Caloramator proteoclasticus sp. nov., a New Moderately Thermophilic Anaerobic Proteolytic Bacterium

The iron-oxidizing system of a moderately thermophilic, extremely acidophilic, gram-positive mixotroph, Sulfobacillus sibiricus N1T, was studied by spectroscopic, high-performance liquid chromatography and inhibitory analyses. Hemes B, A, and O were detected in membranes of S. sibiricus N1T. It is proposed that the electron transport chain from Fe2+ to O2 is terminated by 2 physiological oxidases: aa3-type cytochrome, which dominates in the early-exponential phase of growth, and bo3-type cytochrome, whose role in iron oxidation becomes more prominent upon growth of the culture. Both oxidases were sensitive to cyanide and azide. Cytochrome aa3 was more sensitive to cyanide and azide, with Ki values of 4.1 and 2.5 µmol·L–1, respectively, compared with Ki values for cytochrome bo3, which were 9.5 µmol·L–1 for cyanide and 7.0 µmol·L–1 for azide. This is the first evidence for the participation of a bo3-type oxidase in ferrous iron oxidation. The respiratory chain of the mixotroph contains, in addition to the 2 terminal oxidases, a membrane-bound cytochrome b573.

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Decomposition of Rice Chaff Using a Cocultivation System of Thermobifida fusca and Ureibacillus thermosphaericus

Proceedings ◽

10.3390/proceedings2020066031 ◽

2021 ◽

Vol 66 (1) ◽

pp. 31

Author(s):

Sachiko Nakamura ◽

Norio Kurosawa

Keyword(s):

Lignin Peroxidase ◽

Culture Medium ◽

Reducing Sugars ◽

Thermophilic Bacteria ◽

Thermobifida Fusca ◽

Bacterial Strains ◽

Basal Salt Medium ◽

Moderately Thermophilic ◽

Fuels And Chemicals ◽

Ureibacillus Thermosphaericus

Lignocellulosic biomass comprises cellulose, hemicellulose, and lignin and is a potential source of fuels and chemicals. Although this complex biomass is persistent, it can be cooperatively decomposed by a microbial consortium in nature. In this study, a coculture of the moderately thermophilic bacteria Thermobifida fusca and Ureibacillus thermosphaericus was used for biodegradation of rice chaff. The bacterial strains were incubated in modified Brock’s basal salt medium (pH 8.0) supplemented with yeast extract and rice chaff at 50 °C for 7 days. The concentration of reducing sugars and the enzymatic activities of laccase, lignin peroxidase, cellulase, and xylanase in the supernatant of the culture medium were measured every day. The concentrations of reducing sugars in solo cultures of T. fusca and U. thermosphaericus and a mixed culture of the two strains after 7 days of incubation were 0.047, 0.040, and 0.195 mg/mL, respectively, indicating that the decomposition of rice chaff was enhanced in the coculture. Based on the results, it is thought that the lignin surrounding the cellulose was decomposed by laccase and lignin peroxidase secreted from U. thermosphaericus, resulting in cellulose and hemicellulose in the rice chaff being easily decomposed by enzymes from T. fusca.

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Membrane Lipid Composition of the Moderately Thermophilic Ammonia-Oxidizing Archaeon “Candidatus Nitrosotenuis uzonensis” at Different Growth Temperatures

Applied and Environmental Microbiology ◽

10.1128/aem.01332-19 ◽

2019 ◽

Vol 85 (20) ◽

Cited By ~ 4

Author(s):

Nicole J. Bale ◽

Marton Palatinszky ◽

W. Irene C. Rijpstra ◽

Craig W. Herbold ◽

Michael Wagner ◽

...

Keyword(s):

