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Werner Liesack - One of the best experts on this subject based on the ideXlab platform.
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Hydrogen utilization by Methylocystis sp. strain SC2 expands the known metabolic versatility of type IIa methanotrophs.
Metabolic Engineering, 2020Co-Authors: Anna Hakobyan, Jing Zhu, Timo Glatter, Nicole Paczia, Werner LiesackAbstract:Abstract Methane, a non-expensive natural substrate, is used by Methylocystis spp. as a sole source of carbon and energy. Here, we assessed whether Methylocystis sp. strain SC2 is able to also utilize hydrogen as an energy source. The addition of 2% H2 to the culture headspace had the most significant positive effect on the growth yield under CH4 (6%) and O2 (3%) limited conditions. The SC2 biomass yield doubled from 6.41 (±0.52) to 13.82 (±0.69) mg cell dry weight per mmol CH4, while CH4 consumption was significantly reduced. Regardless of H2 addition, CH4 utilization was increasingly redirected from respiration to fermentation-based pathways with decreasing O2/CH4 mixing ratios. Theoretical thermodynamic calculations confirmed that hydrogen utilization under oxygen-limited conditions doubles the maximum biomass yield compared to fully aerobic conditions without H2 addition. Hydrogen utilization was linked to significant changes in the SC2 proteome. In addition to hydrogenase accessory proteins, the production of Group 1d and Group 2b hydrogenases was significantly increased in both short- and long-term incubations. Both long-term incubation with H2 (37 d) and treatments with chemical inhibitors revealed that SC2 growth under hydrogen-utilizing conditions does not require the activity of complex I. Apparently, strain SC2 has the metabolic capacity to channel hydrogen-derived electrons into the quinone pool, which provides a link between hydrogen oxidation and energy production. In summary, H2 may be a promising alternative energy source in biotechnologically oriented methanotroph projects that aim to maximize biomass yield from CH4, such as the production of high-quality feed protein.
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Unusual Genomic Traits Suggest Methylocystis bryophila S285 to Be Well Adapted for Life in Peatlands.
Genome Biology and Evolution, 2018Co-Authors: Dongfei Han, Svetlana N. Dedysh, Werner LiesackAbstract:The genus Methylocystis belongs to the class Alphaproteobacteria, the family Methylocystaceae, and encompasses aerobic methanotrophic bacteria with the serine pathway of carbon assimilation. All Methylocystis species are able to fix dinitrogen and several members of this genus are also capable of using acetate or ethanol in the absence of methane, which explains their wide distribution in various habitats. One additional trait that enables their survival in the environment is possession of two methane-oxidizing isozymes, the conventional particulate methane monooxygenase (pMMO) with low-affinity to substrate (pMMO1) and the high-affinity enzyme (pMMO2). Here, we report the finished genome sequence of Methylocystis bryophila S285, a pMMO2-possessing methanotroph from a Sphagnum-dominated wetland, and compare it to the genome of Methylocystis sp. strain SC2, which is the first methanotroph with confirmed high-affinity methane oxidation potential. The complete genome of Methylocystis bryophila S285 consists of a 4.53 Mb chromosome and one plasmid, 175 kb in size. The genome encodes two types of particulate MMO (pMMO1 and pMMO2), soluble MMO and, in addition, contains a pxmABC-like gene cluster similar to that present in some gammaproteobacterial methanotrophs. The full set of genes related to the serine pathway, the tricarboxylic acid cycle as well as the ethylmalonyl-CoA pathway is present. In contrast to most described methanotrophs including Methylocystis sp. strain SC2, two different types of nitrogenases, that is, molybdenum-iron and vanadium-iron types, are encoded in the genome of strain S285. This unique combination of genome-based traits makes Methylocystis bryophila well adapted to the fluctuation of carbon and nitrogen sources in wetlands.
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Response of Methylocystis sp. Strain SC2 to Salt Stress: Physiology, Global Transcriptome, and Amino Acid Profiles.
