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Koki Horikoshi - One of the best experts on this subject based on the ideXlab platform.

  • Thioreductor micantisoli gen. nov., sp. nov., a novel mesophilic, sulfur-reducing Chemolithoautotroph within the epsilon-Proteobacteria isolated from hydrothermal sediments in the Mid-Okinawa Trough.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Satoshi Nakagawa, Koki Horikoshi, Ken Takai, Fumio Inagaki, Yoshihiko Sako
    Abstract:

    A novel mesophilic, hydrogen-oxidizing, sulfur-reducing bacterium, designated strain BKB25Ts-Y(T), was isolated from hydrothermal sediments at Iheya North in the Mid-Okinawa Trough, Japan. Cells were Gram-negative, motile rods (1.8-2.1 microm long and 0.5-0.7 microm wide). The isolate was a strictly anaerobic Chemolithoautotroph capable of using molecular hydrogen as the sole energy source and carbon dioxide as the sole carbon source. Elemental sulfur and nitrate served as electron acceptors, respectively yielding hydrogen sulfide and ammonium. Growth was observed at 20-42 degrees C (optimum 32 degrees C; 3 h doubling time), pH 5.0-6.5 (optimum 6.0) and in the presence of 2.0-4.0 % NaCl (optimum 2.5 %) via respiratory S(0) reduction with H(2). The G+C content of the genomic DNA was 37.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate represented the first strain for which taxonomic properties have been characterized within the previously uncultivated epsilon-Proteobacteria Group G. On the basis of the physiological and molecular properties of the novel isolate, the genus name Thioreductor gen. nov. is proposed, with Thioreductor micantisoli sp. nov. as the type species. The type strain is BKB25Ts-Y(T) (=JCM 12457(T)=DSM 16661(T)).

  • Hydrogenimonas thermophila gen. nov., sp. nov., a novel thermophilic, hydrogen-oxidizing Chemolithoautotroph within the epsilon-Proteobacteria, isolated from a black smoker in a Central Indian Ridge hydrothermal field.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Ken Takai, Kenneth H Nealson, Koki Horikoshi
    Abstract:

    A novel thermophilic bacterium, strain EP1-55-1%T, was isolated from an in-situ colonization system deployed in a superheated, deep-sea, hydrothermal vent emission at the Kairei Field on the Central Indian Ridge in the Indian Ocean. The cells were highly motile rods, each possessing a single polar flagellum. Growth was observed between 35 and 65 degrees C (optimum temperature, 55 degrees C; 70 min doubling time) and between pH 4.9 and 7.2 (optimum, pH 5.9). The isolate was a microaerobic-to-anaerobic Chemolithoautotroph capable of using molecular hydrogen as the sole energy source and carbon dioxide as the sole carbon source. Molecular oxygen, nitrate or elemental sulfur (S0) could serve as electron acceptors to support growth. The G+C content of the genomic DNA was 34.6 mol%. Phylogenetic analysis based on 16S rDNA sequences indicated that strain EP1-55-1%T represents the first strain for which taxonomic properties have been characterized within the previously uncultivated phylogroup classified as belonging to the uncultivated epsilon-Proteobacteria group A; the name Hydrogenimonas thermophila gen. nov., sp. nov. is proposed, with strain EP1-55-1%T (=JCM 11971T=ATCC BAA-737T) as the type strain.

  • Lebetimonas acidiphila gen. nov., sp. nov., a novel thermophilic, acidophilic, hydrogen-oxidizing Chemolithoautotroph within the 'Epsilonproteobacteria', isolated from a deep-sea hydrothermal fumarole in the Mariana Arc.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Ken Takai, Tatsunori Nakagawa, Yohey Suzuki, Hisako Hirayama, Kenneth H Nealson, Koki Horikoshi
    Abstract:

    A novel thermophilic, acidophilic bacterium, designated strain Pd55T, was isolated from a self-temperature-recording in situ colonization system deployed in a hydrothermal diffusing flow (maximum temperature of 78 degrees C) at the TOTO caldera in the Mariana Arc. Cells of strain Pd55T were motile, short rods with a single polar flagellum. Growth was observed between 30 and 68 degrees C (optimum growth at 50 degrees C; 120 min doubling time) and between (initial) pH 4.2 and 7.0 (optimum at pH 5.2). The isolate was a strictly anaerobic Chemolithoautotroph capable of using molecular hydrogen as sole energy source and carbon dioxide as sole carbon source. Elemental sulfur served as the sole electron acceptor to support growth. The G+C content of the genomic DNA was 34.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate was related to members of the genera Nautilia and Caminibacter, although it appeared to be a novel lineage prior to the divergence between Nautilia and Caminibacter. Strain Pd55T could also be differentiated from Nautilia and Caminibacter species on the basis of its physiological properties. It is, therefore, proposed that strain Pd55T (=JCM 12420T=DSM 16356T) represents the type strain of a novel species in a new genus, Lebetimonas acidiphila gen. nov., sp. nov.