Lipid Composition ◽

Strong Influence ◽

Thermal Spring ◽

Membrane Lipid ◽

Effect Of Temperature ◽

Environmental Niche ◽

Membrane Lipid Composition ◽

Moderately Thermophilic ◽

Wide Range ◽

Membrane Spanning

ABSTRACT “Candidatus Nitrosotenuis uzonensis” is the only cultured moderately thermophilic member of the thaumarchaeotal order Nitrosopumilales (NP) that contains many mesophilic marine strains. We examined its membrane lipid composition at different growth temperatures (37°C, 46°C, and 50°C). Its lipids were all membrane-spanning glycerol dialkyl glycerol tetraethers (GDGTs), with 0 to 4 cyclopentane moieties. Crenarchaeol (cren), the characteristic thaumarchaeotal GDGT, and its isomer (crenʹ) were present in high abundance (30 to 70%). The GDGT polar headgroups were mono-, di-, and trihexoses and hexose/phosphohexose. The ratio of glycolipid to phospholipid GDGTs was highest in the cultures grown at 50°C. With increasing growth temperatures, the relative contributions of cren and crenʹ increased, while those of GDGT-0 to GDGT-4 (including isomers) decreased. TEX86 (tetraether index of tetraethers consisting of 86 carbons)-derived temperatures were much lower than the actual growth temperatures, further demonstrating that TEX86 does not accurately reflect the membrane lipid adaptation of thermophilic Thaumarchaeota. As the temperature increased, specific GDGTs changed relative to their isomers, possibly representing temperature adaption-induced changes in cyclopentane ring stereochemistry. Comparison of a wide range of thaumarchaeotal core lipid compositions revealed that the “Ca. Nitrosotenuis uzonensis” cultures clustered separately from other members of the NP order and the Nitrososphaerales (NS) order. While phylogeny generally seems to have a strong influence on GDGT distribution, our analysis of “Ca. Nitrosotenuis uzonensis” demonstrates that its terrestrial, higher-temperature niche has led to a lipid composition that clearly differentiates it from other NP members and that this difference is mostly driven by its high crenʹ content. IMPORTANCE For Thaumarchaeota, the ratio of their glycerol dialkyl glycerol tetraether (GDGT) lipids depends on growth temperature, a premise that forms the basis of the widely applied TEX86 paleotemperature proxy. A thorough understanding of which GDGTs are produced by which Thaumarchaeota and what the effect of temperature is on their GDGT composition is essential for constraining the TEX86 proxy. “Ca. Nitrosotenuis uzonensis” is a moderately thermophilic thaumarchaeote enriched from a thermal spring, setting it apart in its environmental niche from the other marine mesophilic members of its order. Indeed, we found that the GDGT composition of “Ca. Nitrosotenuis uzonensis” cultures was distinct from those of other members of its order and was more similar to those of other thermophilic, terrestrial Thaumarchaeota. This suggests that while phylogeny has a strong influence on GDGT distribution, the environmental niche that a thaumarchaeote inhabits also shapes its GDGT composition.

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Identification of Poly(cis-1,4-Isoprene) Degradation Intermediates during Growth of Moderately Thermophilic Actinomycetes on Rubber and Cloning of a Functional lcp Homologue from Nocardia farcinica Strain E1

Applied and Environmental Microbiology ◽

10.1128/aem.72.5.3375-3382.2006 ◽

2006 ◽

Vol 72 (5) ◽

pp. 3375-3382 ◽

Cited By ~ 58

Author(s):

Ebaid M. A. Ibrahim ◽

Matthias Arenskï¿½tter ◽

Heinrich Luftmann ◽

Alexander Steinbï¿½chel

Keyword(s):

Thermophilic Bacteria ◽

Natural Rubber Latex ◽

Gel Permeation Chromatography ◽

Mycolic Acid ◽

Rrna Gene ◽

Ionization Mass ◽

Thermophilic Actinomycetes ◽

Moderately Thermophilic ◽

Nocardia Farcinica ◽

Different Strains

ABSTRACT The enrichment and isolation of thermophilic bacteria capable of rubber [poly(cis-1,4-isoprene)] degradation revealed eight different strains exhibiting both currently known strategies used by rubber-degrading mesophilic bacteria. Taxonomic characterization of these isolates by 16S rRNA gene sequence analysis demonstrated closest relationships to Actinomadura nitritigenes, Nocardia farcinica, and Thermomonospora curvata. While strains related to N. farcinica exhibited adhesive growth as described for mycolic acid-containing actinomycetes belonging to the genus Gordonia, strains related to A. nitritigenes and T. curvata formed translucent halos on natural rubber latex agar as described for several mycelium-forming actinomycetes. For all strains, optimum growth rates were observed at 50ï¿½C. The capability of rubber degradation was confirmed by mineralization experiments and by gel permeation chromatography (GPC). Intermediates resulting from early degradation steps were purified by preparative GPC, and their analysis by infrared spectroscopy revealed the occurrence of carbonyl carbon atoms. Staining with Schiff's reagent also revealed the presence of aldehyde groups in the intermediates. Bifunctional isoprenoid species terminated with a keto and aldehyde function were found by matrix-assisted laser desorption ionization-time-of-flight and electrospray ionization mass spectrometry analyses. Evidence was obtained that biodegradation of poly(cis-1,4-isoprene) is initiated by endocleavage, rather than by exocleavage. A gene (lcp) coding for a protein with high homology to Lcp (latex-clearing protein) from Streptomyces sp. strain K30 was identified in Nocardia farcinica E1. Streptomyces lividans TK23 expressing this Lcp homologue was able to cleave synthetic poly(cis-1,4-isoprene), confirming its involvement in initial polymer cleavage.

