RESUMO
A sulfur-oxidizing, filamentous, gliding micro-organism, strain D3T, was isolated from a sulfidic spring in Goryachy Klyuch, Krasnodar, Russia. The cell walls were Gram-negative. The new isolate was a microaerophilic facultative anaerobe and an obligate chemolithoautotroph. The pH range for growth was pH 6.8-7.6, with an optimum at pH 7.2. The temperature range for growth was 10-46 °C, with an optimum at 32 °C. The G+C content of DNA was 42.1 mol%. Phylogenetic analysis of the 16S rRNA gene showed that strain D3T belongs to the family Beggiatoaceae, order Thiotrichales and was distantly related to the genera of the family Beggiatoaceae(86-88â% sequence similarity). The major respiratory quinone was ubiquinone-6. Major fatty acids were C18:1 ω7 (37.6â%), C16â:â0 (34.7â%) and C16: 1 ω7 (27.7â%). On the basis of its physiological properties and the results of phylogenetic analysis, strain D3T is considered to represent a novel species of a new genus, for which the name Thioflexithrix psekupsensis gen. nov., sp. nov. is proposed. The type strain is D3T (=KCTC 62399=UNIQEM U981).
Assuntos
Filogenia , Enxofre , Thiotrichaceae/classificação , Microbiologia da Água , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Oxirredução , RNA Ribossômico 16S/genética , Federação Russa , Análise de Sequência de DNA , Thiotrichaceae/isolamento & purificação , Ubiquinona/químicaAssuntos
Proteínas de Bactérias/metabolismo , DNA Bacteriano/genética , Proteínas Ferro-Enxofre/metabolismo , Nitrato Redutase/metabolismo , Nitratos/metabolismo , Thiothrix/genética , Thiothrix/metabolismo , Anaerobiose , Proteínas de Bactérias/genética , Proteínas de Bactérias/isolamento & purificação , Temperatura Baixa , DNA Bacteriano/classificação , DNA Bacteriano/isolamento & purificação , Ensaios Enzimáticos , Água Doce , Proteínas Ferro-Enxofre/genética , Proteínas Ferro-Enxofre/isolamento & purificação , Cinética , Nitrato Redutase/genética , Nitrato Redutase/isolamento & purificação , Filogenia , Análise de Sequência de DNA , Sulfetos/metabolismo , Thiothrix/classificação , Thiothrix/isolamento & purificaçãoRESUMO
The lithotrophic capacity of the betaproteobacteria Sphaerotilus natans subsp. sulfidivorans was confirmed at genetic level: functional genes of sulfur metabolism were detected (aprBA, soxB, and sqr, coding for adenylyl phosphosulfate reductase, thiosulfate-cleaving enzyme, and sulfide:quinone oxidoreductase, respectively), and the expression of aprA and soxB genes was demonstrated. An evolutionary scenario for soxB genes in Sphaerotilus representatives is suggested based on comparative analysis of codon occurrence frequency, DNA base composition (G + C content), and topology of phylogenetic trees. The ancestor bacterium of the Sphaerotilus-Leptothrix group was capable of lithotrophic growth in the presence of reduced sulfur compounds. However, in the course of further evolution, the sulfur metabolism genes, including the soxB gene, were lost by some Sphaerotilus strains. As a result, the lithotrophic Sphaerotilus-Leptothrix group split into two phylogenetic lineages, lithotrophic and organotrophic ones.
Assuntos
Betaproteobacteria , Evolução Molecular , Regulação Bacteriana da Expressão Gênica/fisiologia , Regulação Enzimológica da Expressão Gênica/fisiologia , Genes Bacterianos/fisiologia , Filogenia , Enxofre/metabolismo , Composição de Bases/fisiologia , Betaproteobacteria/enzimologia , Betaproteobacteria/genéticaAssuntos
Processos Autotróficos/fisiologia , Azospirillum/fisiologia , Compostos de Enxofre/metabolismo , Aerobiose , Azospirillum/efeitos dos fármacos , Azospirillum/crescimento & desenvolvimento , Azospirillum/metabolismo , Primers do DNA , Transporte de Elétrons , Metabolismo Energético , Inibidores Enzimáticos/farmacologia , Regulação Bacteriana da Expressão Gênica , Oxirredução , Oxirredutases/antagonistas & inibidores , Oxirredutases/metabolismo , Filogenia , Sulfito Oxidase/metabolismo , Tiossulfatos/metabolismoRESUMO
Intraocular pressure was estimated in patients with corneal disorders and secondary glaucoma. 25 patients (29 eyes) with complicated corneal opacities and secondary glaucoma were included into the study. In these patients the most reliable results were revealed using bidirectional corneal applanation (ORA) with contact lens on a cornea. If ORA is not available tonometer TGDc01-diaton should be used.
