成团泛菌MFC-3的分离鉴定及其腐殖质/Fe(Ⅲ)呼吸特性研究  

Isolation and Characterization of a Facultative Anaerobe Pantoea agglomerans MFC-3 and Its Humic Substance-and Fe(Ⅲ)-Respiring Activity

作　　者：武春媛[1,2] 李芳柏[2] 周顺桂[2] 庄莉[2] 王跃强[2] 

机构地区：[1]中国科学院广州地球化学研究所,广州510640 [2]广东省生态环境与土壤研究所广东省农业环境综合治理重点实验室,广州510650

出　　处：《环境科学》2010年第1期237-242,共6页Environmental Science

基　　金：国家自然科学基金项目(20777013;40801119);广东省自然科学基金项目(8151065003000005)

摘　　要：从地下古森林沉积物样品中富集分离到1株腐殖质/Fe(Ⅲ)还原菌MFC-3菌株,经16S rDNA基因序列分析,该菌与成团泛菌Pantoea agglomerans WAB1951的相似性为99%,确定为成团泛菌.通过序批式厌氧实验考察了MFC-3的腐殖质呼吸活性、电子利用情况以及对4种铁氧化物的还原活性.结果表明,MFC-3能够以AQDS为唯一电子受体进行厌氧胞外呼吸,可利用的电子供体有:甲酸、乳酸、丙三醇、柠檬酸、葡萄糖和蔗糖,且AQDS还原速率顺序为:蔗糖>葡萄糖>柠檬酸>乳酸>丙三醇>甲酸;以葡萄糖作为电子供体时,48 h内0.3 mmol.L-1的AQDS被还原,同时4.5 mmol.L-1葡萄糖被消耗,菌数增殖近7倍,证明MFC-3能够进行腐殖质呼吸;MFC-3还能以多种Fe(Ⅲ)氧化物为电子受体进行厌氧呼吸,25 d内分别有2.5 mmol.L-1水铁矿、2.1 mmol.L-1纤铁矿、2.3 mmol.L-1针铁矿及0.8 mmol.L-1赤铁矿被还原溶解.本研究为胞外呼吸研究与应用提供1株适宜的模式菌株.A strain of humic substance-and Fe（Ⅲ）-reducing bacterium was isolated from the subterranean forest sediment and designated as MFC-3.The strain is facultative anaerobic,Gram-negative,motile and rod（1.0-3.0 μm long,0.5-1.0 μm wide） and identified as Pantoea agglomerans with the 16S rDNA sequence analyses.Batch experiments were conducted to investigate its humic substance-and Fe（Ⅲ）-respiring activity.The results showed that MFC-3 was capable of anaerobic respiration on anthraquinone-2,6-disulphonate（AQDS） as the sole terminal electron acceptor with glucose as the electron donor.Within 48 h,MFC-3 could reduce 0.3 mmol·L^-1 AQDS at the expense of 4.5 mmol·L^-1 glucose,and the population of bacteria was increased by 7 times.The strain could use sucrose,glucose,citrate,lactate and formate as electron donors for anaerobic respiration,and the reduction rates of AQDS ranked as sucrose（77%）〉 glucose（66%） 〉 citrate（50%） 〉 lactate（33%） 〉 glycerol（25%）〉 formate（17%）.MFC-3 can also effec.tively reduce four types of Fe（Ⅲ） oxides.After 25 d,the total Fe（Ⅱ） concentration in the tests of using ferrihydrite,α-FeOOH,γ-FeOOH or α-Fe2O3 as electron acceptor reached 2.5,2.1,2.3 and 0.8 mmol·L-1,respectively.As a strain of environmental origin,MFC-3 is quite useful for the study of extracellular respiration and bioremediation of chlorinated organic pollutants in Fe（Ⅲ）/humic substance-rich environments.

关 键 词：成团泛菌 腐殖质 铁氧化物 腐殖质/Fe(Ⅲ)呼吸 胞外呼吸 

分 类 号：X172[环境科学与工程—环境科学]