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

Abstract BACKGROUND 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. RESULTS 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. CONCLUSION 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.