Applied and Environmental Microbiology, 2017Co-Authors: Dongfei Han, Hannes Link, Werner LiesackAbstract:Soil microorganisms have to rapidly respond to salt-induced osmotic stress. Type II methanotrophs of the genus Methylocystis are widely distributed in upland soils but are known to have a low salt tolerance. Here, we tested the ability of Methylocystis sp. strain SC2 to adapt to increased salinity. When exposed to 0.75% NaCl, methane oxidation was completely inhibited for 2.25 h and fully recovered within 6 h. Growth was inhibited for 23.5 h and then fully recovered. Its transcriptome was profiled after 0 min (control), 45 min (early response), and 14 h (late response) of stress exposure. Physiological and transcriptomic stress responses corresponded well. Salt stress induced the differential expression of 301 genes, with sigma factor σ32 being a major controller of the transcriptional stress response. The transcript levels of nearly all the genes involved in oxidizing CH4 to CO2 remained unaffected, while gene expression involved in energy-yielding reactions (nuoA-N) recovered concomitantly with methane oxidation from salt stress shock. Glutamate acted as an osmoprotectant. Its accumulation in late stress response corresponded to increased production of glutamate dehydrogenase 1. Chromosomal genes whose products (stress-induced protein, DNA-binding protein from starved cells, and CsbD family protein) are known to confer stress tolerance showed increased expression. On plasmid pBSC2-1, genes encoding type IV secretion system and single-strand DNA-binding protein were upregulated in late response, suggesting stress-induced activation of the plasmid-borne conjugation machinery. Collectively, our results show that Methylocystis sp. strain SC2 is able to adapt to salt stress, but only within a narrow range of salinities.IMPORTANCE Besides the oxic interface of methanogenic environments, Methylocystis spp. are widely distributed in upland soils, where they may contribute to the oxidation of atmospheric methane. However, little is known about their ability to cope with changes in soil salinity. Growth and methane oxidation of Methylocystis sp. strain SC2 were not affected by the presence of 0.5% NaCl, while 1% NaCl completely inhibited its activity. This places strain SC2 into the low-salt-tolerance range reported for other Methylocystis species. Our results show that, albeit in a narrow range, strain SC2 is able to respond and adapt to salinity changes. It possesses various stress response mechanisms, which allow resumption of growth within 24 h when exposed to 0.75% NaCl. Presumably, these mechanisms allow Methylocystis spp., such as strain SC2, to thrive in upland soils and to adapt to certain fluctuations in soil salinity.
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ammonium induces differential expression of methane and nitrogen metabolism related genes in Methylocystis sp strain sc2
Environmental Microbiology, 2014Co-Authors: Werner Liesack, Bomba Dam, Somasri Dam, Yongkyu KimAbstract:Summary Nitrogen source and concentration are major determinants of methanotrophic activity, but their effect on global gene expression is poorly studied. Methylocystis sp. strain SC2 produces two isozymes of particulate methane monooxygenase. These are encoded by pmoCAB1 (low-affinity pMMO1) and pmoCAB2 (high-affinity pMMO2). We used RNA-Seq to identify strain SC2 genes that respond to standard (10 mM) and high (30 mM) NH4+ concentrations in the medium, compared with 10 mM NO3–. While the expression of pmoCAB1 was unaffected, pmoCAB2 was significantly downregulated (log2 fold changes of −5.0 to −6.0). Among nitrogen metabolism-related processes, genes involved in hydroxylamine detoxification (haoAB) were highly upregulated, while those for assimilatory nitrate/nitrite reduction, high-affinity ammonium uptake and nitrogen regulatory protein PII were downregulated. Differential expression of pmoCAB2 and haoAB was independently validated by end-point reverse transcription polymerase chain reaction. Methane oxidation by SC2 cells exposed to 30 mM NH4+ was inhibited at ≤ 400 ppmv CH4, where pMMO2 but not pMMO1 is functional. When transferred back to standard nitrogen concentration, methane oxidation capability and pmoCAB2 expression were restored. Given that Methylocystis contributes to atmospheric methane oxidation in upland soils, differential expression of pmoCAB2 explains, at least to some extent, the strong inhibitory effect of ammonium fertilizers on this activity.
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Ammonium induces differential expression of methane and nitrogen metabolism‐related genes in Methylocystis sp. strain SC2
Environmental Microbiology, 2014Co-Authors: Bomba Dam, Somasri Dam, Yongkyu Kim, Werner LiesackAbstract:Summary Nitrogen source and concentration are major determinants of methanotrophic activity, but their effect on global gene expression is poorly studied. Methylocystis sp. strain SC2 produces two isozymes of particulate methane monooxygenase. These are encoded by pmoCAB1 (low-affinity pMMO1) and pmoCAB2 (high-affinity pMMO2). We used RNA-Seq to identify strain SC2 genes that respond to standard (10 mM) and high (30 mM) NH4+ concentrations in the medium, compared with 10 mM NO3–. While the expression of pmoCAB1 was unaffected, pmoCAB2 was significantly downregulated (log2 fold changes of −5.0 to −6.0). Among nitrogen metabolism-related processes, genes involved in hydroxylamine detoxification (haoAB) were highly upregulated, while those for assimilatory nitrate/nitrite reduction, high-affinity ammonium uptake and nitrogen regulatory protein PII were downregulated. Differential expression of pmoCAB2 and haoAB was independently validated by end-point reverse transcription polymerase chain reaction. Methane oxidation by SC2 cells exposed to 30 mM NH4+ was inhibited at ≤ 400 ppmv CH4, where pMMO2 but not pMMO1 is functional. When transferred back to standard nitrogen concentration, methane oxidation capability and pmoCAB2 expression were restored. Given that Methylocystis contributes to atmospheric methane oxidation in upland soils, differential expression of pmoCAB2 explains, at least to some extent, the strong inhibitory effect of ammonium fertilizers on this activity.
