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Bernard Ollivier - One of the best experts on this subject based on the ideXlab platform.
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reclassification of the sulfate and nitrate reducing bacterium Desulfovibrio vulgaris subsp oxamicus as Desulfovibrio oxamicus sp nov comb nov
International Journal of Systematic and Evolutionary Microbiology, 2006Co-Authors: Alejandro Lopezcortes, Guy Fauque, Marie-laure Fardeau, Catherine Joulian, Bernard OllivierAbstract:Desulfovibrio vulgaris subsp. oxamicus (type strain, DSM 1925T) was found to use nitrate as a terminal electron acceptor, the latter being reduced to ammonium. Phylogenetic studies indicated that strain DSM 1925T was distantly related to the type strain of Desulfovibrio vulgaris (95.4 % similarity of the small-subunit rRNA gene) and had as its closest phylogenetic relatives two other nitrate- and sulfate-reducing bacteria, namely Desulfovibrio termitidis (99.4 % similarity) and Desulfovibrio longreachensis (98.4 % similarity). Additional experiments were conducted to characterize better strain DSM 1925T. This strain incompletely oxidized lactate and ethanol to acetate. It also oxidized butanol, pyruvate and citrate, but not glucose, fructose, acetate, propionate, butyrate, methanol, glycerol or peptone. The optimum temperature for growth was 37 °C (range 16–50 °C) and the optimum NaCl concentration for growth was 0.1 % (range 0–5 %). Because of significant genotypic and phenotypic differences from Desulfovibrio termitidis and Desulfovibrio longreachensis, reclassification of Desulfovibrio vulgaris subsp. oxamicus as Desulfovibrio oxamicus sp. nov., comb. nov., is proposed. The type strain is strain Monticello 2T (=DSM 1925T=NCIMB 9442T=ATCC 33405T).
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Reclassification of the sulfate- and nitrate-reducing bacterium Desulfovibrio vulgaris subsp. oxamicus as Desulfovibrio oxamicus sp. nov., comb. nov.
International journal of systematic and evolutionary microbiology, 2006Co-Authors: Alejandro López-cortés, Guy Fauque, Marie-laure Fardeau, Catherine Joulian, Bernard OllivierAbstract:Desulfovibrio vulgaris subsp. oxamicus (type strain, DSM 1925(T)) was found to use nitrate as a terminal electron acceptor, the latter being reduced to ammonium. Phylogenetic studies indicated that strain DSM 1925(T) was distantly related to the type strain of Desulfovibrio vulgaris (95.4 % similarity of the small-subunit rRNA gene) and had as its closest phylogenetic relatives two other nitrate- and sulfate-reducing bacteria, namely Desulfovibrio termitidis (99.4 % similarity) and Desulfovibrio longreachensis (98.4 % similarity). Additional experiments were conducted to characterize better strain DSM 1925(T). This strain incompletely oxidized lactate and ethanol to acetate. It also oxidized butanol, pyruvate and citrate, but not glucose, fructose, acetate, propionate, butyrate, methanol, glycerol or peptone. The optimum temperature for growth was 37 degrees C (range 16-50 degrees C) and the optimum NaCl concentration for growth was 0.1 % (range 0-5 %). Because of significant genotypic and phenotypic differences from Desulfovibrio termitidis and Desulfovibrio longreachensis, reclassification of Desulfovibrio vulgaris subsp. oxamicus as Desulfovibrio oxamicus sp. nov., comb. nov., is proposed. The type strain is strain Monticello 2(T) (=DSM 1925(T)=NCIMB 9442(T)=ATCC 33405(T)).
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Biochemical and spectroscopic characterization of an aldehyde oxidoreductase isolated from Desulfovibrio aminophilus.
Journal of inorganic biochemistry, 2005Co-Authors: Anders Thapper, Guy Fauque, Isabel Moura, Bernard Ollivier, Maria G. Rivas, Carlos D. Brondino, José J. G. MouraAbstract:Aldehyde oxidoreductase (AOR) activity has been found in a number of sulfate-reducing bacteria. The enzyme that is responsible for the conversion of aldehydes to carboxylic acids is a mononuclear molybdenum enzyme belonging to the xanthine oxidase family. We report here the purification and characterization of AOR isolated from the sulfate-reducing bacterium Desulfovibrio (D.) aminophilus DSM 12254, an aminolytic strain performing thiosulfate dismutation. The enzyme is a homodimer (ca. 200 kDa), containing a molybdenum centre and two [2Fe-2S] clusters per monomer. UV/Visible and electron paramagnetic resonance (EPR) spectra of D. aminophilus AOR recorded in as-prepared and reduced states are similar to those obtained in AORs from Desulfovibrio gigas, Desulfovibrio desulfuricans and Desulfovibrio alaskensis. Despite AOR from D. aminophilus is closely related to other AORs, it presents lower activity towards aldehydes and no activity towards N-heterocyclic compounds, which suggests another possible role for this enzyme in vivo. A comparison of the molecular and EPR properties of AORs from different Desulfovibrio species is also included.
