论文标题
真菌污染水域的真菌生物修复：评估其降解以及可修正因素对在非trick虫条件下删除的影响
Fungal bioremediation of diuron-contaminated waters: evaluation of its degradation and the effect of amendable factors on its removal in a trickle-bed reactor under non-sterile conditions
论文作者
论文摘要
在环境中，广泛使用除草剂二氮的发生对生态系统和人类健康构成了严重威胁。研究了四种不同的木质氨基丁氏菌真菌，作为去除Diuron的生物降解候选物。其中，versolor的T. versolor是最有效的物种，不仅会迅速降解（83％），而且在7天孵育后，主要代谢物为3,4-二氯苯胺（100％）。在利龙降解期间，发现五个转化产物（TPS）形成，并暂时提出了其中三个结构。根据所鉴定的TPS，将羟基的3-（3,4-二氯苯基）-1-羟基甲基-1-甲基脲（DCPHMU）进一步代谢为N-甲基化合物3-（3-4-二氯苯基）-1-甲基尿果（3,4-二甲基素）（3,4-甲基素）（dcppmmu）和3,4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4-4。 DCPHMU的发现表明羟基化在随后的N-甲基化中的相关作用，有助于更好地理解二龙解毒的主要反应机制。实验还证明了降解反应可能会在细胞内发生，并被细胞色素P450系统催化。通过中央复合设计建立的响应表面方法，有助于评估用T. versicolor固定在Diuron删除的trick流生物反应器中操作变量的影响。最佳性能是在低回收率和进水流量下获得的。此外，结果表明污染物和固定的真菌之间的接触时间在去除二瘤中起着至关重要的作用。这项研究代表了使用真实规模的真菌反应器对被农药污染水进行生物修复的技术的开创性一步。
The occurrence of the extensively used herbicide diuron in the environment poses a severe threat to the ecosystem and human health. Four different ligninolytic fungi were studied as biodegradation candidates for the removal of diuron. Among them, T. versicolor was the most effective species, degrading rapidly not only diuron (83%) but also the major metabolite 3,4-dichloroaniline (100%), after 7-day incubation. During diuron degradation, five transformation products (TPs) were found to be formed and the structures for three of them are tentatively proposed. According to the identified TPs, a hydroxylated intermediate 3-(3,4-dichlorophenyl)-1-hydroxymethyl-1-methylurea (DCPHMU) was further metabolized into the N-dealkylated compounds 3-(3,4-dichlorophenyl)-1-methylurea (DCPMU) and 3,4-dichlorophenylurea (DCPU). The discovery of DCPHMU suggests a relevant role of hydroxylation for subsequent N-demethylation, helping to better understand the main reaction mechanisms of diuron detoxification. Experiments also evidenced that degradation reactions may occur intracellularly and be catalyzed by the cytochrome P450 system. A response surface method, established by central composite design, assisted in evaluating the effect of operational variables in a trickle-bed bioreactor immobilized with T. versicolor on diuron removal. The best performance was obtained at low recycling ratios and influent flow rates. Furthermore, results indicate that the contact time between the contaminant and immobilized fungi plays a crucial role in diuron removal. This study represents a pioneering step forward amid techniques for bioremediation of pesticides-contaminated waters using fungal reactors at a real scale.
