Potential Molds and Bacterial Species Associated with Deterioration of Sweet potatoes in Kebbi State, Northern Nigeria

Abstract

The present study aimed to assess the types of microorganisms associated with two different varieties of sweet potatoes yellow skin with white flesh and white skin with yellow flesh cultivated in Kebbi. The analysis of microorganisms was done using the pour plate method. Two L.G.A and three collection points from each L.G.A were selected and sampled. Eight bacteria and five fungal species were isolated and identified from the two varieties of sweet potatoes. Bacterial species identified were; Staphylococcus aureus, Salmonella spp., E. coli, Bacillus spp., Pseudomonas spp., L. monocytogens, Klebsiella spp., and Erwinia spp., while fungal species isolates are Aspergillus spp., Mucor recemosus, Rhizopus spp., Fusarium oxysporium, and Penicillum spp., in both samples. Results revealed that yellow skin with white flesh sweet potato from Gumben kure had the highest bacterial load 7.2 x 10⁴ cfu/ml. The lowest bacterial load obtained from yellow skin with white-fleshed variety in Gwadangwaji 3.2 x 10⁴cfu/ml. The highest fungal load spore in yellow skin with white-fleshed sweet potato 2.0 x 10⁴sfu/ml was obtained from Kardi and the lowest fungal spores observed in Gulumbe white skin with yellow flesh variety 4.0 x 10⁴sfu/ml. The pathogen city test results revealed that all microorganisms isolated in this research showed varying degrees of tubers rot with Rhizopus spp., had highest and bacterial ranged from 4.0 to 2.0 depths (cm). In conclusion, the presence of these microorganisms isolated and identified from two varieties of sweet potato showed that these species are responsible for these tubers' spoilage in the study area