Antibacterial Properties of the Predominant Microorganisms Isolated from Fermenting Cassava Tubers during fufu Production against Selected Enteropathogenic Bacteria

Abstract

Aim: This research investigated the antibacterial activities of the predominant microorganisms isolated from fermenting cassava mash during fufu production against selected enteropathogenic bacteria. Methodology: Microbiological analysis was carried out on the mash on daily basis during the three-day fermentation period. The pH, TTA and temperature of the fufu were also evaluated. The antibacterial activities of dominant microorganisms from the mash were assayed against the isolated microorganisms and test isolates using disc and agar diffusion methods. Results: The bacteria isolated from the fermenting mash include Bacillus subtilis, Lactobacillus fermentum, L. plantarum, Pediococcus acidilactici, Micrococcus luteus and Staphylococcus aureus while the fungi were Aspergillus flavus, A. niger, A. fumigatus, Geotrichum candidum, Penicillium expansum and Rhizospus stolonifer. The predominant microorganisms were L. plantarum, L. mesenteroides, A. niger, A. fumigatus and G. candidum. The total bacterial, lactic acid bacterial and fungal counts increased from 2.5X105 cfu/ml, 2.0X105 cfu/ml and 1.5X103 cfu/ml to 7.6X106 cfu/ml, 6.7X106 cfu/ml and 1.0X106 cfu/ml respectively. The temperature of cassava mash increased from 26°C to 30°C. The pH decreased from 6.80 to 4.22 while the total titratable acidity increased from 0.70% to 0.94%. Escherichia coli, P. mirabilis, S. typhimurium and S. aureus were inhibited by  L. plantarum and L. mesenteroides while E. agglomerans and K. pneumoniae were resistant to L. plantarum and L. mesenteroides respectively. Aspergillus niger and G. candidum inhibited S. aureus but E. agglomerans, K. pneumoniae, P. mirabilis and S. typhimurium were not affected. Enterobacter agglomerans, E. coli, P. mirabilis and S. aureus were inhibited by A. fumigatus while K. pneumoniae and S. typhimurium were resistant. Conclusion: These results suggested that consumption of fufu and other fermented cassava tubers could enhance less susceptibility to diseases caused by the test bacteria and fufu may be recommended for people suffering from infections caused by these microorganisms.