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Structural and Biochemical Studies of a Moderately Thermophilic Exonuclease I from Methylocaldum szegediense

PLoS ONE ◽

10.1371/journal.pone.0117470 ◽

2015 ◽

Vol 10 (2) ◽

pp. e0117470

Author(s):

Li Fei ◽

SiSi Tian ◽

Ruth Moysey ◽

Mihaela Misca ◽

John J. Barker ◽

...

Keyword(s):

Moderately Thermophilic ◽

Exonuclease I ◽

Biochemical Studies ◽

Methylocaldum Szegediense

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Growth and Phylogenetic Properties of Novel Bacteria Belonging to the Epsilon Subdivision of the Proteobacteria Enriched fromAlvinella pompejana and Deep-Sea Hydrothermal Vents

Applied and Environmental Microbiology ◽

10.1128/aem.67.10.4566-4572.2001 ◽

2001 ◽

Vol 67 (10) ◽

pp. 4566-4572 ◽

Cited By ~ 102

Author(s):

Barbara J. Campbell ◽

Christian Jeanthon ◽

Joel E. Kostka ◽

George W. Luther ◽

S. Craig Cary

Keyword(s):

Deep Sea ◽

Hydrothermal Vent ◽

Hydrothermal Vents ◽

Heterotrophic Bacteria ◽

Geographic Location ◽

Optimal Growth ◽

Small Subunit ◽

Ribosomal Gene ◽

Moderately Thermophilic ◽

Novel Bacteria

ABSTRACT Recent molecular characterizations of microbial communities from deep-sea hydrothermal sites indicate the predominance of bacteria belonging to the epsilon subdivision of Proteobacteria(epsilon Proteobacteria). Here, we report the first enrichments and characterizations of four epsilonProteobacteria that are directly associated withAlvinella pompejana, a deep sea hydrothermal vent polychete, or with hydrothermal vent chimney samples. These novel bacteria were moderately thermophilic sulfur-reducing heterotrophs growing on formate as the energy and carbon source. In addition, two of them (Am-H and Ex-18.2) could grow on sulfur lithoautrotrophically using hydrogen as the electron donor. Optimal growth temperatures of the bacteria ranged from 41 to 45°C. Phylogenetic analysis of the small-subunit ribosomal gene of the two heterotrophic bacteria demonstrated 95% similarity to Sulfurospirillum arcachonense, an epsilon Proteobacteria isolated from an oxidized marine surface sediment. The autotrophic bacteria grouped within a deeply branching clade of the epsilonProteobacteria, to date composed only of uncultured bacteria detected in a sample from a hydrothermal vent along the mid-Atlantic ridge. A molecular survey of various hydrothermal vent environments demonstrated the presence of two of these bacteria (Am-N and Am-H) in more than one geographic location and habitat. These results suggest that certain epsilonProteobacteria likely fill important niches in the environmental habitats of deep-sea hydrothermal vents, where they contribute to overall carbon and sulfur cycling at moderate thermophilic temperatures.

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Pyrrhotite Biooxidation by Moderately Thermophilic Acidophilic Microorganisms

Microbiology ◽

10.1134/s0026261720050057 ◽

2020 ◽

Vol 89 (5) ◽

pp. 510-519

Author(s):

A. G. Bulaev

Keyword(s):

Acidophilic Microorganisms ◽

Moderately Thermophilic

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The Microbiology of Moderately Thermophilic and Transiently Thermophilic Ore Heaps

Biomining ◽

10.1007/978-3-540-34911-2_11 ◽

2007 ◽

pp. 217-235 ◽

Cited By ~ 7

Author(s):

Jason J. Plumb ◽

Rebecca B. Hawkes ◽

Peter D. Franzmann

Keyword(s):

Moderately Thermophilic

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Crassaminicella thermophila sp. nov., a moderately thermophilic bacterium isolated from a deep-sea hydrothermal vent chimney and emended description of the genus Crassaminicella

INTERNATIONAL JOURNAL OF SYSTEMATIC AND EVOLUTIONARY MICROBIOLOGY ◽

10.1099/ijsem.0.005112 ◽

2021 ◽

Vol 71 (11) ◽

Author(s):

Xue-Gong Li ◽

Jin Lin ◽

Shi-Jie Bai ◽

Jie Dai ◽

Ze-Xi Jiao ◽

...

