Detoxification of Ochratoxin A by Bacillus amyloliquefaciens MM28: Whole-Genome Sequencing and Safety Evaluation of a Novel Probiotic Strain

TL;DR

This study identifies a new probiotic strain, Bacillus amyloliquefaciens MM28, that effectively breaks down the harmful toxin Ochratoxin A and shows positive health effects in mice.

Contribution

A novel OTA-detoxifying probiotic strain, B. amyloliquefaciens MM28, is isolated and evaluated for safety and efficacy.

Findings

Bacillus amyloliquefaciens MM28 degraded 86.31% of OTA within 48 hours.

MM28 improved mouse growth and intestinal health in a 28-day study.

MM28 altered gut microbiota composition, increasing beneficial bacteria.

Abstract

Ochratoxin A (OTA), a secondary metabolite produced by Penicillium and Aspergillus species, contaminates food and feed globally, posing serious threats to both livestock and human health. Among current detoxification strategies, probiotic-based degradation of OTA has emerged as a key research focus. This study aimed to isolate safe probiotic strains with high OTA-detoxifying efficacy to support their potential application in feed and food industries. A total of 57 bacterial strains were isolated from environmental samples, including soil, moldy feed, and animal feces. Among these, a novel strain identified as Bacillus amyloliquefaciens MM28 demonstrated strong OTA-degrading activity, removing 86.31% of OTA (0.4 µg/mL) within 48 h. Whole-genome analysis indicated that B. amyloliquefaciens MM28 harbors functional genes related to glucose metabolism, membrane transport, and properties associated with antibacterial, antioxidant, and immunomodulatory activities, suggesting multiple beneficial traits. In a 28-day chronic exposure study, mice were administered B. amyloliquefaciens MM28 via gavage (1 × 108 CFU/mL). Results showed that both female and male mice in the MM28 group exhibited higher body weight and improved growth performance compared to the PBS control group. Furthermore, intestinal morphology was enhanced in the MM28 group, as indicated by greater villus length and villus-length-to-crypt-depth ratio. The expression of proinflammatory cytokines was also reduced in the treated animals. Moreover, analysis of gut microbiota composition revealed that MM28 supplementation led to an increased abundance of Bacteroides and Desulfovibrio, alongside a reduction in Lachnospira and Oscillospira. In conclusion, this study demonstrates that Bacillus amyloliquefaciens MM28 is a safe and efficient strain capable of degrading OTA. These findings highlight its promising potential as a biological detoxifying agent in food and feed industries.

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