Visualisation and quantification of fumonisins bound by lactic acid bacteria isolates from traditional African maize-based fermented cereals, ogi and mahewu

Abstract

Consumption of fumonisin contaminated foods has a negative influence on the health of both humans (causing tumours in the liver and kidneys, well known for oesophageal cancer in Eastern Cape in South Africa) and animals (leucoencephalomalacia in horses). Lactic acid bacteria (LAB) have emerged as a promising natural detoxification agent against mycotoxins.The aim of this study was to visualize the interaction between fumonisins (fumonisin B1 (FB1) and fumonisin B2 (FB2)) and LAB, namely Lactobacillus plantarum FS2, L. delbrueckii subsp. delbrueckii CIP 57.8T and Pediococcus pentosaceus D39, isolated from traditional fermented maize-based products (ogi and mahewu) using confocal laser scanning microscopy (CLSM) and to then quantify the LAB-bound fumonisin using high performance liquid chromatography (HPLC). The objective was to obtain a physically visible and quantifiable binding interaction between fumonisins and LAB strains (viable and non-viable cells) with the aim of utilising LAB as a possible detoxifying agent. Fumonisins were derivatized using naphthalene-2, 3-dicarboxaldehyde (NDA) and then combined with non-fluorescent LAB cells (viable and non-viable). For the quantification of bound fumonisins, viable and nonviable cells were incubated in presence of predetermined concentrations of fumonisins and the level of fumonisin in the suspension was determined. Confocal scanning microscopy showed the derivatized green fluorescent fumonisins binding to the surface of each of the LAB cells.For viable cells, L. plantarum FS2 bound FB1 most effectively while P. pentosaceus D39 bound the least level of FB1. The highest levels of FB2 were bound by L. plantarum R 1096 and the least by L. delbrueckii CIP 57.8 T. For non-viable cells L. plantarum FS2 was also the most effective for binding both fumonisins with P. pentosaceus D39 and L. delbrueckii CIP 57.8 T being the least effective for FB1 and FB2, respectively. To our knowledge, this is the 2 first study to visualize the interaction between LAB and fumonisins. We demonstrate that LAB isolates from indigenous fermented maize based beverages bind fumonisins and thus present a potential strategy for their reduction in these traditional foods.

Reduction of Mycotoxins during Fermentation of Whole Grain Sorghum to Whole Grain Ting (a Southern African Food)

“…The high percentage FB reduction of over 90% in all of the LAB-fermented LT- ting samples recorded in this study (Figure 1a) is worthy of note. Similar findings have been reported in other African fermented foods such as fermented maize gruel, ogi and mahewu [28,37,38,39]. This is particularly important, considering the deleterious effect of these FBs and their harmful effects to inhabitants of southern Africa and the world at large.…”

The fate of mycotoxins during secondary food processing of maize for human consumption

“…FB1 and FB2 were bound to the bacterial cell wall with different efficiencies depending on the analyzed LAB species/strain and on the FB (more FB1 was bound compared to FB2). Interestingly, like as for AF (Haskard et al., 2001), the interaction was here not dependent on the viability of the cells (Dawlal, Brabet, Thantsha, & Buys, 2019). Binding of FBs by LAB obviously involves peptidoglycan as cell wall component and the tricarballylic acid groups of FBs (Niderkorn, Morgavi, Aboab, Lemaire, & Boudra, 2009).…”

Volatile Flavor Compounds Profile and Fermentation Characteristics of Milk Fermented by Lactobacillus delbrueckii subsp. bulgaricus

“…Lactobacillus delbrueckii subsp. bulgaricus is a non-pathogenic, lactic acid-producing, gram-positive rod bacteria that is frequently found in a variety of ecological niches, such as dairy foods (Batdorj et al, 2007; Karami et al, 2017), plants (Dawlal et al, 2019), and human intestine (Ren et al, 2014). In recent years, scientific understanding of the metabolism and functions of L. delbrueckii subsp.…”