  • Hydrogenivirga okinawensis sp. nov., a thermophilic sulfur-oxidizing Chemolithoautotroph isolated from a deep-sea hydrothermal field, Southern Okinawa Trough.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Takuro Nunoura, Yohey Suzuki, Ken Takai, Masayuki Miyazaki, Koki Horikoshi
    Abstract:

    A novel extremely thermophilic sulfur-oxidizing bacterium, strain LS12-2(T), was isolated from a deep-sea hydrothermal field at the Yonaguni Knoll IV, Southern Okinawa Trough. Cells of strain LS12-2(T) were motile rods, 1.5-4.0 microm in length and 0.4-0.5 microm in width. Strain LS12-2(T) was an obligate Chemolithoautotroph that could utilize elemental sulfur or thiosulfate as an electron donor and nitrate or oxygen as an electron acceptor. Growth was observed at 65-85 degrees C (optimum 70-75 degrees C), pH 5.8-8.3 (optimum pH 6.9-7.5), 1.0-4.0 % (w/v) NaCl (optimum 2.5 %) and 1.0-7.0 % O(2) in the gas phase (optimum 3.0 %). Fatty acids detected were C(16 : 0) (8.0 %), C(18 : 0) (9.0 %), C(18 : 1) (62.5 %) and C(20 : 1) (20.5 %). The genomic DNA G+C content was 51.3 mol%. 16S rRNA gene sequence analysis indicated that strain LS12-2(T) belonged to the genus Hydrogenivirga. Based on physiological and phylogenetic characteristics of the isolate, it is proposed that this strain represents a novel species in the genus Hydrogenivirga, Hydrogenivirga okinawensis sp. nov. The type strain of Hydrogenivirga okinawensis is LS12-2(T) (=JCM 13302(T)=DSM 17378(T)).

  • Balnearium lithotrophicum gen. nov., sp. nov., a novel thermophilic, strictly anaerobic, hydrogen-oxidizing Chemolithoautotroph isolated from a black smoker chimney in the Suiyo Seamount hydrothermal system.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Ken Takai, Satoshi Nakagawa, Yoshihiko Sako, Koki Horikoshi
    Abstract:

    A novel, extremely thermophilic bacterium, designated strain 17S(T), was isolated from a deep-sea hydrothermal vent chimney at the Suiyo Seamount in the Izu-Bonin Arc, Japan. The cells were rods with no apparent motility, most of which were narrow in the middle in the exponential-growth phase and had several polar flagella at both ends. Growth was observed between 45 and 80 degrees C (optimum temperature, 70-75 degrees C; doubling time, 80 min) and between pH 5.0 and 7.0 (optimum pH, 5.4). The isolate was a strictly anaerobic Chemolithoautotroph that was capable of using molecular hydrogen as its sole energy source and carbon dioxide as its sole carbon source. Elemental sulfur (S(0)) was required for growth as an electron acceptor. The G+C content of the genomic DNA was 34.6 mol%. Phylogenetic analysis based on 16S rDNA sequences indicated that the isolate was related to Thermovibrio ruber ED11/3LLK(T) and Desulfurobacterium thermolithotrophum BSA(T), whilst it appeared to be a novel lineage prior to the divergence of these genera. This isolate could also be differentiated from both T. ruber ED11/3LLK(T) and D. thermolithotrophum BSA(T) on the basis of physiological properties. The name Balnearium lithotrophicum gen. nov., sp. nov. is proposed for this isolate (type strain, 17S(T)=JCM 11970(T)=ATCC BAA-736(T)).

Ken Takai - One of the best experts on this subject based on the ideXlab platform.

  • Balnearium lithotrophicum gen. nov., sp. nov., a novel thermophilic, strictly anaerobic, hydrogen-oxidizing Chemolithoautotroph isolated from a black smoker chimney in the Suiyo Seamount hydrothermal system.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Ken Takai, Satoshi Nakagawa, Yoshihiko Sako, Koki Horikoshi
    Abstract:

    A novel, extremely thermophilic bacterium, designated strain 17S(T), was isolated from a deep-sea hydrothermal vent chimney at the Suiyo Seamount in the Izu-Bonin Arc, Japan. The cells were rods with no apparent motility, most of which were narrow in the middle in the exponential-growth phase and had several polar flagella at both ends. Growth was observed between 45 and 80 degrees C (optimum temperature, 70-75 degrees C; doubling time, 80 min) and between pH 5.0 and 7.0 (optimum pH, 5.4). The isolate was a strictly anaerobic Chemolithoautotroph that was capable of using molecular hydrogen as its sole energy source and carbon dioxide as its sole carbon source. Elemental sulfur (S(0)) was required for growth as an electron acceptor. The G+C content of the genomic DNA was 34.6 mol%. Phylogenetic analysis based on 16S rDNA sequences indicated that the isolate was related to Thermovibrio ruber ED11/3LLK(T) and Desulfurobacterium thermolithotrophum BSA(T), whilst it appeared to be a novel lineage prior to the divergence of these genera. This isolate could also be differentiated from both T. ruber ED11/3LLK(T) and D. thermolithotrophum BSA(T) on the basis of physiological properties. The name Balnearium lithotrophicum gen. nov., sp. nov. is proposed for this isolate (type strain, 17S(T)=JCM 11970(T)=ATCC BAA-736(T)).

