New trends for the efficient bio-degradation of food contaminant zearalenone using a plant rhizobacterial strain: an in-vitro study

Abstract

Zearalenone (ZEN) is one of the most damaging and well-known toxins present in foods and animal feeds throughout the world. Klebsiella pneumoniae strains isolated from maize roots through soil samples were able to completely remove ZEN from LB medium after a 72-h fermentation through the enzymatic degradation and absorption of the toxin. The removing properties, including ZEN concentrations, incubation pH, incubation temperatures, bacterial concentrations, culture supernatant, and cell wall effect on degradation were evaluated. The K. pneumoniae strain culture supernatant has a strong ability to remove ZEN, and the degradation rate was more than 70%. The cell wall also has a certain ability to remove ZEN up to 18.51%, while the bacterial content has almost 5.61% ability to degrade ZEN. The removal rate and degradation metabolites alpha/beta-zearalenol, alpha/beta-zearalanol, zearalanone, and ZEN-sulphate were evaluated and confirmed by High Performance Liquid Chromatography (HPLC) and Ultra-Performance Liquid Chromatography Tandem Mass Spectrometry analyses. The mechanism of ZEN and its derivatives degradation by this bacterial strain will be further studied so that novel degrading enzymes can be isolated which can be used as bio-detoxifier.