Plasmid-mediated Detoxification of Mycotoxin Zearalenone in Pseudomonas Sp. ZEA-1

The Pseudomonas sp. Strain ZEA-1 was isolated from rhizosphere of corn plant by an enrichment technique showed capability of utilizing zearalenone as the sole source of carbon. The bacterium rapidly utilized zearalenone beyond 200 µg/ml and showed prolific growth in a minimal medium containing 100 µg/ml zearalenone source. The course of ZEA degradation as well as the formation of its metabolites was observed by UV Spectrophotometer and thin layer chromatography analysis. Toxicity of biotransformation products of zearalenone was tested in a toxicity assay with the shrimp Artemia salina. Residual toxicity of these metabolites against A.salinia was reduced. The wild type strain ZEA-1 transferred zearalenone degradation property to E.coli strain. The transconjugant harboured a plasmid of the same molecular size (approximately 120 Kb) as that of donor strain, while cured strain was plasmidless and did not utilize zearalenone.