  • Thioreductor micantisoli gen. nov., sp. nov., a novel mesophilic, sulfur-reducing Chemolithoautotroph within the epsilon-Proteobacteria isolated from hydrothermal sediments in the Mid-Okinawa Trough.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Satoshi Nakagawa, Koki Horikoshi, Ken Takai, Fumio Inagaki, Yoshihiko Sako
    Abstract:

    A novel mesophilic, hydrogen-oxidizing, sulfur-reducing bacterium, designated strain BKB25Ts-Y(T), was isolated from hydrothermal sediments at Iheya North in the Mid-Okinawa Trough, Japan. Cells were Gram-negative, motile rods (1.8-2.1 microm long and 0.5-0.7 microm wide). The isolate was a strictly anaerobic Chemolithoautotroph capable of using molecular hydrogen as the sole energy source and carbon dioxide as the sole carbon source. Elemental sulfur and nitrate served as electron acceptors, respectively yielding hydrogen sulfide and ammonium. Growth was observed at 20-42 degrees C (optimum 32 degrees C; 3 h doubling time), pH 5.0-6.5 (optimum 6.0) and in the presence of 2.0-4.0 % NaCl (optimum 2.5 %) via respiratory S(0) reduction with H(2). The G+C content of the genomic DNA was 37.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate represented the first strain for which taxonomic properties have been characterized within the previously uncultivated epsilon-Proteobacteria Group G. On the basis of the physiological and molecular properties of the novel isolate, the genus name Thioreductor gen. nov. is proposed, with Thioreductor micantisoli sp. nov. as the type species. The type strain is BKB25Ts-Y(T) (=JCM 12457(T)=DSM 16661(T)).

  • Hydrogenivirga okinawensis sp. nov., a thermophilic sulfur-oxidizing Chemolithoautotroph isolated from a deep-sea hydrothermal field, Southern Okinawa Trough.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Takuro Nunoura, Yohey Suzuki, Ken Takai, Masayuki Miyazaki, Koki Horikoshi
    Abstract:

    A novel extremely thermophilic sulfur-oxidizing bacterium, strain LS12-2(T), was isolated from a deep-sea hydrothermal field at the Yonaguni Knoll IV, Southern Okinawa Trough. Cells of strain LS12-2(T) were motile rods, 1.5-4.0 microm in length and 0.4-0.5 microm in width. Strain LS12-2(T) was an obligate Chemolithoautotroph that could utilize elemental sulfur or thiosulfate as an electron donor and nitrate or oxygen as an electron acceptor. Growth was observed at 65-85 degrees C (optimum 70-75 degrees C), pH 5.8-8.3 (optimum pH 6.9-7.5), 1.0-4.0 % (w/v) NaCl (optimum 2.5 %) and 1.0-7.0 % O(2) in the gas phase (optimum 3.0 %). Fatty acids detected were C(16 : 0) (8.0 %), C(18 : 0) (9.0 %), C(18 : 1) (62.5 %) and C(20 : 1) (20.5 %). The genomic DNA G+C content was 51.3 mol%. 16S rRNA gene sequence analysis indicated that strain LS12-2(T) belonged to the genus Hydrogenivirga. Based on physiological and phylogenetic characteristics of the isolate, it is proposed that this strain represents a novel species in the genus Hydrogenivirga, Hydrogenivirga okinawensis sp. nov. The type strain of Hydrogenivirga okinawensis is LS12-2(T) (=JCM 13302(T)=DSM 17378(T)).

  • Lebetimonas acidiphila gen. nov., sp. nov., a novel thermophilic, acidophilic, hydrogen-oxidizing Chemolithoautotroph within the 'Epsilonproteobacteria', isolated from a deep-sea hydrothermal fumarole in the Mariana Arc.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Ken Takai, Tatsunori Nakagawa, Yohey Suzuki, Hisako Hirayama, Kenneth H Nealson, Koki Horikoshi
    Abstract:

    A novel thermophilic, acidophilic bacterium, designated strain Pd55T, was isolated from a self-temperature-recording in situ colonization system deployed in a hydrothermal diffusing flow (maximum temperature of 78 degrees C) at the TOTO caldera in the Mariana Arc. Cells of strain Pd55T were motile, short rods with a single polar flagellum. Growth was observed between 30 and 68 degrees C (optimum growth at 50 degrees C; 120 min doubling time) and between (initial) pH 4.2 and 7.0 (optimum at pH 5.2). The isolate was a strictly anaerobic Chemolithoautotroph capable of using molecular hydrogen as sole energy source and carbon dioxide as sole carbon source. Elemental sulfur served as the sole electron acceptor to support growth. The G+C content of the genomic DNA was 34.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate was related to members of the genera Nautilia and Caminibacter, although it appeared to be a novel lineage prior to the divergence between Nautilia and Caminibacter. Strain Pd55T could also be differentiated from Nautilia and Caminibacter species on the basis of its physiological properties. It is, therefore, proposed that strain Pd55T (=JCM 12420T=DSM 16356T) represents the type strain of a novel species in a new genus, Lebetimonas acidiphila gen. nov., sp. nov.