Ian R Mcdonald - One of the best experts on this subject based on the ideXlab platform.
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Methylocystis rosea sp nov a novel methanotrophic bacterium from arctic wetland soil svalbard norway 78 n
International Journal of Systematic and Evolutionary Microbiology, 2006Co-Authors: Ingvild Wartiainen, Anne Grethe Hestnes, Ian R Mcdonald, Mette Marianne SvenningAbstract:A Gram-negative, rod-shaped, non-motile, non-spore-forming, pink-pigmented bacterium, SV97T, was isolated from a wetland soil near Ny-Alesund, Svalbard Islands, Norway (78° N). On the basis of 16S rRNA gene sequence similarity, strain SV97T was shown to belong to the Alphaproteobacteria and was highly related to a number of non-characterized Methylocystis strains with GenBank accession nos AJ458507 and AJ458502 (100 %) and AF177299, AJ458510, AJ458467, AJ458471, AJ431384, AJ458475, AJ458484, AJ458501 and AJ458466 (99 %). The most closely related type strains were Methylocystis parvus OBBPT (97·2 %) and Methylocystis echinoides IMET 10491T (97 %). The closest related recognized species within the genus Methylosinus was Methylosinus sporium NCIMB 11126T (96·0 % similarity). Chemotaxonomic and phenotypic data (C18 : 1 ω8 as the major fatty acid, non-motile, no rosette formation) supported the affiliation of strain SV97T to the genus Methylocystis. The results of DNA–DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain SV97T from the two recognized Methylocystis species. Strain SV97T therefore represents a novel species, for which the name Methylocystis rosea sp. nov. is proposed, with the type strain SV97T (=DSM 17261T=ATCC BAA-1196T).
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Methylocystis rosea sp. nov., a novel methanotrophic bacterium from Arctic wetland soil, Svalbard, Norway (78° N)
International Journal of Systematic and Evolutionary Microbiology, 2006Co-Authors: Ingvild Wartiainen, Anne Grethe Hestnes, Ian R Mcdonald, Mette Marianne SvenningAbstract:A Gram-negative, rod-shaped, non-motile, non-spore-forming, pink-pigmented bacterium, SV97T, was isolated from a wetland soil near Ny-Alesund, Svalbard Islands, Norway (78 degrees N). On the basis of 16S rRNA gene sequence similarity, strain SV97T was shown to belong to the Alphaproteobacteria and was highly related to a number of non-characterized Methylocystis strains with GenBank accession nos AJ458507 and AJ458502 (100 %) and AF177299, AJ458510, AJ458467, AJ458471, AJ431384, AJ458475, AJ458484, AJ458501 and AJ458466 (99 %). The most closely related type strains were Methylocystis parvus OBBP(T) (97.2 %) and Methylocystis echinoides IMET 10491T (97%). The closest related recognized species within the genus Methylosinus was Methylosinus sporium NCIMB 11126T (96.0% similarity). Chemotaxonomic and phenotypic data (C(18:1)omega8 as the major fatty acid, non-motile, no rosette formation) supported the affiliation of strain SV97T to the genus Methylocystis. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain SV97(T) from the two recognized Methylocystis species. Strain SV97T therefore represents a novel species, for which the name Methylocystis rosea sp. nov. is proposed, with the type strain SV97T (= DSM 17261T = ATCC BAA-1196T).
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Methylocystis rosea sp nov a novel methanotrophic bacterium from arctic wetland soil svalbard norway 78 n
International Journal of Systematic and Evolutionary Microbiology, 2006Co-Authors: Ingvild Wartiainen, Anne Grethe Hestnes, Ian R Mcdonald, Mette Marianne SvenningAbstract:A Gram-negative, rod-shaped, non-motile, non-spore-forming, pink-pigmented bacterium, SV97T, was isolated from a wetland soil near Ny-Alesund, Svalbard Islands, Norway (78 degrees N). On the basis of 16S rRNA gene sequence similarity, strain SV97T was shown to belong to the Alphaproteobacteria and was highly related to a number of non-characterized Methylocystis strains with GenBank accession nos AJ458507 and AJ458502 (100 %) and AF177299, AJ458510, AJ458467, AJ458471, AJ431384, AJ458475, AJ458484, AJ458501 and AJ458466 (99 %). The most closely related type strains were Methylocystis parvus OBBP(T) (97.2 %) and Methylocystis echinoides IMET 10491T (97%). The closest related recognized species within the genus Methylosinus was Methylosinus sporium NCIMB 11126T (96.0% similarity). Chemotaxonomic and phenotypic data (C(18:1)omega8 as the major fatty acid, non-motile, no rosette formation) supported the affiliation of strain SV97T to the genus Methylocystis. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain SV97(T) from the two recognized Methylocystis species. Strain SV97T therefore represents a novel species, for which the name Methylocystis rosea sp. nov. is proposed, with the type strain SV97T (= DSM 17261T = ATCC BAA-1196T).
