Bacillus YB4 with dual detoxification mechanism and probiotic potential for zearalenone degradation

Zearalenone (ZEN) is a widespread mycotoxin contaminating cereals and feed, posing health risks to livestock and humans. Biological detoxification using ZEN-degrading Bacillus strains has attracted growing interest, yet most reported strains lack clear mechanisms or sufficient probiotic traits for practical use. This study aimed to isolate and characterize a novel ZEN-degrading Bacillus strain with superior efficiency and to elucidate its mechanism.

A ZEN-degrading bacterial strain, designated YB4 and identified as Bacillus sp., was isolated from fecal samples. The strain exhibited a dual detoxification mechanism: extracellular enzymatic degradation accounted for the majority of ZEN removal (72.33%), with cell adsorption serving as a complementary pathway (26.73%) - a combined mode rarely reported in single Bacillus isolates. Under optimized conditions determined using response surface methodology (37 °C, pH 6.5, 20 g kg^-1 inoculum), YB4 achieved a degradation rate of 94.12 ± 0.86% within 48 h. Unlike many previously reported ZEN-degrading Bacillus strains that function solely via enzymatic hydrolysis or adsorption, YB4 integrates both mechanisms, offering enhanced detoxification efficiency. Furthermore, YB4 demonstrated strong environmental tolerance (surviving at 70 g kg^-1 NaCl and 3 g kg^-1 bile salts), a trait critical for probiotic application in the gastrointestinal tract and lacking in several earlier isolates.

YB4 is a novel Bacillus strain distinguished by its dual enzymatic-adsorptive mechanism and robust salt/bile tolerance. These features position it as a promising candidate for biological detoxification, advancing beyond existing strains that typically rely on a single pathway or show limited environmental resilience. © 2026 Society of Chemical Industry.