Phenotypic and molecular differentiation of lactic acid bacteria in fonio millet ogi fermentation and their potential as starter cultures

Abstract

This study focused on the phenotypic and 16S rRNA characterization of lactic acid bacteria (LAB) isolated from spontaneously fermented fonio ogi and evaluation of their starter cultures potentials. The isolates were screened for biochemical characteristics, acidification, organic acid production and growth kinetics. Phenotypically, LABs (n = 28) were identified to be inclusive of Lactiplantibacillus plantarum, Lactiplantibacillus pentosus, Limosilactobacillus fermentum and Pediococcus species. However, genotypic typing revealed the strains as Lactiplantibacillus plantarum, Levilactobacillus brevis, and Pediococcus pentosaceus well as presence of non lactobacillus strains. Suitability for starter cultures revealed higher acidification and organic acid production for strains of Lactiplantibacillus plantarum and Pediococcus pentosaceus to between 3.20–3.65 (pH); 4.67- 6.67 total titratable acidity (TTA); 46.4 − 57.4 mg/g (lactic acid), 0.27–0.36 h (maximum specific growth rate). The selected LABs were shown to be strain specific and strains with rapid rate of acidification, high organic acid production and low pH exhibited significant potential for starter culture.