| Abstract | Five strains of filamentous, sulfur-oxidizing bacteria were isolated from sulfur mats of different sulfide springs from various regions of the Northern Caucasus, Russia. A phylogenetic analysisbased on 16S rRNA gene sequence comparison showed that all of the isolates are affiliated with the filamentous, colourless, sulfur-oxidizing bacteria of the genus Thiothrix within the Gammaproteobacteria and are closely related to Thiothrix fructosivorans. All strains are capable of growing heterotrophically, lithoautotrophically with thiosulfate or sulfide as the sole energy source and mixotrophically. Strains G1T, G2, P and K2 are able to fix molecular nitrogen, but strain BLT is not. Randomly amplified polymorphic DNA (RAPD)-PCR analysis was used to assess the level of genetic relationships among the Thiothrix isolates. The Nei and Li similarity index revealed high genetic similarity among strains G1T, G2, P and K2 (above 75 %), indicating that they are closely related. In combination with physiological and morphological data, strains G1T, G2, P and K2 can be considered as members of the same species. The lowest genetic similarity (approx.20 %) was reached between strain BLT and the other isolated Thiothrix strains. Strains BLT and G1T shared 35% DNA-DNA relatedness and showed 51 and 53% relatedness, respectively, to Thiothrix fructosivorans ATCC 49749. On the basis of this polyphasic analysis, strains G1T, G2, P and K2 represent a novel species within the genus Thiothrix, for which the name Thiothrix caldifontis sp. nov. is proposed, with strain G1T (5DSM 21228T 5VKM B-2520T) as the type strain. In addition, strain BLT represents a second novel species, Thiothrix lacustris sp. nov., with strain BLT (5DSM 21227T 5VKM B-2521T) as the type strain. |
| Text | 42365 2009 10.1099/ijs.0.009456 0 ISI Web of Science WOS 000273135700035 Thiothrix filamentous bacteria bulking THIOTHRIX CALDIFONTIS SP. NOV. AND THIOTHRIX LACUSTRIS SP. NOV., NOVEL GAMMAPROTEOBACTERIA ISOLATED FROM SULFIDE SPRINGS CHERNOUSOVA E. 1,2 ; GRIDNEVA E. 1 ; GRABOVICH M. 1 ; DUBININA G. 3 ; AKIMOV V. 2 ; ROSSETTI S. 4 ; KUEVER J. 5 1 Department of Biology, University of Voronezh, Universitetskaya pl. 1, 394006 Voronezh, Russia; 2 G. K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Prospect Nauki 5, 142290 Pushchino, Russia; 3 S. N. Winogradsky Institute of Microbiology, Russian Academy of Sciences, Prospect 60 letiya Oktyabrya 7/2, 117312 Moscow, Russia; 4 Water Research Institute, CNR, Via Reno 1, 00198 Rome, Italy; 5 Department of Microbiology, Bremen Institute for Materials Testing, Paul Feller Str. 1, D 28199 Bremen, Germany; Five strains of filamentous, sulfur oxidizing bacteria were isolated from sulfur mats of different sulfide springs from various regions of the Northern Caucasus, Russia. A phylogenetic analysisbased on 16S rRNA gene sequence comparison showed that all of the isolates are affiliated with the filamentous, colourless, sulfur oxidizing bacteria of the genus Thiothrix within the Gammaproteobacteria and are closely related to Thiothrix fructosivorans. All strains are capable of growing heterotrophically, lithoautotrophically with thiosulfate or sulfide as the sole energy source and mixotrophically. Strains G1T, G2, P and K2 are able to fix molecular nitrogen, but strain BLT is not. Randomly amplified polymorphic DNA RAPD PCR analysis was used to assess the level of genetic relationships among the Thiothrix isolates. The Nei and Li similarity index revealed high genetic similarity among strains G1T, G2, P and K2 above 75 % , indicating that they are closely related. In combination with physiological and morphological data, strains G1T, G2, P and K2 can be considered as members of the same species. The lowest genetic similarity approx.20 % was reached between strain BLT and the other isolated Thiothrix strains. Strains BLT and G1T shared 35% DNA DNA relatedness and showed 51 and 53% relatedness, respectively, to Thiothrix fructosivorans ATCC 49749. On the basis of this polyphasic analysis, strains G1T, G2, P and K2 represent a novel species within the genus Thiothrix, for which the name Thiothrix caldifontis sp. nov. is proposed, with strain G1T 5DSM 21228T 5VKM B 2520T as the type strain. In addition, strain BLT represents a second novel species, Thiothrix lacustris sp. nov., with strain BLT 5DSM 21227T 5VKM B 2521T as the type strain. 59 Thiothrix caldifontis sp. nov. and Thiothrix lacustris sp. nov., gammaproteobacteria isolated from sulfide springs Rossetti_Thiothrix.pdf Articolo in rivista Society for General Microbiology. 1466 5026 International journal of systematic and evolutionary microbiology Print International journal of systematic and evolutionary microbiology Print Int. j. syst. evol. microbiol. Print IJSEM Print Print simona.rossetti ROSSETTI SIMONA TA.P07.014.005 Risanamento di acque di falda |