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Methylocystis rosea sp. nov., a novel methanotrophic bacterium from Arctic wetland soil, Svalbard, Norway (78 degrees N).
International journal of systematic and evolutionary microbiology, 2006Co-Authors: Ingvild Wartiainen, Anne Grethe Hestnes, Ian R Mcdonald, Mette Marianne SvenningAbstract:A Gram-negative, rod-shaped, non-motile, non-spore-forming, pink-pigmented bacterium, SV97T, was isolated from a wetland soil near Ny-Alesund, Svalbard Islands, Norway (78 degrees N). On the basis of 16S rRNA gene sequence similarity, strain SV97T was shown to belong to the Alphaproteobacteria and was highly related to a number of non-characterized Methylocystis strains with GenBank accession nos AJ458507 and AJ458502 (100 %) and AF177299, AJ458510, AJ458467, AJ458471, AJ431384, AJ458475, AJ458484, AJ458501 and AJ458466 (99 %). The most closely related type strains were Methylocystis parvus OBBP(T) (97.2 %) and Methylocystis echinoides IMET 10491T (97%). The closest related recognized species within the genus Methylosinus was Methylosinus sporium NCIMB 11126T (96.0% similarity). Chemotaxonomic and phenotypic data (C(18:1)omega8 as the major fatty acid, non-motile, no rosette formation) supported the affiliation of strain SV97T to the genus Methylocystis. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain SV97(T) from the two recognized Methylocystis species. Strain SV97T therefore represents a novel species, for which the name Methylocystis rosea sp. nov. is proposed, with the type strain SV97T (= DSM 17261T = ATCC BAA-1196T).
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analysis of methane monooxygenase genes in mono lake suggests that increased methane oxidation activity may correlate with a change in methanotroph community structure
Applied and Environmental Microbiology, 2005Co-Authors: Samantha B. Joye, Johannes C M Scholten, Hendrik Schafer, Ian R Mcdonald, Colin J MurrellAbstract:Mono Lake is an alkaline hypersaline lake that supports high methane oxidation rates. Retrieved pmoA sequences showed a broad diversity of aerobic methane oxidizers including the type I methanotrophs Methylobacter (the dominant genus), Methylomicrobium, and Methylothermus, and the type II methanotroph Methylocystis. Stratification of Mono Lake resulted in variation of aerobic methane oxidation rates with depth. Methanotroph diversity as determined by analysis of pmoA using new denaturing gradient gel electrophoresis primers suggested that variations in methane oxidation activity may correlate with changes in methanotroph community composition.
Hans-peter Kleber - One of the best experts on this subject based on the ideXlab platform.
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Screening for soluble methane monooxygenase in methanotrophic bacteria using combined molecular and biochemical methods for hydroxylase detection
Journal of Basic Microbiology, 2003Co-Authors: Stephan Grosse, Claudia Mueller, Gerlind Rogge, Karin-dagmar Wendlandt, Carlos B. Miguez, Hans-peter KleberAbstract:Three well known methanotrophic bacteria (Methylosinus trichosporium OB3b, Methylocystis sp. WI 14, and Methylocystis sp. GB 25) and three newly isolated methanotrophic bacteria (Methylocystis sp. WI 11, Methylocystis sp. X, and FI-9) were screened for sMMO considering the existence of hydroxylase (component A) genes as well as its gene expression. For these purposes monoclonal antibodies that specifically recognize each subunit of the hydroxylase of Methylocystis sp. WI 14 (alpha-subunit [9E5/F2], beta-subunit [4E2/G11], gamma-subunit [10G3/D7]) were produced. PCR amplification using well known primers showed that the hydroxylase encoding genes appear to be only present in M. trichosporium OB3b, Methylocystis sp. WI 11 and WI 14, and in the isolate FI-9. Western and ELISA analysis using the monoclonal antibodies revealed that all subunits of hydroxylase were present. However, in FI-9, only the alpha-subunit of the hydroxylase might be expressed. Surprisingly, in Methylocystis sp. GB 25, where no sMMO activity and no amplification with sMMO specific primers was obtained, the antibody 4E2/G11 recognized a protein band with exactly the same molecular mass as the beta-subunit of the hydroxylase. Methylocystis sp. X showed no positive reaction in any of the tests. In combination with the detection methods currently used, the described antibodies provide a powerful tool for detecting even partially expressed hydroxylase genes.