  • Hydrogenimonas thermophila gen. nov., sp. nov., a novel thermophilic, hydrogen-oxidizing Chemolithoautotroph within the epsilon-Proteobacteria, isolated from a black smoker in a Central Indian Ridge hydrothermal field.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Ken Takai, Kenneth H Nealson, Koki Horikoshi
    Abstract:

    A novel thermophilic bacterium, strain EP1-55-1%T, was isolated from an in-situ colonization system deployed in a superheated, deep-sea, hydrothermal vent emission at the Kairei Field on the Central Indian Ridge in the Indian Ocean. The cells were highly motile rods, each possessing a single polar flagellum. Growth was observed between 35 and 65 degrees C (optimum temperature, 55 degrees C; 70 min doubling time) and between pH 4.9 and 7.2 (optimum, pH 5.9). The isolate was a microaerobic-to-anaerobic Chemolithoautotroph capable of using molecular hydrogen as the sole energy source and carbon dioxide as the sole carbon source. Molecular oxygen, nitrate or elemental sulfur (S0) could serve as electron acceptors to support growth. The G+C content of the genomic DNA was 34.6 mol%. Phylogenetic analysis based on 16S rDNA sequences indicated that strain EP1-55-1%T represents the first strain for which taxonomic properties have been characterized within the previously uncultivated phylogroup classified as belonging to the uncultivated epsilon-Proteobacteria group A; the name Hydrogenimonas thermophila gen. nov., sp. nov. is proposed, with strain EP1-55-1%T (=JCM 11971T=ATCC BAA-737T) as the type strain.

Kathleen M Scott - One of the best experts on this subject based on the ideXlab platform.

  • isotope discrimination by form ic rubisco from ralstonia eutropha and rhodobacter sphaeroides metabolically versatile members of proteobacteria from aquatic and soil habitats
    Environmental Microbiology, 2019
    Co-Authors: Phaedra Thomas, Amanda J Boller, Sriram Satagopan, Robert F Tabita, Colleen M Cavanaugh, Kathleen M Scott
    Abstract:

    : RubisCO, the CO2 fixing enzyme of the Calvin-Benson-Bassham (CBB) cycle, is responsible for the majority of carbon fixation on Earth. RubisCO fixes 12 CO2 faster than 13 CO2 resulting in 13 C-depleted biomass, enabling the use of δ13 C values to trace CBB activity in contemporary and ancient environments. Enzymatic fractionation is expressed as an e value, and is routinely used in modelling, for example, the global carbon cycle and climate change, and for interpreting trophic interactions. Although values for spinach RubisCO (e = ~29‰) have routinely been used in such efforts, there are five different forms of RubisCO utilized by diverse photolithoautotrophs and Chemolithoautotrophs and e values, now known for four forms (IA, B, D and II), vary substantially with e = 11‰ to 27‰. Given the importance of e values in δ13 C evaluation, we measured enzymatic fractionation of the fifth form, form IC RubisCO, which is found widely in aquatic and terrestrial environments. Values were determined for two model organisms, the 'Proteobacteria' Ralstonia eutropha (e = 19.0‰) and Rhodobacter sphaeroides (e = 22.4‰). It is apparent from these measurements that all RubisCO forms measured to date discriminate less than commonly assumed based on spinach, and that enzyme e values must be considered when interpreting and modelling variability of δ13 C values in nature.

  • Reclassification of Thiomicrospira hydrogeniphila (Watsuji et al. 2016) to Thiomicrorhabdus hydrogenophila comb. nov., with emended description of Thiomicrorhabdus (Boden et al., 2017)
    International Journal of Systematic and Evolutionary Microbiology, 2017
    Co-Authors: Rich Boden, Kathleen M Scott, Lee P. Hutt
    Abstract:

    The genus Thiomicrorhabdus (Tmr) in the Piskirickettsiaceae in the Thiotrichales of the Gammaproteobacteria contains four species of sulfur-oxidising obligate Chemolithoautotroph with validly published names, all previously classified as Thiomicrospira (Tms) species. Here we demonstrate that Thiomicrospira hydrogeniphila , a recently published hydrogen-utilising Chemolithoautotroph closely related to Thiomicrorhabdus frisia (type species of Thiomicrorhabdus ) should be classified as a member of the genus Thiomicrorhabdus and not Thiomicrospira , as Thiomicrorhabdus hydrogeniphila comb. nov., on the basis of comparative physiology and morphology as well as 16S rRNA (rrs) gene identity of Tms. hydrogeniphila MAS2T being closer to that of Tmr. frisia JB-A2T (99.1 %) than to Tms. pelophila DSM 1534T (90.5 %) or Hydrogenovibrio marinus MH-110T (94.1 %), and on the basis of the topology of 16S rRNA gene maximum likelihood trees, which clearly place Tms. hydrogeniphila within the genus Thiomicrorhabdus . It was also noted that thiosulfate-grown Thiomicrorhabdus spp. can be distinguished from Thiomicrospira spp. or Hydrogenovibrio spp. on the basis of the 3 dominant fatty acids (C16 : 1, C18 : 1 and C16 : 0), and from other Thiomicrorhabdus spp. on the basis of the fourth dominant fatty acid, which varies between the species of this genus – which could provide a useful diagnostic method. We provide an emended description of Thiomicrorhabdus (Boden R, Scott KM, Williams J, Russel S, Antonen K et al. Int J Syst Evol Microbiol 2017;67:1140–1151) to take into account the properties of Thiomicrorhabdus hydrogeniphila comb. nov.

