| 摘要: | 1,1,1-三氯乙烷(1,1,1-Trichloroethane)是地下水污染的常見來源之一，不僅導致人類患癌，也抑制Dehalococcoides mccartyi(D. mccartyi) 進行三氯乙烯(Trichloroethene)的還原脫氯反應，而三氯乙烯也是主要地下水污染物之一。在研究中Acetobacterium woodii (A. woodii) 具有1,1,1-三氯乙烷的降解能力。然而，目前對於其降解機制仍不清楚。在本研究中欲探討在果糖生長下的A. woodii降解1,1,1-三氯乙烷時所參與的代謝途徑以及嘗試透過在1,1,1-三氯乙烷和三氯乙烯共汙染下共培養A. woodii和D. mccartyi以消除1,1,1-三氯乙烷抑制三氯乙烯脫氯作用。結果顯示，A. woodii能夠降解最高至2 mM的 1,1,1-三氯乙烷。為了進一步探討其潛在機制，我們使用轉錄組分析和RT-qPCR方法。結果表明，1,1,1-三氯乙烷誘導了22個與Wood-Ljungdahl途徑相關基因的上調表達，推測其可能與1,1,1-三氯乙烷的降解有相關性。為了減少1,1,1-三氯乙烷對D. mccartyi進行三氯乙烯脫氯的負面影響，接著我們建立了一個由D. mccartyi CWV2和A. woodii組成的共培養系統，該系統能夠協同降解1,1,1-三氯乙烷和三氯乙烯。本研究不僅為探討了A. woodii對1,1,1-三氯乙烷的降解機制提供了新的見解，也在1,1,1-三氯乙烷和三氯乙烯共污染的場地中利用A. woodii進行生物修復提供了多種策略。;1,1,1-Trichloroethane (1,1,1-TCA), one of the common sources of groundwater contamination, not only causes cancer in humans but also inhibits the reductive dechlorination of trichloroethene (TCE) by Dehalococcoides mccartyi (D. mccartyi), which is the major groundwater contamination. Previous studies have reported that Acetobacterium woodii (A. woodii) exhibits 1,1,1-TCA degradation activity. However, the degradation mechanism remains unclear. This study aimed to identify for the key pathways involved in the degradation of 1,1,1-TCA by A. woodii when grown on fructose as a primary substrate, and to establish a co-culture consisting of D. mccartyi and A. woodii to alleviate the inhibitory effect of 1,1,1-TCA on the dechlorination of TCE. The results showed that A. woodii can degrade 2 mM of 1,1,1-TCA. To investigate the underlying mechanisms of 1,1,1-TCA degradation, we adopted transcriptomic analysis and RT-qPCR methods. The results indicated that 1,1,1-TCA induced the up-regulation of twenty-two genes related to Wood-Ljungdahl pathway, suggesting that this pathway was involved. To alleviate the negative impact of 1,1,1-TCA on TCE degradation by D. mccartyi, we established a co-culture consisting of D. mccartyi strain CWV2 and A. woodii to synergistically degrade both 1,1,1-TCA and TCE by providing fructose as the sole carbon source. This study not only provides new insight to reveal the degradation mechanism of 1,1,1-TCA by A. woodii, but also provide strategies for removing 1,1,1-TCA by A. woodii and then dechlorination of TCE in the both 1,1,1-TCA and TCE co-contaminated sites. |