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Purification and Characterization of the Soluble Methane Monooxygenase of the Type II Methanotrophic Bacterium Methylocystis sp. Strain WI 14
Applied and Environmental Microbiology, 1999Co-Authors: Stephan Grosse, Ian R Mcdonald, Karin-dagmar Wendlandt, Carlos B. Miguez, Louise Laramée, Hans-peter KleberAbstract:Methane monooxygenase (MMO) catalyzes the oxidation of methane to methanol as the first step of methane degradation. A soluble NAD(P)H-dependent methane monooxygenase (sMMO) from the type II methanotrophic bacterium WI 14 was purified to homogeneity. Sequencing of the 16S rDNA and comparison with that of other known methanotrophic bacteria confirmed that strain WI 14 is very close to the genus Methylocystis. The sMMO is expressed only during growth under copper limitation (
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purification and characterization of the soluble methane monooxygenase of the type ii methanotrophic bacterium Methylocystis sp strain wi 14
Applied and Environmental Microbiology, 1999Co-Authors: Stephan Grosse, Ian R Mcdonald, Karin-dagmar Wendlandt, Carlos B. Miguez, Louise Laramée, Hans-peter KleberAbstract:Methane monooxygenase (MMO) catalyzes the oxidation of methane to methanol as the first step of methane degradation. A soluble NAD(P)H-dependent methane monooxygenase (sMMO) from the type II methanotrophic bacterium WI 14 was purified to homogeneity. Sequencing of the 16S rDNA and comparison with that of other known methanotrophic bacteria confirmed that strain WI 14 is very close to the genus Methylocystis. The sMMO is expressed only during growth under copper limitation (<0.1 μM) and with ammonium or nitrate ions as the nitrogen source. The enzyme exhibits a low substrate specificity and is able to oxidize several alkanes and alkenes, cyclic hydrocarbons, aromatics, and halogenic aromatics. It has three components, hydroxylase, reductase and protein B, which is involved in enzyme regulation and increases sMMO activity about 10-fold. The relative molecular masses of the native components were estimated to be 229, 41, and 18 kDa, respectively. The hydroxylase contains three subunits with relative molecular masses of 57, 43, and 23 kDa, which are present in stoichiometric amounts, suggesting that the native protein has an α2β2γ2 structure. We detected 3.6 mol of iron per mol of hydroxylase by atomic absorption spectrometry. sMMO is strongly inhibited by Hg2+ ions (with a total loss of enzyme activity at 0.01 mM Hg2+) and Cu2+, Zn2+, and Ni2+ ions (95, 80, and 40% loss of activity at 1 mM ions). The complete sMMO gene sequence has been determined. sMMO genes from strain WI 14 are clustered on the chromosome and show a high degree of homology (at both the nucleotide and amino acid levels) to the corresponding genes from Methylosinus trichosporium OB3b, Methylocystis sp. strain M, and Methylococcus capsulatus (Bath).
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Purification and properties of methanol dehydrogenase from Methylocystis sp. GB 25
Journal of Basic Microbiology, 1997Co-Authors: Stephan Grosse, Karin-dagmar Wendlandt, Hans-peter KleberAbstract:Methanol dehydrogenase (MDH) from Methylocystis sp. GB 25, which belongs to the group II of methanotrophic bacteria, is able to catalyse the oxidation of methanol to formate directly. The enzyme was purified 20-fold by a 5 step procedure to electrophoretic homogeneity. After cell disruption by French press, about 95% of MDH-activity was found in the soluble fraction. The relative molecular mass of the native enzyme has been estimated to be 122 kDa by gel filtration and 115 kDa by the method of Hedrick and Smith (1968). It seems to be composed of two identical subunits with a relative molecular mass of 62 kDa (estimated by SDS gel electrophoresis). The isoelectric point was found to be about 8.3. The amino terminal sequence shows a strong similarity to the alpha-chain of MDH from the facultative methylotrophic bacterium Methylobacterium extorquens AM1. PQQ, the probable prosthetic group of MDH, could be detected in the supernatant of the culture by using the apoenzyme of a membrane-bound glucose dehydrogenase from Pseudomonas aeruginosa but not absolutely in the absorption spectra of the enzyme after DEAE-chromatography. The purified MDH has an optimum activity at pH 9.0 and at 45 degrees C. MDH of Methylocystis sp. GB 25 oxidises only primary alcohols from methanol to heptanol and aldehydes from formaldehyde to propionaldehyde and the glutaraldehyde, respectively. The estimated Km-values show no dependence upon the chain length of substrates.
Jeremy D Semrau - One of the best experts on this subject based on the ideXlab platform.
