The antimicrobial activity of lactic acid bacteria from fermented maize (kenkey) and their interactions during fermentation

Abstract

A total of 241 lactic acid bacteria belonging to Lactobacillus plantarum, Pediococcus pentosaceus, Lactobacillus fermentum/reuteri and Lactobacillus brevis from various processing stages of maize dough fermentation were investigated. Results indicated that each processing stage has its own microenvironment with strong antimicrobial activity. About half of the Lact. plantarum and practically all of the Lact. fermentum/reuteri investigated were shown to inhibit other Gram-positive and Gram-negative bacteria, explaining the elimination of these organisms during the initial processing stages. Further, widespread microbial interactions amounting to 85% to 18% of all combinations tested were demonstrated amongst lactic acid bacteria within the various processing stages, i.e. raw material, steeping, 0 h and 48 h of fermentation, explaining the microbial succession taking place amongst lactic acid bacteria during fermentation. The antimicrobial effect was explained by the combined effect of acids, compounds sensitive to proteolytic enzymes and other compounds with antimicrobial activity with the acid production being the most important factor. The pattern of antimicrobial factors was not species-specific and the safety and storage stability of fermented maize seem to depend on a mixed population of lactic acid bacteria with different types of antimicrobial characteristics. This means that introduction of pure cultures as starters may impose a risk to the product.

Characterization and Determination of Origin of Lactic Acid Bacteria from a Sorghum-Based Fermented Weaning Food by Analysis of Soluble Proteins and Amplified Fragment Length Polymorphism Fingerprinting

“…These two species dominated the fermentation processes in this study. They have been isolated previously from a variety of food products and environmental sources and reportedly are two of the most dominant species during fermentation of sorghum-based infant-weaning foods (29,31).…”

“…Various members of this group are used commercially as starter cultures in the manufacture of food products, including dairy products (39), fermented vegetables (25), fermented doughs (45), alcoholic beverages (33,34), probiotics in animal feeds (8), and meat products (44). Lactic acid bacteria have also been used for lactic acid fermentation of sorghum-or maizebased cereals used as infant-weaning foods (26,27,31,38).…”

Antimicrobial activity of lactic acid bacteria isolated from fermented milk products

“…Antimicrobial activity of LAB may be due to decrease in pH, depletion of nutrients and production of antimicrobial compounds (Olsen et al, 1995), including bacteriocins (Parente and Ricciardi, 1999), and various organic acids such as lactic acids, acetic acid. Microbial food safety is an increasing public health concern worldwide and many Gram negative bacteria such as E. coli, Klebsiella sp.…”

Partial Characterization of Bacteriocins Produced by Lactobacillus reuteri 2-20B and Pediococcus acidilactici 0-11A Isolated from Fura, a Millet-Based Fermented Food in Ghana

“…Several bacteriocin producing LAB have been isolated from various traditional spontaneous fermented foods such as bosa , kenkey (Olsen et al, 1995), and ogi and fufu (Sanni et al, 1999;Olukoya et al, 1993). Similarly, strains of Lb.…”