A New Thioalkalivibrio sp. Strain Isolated from Petroleum-Contaminated Brackish Estuary Sediments: A New Candidate for Bio-Based Application for Sulfide Oxidation in Halo-Alkaline Conditions (original) (raw)

Thioalkalivibrio sulfidiphilus sp. nov., a haloalkaliphilic, sulfur-oxidizing gammaproteobacterium from alkaline habitats

Research Article, 2012

A moderately salt-tolerant and obligately alkaliphilic, chemolithoautotrophic sulfur-oxidizing bacterium, strain HL-EbGr7 T, was isolated from a full-scale bioreactor removing H2S from biogas under oxygen-limited conditions. Another strain, ALJ17, closely related to HL-EbGr7 T , was isolated from a Kenyan soda lake. Cells of the isolates were relatively long, slender rods, motile by a polar flagellum. Although both strains were obligately aerobic, micro-oxic conditions were preferred, especially at the beginning of growth. Chemolithoautotrophic growth was observed with sulfide and thiosulfate in a pH range of 8.0–10.5 (optimum at pH 10.0) and a salinity range of 0.2–1.5 M total Na+ (optimum at 0.4 M). The genome sequence of strain HL-EbGr7 T demonstrated the presence of genes encoding the reverse Dsr pathway and a truncated Sox pathway for sulfur oxidation and enzymes of the Calvin–Benson cycle of autotrophic CO2 assimilation with ribulose-bisphosphate carboxylase/oxygenase (RuBisCO) type I. The dominant cellular fatty acids were C18 : 1 v7, C16 : 0 and C19 : 0 cyclo.

Microbiological analysis of the population of extremely haloalkaliphilic sulfur-oxidizing bacteria dominating in lab-scale sulfide-removing bioreactors

Applied Microbiology and Biotechnology, 2008

Thiopaq biotechnology for partial sulfide oxidation to elemental sulfur is an efficient way to remove H2S from biogases. However, its application for high-pressure natural gas desulfurization needs upgrading. Particularly, an increase in alkalinity of the scrubbing liquid is required. Therefore, the feasibility of sulfide oxidation into elemental sulfur under oxygen limitation was tested at extremely haloalkaline conditions in lab-scale bioreactors using mix sediments from hypersaline soda lakes as inoculum. The microbiological analysis, both culture dependent and independent, of the successfully operating bioreactors revealed a domination of obligately chemolithoautotrophic and extremely haloalkaliphilic sulfur-oxidizing bacteria belonging to the genus Thioalkalivibrio. Two subgroups were recognized among the isolates. The subgroup enriched from the reactors operating at pH 10 clustered with Thioalkalivibrio jannaschii–Thioalkalivibrio versutus core group of the genus Thioalkalivibrio. Another subgroup, obtained mostly with sulfide as substrate and at lower pH, belonged to the cluster of facultatively alkaliphilic Thioalkalivibrio halophilus. Overall, the results clearly indicate a large potential of the genus Thiolalkalivibrio to efficiently oxidize sulfide at extremely haloalkaline conditions, which makes it suitable for application in the natural gas desulfurization.

Genetic diversity and biogeography of haloalkaliphilic sulphur-oxidizing bacteria belonging to the genus Thioalkalivibrio

FEMS Microbiology Ecology, 2000

A group of 85 isolates of haloalkaliphilic obligately chemolithoautotrophic sulphur-oxidizing bacteria belonging to the genus Thioalkalivibrio were recently obtained from soda lakes in Mongolia, Kenya, California, Egypt and Siberia. They have been analyzed by repetitive extragenic palindromic (rep)-PCR genomic fingerprinting technique with BOX-and (GTG)5-primer set. Cluster analysis was performed using combined fingerprint profiles and a dendrogram similarity value (r) of 0.8 was used to define the same genotype. Fifty-six genotypes were found among the isolates, revealing a high genetic diversity. The strains can be divided into two major clusters, including isolates from the Asiatic (Siberia and Mongolia) and the African (Kenya and Egypt) continents, respectively. The majority (85.9%) of the genotypes were found in only one area, suggesting an endemic character of the Thioalkalivibrio strains. Furthermore, a correlation between fingerprint clustering, geographic origin and the characteristics of the lake of origin was found. FEMS Microbiol Ecol 56 (2006) 95-101 c

