奥奈达希瓦氏菌MR-1的Fe(Ⅲ)还原特性及其影响因素

Dissimilatory Fe(Ⅲ) reduction by Shewanclla oneidensis MR-1 and impact factors

研究奥奈达希瓦氏菌MR-1的Fe(Ⅲ)还原特性,并考察不同电子供体、不同形态Fe(Ⅲ)、溶解氧、pH等对奥奈达希瓦氏菌MR-1还原Fe(Ⅲ)的影响。结果表明,奥奈达希瓦氏菌MR-1对Fe(Ⅲ)有还原能力,以乙酸盐、乳酸盐和丙酮酸盐作为Fe(Ⅲ)还原的唯一电子供体,Fe(Ⅲ)还原率分别达到39.12%、50.89%和44.98%;以FeCl3、Fe(OH)3和柠檬酸铁等不同形态Fe(Ⅲ)为菌株MR-1的唯一电子受体,Fe(Ⅲ)还原率分别达到44.72%、51.54%和10.45%;溶解氧的存在可抑制Fe(Ⅲ)异化还原;菌株MR-1可在pH 5.0～9.0范围内进行Fe(Ⅲ)还原;两种不同的蛋白质变性剂SDS和OGP作用下的Fe(Ⅲ)还原结果表明,菌株MR-1的Fe(Ⅲ)还原功能蛋白主要位于细胞外膜;同时,投加一定量的单宁酸和焦性没食子酸可提高Fe(Ⅲ)还原率,螯合铁的还原率分别达到76.37%和68.73%。

Dissimilatory Fe（Ⅲ） reduction by Shewanclla oneidensis MR-1 was studied,and impact factors such as electronic donors,Fe（Ⅲ） forms,dissolved oxygen content and pH were investigated.The results showed that Fe（Ⅲ） could be reduced by Shewanclla oneidensis MR-1,and iron reduction rates were 39.12%,50.89% and 44.98% using the acetate,lactate and pyruvate as the sole electronic donor of strain MR-1,respectively.The forms of Fe（Ⅲ） could influence their reduction,and iron reduction rates were 44.72%,51.54% and 10.45% using ferric trichloride,ferric hydroxide and ferric citrate as the sole electronic receptor of strain MR-1,respectively.Dis-solved oxygen inhibited the dissimilatory iron reduction.Strain MR-1 could reduce Fe（Ⅲ） in the range of pH 5.0 to 9.0.The effects of protein denaturants SDS and OGP suggested that Fe（Ⅲ） reduction function proteins of strain MR-1 were mainly localized to the soluble outer membrane fraction.Tannins acid and pyrogallic acid could en-hance Fe（Ⅲ） reduction,and iron reduction rates were 76.37% and 68.73%,respectively.