  • transcriptional response of the sulfur Chemolithoautotroph thiomicrospira crunogena to dissolved inorganic carbon limitation
    Journal of Bacteriology, 2012
    Co-Authors: Kimberly P Dobrinski, Steven A Enkemann, Sean J Yoder, Edward M Haller, Kathleen M Scott
    Abstract:

    The hydrothermal vent gammaproteobacterium Thiomicrospira crunogena inhabits an unstable environment and must endure dramatic changes in habitat chemistry. This sulfur Chemolithoautotroph responds to changes in dissolved inorganic carbon (DIC) (DIC = CO2 + HCO3− + CO3−2) availability with a carbon-concentrating mechanism (CCM) in which whole-cell affinity for DIC, as well as the intracellular DIC concentration, increases substantially under DIC limitation. To determine whether this CCM is regulated at the level of transcription, we resuspended cells that were cultivated under high-DIC conditions in chemostats in growth medium with low concentrations of DIC and tracked CCM development in the presence and absence of the RNA polymerase inhibitor rifampin. Induction of the CCM, as measured by silicone oil centrifugation, was hindered in the presence of rifampin. Similar results were observed for carboxysome gene transcription and assembly, as assayed by quantitative reverse transcription-PCR (qRT-PCR) and transmission electron microscopy, respectively. Genome-wide transcription patterns for cells grown under DIC limitation and those grown under ammonia limitation were assayed via microarrays and compared. In addition to carboxysome genes, two novel genes (Tcr_1019 and Tcr_1315) present in other organisms, including Chemolithoautotrophs, but whose function(s) has not been elucidated in any organism were found to be upregulated under low-DIC conditions. Likewise, under ammonia limitation, in addition to the expected enhancement of ammonia transporter and PII gene transcription, the transcription of two novel genes (Tcr_0466 and Tcr_2018) was measurably enhanced. Upregulation of all four genes (Tcr_1019, 4-fold; Tcr_131, ∼7-fold; Tcr_0466, >200-fold; Tcr_2018, 7-fold), which suggests that novel components are part of the response to nutrient limitation by this organism, was verified via qRT-PCR.

  • expression and function of four carbonic anhydrase homologs in the deep sea Chemolithoautotroph thiomicrospira crunogena
    Applied and Environmental Microbiology, 2010
    Co-Authors: Kimberly P Dobrinski, Amanda J Boller, Kathleen M Scott
    Abstract:

    The hydrothermal vent Chemolithoautotroph Thiomicrospira crunogena grows rapidly in the presence of low concentrations of dissolved inorganic carbon (DIC) (= CO2 + HCO3− + CO3−2). Its genome encodes α-carbonic anhydrase (α-CA), β-CA, carboxysomal β-like CA (CsoSCA), and a protein distantly related to γ-CA. The purposes of this work were to characterize the gene products, determine whether they were differentially expressed, and identify those that are necessary for DIC uptake and fixation. When expressed in Escherichia coli, CA activity was detectable for α-CA, β-CA, and CsoSCA but not for the γ-CA-like protein. α-CA and CsoSCA but not β-CA were inhibited by sulfonamide inhibitors. CsoSCA was also inhibited by dithiothreitol. When grown under DIC limitation in chemostats, T. crunogena transcribed csoSCA more frequently than when ammonia limited, while genes encoding α-CA and β-CA were not differentially transcribed under these conditions. Cell extracts from T. crunogena grown under both DIC- and ammonia-limited conditions had CA activity that was strongly inhibited by sulfonamides, though extracts from nitrogen-limited cells had some CA activity that was resistant, perhaps due to a higher level of β-CA activity. Based on predictions from the SignalP software program, subcellular location when expressed in E. coli, and carbonic anhydrase assays conducted on intact T. crunogena cells, α-CA is located in the periplasm. However, inhibition of α-CA by acetazolamide had only a minor impact on rates of DIC uptake or fixation. Conversely, inhibition of CsoSCA with ethoxyzolamide inhibited carbon fixation but not DIC uptake, consistent with this enzyme functioning to facilitate DIC interconversion and fixation within carboxysomes.

  • genome of the epsilonproteobacterial Chemolithoautotroph sulfurimonas denitrificans
    Applied and Environmental Microbiology, 2008
    Co-Authors: Stefan M Sievert, Kathleen M Scott, Martin G Klotz, Patrick S G Chain, Loren Hauser, James Hemp, Michael Hugler, Miriam Land, Alla Lapidus
    Abstract:

    Sulfur-oxidizing epsilonproteobacteria are common in a variety of sulfidogenic environments. These autotrophic and mixotrophic sulfur-oxidizing bacteria are believed to contribute substantially to the oxidative portion of the global sulfur cycle. In order to better understand the ecology and roles of sulfur-oxidizing epsilonproteobacteria, in particular those of the widespread genus Sulfurimonas, in biogeochemical cycles, the genome of Sulfurimonas denitrificans DSM1251 was sequenced. This genome has many features, including a larger size (2.2 Mbp), that suggest a greater degree of metabolic versatility or responsiveness to the environment than seen for most of the other sequenced epsilonproteobacteria. A branched electron transport chain is apparent, with genes encoding complexes for the oxidation of hydrogen, reduced sulfur compounds, and formate and the reduction of nitrate and oxygen. Genes are present for a complete, autotrophic reductive citric acid cycle. Many genes are present that could facilitate growth in the spatially and temporally heterogeneous sediment habitat from where Sulfurimonas denitrificans was originally isolated. Many resistance-nodulation-development family transporter genes (10 total) are present; of these, several are predicted to encode heavy metal efflux transporters. An elaborate arsenal of sensory and regulatory protein-encoding genes is in place, as are genes necessary to prevent and respond to oxidative stress.