Thialkalivibrio halophilus sp. nov., a novel obligately chemolithoautotrophic, facultatively alkaliphilic, and extremely salt-tolerant, sulfur-oxidizing bacterium from a hypersaline alkaline lake

Extremophiles, 2004

A new chemolithoautotrophic, facultatively alkaliphilic, extremely salt-tolerant, sulfur-oxidizing bacterium was isolated from an alkaline hypersaline lake in the Altai Steppe (Siberia, Russia). According to 16S rDNA analysis and DNA-DNA hybridization, strain HL 17 T was identified as a new species of the genus Thialkalivibrio belonging to the c subdivision of the Proteobacteria for which the name Thialkalivibrio halophilus is proposed. Strain HL 17 T is an extremely salttolerant bacterium growing at sodium concentrations between 0.2 and 5 M, with an optimum of 2 M Na + . It grew at high concentrations of NaCl and of Na 2 CO 3 / NaHCO 3 (soda). Strain HL 17 T is a facultative alkaliphile growing at pH range 7.5-9.8, with a broad optimum between pH 8.0 and 9.0. It used reduced inorganic sulfur compounds (thiosulfate, sulfide, polysulfide, elemental sulfur, and tetrathionate) as energy sources and electron donors. In continuous culture under energy limitation, thiosulfate was stoichiometrically oxidized to sulfate. In sodium carbonate medium under alkaline conditions, the maximum growth rate was similar, while the biomass yield was lower as compared with the NaClgrown culture. The maximum sulfur-oxidizing capacity measured in washed cells was higher in the soda buffer independent of the growth conditions. The compatible solute content of the biomass was higher in the sodium chloride-grown culture than in the sodium carbonate/ bicarbonate-grown culture. The data suggest that the osmotic pressure differences between soda and NaCl solutions might be responsible for the difference observed in compatible solutes production. This may have important implications in overall energetic metabolism of high salt adaptation.

Growth kinetics of haloalkaliphilic, sulfur-oxidizing bacterium Thioalkalivibrio versutus strain ALJ 15 in continuous culture

Extremophiles, 2004

The chemolithoautotrophic, sulfur-oxidizing bacterium Thioalkalivibrio versutus strain ALJ 15, isolated from a soda lake in Kenya, was grown in a continuous culture, with thiosulfate or polysulfide as growth-limiting energy source and oxygen as electron acceptor, at pH 10 and at pH 0.6, 2 M and 4 M total sodium. The end product of the sulfur-compound oxidation was sulfate. Elemental sulfur and a cell-bound, polysulfide-like compound appeared as intermediates during substrate oxidation. In the thiosulfate-limited culture, the biomass yields and maximum specific growth rates decreased two and three times, respectively, with increasing sodium concentration. The apparent affinity constant measured for thiosulfate and polysulfide was in the micromolar range (K s =6±3 lM). The maintenance requirement (m s =8±5 mmol S 2 O 3 2 /g dry weight h )1 ) was in the range of values found for other autotrophic sulfur-oxidizing bacteria. The organism had a comparable maximum specific rate of oxygen uptake with thiosulfate, polysulfide, and sulfide, while elemental sulfur was oxidized at a lower rate. Glycine betaine was the main organic compatible solute. The respiration rates with different species of polysulfides (S n 2) ) were tested. All polysulfide species were completely oxidized at high rates to sulfate. Overall data demonstrated efficient growth and sulfur compounds oxidation of haloalkaliphilic chemolithoautotrophic bacteria from soda lakes.

