungi were later grown on freshly prepared Sabouraud Dextrose Agar plates. Pathogenicity test was carried out by inoculating isolated microbes into healthy cowpea seeds. Three fungi belonging to the genera; Mucor, Aspergillus, and Rhizopus sp were identified. The pathogenicity test showed that the cowpea seeds were infected and the weight reduced drastically. The weight of the cowpea seeds (white) before inoculation was 0.24 ± 0.03. The weight after being inoculated with Mucor sp, Rhizopus sp, and Aspergillus flavus was 0.22 ± 0.12, 0.18 ± 0.09, and 0.25 ± 0.20, respectively. The weight of the cowpea seeds (brown) before inoculation was 0.18 ± 0.05. The weight after inoculation with Mucor sp, Rhizopus sp, and Aspergillus flavus recorded 0.25 ± 0.17, 0.18 ± 0.09, and 0.31 ± 0.12, respectively. The pathogenicity test showed that the microorganisms had effects on the cowpea seeds which was observed in the increased weight of the seeds. Furthermore, the microorganisms isolated in this study could be dangerous to health if proper measures are not taken during preparation.