Satoshi Nakagawa - One of the best experts on this subject based on the ideXlab platform.

  • Thioreductor micantisoli gen. nov., sp. nov., a novel mesophilic, sulfur-reducing Chemolithoautotroph within the epsilon-Proteobacteria isolated from hydrothermal sediments in the Mid-Okinawa Trough.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Satoshi Nakagawa, Koki Horikoshi, Ken Takai, Fumio Inagaki, Yoshihiko Sako
    Abstract:

    A novel mesophilic, hydrogen-oxidizing, sulfur-reducing bacterium, designated strain BKB25Ts-Y(T), was isolated from hydrothermal sediments at Iheya North in the Mid-Okinawa Trough, Japan. Cells were Gram-negative, motile rods (1.8-2.1 microm long and 0.5-0.7 microm wide). The isolate was a strictly anaerobic Chemolithoautotroph capable of using molecular hydrogen as the sole energy source and carbon dioxide as the sole carbon source. Elemental sulfur and nitrate served as electron acceptors, respectively yielding hydrogen sulfide and ammonium. Growth was observed at 20-42 degrees C (optimum 32 degrees C; 3 h doubling time), pH 5.0-6.5 (optimum 6.0) and in the presence of 2.0-4.0 % NaCl (optimum 2.5 %) via respiratory S(0) reduction with H(2). The G+C content of the genomic DNA was 37.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate represented the first strain for which taxonomic properties have been characterized within the previously uncultivated epsilon-Proteobacteria Group G. On the basis of the physiological and molecular properties of the novel isolate, the genus name Thioreductor gen. nov. is proposed, with Thioreductor micantisoli sp. nov. as the type species. The type strain is BKB25Ts-Y(T) (=JCM 12457(T)=DSM 16661(T)).

  • Balnearium lithotrophicum gen. nov., sp. nov., a novel thermophilic, strictly anaerobic, hydrogen-oxidizing Chemolithoautotroph isolated from a black smoker chimney in the Suiyo Seamount hydrothermal system.
    International journal of systematic and evolutionary microbiology, 2020
    Co-Authors: Ken Takai, Satoshi Nakagawa, Yoshihiko Sako, Koki Horikoshi
    Abstract:

    A novel, extremely thermophilic bacterium, designated strain 17S(T), was isolated from a deep-sea hydrothermal vent chimney at the Suiyo Seamount in the Izu-Bonin Arc, Japan. The cells were rods with no apparent motility, most of which were narrow in the middle in the exponential-growth phase and had several polar flagella at both ends. Growth was observed between 45 and 80 degrees C (optimum temperature, 70-75 degrees C; doubling time, 80 min) and between pH 5.0 and 7.0 (optimum pH, 5.4). The isolate was a strictly anaerobic Chemolithoautotroph that was capable of using molecular hydrogen as its sole energy source and carbon dioxide as its sole carbon source. Elemental sulfur (S(0)) was required for growth as an electron acceptor. The G+C content of the genomic DNA was 34.6 mol%. Phylogenetic analysis based on 16S rDNA sequences indicated that the isolate was related to Thermovibrio ruber ED11/3LLK(T) and Desulfurobacterium thermolithotrophum BSA(T), whilst it appeared to be a novel lineage prior to the divergence of these genera. This isolate could also be differentiated from both T. ruber ED11/3LLK(T) and D. thermolithotrophum BSA(T) on the basis of physiological properties. The name Balnearium lithotrophicum gen. nov., sp. nov. is proposed for this isolate (type strain, 17S(T)=JCM 11970(T)=ATCC BAA-736(T)).

  • enrichment and genomic characterization of a n2o reducing Chemolithoautotroph from a deep sea hydrothermal vent
    Frontiers in Bioengineering and Biotechnology, 2018
    Co-Authors: Sayaka Mino, Ken Takai, Satoshi Nakagawa, Naoki Yoneyama, Tomoo Sawabe
    Abstract:

    Nitrous oxide (N2O) is a greenhouse gas and also leads to stratospheric ozone depletion. In natural environments, only a single N2O sink process is the microbial reduction of N2O to N2, which is mediated by nitrous oxide reductase (NosZ) encoded by nosZ gene. The nosZ phylogeny has two distinct clades, clade I and formerly overlooked clade II. In deep-sea hydrothermal environments, several members of the class Campylobacteria are shown to harbor clade II nosZ gene and perform the complete denitrification of nitrate to N2; however, little is known about their ability to grow on exogenous N2O as the sole electron acceptor. Here, we obtained an enrichment culture from a deep-sea hydrothermal vent in the Southern Mariana Trough, which showed a respiratory N2O reduction with H2 as an electron donor. The single OTU belonging to the genus Hydrogenimonas within the class Campylobacteria was predominant throughout the cultivation period. Metagenomic analyses using a combination of short-read and long-read sequence data succeeded in reconstructing a complete genome of the dominant Hydrogenimonas OTU, which encoded clade II nosZ gene. This study represents the first cultivation analysis that shows the occurrence of N2O-respiring microorganisms in a deep-sea hydrothermal vent and provides the opportunity to assess their capability to reduce N2O emission from the environments.

