ANTIMICROBIAL POTENTIAL OF MUCIN EXTRACTED FROM GIANT AFRICAN LAND SNAIL (ACHATINA FULICA) ON MICROORGANISMS ISOLATED FROM SOKOTO WHITE COWPEA (VIGNA UNGUICULATA (L.) WALP.)

Abstract

Cowpea (Vigna unguiculata), especially the Sokoto white variety, is a vital legume widely consumed in Nigeria due to its nutritional and economic value. Despite this importance, stored grains are vulnerable to microbial contamination, which undermines quality and food safety. Mucin extracted from the giant African land snail (Achatina fulica) has been noted for antimicrobial properties, yet its effect on cowpea-associated microbes remains insufficiently studied. This research evaluated the antimicrobial activity of snail mucin against microorganisms isolated from stored Sokoto white cowpea. Samples were collected from five major markets in Ogun State and subjected to standard microbiological analyses. Bacteria were identified through morphological, Gram, and biochemical tests, while fungal isolates were characterized using lactophenol cotton blue staining. Five bacterial species (Shigella sp., Enterococci sp., Staphylococcus sp., and Pseudomonas sp.) and five fungal species (Aspergillus flavus, A. niger, A. fumigatus, Fusarium sp., and Trichoderma sp.) were detected. Bacterial counts ranged from 30 to 292 cfu/g, while fungi recorded 52–384 cfu/g, with some plates yielding uncountable colonies. Aflatoxigenicity screening revealed A. flavus and Fusarium sp. as toxin producers. Antimicrobial testing indicated that snail mucin showed no inhibition against most isolates, except for A. flavus, which displayed a minimal inhibition zone (6.10 ± 0.05 mm). In contrast, conventional antibiotics demonstrated significant efficacy against bacterial isolates. These results underscore the microbial risks associated with cowpea storage and reveal that snail mucin has limited antifungal activity. Improved storage and handling practices remain essential for minimizing contamination and safeguarding food safety.