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genomic and transcriptomic analyses of the facultative methanotroph Methylocystis sp strain sb2 grown on methane or ethanol
Applied and Environmental Microbiology, 2014Co-Authors: Alexey Vorobev, Stéphane Vuilleumier, Sheeja Jagadevan, Sunit Jain, Karthik Anantharaman, Gregory J Dick, Jeremy D SemrauAbstract:A minority of methanotrophs are able to utilize multicarbon compounds as growth substrates in addition to methane. The pathways utilized by these microorganisms for assimilation of multicarbon compounds, however, have not been explicitly examined. Here, we report the draft genome of the facultative methanotroph Methylocystis sp. strain SB2 and perform a detailed transcriptomic analysis of cultures grown with either methane or ethanol. Evidence for use of the canonical methane oxidation pathway and the serine cycle for carbon assimilation from methane was obtained, as well as for operation of the complete tricarboxylic acid (TCA) cycle and the ethylmalonyl-coenzyme A (EMC) pathway. Experiments with Methylocystis sp. strain SB2 grown on methane revealed that genes responsible for the first step of methane oxidation, the conversion of methane to methanol, were expressed at a significantly higher level than those for downstream oxidative transformations, suggesting that this step may be rate limiting for growth of this strain with methane. Further, transcriptomic analyses of Methylocystis sp. strain SB2 grown with ethanol compared to methane revealed that on ethanol (i) expression of the pathway of methane oxidation and the serine cycle was significantly reduced, (ii) expression of the TCA cycle dramatically increased, and (iii) expression of the EMC pathway was similar. Based on these data, it appears that Methylocystis sp. strain SB2 converts ethanol to acetyl-coenzyme A, which is then funneled into the TCA cycle for energy generation or incorporated into biomass via the EMC pathway. This suggests that some methanotrophs have greater metabolic flexibility than previously thought and that operation of multiple pathways in these microorganisms is highly controlled and integrated.
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Mercury binding by methanobactin from Methylocystis strain SB2.
Journal of Inorganic Biochemistry, 2014Co-Authors: Bipin S. Baral, Alexey Vorobev, Nathan L. Bandow, Brittani C. Freemeier, Brandt H. Bergman, Timothy J. Herdendorf, Nathalie Fuentes, Luke Ellias, Erick A. Turpin, Jeremy D SemrauAbstract:Abstract Methanobactin (mb) is a post-translationally modified copper-binding compound, or chalkophore, secreted by many methane-oxidizing bacteria or methanotrophs in response to copper limitation. In addition to copper, methanobactin from Methylosinus trichosporium OB3b (mb-OB3b) has been shown to bind a variety of metals including Hg 2+ . In this report, Hg binding by the structurally unique methanobactin from Methylocystis strain SB2 (mb-SB2) was examined and compared to mb-OB3b. Mb-SB2 is shown to bind the common forms of Hg found in aqueous environments, Hg 2+ , Hg(CN) 2 and CH 3 Hg + . The spectral and thermodynamic properties of binding for each form of mercury differed. UV-visible absorption spectra suggested that Hg 2 + binds to both the oxazolone and imidazolone rings of mb-SB2, whereas CH 3 Hg + appeared to only bind to the oxazolone ring. Hg(CN) 2 showed spectral properties between Hg 2 + and CH 3 Hg + . Isothermal titration calorimetry (ITC) showed both Hg(CN) 2 and CH 3 Hg + fit into two-site binding models. For Hg(CN) 2 the first site was exothermic and the second endothermic. Both binding sites in CH 3 Hg + were exothermic, but at equilibrium the reaction never moved back to the baseline, suggesting a slow residual reaction. ITC results for Hg 2 + were more complex and suggested a 3- or 4-site model. The spectral, kinetic and thermodynamic changes following Hg binding by mb-SB2 also differed from the changes associated with mb-OB3b. Like mb-OB3b, copper did not displace Hg bound to mb-SB2. In contrast to mb-OB3b Hg 2+ could displace Cu from Cu-containing mb-SB2 and preferentially bound Hg 2 + over Cu 2 + at metal to mb-SB2 molar ratios above 1.0.
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priority pollutant degradation by the facultative methanotroph Methylocystis strain sb2
Applied Microbiology and Biotechnology, 2013Co-Authors: Sheeja Jagadevan, Jeremy D SemrauAbstract:Methylocystis strain SB2, a facultative methanotroph capable of growth on multi-carbon compounds, was screened for its ability to degrade the priority pollutants 1,2-dichloroethane (1,2-DCA), 1,1,2-trichloroethane (1,1,2-TCA), and 1,1-dichloroethylene (1,1-DCE), as well as cis-dichloroethylene (cis-DCE) when grown on methane or ethanol. Methylocystis strain SB2 degraded 1,2-DCA and 1,1,2-TCA when grown on either substrate and cis-DCE when grown on methane. Growth of Methylocystis strain SB2 on methane was inhibited in the presence of all compounds, while only 1,1-DCE and cis-DCE inhibited growth on ethanol. No degradation of any chlorinated hydrocarbon was observed in ethanol-grown cultures when particulate methane monooxygenase (pMMO) activity was inhibited with the addition of acetylene, indicating that competition for binding to the pMMO between the chlorinated hydrocarbons and methane limited both methanotrophic growth and pollutant degradation when this strain was grown on methane. Characterization of Methylocystis strain SB2 found no evidence of a high-affinity form of pMMO for methane, nor could this strain utilize 1,2-DCA or its putative oxidative products 2-chloroethanol or chloroactetic acid as sole growth substrates, suggesting that this strain lacks appropriate dehydrogenases for the conversion of 1,2-DCA to glyoxylate. As ethanol: (1) can be used as an alternative growth substrate for promoting pollutant degradation by Methylocystis strain SB2 as the pMMO is not required for its growth on ethanol and (2) has been used to enhance the mobility of chlorinated hydrocarbons in situ, it is proposed that ethanol can be used to enhance both pollutant transport and biodegradation by Methylocystis strain SB2.
