芘降解菌之分離及其土壤生物復育之應用

Isolation of Pyrene-Degrading Bacteria and Their Application on Soil Bioremediation

多環芳香族碳氫化合物（Polycyclic Aromatic Hydrocarbons，縮寫為PAHs）因具生物毒性、致突變性與致癌性，且在土壤環境中分布甚廣，故廣泛受到學者之重視。芘（pyrene）為四環芳香族碳氫化合物，生物復育（bioremediation）因具有低化學品添加與低耗能之特性，分離具芘降解能力之微生物將可作為應用於PAH污染生物復育之參考。本研究由南台灣地區不同加油站及化工廠周邊之排水溝污泥做為菌種分離源，以含有100 mgL^（-1）的芘之基礎培養基提供唯一碳源與能源，進行增殖培養，以馴養、篩選並純化可降解芘的菌株。利用外加芘至三種不同土壤（包括：砂頁岩沖積土、粘板岩沖積土與紅壤）中模擬受芘污染土壤之生物復育，比較各試驗菌株於不同土壤中降解芘之降解成效，以評估菌種生物復育應用之可行性，結果顯示各分離菌株於模擬污染土壤中培養40天，芘之降解率約為29~68%，其中菌株W1及N1之降解效果較其他菌株顯著，不同土壤種類中，各菌株之芘生物降解率並無明顯差異。

Polycyclic aromatic hydrocarbons （PAHs） are hydraphobic and highly persistent pollutants in soil environment. The environmental fate of PAHs is of concern cause of their mutagenicity, ecotoxicity, and carcinogenic potential of high molecular weight PAHs. Pyrene, a four-ring PAH with structural similarity to several carcinogenic PAHs, bioremediation is the tool to transform pyrene to less/non harzardous forms with less input of chemicals and energy. Thus, a deeper understanding of the pyrene biodegradation will facilitate better ways to remediate pyrene pollution. In this study, the pyrene degraders are isolated from the sludge samples from various disposing sties of petroleum stations and factories in southern Taiwan and enrichment was carried out with 100 mgL^（-1） pyrene as a sole carbon and energy source in a mineral medium. N1 and W1 strains showed the higher degradation activity to mineralize 100 mg kg-1 pyrene in sandy alluvial soil.