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年度	100	專案性質	實驗性質
專案類別	研究專案	研究主題	整治
申請機構	國立台灣大學	申請系所	生物環境系統工程學系
專案主持人	廖秀娟	職等/職稱	教授
專案中文名稱	利用現地分離之砷氧化菌做為含砷地下水生物復育之可行性探討
中文關鍵字	砷、生物吸附劑、生物復育
專案英文名稱	Bioremediation of arsenic-contaminated groundwater using in situ isolated arsenite-oxidizing bacteria
英文關鍵字	Arsenic; biosorbent；bioremediation
執行金額
執行期間	2011/11/26 至 2012/11/25
計畫中文摘要	砷 (Arsenic, As) 的毒性影響了全世界數百萬的民眾。台灣即使在1960年 代已發現地下水砷汙染的問題，然而很少文獻針對微生物與地下水砷釋放之間的 關係作深入研究。在此研究當中，我們分離出現地之台灣烏腳病疫區砷污染地下 水中之砷氧化菌，命名為As7325。並利用核酸序列比對工具(BLAST)，比對其 16S rRNA發現As7325是與Pseudomonas同屬之菌種。而As7325最適宜之生長溫度 和pH分別為30℃及7。As7325為一種兼性厭氧菌。除此之外，經由聚合酶鏈鎖反 應技術，發現As7325具有可將砷氧化之砷氧化酶基因aoxB，由此可推論出 As7325為具砷氧化或解毒機制之細菌。另外，As7325在好氧條件之下，可於一天 以內氧化烏腳病疫區砷汙染地下水含30μM (~2200 μg/L)之三價砷成五價砷。我們 更進一步利用As7325作為一種生物吸附劑移除地下水中的五價砷，結果顯示，在 兩天內 5g/L冷凍乾燥的As7325能分別吸附濃度為500及1000 ppb的五價砷各達 37%及60%的效能；而在第六天時，其吸附效率則分別能達到87%及100%。因 此，由本研究結果得知，As7325具有對於現地砷汙染地下水之生物復育的重要潛 能。本期末報告內容報告全程計畫執行期間之成果，計畫執行成果符合計畫預 期，執行進度亦符合預定進度。
計畫英文摘要	Arsenic poisoning affects millions of people worldwide. Although groundwater arsenic problems in Taiwan have been recognized since 1960s, few reports have been published about the relationship between microbes and arsenic release into groundwater. In this study, we isolated an indigenous arsenite-oxidizing bacterium As7325 from arsenic contaminated shallow alluvial aquifer in the Blackfoot Disease endemic area. The Basic Local Alignment Search Tool (BLAST) search of the 16S rRNA showed that strain As7325 belongs to the genus of Pseudomonas. The optimal temperature for growth was 30oC and the pH was about 7. Bacterial strain As7325 is a facultative anaerobe. In addition, the cytoplasmic arsenite oxidase aoxB was amplified by PCR, suggesting that strain As7325 contains arsenic oxidation/detoxification mechanisms. Furthermore, strain As7325 was able to oxidize 30 μM (~ 2200 μg/L) arsenite within 1 day using environmental groundwater under aerobic conditions. We also used As7325 as a biosorbent to remove arsenic in groundwater. The results showed that 5 g/L lyophilized cell pellet of strain As7325 can adsorb 500 and 1000 ppb arsenate with 37% and 60%, respectively within 2 days. The adsorption efficiency for 500 and 1000 ppb arsenate reached 87% and 100%, respectively at 6-day. Therefore, strain As7325 shows its great potential for bioremediation of groundwater arsenic in situ. In this final progress report, we showed that current results and progress fulfill the anticipated results and progress as proposed in the proposal.