Aflatoxin B1 (AFB1) biodegradation by a lignolytic phenoloxidase of Trametes hirsuta

Author: mycolabadmin
2/21/2025
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Summary

Scientists discovered that a mushroom called Trametes hirsuta produces a special enzyme that can break down aflatoxin B1, a dangerous toxin that contaminates foods like peanuts, corn, and nuts. This enzyme is unique because it works without needing additional chemicals as helpers, making it practical for real-world use. The enzyme successfully degraded 77.9% of the toxin under simple conditions, and researchers suggest it could be applied directly to contaminated food surfaces as a safe, natural way to reduce food poisoning risks.

Background

Aflatoxin B1 (AFB1) is a highly potent mycotoxin produced by Aspergillus species that contaminates crops and food products, posing serious risks to human and animal health due to its hepatocarcinogenic, mutagenic, and teratogenic properties. Current mitigation efforts include chemical and physical methods, but these have limitations such as high costs, residue persistence, and incomplete effectiveness. Biological detoxification using microorganisms and their enzymes offers a promising alternative approach.

Objective

This study aimed to identify and characterize the specific enzyme(s) from Trametes hirsuta responsible for AFB1 biodegradation in culture supernatants. The researchers focused on isolating and purifying the extracellular enzyme(s) and determining their biochemical properties and catalytic mechanisms.

Results

A lignolytic phenoloxidase with molecular mass of 55.6 kDa was identified as the responsible enzyme, achieving 77.9% AFB1 degradation under optimized conditions. The enzyme exhibited a Vmax of 11.49 µM per minute and Km of 23.67 µM, indicating strong affinity and efficient catalytic capacity. Notably, this enzyme achieved cofactor-free degradation without requiring hydrogen peroxide, a unique characteristic among fungal lignolytic phenoloxidases.

Conclusion

This is the first lignolytic phenoloxidase from T. hirsuta capable of effective AFB1 degradation without cofactors, representing a novel enzymatic approach for mycotoxin remediation. The enzyme’s ability to function under mild conditions with only ambient oxygen makes it suitable for practical applications such as treating contaminated surfaces of fruits, vegetables, and nuts. Future research should focus on gene isolation, heterologous expression, and analysis of reaction product toxicity to fully harness its potential.

Published in:Scientific Reports,
Study Type:Experimental Research,
Source: PMID: 39984639, DOI: 10.1038/s41598-025-90711-y