Isolation And Characterization Of Lactic Acid Bacteria Involved In Fermentation Of Cereal-Based Products

ABSTRACT

The isolation and characterization of lactic acid bacteria (LAB) responsible for the fermentation of some cereal -based products (Akamu, Kunu-zaki and Burukutu) were evaluated in order to access their use as starter cultures. Representatives of the LAB were isolated at 12h intervals during the course of fermentation characterized and identified using morphological, physiological, biochemical and the API 5OCHL methods. Changes in pH, titratable acidity and LAB counts were also investigated during the cereal basedproducts fermentation. The isolates obtained were accessed for potential as starter cultures based on the comparative performance of single isolates to a substrate and pH reduction. Isolates were Lactobacillusplantarum, Lactobacillus cellobiosus, Lactobacillus pentosus, Leuconostoc mesenteroides and Pediococcus pentosaceus. Results indicated a predominance of Lactobacilli among the isolates. LAB counts in the cereal based-products were isolated at levels of 106, 1 log cful ml respectively. A rapid decrease in pH was associated with an increase in titratable acidity. The isolates fermented the sterilized cereals. All isolates produced akamu having pH values of 4.5 and 4.9 after 96hrs, anova showed significant difference between pH of all the isolates in the two substrates used at p 0.005.