Construction of trichothecene detection system and screening system for detoxifying microorganisms

毛霉烯类是由镰刀菌等属产生的真菌毒素。它们污染重要的农作物，并可能对人类和牲畜造成严重的健康问题。在本研究中，我们在酿酒酵母中发现了22个三氯乙烯抗性基因。我们构建了多个基因缺失突变体，其中缺失pdr5、erg6和rpb4的三个突变体对各种三氯乙烯表现出最高的敏感性。我们利用纸片扩散法建立了一个有效的检测体系，可以检测到小麦和小麦花中临时含量的脱氧雪腐镰刀菌烯醇。接下来，我们筛选了能解毒T-2毒素、脱氧雪腐镰刀菌烯醇和4-乙酰雪腐镰刀菌烯醇的微生物。我们主要从土壤中采集了约1万株微生物，发现有10%以上的微生物能够脱乙酰化T-2毒素和4-乙酰雪腐镰刀菌烯醇，从而降低了毒性。然而，没有任何生物可以解毒脱氧雪腐镰刀菌烯醇。

Trichothecenes are mycotoxins which are produced by Fusarium and other genera. They contaminate important crops, and can cause serious health problems in humans and livestock. In this research, we found 22 trichothecene resistance genes in Saccharomyces cerevisiae. We constructed multiple gene deletion mutants, and among them, the triple mutant which deleted pdr5, erg6, and rpb4, showed the highest sensitivity toward various trichothecenes. We constructed an effective detective system using disc diffusion test, which allows us to detect deoxynivalenol contaminated with the provisional level in wheat and wheat flower. Next, we screened for microoganisms which can detoxify T-2 toxin, deoxynivalenol and 4-acetylnivalenol. We collected ~10,000 microorganisms mainly from soil, and we found that there were more than 10% microorganisms can deacetylate T-2 toxin and 4-acetyl nivalenol, which resulted in reducing toxicity. However, no organisms can detoxify deoxynivalenol.