Aflatoxin M1 reduction by microorganisms isolated from kefir grains

Abstract

Aflatoxin M1 (AFM1) is a mycotoxin that often contaminates milk. Like other mycotoxins, it is thermostable and potentially carcinogenic. The present work was carried out to evaluate the ability of microorganisms isolated from Indonesian kefir grains to reduce AFM1 in contaminated phosphate buffer saline (PBS). Fourteen isolates of lactic acid bacteria, both aerobic (LAE) and anaerobic (LAN), and nine isolates of yeast (YEA) were used. The significantly highest AFM1 reduction percentage was shown by the isolate LAE7 (29.3 ± 0.6%) after 4 h incubation. DNA sequencing of LAE7 and YEA2 isolates showed that these isolates had homology (level of similarity) with species of Lactobacillus kefiri strain A/K and Saccharomyces cerevisiae NRRL Y-12632, respectively. The present work proved that isolates from Indonesian kefir grains could reduce AFM1 and have the potential for practical use.