  • endemicity of the cosmopolitan mesophilic Chemolithoautotroph sulfurimonas at deep sea hydrothermal vents
    The ISME Journal, 2017
    Co-Authors: Sayaka Mino, Satoshi Nakagawa, Hiroko Makita, Tomohiro Toki, Junichi Miyazaki, Stefan M Sievert, Martin F Polz, Fumio Inagaki, Anne Godfroy
    Abstract:

    Endemicity of the cosmopolitan mesophilic Chemolithoautotroph Sulfurimonas at deep-sea hydrothermal vents

  • Endemicity of the cosmopolitan mesophilic Chemolithoautotroph Sulfurimonas at deep-sea hydrothermal vents
    The ISME Journal, 2017
    Co-Authors: Sayaka Mino, Satoshi Nakagawa, Hiroko Makita, Tomohiro Toki, Junichi Miyazaki, Stefan M Sievert, Martin F Polz, Fumio Inagaki, Anne Godfroy, Shingo Kato
    Abstract:

    Rich animal and microbial communities have been found at deep-sea hydrothermal vents. Although the biogeography of vent macrofauna is well understood, the corresponding knowledge about vent microbial biogeography is lacking. Here, we apply the multilocus sequence analysis (MLSA) to assess the genetic variation of 109 Sulfurimonas strains with ⩾98% 16S rRNA gene sequence similarity, which were isolated from four different geographical regions (Okinawa Trough (OT), Mariana Volcanic Arc and Trough (MVAT), Central Indian Ridge (CIR) and Mid-Atlantic Ridge (MAR)). Sequence typing based on 11 protein-coding genes revealed high genetic variation, including some allele types that are widespread within regions, resulting in 102 nucleotide sequence types (STs). This genetic variation was predominantly due to mutation rather than recombination. Phylogenetic analysis of the 11 concatenated genes showed a clear geographical isolation corresponding to the hydrothermal regions they originated from, suggesting limited dispersal. Genetic differentiation among Sulfurimonas populations was primarily influenced by geographical distance rather than gas composition of vent fluid or habitat, although in situ environmental conditions of each microhabitat could not be examined. Nevertheless, Sulfurimonas may possess a higher dispersal capability compared with deep-sea hydrothermal vent thermophiles. This is the first report on MLSA of deep-sea hydrothermal vent Epsilonproteobacteria, which is indicative of allopatric speciation.

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  • genome of the epsilonproteobacterial Chemolithoautotroph sulfurimonas denitrificans
    Applied and Environmental Microbiology, 2008
    Co-Authors: Stefan M Sievert, Kathleen M Scott, Martin G Klotz, Patrick S G Chain, Loren Hauser, James Hemp, Michael Hugler, Miriam Land, Alla Lapidus
    Abstract:

    Sulfur-oxidizing epsilonproteobacteria are common in a variety of sulfidogenic environments. These autotrophic and mixotrophic sulfur-oxidizing bacteria are believed to contribute substantially to the oxidative portion of the global sulfur cycle. In order to better understand the ecology and roles of sulfur-oxidizing epsilonproteobacteria, in particular those of the widespread genus Sulfurimonas, in biogeochemical cycles, the genome of Sulfurimonas denitrificans DSM1251 was sequenced. This genome has many features, including a larger size (2.2 Mbp), that suggest a greater degree of metabolic versatility or responsiveness to the environment than seen for most of the other sequenced epsilonproteobacteria. A branched electron transport chain is apparent, with genes encoding complexes for the oxidation of hydrogen, reduced sulfur compounds, and formate and the reduction of nitrate and oxygen. Genes are present for a complete, autotrophic reductive citric acid cycle. Many genes are present that could facilitate growth in the spatially and temporally heterogeneous sediment habitat from where Sulfurimonas denitrificans was originally isolated. Many resistance-nodulation-development family transporter genes (10 total) are present; of these, several are predicted to encode heavy metal efflux transporters. An elaborate arsenal of sensory and regulatory protein-encoding genes is in place, as are genes necessary to prevent and respond to oxidative stress.

  • the genome of the epsilon proteobacterial Chemolithoautotroph sulfurimonas denitrificans
    Sievert S. M. Scott K. M. Klotz M. G. Chain P. S. G. Hauser L. J. Hemp J. Hügler Michael Land M. Lapidus A. Larimer F. W. Lucas S. Malfatti S. A. Meye, 2008
    Co-Authors: Stefan M Sievert, Kathleen M Scott, Alla Lapidus, Martin G Klotz, Patrick S G Chain, James Hemp, Michael Hugler, Miriam Land, Lauren Hauser, Frank W Larimer
    Abstract:

    Sulfur-oxidizing epsilonproteobacteria are common in a variety of sulfidogenic environments. These autotrophic and mixotrophic sulfur-oxidizing bacteria are believed to contribute substantially to the oxidative portion of the global sulfur cycle. In order to better understand the ecology and roles of sulfur-oxidizing epsilonproteobacteria, in particular those of the widespread genus Sulfurimonas, in biogeochemical cycles, the genome of Sulfurimonas denitrificans DSM1251 was sequenced. This genome has many features, including a larger size (2.2 Mbp), that suggest a greater degree of metabolic versatility or responsiveness to the environment than seen for most of the other sequenced epsilonproteobacteria. A branched electron transport chain is apparent, with genes encoding complexes for the oxidation of hydrogen, reduced sulfur compounds, and formate and the reduction of nitrate and oxygen. Genes are present for a complete, autotrophic reductive citric acid cycle. Many genes are present that could facilitate growth in the spatially and temporally heterogeneous sediment habitat from where Sulfurimonas denitrificans was originally isolated. Many resistance-nodulation-development family transporter genes (10 total) are present; of these, several are predicted to encode heavy metal efflux transporters. An elaborate arsenal of sensory and regulatory protein-encoding genes is in place, as are genes necessary to prevent and respond to oxidative stress.

