Abstract

This study investigated characterization of Ogi Nigerian local lactic acid bacteria (LAB) for functional yoghurt production. Ogi LAB isolates (white corn, yellow corn and brown corn) and yoghurt samples were subjected to morphological, biochemical and sugar fermentation tests. The colony was white or cream-colored, rod- and cocci-form cells, all Gram-positive, which indicates the presence of different LAB species. Biochemical characterization demonstrated predominance for catalase-negative, motility and general failure to grow on citrate or produce hydrogen sulphide, confirming conformity to typical LAB traits. Sugar fermentation tests confirmed extensive carbohydrate metabolism since all isolates fermented glucose, fructose, galactose, lactose, maltose, sucrose, mannose, mannitol and arabinose. The uniform and widespread fermentative profile demonstrates strong enzymatic potential and versatility for both cerealand milk-based substrates. The greater similarity between Ogi-derived and yoghurt-derived isolates indicates that indigenous LAB strains possess equivalent technological characteristics to industrial dairy starter cultures. The findings highlight the potentiality of Ogi LAB as yoghurt starter cultures for generating yoghurt with a capacity to enhance product quality, stability and nutritional values.

Keywords: Ogi; Indigenous fermentation; Yoghurt production; Functional foods; Carbohydrate fermentation; Lactic acid bacteria