Effective degradation of zearalenone by multiple microbial isolates

Abstract

Zearalenone (ZEN) is an estrogenic mycotoxin synthesized by specific fungal species that frequently colonize cereal crops such as maize, which is a fundamental component of animal feed. This mycotoxin induces significant reproductive disorders in swine and other livestock, resulting in considerable economic loss in the animal husbandry sector. ZEN contamination has emerged as a critical issue concerning global food and feed safety. The objective of this research was to isolate and characterize microorganisms from samples that can effectively detoxify ZEN. The samples were from six distinct sources: porcine feces, piggery soil, avian intestines, unpasteurized bovine milk, and feed that was left to mold. The spread plate technique was used to culture the samples and obtain pure cultures. The samples were identified by bacterial morphology and 16S rRNA gene sequencing. All the bacterial isolates identified in this study exhibited mycotoxin-degrading capabilities and included known ZEN-degrading species, <i>Bacillus amyloliquefaciens</i> and <i>B. subtilis</i>, with ZEN degradation ranging from 84.21% to 99.58%. A pure culture derived from piggery soil displayed particularly robust ZEN-degrading potential. Microscopic, biochemical, and molecular assessments substantiated the classification of this isolate as <i>Priestia megaterium</i>. This bacterium demonstrated ZEN-degrading ability (up to 0.5 mg/mL) and an elevated level of tolerance to various antibiotics (Multiple Antibiotic Resistance (MAR) index = 0.07). Additional research is necessary to investigate its potential application in the detoxification of ZEN.