Abstract
The increased consumption of plant-based foods has intensified the concern related to mycotoxin intoxication. This study aimed to investigate the effect of selected lactic acid bacteria (LAB) strains on the growth of Aspergillus parasiticus NRRL 2999 and its production of aflatoxin (AF). The ability of the heat-killed (100°C for 1 h) LAB strains to bind aflatoxin M1 (AFM1) in milk and aflatoxin B1 (AFB1), ochratoxin A (OTA), and zearalenone (ZEN) in potassium phosphate buffer (PPB) was also evaluated in vitro. Ten LAB strains were tested individually, by inoculating them simultaneously with the fungus or after incubation of the fungus for 24 or 48 h at 25°C. Double layer yeast extract sucrose (YES) agar, de Man Rogosa and Sharpe (MRS) agar, and YES broth were incubated for 7 days at 25°C to follow the development of the fungus. Levilactobacillus spp. 3QB398 and Levilactobacillus brevis 2QB422 strains were able to delay the growth of A. parasiticus in YES broth, even when these strains were inoculated 24 h after the fungus. The inhibitory effect of these LAB strains was confirmed by the reduction of fungus colony size, suggesting dominance of LAB by competition (a Lotka-Voltera effect). The production of AFB1 by A. parasiticus was inhibited when the fungus was inoculated simultaneously with Lactiplantibacillus plantarum 3QB361 or L. plantarum 3QB350. No AFB1 was found when Levilactobacillus spp. 2QB383 was present, even when the LAB was inoculated 48 h after the fungus. In binding studies, seven inactivated LAB strains were able to promote a reduction of at least 50% the level of AFB1, OTA, and ZEN. This reduction varied depending on the pH of the PPB. In milk, however, only two inactivated LAB strains were able to reduce AFM1, with a reduction of 33 and 45% for Levilactobacillus spp. 3QB398 (Levilactobacillus spp.) and L. brevis 2QB422, respectively. Nevertheless, these results clearly indicate the potential of using LAB for mycotoxin reduction.
Highlights
An important food safety concern is the presence of natural contaminants such as the mycotoxins (Schatzmayr and Streit, 2013; Eskola et al, 2020; Baazeem et al, 2021)
Effect of Lactic Acid Bacteria on Growth of Mycotoxigenic Aspergillus parasiticus The screening of lactic acid bacteria (LAB) performed in microtiter plate (250 μl) was not conclusive but it gave an indication that all tested LAB strains had an impact on the growth of the fungus (Table 3)
From the 10 LAB strains tested in the present study, all had an effect on mycotoxins
Summary
An important food safety concern is the presence of natural contaminants such as the mycotoxins (Schatzmayr and Streit, 2013; Eskola et al, 2020; Baazeem et al, 2021). In 2019, mycotoxins were reported to be the main hazard in food products at EU borders (RASFF, 2020). As recently as 2020, a survey of global food crop contamination reported an incidence of 25% of mycotoxins above the EU and Codex limits (Eskola et al, 2020). The incidence of AFM1 in milk is of concern, because milk is the main nutritional source for infants and children (Conteçotto et al, 2021). Considering the health risks posed by AFM1, several countries have set maximum permissible levels (MPL) for this toxin in milk. The European Union and the United States Food and Drug Administration (FDA) have set MPLs of 0.05 and 0.5 μg L−1 for AFM1 in milk, respectively (Oliveira et al, 2014)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