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Genome sequence of the methanotrophic alphaproteobacterium Methylocystis sp. strain Rockwell (ATCC 49242).
Journal of Bacteriology, 2011Co-Authors: Alan Dispirito, Jeremy D Semrau, Marina G. Kalyuzhnaya, Mike S M Jetten, K Dimitri Kits, Martin G Klotz, Huub J M Op Den Camp, Stéphane VuilleumierAbstract:Methylocystis sp. strain Rockwell (ATCC 49242) is an aerobic methane-oxidizing alphaproteobacterium isolated from an aquifer in southern California. Unlike most methanotrophs in the Methylocystaceae family, this strain has a single pmo operon encoding particulate methane monooxygenase but no evidence of the genes encoding soluble methane monooxygenase. This is the first reported genome sequence of a member of the Methylocystis species of the Methylocystaceae family in the order Rhizobiales.
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Characterization of a novel facultative Methylocystis species capable of growth on methane, acetate and ethanol
Environmental Microbiology Reports, 2010Co-Authors: Sung Woo Lee, Alan Dispirito, Sukhwan Yoon, Jeremy D SemrauAbstract:Summary A non-motile strain of Methylocystis, strain SB2, isolated from a spring bog in southeast Michigan, had a curved rod morphology with a typical type II intracytoplasmic membrane system. This organism expressed the membrane-bound or particulate methane monooxygenase (pMMO) as well as a chalkophore with high affinity for copper and did not express the cytoplasmic or soluble methane monooxygenase (sMMO). Strain SB2 was found to grow within the pH range of 6–9, with optimal growth at 6.8. Growth was observed at temperatures ranging between 10°C and 30°C, with no growth at 37°C. The DNA G+C content was 62.9 mol%. Predominant fatty acids were 18:1ω7c (72.7%) and 18:1ω9c (24%) when grown on methane. Phylogenetic comparisons based on both pmoA and 16S rRNA sequences indicated that this organism belonged to the Methylocystis genus, and was closely related to Methylocystis rosea SV97T and Methylocystis echinoides IMET10491T (98% 16S rRNA gene sequence similarity to both strains). DNA : DNA hybridizations indicated that strain SB2 had 70% similarity with M. rosea SV97T. Unlike M. rosea SV97T, strain SB2 was able to utilize not only methane for growth, but also ethanol and acetate. Furthermore, the predominant fatty acids in strain SB2 were different from those found in M. rosea SV97T, i.e. 54.2% and 39.7% of fatty acids are 18:1ω8 and 18:1ω7 in M. rosea SV97T, while 18:1ω8 is completely absent in strain SB2.
Mette Marianne Svenning - One of the best experts on this subject based on the ideXlab platform.
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Methylocystis rosea sp nov a novel methanotrophic bacterium from arctic wetland soil svalbard norway 78 n
International Journal of Systematic and Evolutionary Microbiology, 2006Co-Authors: Ingvild Wartiainen, Anne Grethe Hestnes, Ian R Mcdonald, Mette Marianne SvenningAbstract:A Gram-negative, rod-shaped, non-motile, non-spore-forming, pink-pigmented bacterium, SV97T, was isolated from a wetland soil near Ny-Alesund, Svalbard Islands, Norway (78° N). On the basis of 16S rRNA gene sequence similarity, strain SV97T was shown to belong to the Alphaproteobacteria and was highly related to a number of non-characterized Methylocystis strains with GenBank accession nos AJ458507 and AJ458502 (100 %) and AF177299, AJ458510, AJ458467, AJ458471, AJ431384, AJ458475, AJ458484, AJ458501 and AJ458466 (99 %). The most closely related type strains were Methylocystis parvus OBBPT (97·2 %) and Methylocystis echinoides IMET 10491T (97 %). The closest related recognized species within the genus Methylosinus was Methylosinus sporium NCIMB 11126T (96·0 % similarity). Chemotaxonomic and phenotypic data (C18 : 1 ω8 as the major fatty acid, non-motile, no rosette formation) supported the affiliation of strain SV97T to the genus Methylocystis. The results of DNA–DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain SV97T from the two recognized Methylocystis species. Strain SV97T therefore represents a novel species, for which the name Methylocystis rosea sp. nov. is proposed, with the type strain SV97T (=DSM 17261T=ATCC BAA-1196T).