  • the genome of deep sea vent Chemolithoautotroph thiomicrospira crunogena xcl 2
    PLOS Biology, 2006
    Co-Authors: Kathleen M Scott, Stefan M Sievert, Patrick S G Chain, Fereniki N Abril, Lois A Ball, Chantell J Barrett, Rodrigo A Blake, Amanda J Boller, Justine Clark
    Abstract:

    Presented here is the complete genome sequence of Thiomicrospira crunogena XCL-2, representative of ubiquitous Chemolithoautotrophic sulfur-oxidizing bacteria isolated from deep-sea hydrothermal vents. This gammaproteobacterium has a single chromosome (2,427,734 base pairs), and its genome illustrates many of the adaptations that have enabled it to thrive at vents globally. It has 14 methyl-accepting chemotaxis protein genes, including four that may assist in positioning it in the redoxcline. A relative abundance of coding sequences (CDSs) encoding regulatory proteins likely control the expression of genes encoding carboxysomes, multiple dissolved inorganic nitrogen and phosphate transporters, as well as a phosphonate operon, which provide this species with a variety of options for acquiring these substrates from the environment. Thiom. crunogena XCL-2 is unusual among obligate sulfur-oxidizing bacteria in relying on the Sox system for the oxidation of reduced sulfur compounds. The genome has characteristics consistent with an obligately Chemolithoautotrophic lifestyle, including few transporters predicted to have organic allocrits, and Calvin-Benson-Bassham cycle CDSs scattered throughout the genome.

  • the genome of deep sea vent Chemolithoautotroph thiomicrospira crunogena xcl 2
    Lawrence Berkeley National Laboratory, 2006
    Co-Authors: Kathleen M Scott, Stefan M Sievert, Patrick S G Chain, Fereniki N Abril, Lois A Ball, Chantell J Barrett, Rodrigo A Blake, Amanda J Boller, Justine Clark
    Abstract:

    Presented here is the complete genome sequence of Thiomicrospira crunogena XCL-2, representative of ubiquitous Chemolithoautotrophic sulfur-oxidizing bacteria isolated from deep-sea hydrothermal vents. This gammaproteobacterium has a single chromosome (2,427,734 bp), and its genome illustrates many of the adaptations that have enabled it to thrive at vents globally. It has 14 methyl-accepting chemotaxis protein genes, including four that may assist in positioning it in the redoxcline. A relative abundance of CDSs encoding regulatory proteins likely control the expression of genes encoding carboxysomes, multiple dissolved inorganic nitrogen and phosphate transporters, as well as a phosphonate operon, which provide this species with a variety of options for acquiring these substrates from the environment. T. crunogena XCL-2 is unusual among obligate sulfur oxidizing bacteria in relying on the Sox system for the oxidation of reduced sulfur compounds. A 38 kb prophage is present, and a high level of prophage induction was observed, which may play a role in keeping competing populations of close relatives in check. The genome has characteristics consistent with an obligately Chemolithoautotrophic lifestyle, including few transporters predicted to have organic allocrits, and Calvin-Benson-Bassham cycle CDSs scattered throughout the genome.

  • complete genome sequence of the ammonia oxidizing bacterium and obligate Chemolithoautotroph nitrosomonas europaea
    Journal of Bacteriology, 2003
    Co-Authors: Patrick S G Chain, Miriam Land, Frank W Larimer, Jane Lamerdin, Warren Regala
    Abstract:

    Nitrosomonas europaea (ATCC 19718) is a gram-negative obligate Chemolithoautotroph that can derive all its energy and reductant for growth from the oxidation of ammonia to nitrite. Nitrosomonas europaea participates in the biogeochemical N cycle in the process of nitrification. Its genome consists of a single circular chromosome of 2,812,094 bp. The GC skew analysis indicates that the genome is divided into two unequal replichores. Genes are distributed evenly around the genome, with ∼47% transcribed from one strand and ∼53% transcribed from the complementary strand. A total of 2,460 protein-encoding genes emerged from the modeling effort, averaging 1,011 bp in length, with intergenic regions averaging 117 bp. Genes necessary for the catabolism of ammonia, energy and reductant generation, biosynthesis, and CO 2 and NH 3 assimilation were identified. In contrast, genes for catabolism of organic compounds are limited. Genes encoding transporters for inorganic ions were plentiful, whereas genes encoding transporters for organic molecules were scant. Complex repetitive elements constitute ca. 5% of the genome. Among these are 85 predicted insertion sequence elements in eight different families. The strategy of N. europaea to accumulate Fe from the environment involves several classes of Fe receptors with more than 20 genes devoted to these receptors. However, genes for the synthesis of only one siderophore, citrate, were identified in the genome. This genome has provided new insights into the growth and metabolism of ammonia-oxidizing bacteria.