Antifungal activity of two Lactobacillus strains with potential probiotic properties

Abstract

Aflatoxin (highly toxic and carcinogenic secondary metabolites produced by fingi) contamination is a serious problem worldwide. Modern agriculture and animal production systems need to use high‐quality and mycotoxin‐free feedstuffs. The use of microorganisms to preserve food has gained importance in recent years due to the demand for reduced use of chemical preservatives by consumers. Lactic acid bacteria are known to produce various antimicrobial compounds that are considered to be important in the biopreservation of food and feed. Lactobacillus rhamnosus L60 and Lactobacillus fermentum L23 are producers of secondary metabolites, such as organic acids, bacteriocins and, in the case of L60, hydrogen peroxide. The antifungal activity of lactobacilli strains was determined by coculture with Aspergillus section Flavi strains by two qualitative and one quantitative methods. Both L23 and L60 completely inhibited the fungal growth of all aflatoxicogenic strains assayed. Aflatoxin B 1 production was reduced 95.7–99.8% with L60 and 27.5–100% with L23. Statistical analysis of the data revealed the influence of L60 and L23 on growth parameters and aflatoxin B 1 production. These results are important given that these aflatoxicogenic fungi are natural contaminants of feed used for animal production, and could be effectively controlled by Lactobacillus L60 and L23 strains with probiotic properties.

Isolation of Lactobacillus strain from curdled milk and investigation of their antimycotoxinogen activity

“…flavus producing aflatoxin was investigated with four methods, in the case of seven isolated LAB (Fguiri et al, ). In addition, Gerbaldo et al (), confirmed that Lactobacillus rhamnosus L60 and Lactobacillus fermentum L23 are the most producing of secondary metabolites, such as organic acids, bacteriocins, and hydrogen peroxide. The antifungal activity of these strains inhibited completely the fungal growth of all aflatoxicogenic strains assayed.…”

“…The development of isolates on MRS medium gives colonies of various shapes, sizes, and colors (Figure 1). Several studies demonstrate that the research of LAB from fermented milk have an important role in the field of bio-preservation (Fguiri, Ziadi, Rekaya, Arroum, & Khorchani, 2017;Gerbaldo, Barberis, Pascual, Dalcero, & Barberis, 2012;Samaneh, Mohammad, Giti, & Mohammad, 2016). In addition, the MRS is considered as an ideal medium for the growth of LAB through its richness on different nutrient (De Man et al, 1960).…”

Inhibitory properties ofEnterococcusspp. isolated from faeces of healthy dogs

“…These results suggest that E. faecium could produce some inhibitory metabolites of the AFB 1 production; on the other hand the competence for essential compound by AFs production must also be considered. Recently, Gerbaldo et al [27] found that two Lactobacillus spp. producers of secondary active metabolites completely inhibited the fungal growth of all aflatoxigenic strains assayed; and AFB 1 production was reduced significantly (95.7 to 100%).…”

“…and Enterococcus spp., among others, produce antimicrobial compounds that are important in the bio-preservation of foods and feeds. [25][26][27] LAB have been widely used in food and are "generally regarded as safe" organisms (GRAS). They are used in commercial applications to improve the shelf life of fermented products and to reduce potential health hazards associated with bacteria and mycotoxins.…”

Production of proteinaceous antifungal substances from Lactobacillus plantarum ALAC‐4 isolated from Inner Mongolian traditional fermented dairy food

“…Two probiotic strains, Lactobacillus rhamnosus L60 and Lactobacillus fermentum L23, were able to inhibit the growth of Aspergillus flavus strains and levels of aflatoxin B1 produced by them (Gerbaldo et al . ). Belguesmia et al .…”