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Methylocystis rosea sp. nov., a novel methanotrophic bacterium from Arctic wetland soil, Svalbard, Norway (78° N)
International Journal of Systematic and Evolutionary Microbiology, 2006Co-Authors: Ingvild Wartiainen, Anne Grethe Hestnes, Ian R Mcdonald, Mette Marianne SvenningAbstract:A Gram-negative, rod-shaped, non-motile, non-spore-forming, pink-pigmented bacterium, SV97T, was isolated from a wetland soil near Ny-Alesund, Svalbard Islands, Norway (78 degrees N). On the basis of 16S rRNA gene sequence similarity, strain SV97T was shown to belong to the Alphaproteobacteria and was highly related to a number of non-characterized Methylocystis strains with GenBank accession nos AJ458507 and AJ458502 (100 %) and AF177299, AJ458510, AJ458467, AJ458471, AJ431384, AJ458475, AJ458484, AJ458501 and AJ458466 (99 %). The most closely related type strains were Methylocystis parvus OBBP(T) (97.2 %) and Methylocystis echinoides IMET 10491T (97%). The closest related recognized species within the genus Methylosinus was Methylosinus sporium NCIMB 11126T (96.0% similarity). Chemotaxonomic and phenotypic data (C(18:1)omega8 as the major fatty acid, non-motile, no rosette formation) supported the affiliation of strain SV97T to the genus Methylocystis. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain SV97(T) from the two recognized Methylocystis species. Strain SV97T therefore represents a novel species, for which the name Methylocystis rosea sp. nov. is proposed, with the type strain SV97T (= DSM 17261T = ATCC BAA-1196T).
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Methylocystis rosea sp nov a novel methanotrophic bacterium from arctic wetland soil svalbard norway 78 n
International Journal of Systematic and Evolutionary Microbiology, 2006Co-Authors: Ingvild Wartiainen, Anne Grethe Hestnes, Ian R Mcdonald, Mette Marianne SvenningAbstract:A Gram-negative, rod-shaped, non-motile, non-spore-forming, pink-pigmented bacterium, SV97T, was isolated from a wetland soil near Ny-Alesund, Svalbard Islands, Norway (78 degrees N). On the basis of 16S rRNA gene sequence similarity, strain SV97T was shown to belong to the Alphaproteobacteria and was highly related to a number of non-characterized Methylocystis strains with GenBank accession nos AJ458507 and AJ458502 (100 %) and AF177299, AJ458510, AJ458467, AJ458471, AJ431384, AJ458475, AJ458484, AJ458501 and AJ458466 (99 %). The most closely related type strains were Methylocystis parvus OBBP(T) (97.2 %) and Methylocystis echinoides IMET 10491T (97%). The closest related recognized species within the genus Methylosinus was Methylosinus sporium NCIMB 11126T (96.0% similarity). Chemotaxonomic and phenotypic data (C(18:1)omega8 as the major fatty acid, non-motile, no rosette formation) supported the affiliation of strain SV97T to the genus Methylocystis. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain SV97(T) from the two recognized Methylocystis species. Strain SV97T therefore represents a novel species, for which the name Methylocystis rosea sp. nov. is proposed, with the type strain SV97T (= DSM 17261T = ATCC BAA-1196T).
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Methylocystis rosea sp. nov., a novel methanotrophic bacterium from Arctic wetland soil, Svalbard, Norway (78 degrees N).
International journal of systematic and evolutionary microbiology, 2006Co-Authors: Ingvild Wartiainen, Anne Grethe Hestnes, Ian R Mcdonald, Mette Marianne SvenningAbstract:A Gram-negative, rod-shaped, non-motile, non-spore-forming, pink-pigmented bacterium, SV97T, was isolated from a wetland soil near Ny-Alesund, Svalbard Islands, Norway (78 degrees N). On the basis of 16S rRNA gene sequence similarity, strain SV97T was shown to belong to the Alphaproteobacteria and was highly related to a number of non-characterized Methylocystis strains with GenBank accession nos AJ458507 and AJ458502 (100 %) and AF177299, AJ458510, AJ458467, AJ458471, AJ431384, AJ458475, AJ458484, AJ458501 and AJ458466 (99 %). The most closely related type strains were Methylocystis parvus OBBP(T) (97.2 %) and Methylocystis echinoides IMET 10491T (97%). The closest related recognized species within the genus Methylosinus was Methylosinus sporium NCIMB 11126T (96.0% similarity). Chemotaxonomic and phenotypic data (C(18:1)omega8 as the major fatty acid, non-motile, no rosette formation) supported the affiliation of strain SV97T to the genus Methylocystis. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain SV97(T) from the two recognized Methylocystis species. Strain SV97T therefore represents a novel species, for which the name Methylocystis rosea sp. nov. is proposed, with the type strain SV97T (= DSM 17261T = ATCC BAA-1196T).