【摘要】：鐵生物異化還原作用是鐵地球化學(xué)循環(huán)過程中的重要環(huán)節(jié),因其對環(huán)境中的重金屬及難降解有機污染物具有良好的固定和降解能力而受到了廣泛的關(guān)注。開展鐵還原菌分離及其特性研究將有助于深入了解微生物鐵還原過程,不僅可以豐富污染修復(fù)的生物材料,而且為污染修復(fù)應(yīng)用提供重要的理論依據(jù)。本研究從污水處理廠的污泥中分離純化得到高效的鐵還原菌,并研究純培養(yǎng)條件下鐵還原菌在不同碳源體系中的鐵還原能力、對不同F(xiàn)e(Ⅲ)的利用能力和電子穿梭體對鐵還原過程的影響,并初步研究該鐵還原菌共代謝降解三氯乙烯的能力。主要研究成果如下：分離獲得的鐵還原菌為短桿狀革蘭氏陰性菌,其最佳的生長條件為pH7,溫度35℃、黑暗條件。異化鐵生物還原過程的最佳碳濃度為1.5mol/L,蔗糖和葡萄糖是研究菌株的最佳碳源,其后依次是丙酮酸鈉、乙酸鈉和乳酸鈉。蔗糖和葡萄糖為碳源時,Fe(Ⅲ)還原率分別為81%和57.2%。碳源明顯影響著異化鐵還原過程中的脫氫酶活性、pH和H2分壓。各碳源體系中脫氫酶活性依次為丙酮酸鈉蔗糖葡萄糖乙酸鈉乳酸鈉,體系pH值變化幅度大小依次為乙酸鈉乳酸鈉丙酮酸鈉葡萄糖蔗糖,蔗糖、丙酮酸鈉和葡萄糖作為電子供體所產(chǎn)生的H2量遠大于乳酸鹽和乙酸鹽。核黃素(VB2)、鈷胺素(VB12)、黃腐酸(FA)和蒽醌-2,6-二磺酸鈉(AQDS)這四種電子傳遞物質(zhì)中,VB2和VB12僅能作為碳源被鐵還原菌利用,充當電子供體。FA和AQDS可作為電子穿梭體明顯促進Fe(OH)3的還原,增大鐵生物還原過程的還原潛勢,加速Fe(Ⅲ)還原速度。分離獲得的鐵還原菌不能以TCE作為碳源來降解TCE,但以蔗糖為共代謝底物時,在最適蔗糖濃度0.125mol/L時其降解率為40.1%；在共代謝體系中添加Fe(OH)3,TCE降解率提高至48.75%；共代謝體系中同時添加電子受體Fe(OH)3和電子穿梭體FA可以進一步提高TCE降解率。
[Abstract]:Iron biological alienation reduction is an important part in the process of iron geochemical cycle. It has attracted extensive attention because of its good fixation and degradation ability to heavy metals and refractory organic pollutants in the environment. The study on the separation and characteristics of iron reducing bacteria will be helpful to understand the process of iron reduction of microorganisms, which can not only enrich the biological materials for remediation of pollution, but also provide important theoretical basis for the application of remediation of pollution. In this study, high efficiency iron reducing bacteria were isolated and purified from sludge of sewage treatment plant, and the iron reducing ability of iron reducing bacteria in different carbon source systems was studied under pure culture conditions. The utilization ability of different Fe (鈪，

本文編號：2213148