A Sulfur Oxygenase from the Haloalkaliphilic Bacterium Thioalkalivibrio paradoxus with Atypically Low Reductase Activity

Journal of Bacteriology, 2016

Sequence comparisons showed that the sulfur oxygenase reductase (SOR) of the haloalkaliphilic bacterium Thioalkalivibrio paradoxus Arh 1 ( Tp SOR) is branching deeply within dendrograms of these proteins (29 to 34% identity). A synthetic gene encoding Tp SOR expressed in Escherichia coli resulted in a protein 14.7 ± 0.9 nm in diameter and an apparent molecular mass of 556 kDa. Sulfite and thiosulfate were formed from elemental sulfur in a temperature range of 10 to 98°C (optimum temperature ≈ 80°C) and a pH range of 6 to 11.5 (optimum pH ≈ 9; 308 ± 78 U/mg of protein). Sulfide formation had a maximum specific activity of 0.03 U/mg, or <1% of the corresponding activity of other SORs. Hence, reductase activity seems not to be an integral part of the reaction mechanism. Tp SOR was most active at NaCl or glycine betaine concentrations of 0 to 1 M, although 0.2% of the maximal activity was detected even at 5 M NaCl and 4 M betaine. The melting point of Tp SOR was close to 80°C, when m...

Evaluating the Potential of Halothiobacillus Bacteria for Sulfur Oxidation and Biomass Production under Saline Soil

Geomicrobiology Journal, 2020

Salinity negatively affects growth of sulfur-oxidizing bacteria (SOB) and their sulfate production ability, meanwhile decreases the available sulfate for plants in soil. The aim of this study was to isolate and characterize the bacteria of genus Halothiobacillus, as a salt-tolerant SOB, from saline and sulfidic habitats of Iran for the first time and evaluating the effect of salinity on their biomass and sulfate production during the oxidation of different sulfur sources. Isolation process and surveying the morphological, biochemical and 16S rRNA gene analysis resulted into identification of three species (eight strains) of Halothiobacillus genus including H. neapolitanus, H. hydrothermalis and H. halophilus. Salinity (0, 0.5, 1, 2 and 4 M NaCl) had a significant impact (p 0.01) on bacterial biomass and sulfate production during the oxidation of thiosulfate and elemental sulfur. Biomass and sulfate production by strains was accompanied by a decrease in residual content of thiosulfate (RCT) in medium. The amount of produced biomass and sulfate in medium supplemented by thiosulfate was much higher than elemental sulfur. The highest amount of biomass and sulfate was produced by H. neapolitanus strain I19 at 0.5 and 1 M NaCl concentration. The results of this study could be the first step to focus on the application of these bacteria to increase sulfate storage of saline soils and crop production.

Isolation and characterisation of Thiobacillus halophilus sp. nov., a sulphur-oxidising autotrophic eubacterium from a Western Australian hypersaline lake

Archives of Microbiology, 1991

The isolation of a novel obligately chemolithotrophic, halophilic and extremely halotolerant Thiobacillus from a hypersaline lake is described. Attempts to demonstrate sulphur-and ferrous iron-oxidizing chemolithotrophs in neighbouring hypersaline lakes were unsuccessful. The organism isolated differs from any other Thiobacillus species previously described and is formally named as Thiobacillus halophilus. It possesses ribulose bisphosphate carboxylase and grows chemolithoautotrophically on thiosulphate, tetrathionate and sulphur, oxidising them to sulphate. Kinetic constants for oxidation of sulphide, thiosulphate, trithionate and tetrathionate are presented. The organism is obligately halophilic, growing best with 0.8-1.0 M NaC1, and tolerating up to 4 M NaC1. Optimum growth was obtained at about 30°C and pH 7.0-7.3. It contains ubiquinone Q-8 and its DNA contains 45 mol % G + C. Organisms of this type might contribute significantly to the autotrophic fixation of carbon dioxide in some hypersaline extreme environments of the kind described.