Browsing by Author "Ayodeji, O. C."

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Characterization and screening of lactic acid bacteria (LAB) and yeast from fermented sorghum and maize products for use as starter culture.
(Science domain International, 2021) Ayodeji, O. C.; Afolabi, F. T.; Abdulkadir M.
This study focused on the isolation, Characterization and screening of lactic acid bacteria and yeast for use as starter culture in order to eradicate the problem of excessive microbial contamination and the presence of mycotoxins. Lactobacillus plantarum and Saccharomyces cerevisiae were the predominant microorganisms isolated from the samples collected. The isolates were screened for their ability to produce enzymes and metabolites. Lactic acid bacteria produce a variety of antimicrobial compounds such as lactic acid, hydrogen peroxide, diacetyl on them as a natural competitive means to overcome other microorganism sharing the same niche. They were also screened for their ability to withstand some physiological stress like acid tolerance, temperature, salt concentration and antibacterial activity; the isolates produced significant values of enzymes and, antimicrobial metabolites. The antimicrobial activity of Lactobacillus plantarum is mainly attributed to the low pH due to Lactic acid production. The antimicrobial activity of the Saccharomyces cerevisiae appears to be mainly due to the competition with the other microorganisms. In addition, depletion of Oxygen and production of CO2, competition for nutrients and the production of antimicrobial substances could have been responsible for the overall antimicrobial activity of both cultures. According to the results obtained, both lactic acid bacteria and yeast proved to be a good source of starter culture.
The effect of using biological treatment on microbial growth during the malting of sorghum
(Science Domain international, 2021) Ayodeji, O. C.; Afolabi, F. T.; Abdulkadir, M.; Fasiku, O.
Malting is an important industrial product with a huge market outlet. Sorghum grain carries a numerous and variable, microbial population that mainly consists of bacteria, yeasts, and filamentous fungi. Sorghum malt is heavily reliant on chemical control of moulds and coliforms. This research aimed at investigating ways of improving malt quality and safety, using starter cultures of lactic acid bacteria and yeast, during the steeping stage of malting. All the steep treatments contained a sizeable population of moulds, greater than 4logcfu/mL, at 0hrs of steeping. A 3Log decrease was recorded in the steep treatment containing only single culture of Lactobacillus plantarum All the steeping treatments achieved varying levels of anti-nutrient reduction. The Lactobacillus plantarum CLB8 steep reduced the phytate level by as much as 47% when compared to the phytate level in sorghum grain. The combined cultures of Lactobacillus plantarum CLB8 and Saccharomyces cerevisiaeCYT1 reduced the phytate content by as much as 40% when compared to the sorghum grain without treatment. When compared to the control steep, the Lactobacillus plantarum CLB8 steep improved the anti-nutrient degradation by 31%. The combined cultures of Lactobacillus plantarum CLB8 and Saccharomyces cerevisiae CYT1 reduced the phytate content by as much as 23% when compared with the control steep. The polyphenol content was reduced by about 46% in the Lactobacillus plantarum CLB8 steep and 29% in the combined cultures of Lactobacillus plantarum CLB8 and Saccharomyces cerevisiae CYT1 steep when compared to the polyphenol content in the whole sorghum grain. Only the Lactobacillus plantarum CLB8 steep had better polyphenol reduction than the control with a 9.6% reduction more than the control. It was concluded that lactic acid bacteria can be apply as a biological control organism in malting of grains.