FUNGAL DEGRADATION OF CHEMICAL WARFARE AGENTS

根据1997年4月29日生效的《化学武器公约》，化学武器应在十年内销毁。包括日本在内的65个国家已经批准了该条约。在许多类型的化学武器中，生产和储存最多的毒剂被发现是双(2-氯乙基)硫化物，也被称为Yperite或芥子气。Yperite具有明显的细胞毒性，也是一种致癌和致突变的烷基化试剂。Yperite的大规模焚烧始于1990年。然而，在焚烧和中和过程中，出现了几个缺点。作为焚烧的替代方法，已经提出了几种方法。生物修复工艺一直被认为比其他传统工艺更有优势，因为它对环境的影响最小，而且成本效益很高。担子菌是唯一已知的完全降解木材成分的生物，包括木质素，木质素是最难分解的…之一。更多的芳香生物材料。降解木质素的担子菌称为白腐菌，其他的称为褐腐菌。利用真菌降解木质素的能力，利用真菌对三硝基甲苯、氯苯酚、氯化二苯并对二恶英和多环烃等进行生物修复。它们表现出很强的代谢TDG的能力，无论是为了消除异物，还是为了满足硫需求。然后，为了阐明反应机理，以苯硫醚为例，显示了硫键的有效断裂。最后，对Yperite的真菌降解进行了尝试。Yperite被非酶水解，通过中间产物半Yperite生成TDG。白腐菌和褐腐菌都能进一步代谢TDG。乙二醇和巯基乙醇为代谢中间产物。真菌能够利用TDG和硫醇作为其生长的硫源，因此TDG在非含硫介质中的降解受到刺激。较少

According to the Chemical Weapons Convention (effective on the 29th of April, 1997), chemical weapons should be destroyed within ten years. More than 65 countries, including Japan, have ratified the Treaty. Among many types of chemical weapons, the agent which has been the most produced and stored was found to be bis(2-chloroethyl) sulfide, also known as Yperite or mustard gas. Yperite is markedly cytotoxic and is also a carcinogenic and mutagenic alkylating agent. Large-scale incineration of Yperite was started in 1990. However, during incineration and neutralization, the occurrence of several drawbacks has been pointed out. As an alternative to incineration, several methods have been proposed. The bioremediation process has been thought to be advantageous over other conventional processes because of a minimal impact on the environment and of cost effectiveness. Basidiomycetes are the only known organisms to completely degrade wood components including lignin, one of the most recalcit … More rant aromatic biomaterials. Lignin-degrading basidiomycetes are called white-rot fungi, and the others are called brown-rot fungi. Utilizing the ability of lignin degradation, fungal bioremediation has been applied to trinitrotoluene, chlorophenols, chlorinated dibenzo-p-dioxins, and polycyclic hydrocarbons etc.In this study, we initiate the biodegradation of thiodiglycol (TDG ; hydrolyzed product of Yperite) by either white-rot or brown-rot basidiomycetes. They exhibited a strong ability to metabolize TDG either for xenobiotic elimination or for sulfur demand. Then, to elucidate reaction mechanisms, benzyl sulfide was utilized, showing effective cleavage of sulfide bond. Finally, the fungal degradation of Yperite was attempted. Yperite was non-enzymatically hydrolyzed to produce TDG via the intermediate formation of a half-Yperite. TDG was further metabolized by both white- and brown-rot fungi. Ethylene glycol and mercaptoethanol were identified as metabolic intermediates. Fungi were capable of utilizing TDG and mercapto-ethanol as a sulfur source for their growth ; therefore, the degradation of TDG was stimulated in non-sulfur containing media. Less