Geobacter soli sp. nov., a dissimilatory Fe(III)-reducing bacterium isolated from forest soil

Abstract

A novel Fe(III)-reducing bacterium, designated GSS01 T , was isolated from a forest soil sample using a liquid medium containing acetate and ferrihydrite as electron donor and electron acceptor, respectively. Cells of strain GSS01 T were strictly anaerobic, Gram-stain-negative, motile, nonspore-forming and slightly curved rod-shaped. Growth occurred at 16-40 6C and optimally at 30 6C. The DNA G+C content was 60.9 mol%. The major respiratory quinone was MK-8. The major fatty acids were C 16 : 0 , C 18 : 0 and C 16 : 1 v7c/C 16 : 1 v6c. Strain GSS01 T was able to grow with ferrihydrite, Fe(III) citrate, Mn(IV), sulfur, nitrate or anthraquinone-2,6-disulfonate, but not with fumarate, as sole electron acceptor when acetate was the sole electron donor. The isolate was able to utilize acetate, ethanol, glucose, lactate, butyrate, pyruvate, benzoate, benzaldehyde, mcresol and phenol but not toluene, p-cresol, propionate, malate or succinate as sole electron donor when ferrihydrite was the sole electron acceptor. Phylogenetic analyses based on 16S rRNA gene sequences revealed that strain GSS01 T was most closely related to Geobacter sulfurreducens PCA T (98.3 % sequence similarity) and exhibited low similarities (94.9-91.8 %) to the type strains of other species of the genus Geobacter. The DNA-DNA relatedness between strain GSS01 T and G. sulfurreducens PCA T was 41.4±1.1 %. On the basis of phylogenetic analysis, phenotypic characterization and physiological tests, strain GSS01 T is believed to represent a novel species of the genus Geobacter, and the name Geobacter soli sp. nov. is proposed. The type strain is GSS01 T (5KCTC 4545 T 5MCCC 1K00269 T ).

Geographic distribution of cadmium and its interaction with the microbial community in the Longjiang River: risk evaluation after a shocking pollution accident

“…For example, Geobacter is a genus of proteobacteria and the third largest genus of all the samples. Geobacter is an important metal ion-reducing bacterium that can reduce Fe(III) 38 , Pd(II) 39 and uranium (VI) 40 . Geobacter can be used for the precipitation of uranium out of groundwater 41 , as a new alternative for synthesizing Pd(0) nanocatalyst, and also has potential applications for microbial metal recovery from metal-containing waste streams 39 .…”

The electrically conductive pili ofGeobacter soli

“…Geobacter soli, distinct from G. sulfurreducens (18) and G. anodireducens (19), 77 was the first Geobacter species isolated from forest soil (20). The physiological 78 properties of G. soli are different from those of G. sulfurreducens, and these 79 properties determine its special environmental significance, although both strains are 80 highly similar based on phylogenetic analysis (20). For example, G. soli can 81 anaerobically oxidize aromatic compounds, including phenol, benzoate and 82 benzaldehyde, while G. sulfurreducens cannot (20,21).…”

“…The physiological 78 properties of G. soli are different from those of G. sulfurreducens, and these 79 properties determine its special environmental significance, although both strains are 80 highly similar based on phylogenetic analysis (20). For example, G. soli can 81 anaerobically oxidize aromatic compounds, including phenol, benzoate and 82 benzaldehyde, while G. sulfurreducens cannot (20,21). In addition, G. soli has faster 83 Fe(III) oxide reduction and higher current production than G. sulfurreducens (Fig.…”

“…The wild-type strain G. sulfurreducens PCA (DSM 12127) was purchased from the 284 German Collection of Microorganisms and Cell Culture. G. soli GSS01 was provided 285 by Zhou's lab (20). Both strains were cultured at 30 °C under strict anaerobic 286 conditions (80%/20%; N2/CO2) and used for the construction of related mutants.…”

Characterization of the genome fromGeobacter anodireducens, a strain with enhanced current production in bioelectrochemical systems

“…Nearly all of the research regarding mechanisms of EET by Geobacter has been conducted in G. sulfurreducens strain PCA because it was the rst to have a genome sequence, it can be genetically manipulated, and its metabolic traits such as rapid growth with fumarate as the electron acceptor make it easy to cultivate in the lab. 21,22 However, G. sulfurreducens is not the most environmentally representative strain as it does not reduce Fe(III) oxides or produce current as effectively as some other Geobacter species [23][24][25][26][27] and it rarely shows up in environmental samples. 3 Although it is apparent that Geobacter species do not use soluble avin shuttles like Shewanella, there does not seem to be one single pathway for EET amongst the genus.…”