Keyword(s):

16S Rrna ◽

16S Rrna Gene ◽

Hydrothermal Vent ◽

Type Species ◽

Rrna Gene ◽

Chromosomal Dna ◽

Content Type ◽

Moderately Thermophilic ◽

Link Type ◽

Emended Description

A novel moderately thermophilic, anaerobic, heterotrophic bacterium (strain SY095T) was isolated from a hydrothermal vent chimney located on the Southwest Indian Ridge at a depth of 2730 m. Cells were Gram-stain-positive, motile, straight to slightly curved rods forming terminal endospores. SY095T was grown at 45–60 °C (optimum 50–55 °C), pH 6.0–7.5 (optimum 7.0), and in a salinity of 1–4.5 % (w/v) NaCl (optimum 2.5 %). Substrates utilized by SY095T included fructose, glucose, maltose, N-acetyl glucosamine and tryptone. Casamino acid and amino acids (glutamate, glutamine, lysine, methionine, serine and histidine) were also utilized. The main end products from glucose fermentation were acetate, H2 and CO2. Elemental sulphur, sulphate, thiosulphate, sulphite, fumarate, nitrate, nitrite and Fe(III) were not used as terminal electron acceptors. The predominant cellular fatty acids were C14 : 0 (60.5%) and C16 : 0 (7.6 %). The main polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, five unidentified phospholipids and two unidentified aminophospholipids. No respiratory quinones were detected. The chromosomal DNA G+C content was 30.8 mol%. The results of phylogenetic analysis of the 16S rRNA gene sequences indicated that SY095T was closely related to Crassaminicella profunda Ra1766HT (95.8 % 16S rRNA gene sequence identity). SY095T exhibited 78.1 % average nucleotide identity (ANI) to C. profunda Ra1766HT. The in silico DNA–DNA hybridization (DDH) value indicated that SY095T shared 22.7 % DNA relatedness with C. profunda Ra1766HT. On the basis of its phenotypic, genotypic and phylogenetic characteristics, SY095T is suggested to represent a novel species of the genus Crassaminicella , for which the name Crassaminicella thermophila sp. nov. is proposed. The type strain is SY095T (=JCM 34213=MCCC 1K04191). An emended description of the genus Crassaminicella is also proposed.

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Identification and Characterization of a Novel Thermostable and Salt-Tolerant β-1,3 Xylanase from Flammeovirga pacifica Strain WPAGA1

Biomolecules ◽

10.3390/biom10091287 ◽

2020 ◽

Vol 10 (9) ◽

pp. 1287

Author(s):

Zhiwei Yi ◽

Zhengwen Cai ◽

Bo Zeng ◽

Runying Zeng ◽

Guangya Zhang

Keyword(s):

Thermal Stability ◽

Salt Tolerance ◽

3D Structure ◽

Catalytic Efficiency ◽

Dynamics Simulation ◽

Carbohydrate Binding ◽

Salt Tolerant ◽

Excellent Thermal Stability ◽

Moderately Thermophilic

β-1,3 xylanase is an important enzyme in the biorefinery process for some algae. The discovery and characterization of new β-1,3 xylanase is a hot research topic. In this paper, a novel β-1,3 xylanase (Xyl88) is revealed from the annotated genome of Flammeovirga pacifica strain WPAGA1. Bioinformatic analysis shows that Xyl88 belongs to the glycoside hydrolase 26 (GH26) with a suspected CBM (carbohydrate-binding module) sequence. The activity of rXyl88 is 75% of the highest enzyme activity (1.5 mol/L NaCl) in 3 mol/L NaCl buffer, which suggests good salt tolerance of rXy188. The optimum reaction temperature in the buffer without NaCl and with 1.5 mol/L NaCl is 45 °C and 55 °C, respectively. Notably, the catalytic efficiency of rXyl88 (kcat/Km) is approximately 20 higher than that of the thermophilic β-1,3 xylanase that has the highest catalytic efficiency. Xyl88 in this study becomes the most efficient enzyme ever found, and it is also the first reported moderately thermophilic and salt-tolerant β-1,3 xylanase. Results of molecular dynamics simulation further prove the excellent thermal stability of Xyl88. Moreover, according to the predicted 3D structure of the Xyl88, the surface of the enzyme is distributed with more negative charges, which is related to its salt tolerance, and significantly more hydrogen bonds and Van der Waals force between the intramolecular residues, which is related to its thermal stability.

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