Nevin Kelly P, Holmes Dawn E, Woodard Trevor L, Hinlein Erich S, Ostendorf David W, Lovley Derek R
Department of Microbiology, University of Massachusetts Amherst, Amherst, MA 01003, USA.
Department of Civil and Environmental Engineering, University of Massachusetts Amherst, Amherst, MA 01003, USA.
Int J Syst Evol Microbiol. 2005 Jul;55(Pt 4):1667-1674. doi: 10.1099/ijs.0.63417-0.
Fe(III)-reducing isolates were recovered from two aquifers in which Fe(III) reduction is known to be important. Strain Bem(T) was enriched from subsurface sediments collected in Bemidji, MN, USA, near a site where Fe(III) reduction is important in aromatic hydrocarbon degradation. Strains P11, P35(T) and P39 were isolated from the groundwater of an aquifer in Plymouth, MA, USA, in which Fe(III) reduction is important because of long-term inputs of acetate as a highway de-icing agent to the subsurface. All four isolates were Gram-negative, slightly curved rods that grew best in freshwater media. Strains P11, P35(T) and P39 exhibited motility via means of monotrichous flagella. Analysis of the 16S rRNA and nifD genes indicated that all four strains are delta-proteobacteria and members of the Geobacter cluster of the Geobacteraceae. Differences in phenotypic and phylogenetic characteristics indicated that the four isolates represent two novel species within the genus Geobacter. All of the isolates coupled the oxidation of acetate to the reduction of Fe(III) [iron(III) citrate, amorphous iron(III) oxide, iron(III) pyrophosphate and iron(III) nitrilotriacetate]. All four strains utilized ethanol, lactate, malate, pyruvate and succinate as electron donors and malate and fumarate as electron acceptors. Strain Bem(T) grew fastest at 30 degrees C, whereas strains P11, P35(T) and P39 grew equally well at 17, 22 and 30 degrees C. In addition, strains P11, P35(T) and P39 were capable of growth at 4 degrees C. The names Geobacter bemidjiensis sp. nov. (type strain Bem(T)=ATCC BAA-1014(T)=DSM 16622(T)=JCM 12645(T)) and Geobacter psychrophilus sp. nov. (strains P11, P35(T) and P39; type strain P35(T)=ATCC BAA-1013(T)=DSM 16674(T)=JCM 12644(T)) are proposed.
从两个已知铁（III）还原作用很重要的含水层中分离出了铁（III）还原菌株。菌株Bem(T)是从美国明尼苏达州贝米吉市收集的地下沉积物中富集得到的，该地点附近铁（III）还原在芳烃降解过程中起着重要作用。菌株P11、P35(T)和P39是从美国马萨诸塞州普利茅斯市一个含水层的地下水中分离出来的，由于长期向地下输入醋酸盐作为公路除冰剂，该含水层中铁（III）还原作用很重要。所有这四株分离菌均为革兰氏阴性、略弯曲的杆菌，在淡水培养基中生长最佳。菌株P11、P35(T)和P39通过单端鞭毛运动。对16S rRNA和nifD基因的分析表明，所有这四株菌株均为δ-变形菌纲，属于地杆菌科的地杆菌属簇。表型和系统发育特征的差异表明，这四株分离菌代表了地杆菌属内的两个新物种。所有分离菌都能将醋酸盐的氧化与铁（III）[柠檬酸铁（III）、无定形氧化铁（III）、焦磷酸铁（III）和次氮基三乙酸铁（III）]的还原偶联起来。所有这四株菌株都利用乙醇、乳酸、苹果酸、丙酮酸和琥珀酸作为电子供体，利用苹果酸和富马酸作为电子受体。菌株Bem(T)在30℃时生长最快，而菌株P11、P35(T)和P39在17℃、22℃和30℃时生长情况相同。此外，菌株P11、P35(T)和P39能够在4℃下生长。提出了新物种贝米吉地杆菌（Geobacter bemidjiensis sp. nov.）（模式菌株Bem(T)=ATCC BAA-1014(T)=DSM 16622(T)=JCM 12645(T)）和嗜冷地杆菌（Geobacter psychrophilus sp. nov.）（菌株P11、P35(T)和P