Guy Fauque - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Desulfovibrio salinus sp. nov., a slightly halophilic sulfate-reducing bacterium isolated from a saline lake in Tunisia
International Journal of Systematic and Evolutionary Microbiology, 2018Co-Authors: Zouhaier Ben Ali Gam, Guy Fauque, Jean-luc Cayol, Abdoulaye Thioye, Manon Joseph, Marc LabatAbstract:A novel slightly halophilic sulfate-reducing bacterium, designated strain P1BSR T , was isolated from water of a saline lake in Tunisia. Strain P1BSR T had motile (single polar flagellum), Gram-negative, rod-shaped, non-spore-forming cells, occurring singly or in pairs. Strain P1BSR T grew at temperatures between 15 and 45 C (optimum 40 C), and in a pH range between 6 and 8.5 (optimum pH 6.7). The strain required NaCl for growth (1 % w/v), and tolerated high NaCl concentration (up to 12 % w/v) with an optimum of 3 % (w/v). Sulfate, thiosulfate and sulfite served as terminal electron acceptors, but not elemental sulfur, fumarate, nitrate and nitrite. Strain P1BSR T utilized lactate, pyruvate, formate, D-fructose and glycerol as carbon and energy sources. The main cellular fatty acid was C 16 : 0 (50.8 %). The genomic DNA G+C content was 47.7 mol%. Phylogenetic analysis of 16S rRNA gene sequence similarity indicated that strain P1BSR T was affiliated to the genus Desulfovibrio, with the type strains Desulfovibrio salexigens (96.51 %), Desulfovibrio zosterae (95.68 %), Desulfovibrio hydrothermalis (94.81 %) and Desulfovibrio ferrireducens (94.73 %) as its closest phylogenetic relatives. On the basis of genotypic, phenotypic and phylogenetic characteristics, it is proposed to assign strain P1BSR T to a novel species of the genus Desulfovibrio, Desulfovibrio salinus sp. nov. The type strain is P1BSR T (=DSM 101510 T =JCM 31065 T). Sulfate-reducing prokaryotes (SRPs) are mainly chemohe-terotrophs, both Bacteria and Archaea (250 species of 65 genera), that can use sulfate as a terminal electron acceptor in their energy metabolism [1, 2]. Owing to their broad metabolic capacities, sulfate-reducing bacteria (SRB) are important in the mineralization of organic matter in anoxic marine sediments. Dissimilatory sulfate reduction has been observed in various hypersaline environments such as salt-erns, the Dead Sea and the Great Salt Lake [3]. However, most of the halophilic SRPs isolated so far are marine or slightly halophilic microorganisms [with optimum salinity ranging from 1 to 4 % (w/v) NaCl] belonging to several gen-era of SRPs, including Desulfovibrio, Desulfonatronovibrio and Desulfonatronobacter species [3-6]. The first SRB species belonging to the genus Desulfovibrio isolated from a hypersaline environment was Desulfovibrio salexigens, which did not grow at NaCl concentrations higher than 12 % (w/v) [7]. Cord-Ruwish [8] then isolated several strains of SRBs from hypersaline oilfield water containing about 10 % (w/v) NaCl. One isolate grew slowly up to 27 % (w/v) NaCl but has not been described in more detail since. One year later, Trüper and Galinski [9] isolated a few SRB strains from hot brines in the Red Sea that were similar to Desulfovibrio halophilus, a moderately halophilic sulfate reducer isolated by Caumette et al. [10] from the hypersa-line Solar Lake in Sinai. The latter isolate grew in salinity ranging from 3 to 18 % (w/v), and optimally at 6-7 % (w/v) NaCl. However, since 1991, no novel SRB species belonging to the genus Desulfovibrio has been characterized that grows in salt concentrations above 10 % NaCl (w/v). No pure culture of extreme halophilic SRB (i.e. growing under saturating salt conditions) has been isolated until now. In this study, we report the isolation and characterization of a mesophilic, slightly halophilic SRB isolated from water samples of a Tunisian saline lake that is able to grow in up to 12 % NaCl (w/v), but grows optimally at 3 % (w/v). This SRB isolate is proposed to represent a novel species of the genus Desulfovibrio. Water samples were collected from a continental saline lake located in the middle-east of Tunisia and transported to the laboratory at ambient temperature. Bacteria were
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reclassification of the sulfate and nitrate reducing bacterium Desulfovibrio vulgaris subsp oxamicus as Desulfovibrio oxamicus sp nov comb nov
International Journal of Systematic and Evolutionary Microbiology, 2006Co-Authors: Alejandro Lopezcortes, Guy Fauque, Marie-laure Fardeau, Catherine Joulian, Bernard OllivierAbstract:Desulfovibrio vulgaris subsp. oxamicus (type strain, DSM 1925T) was found to use nitrate as a terminal electron acceptor, the latter being reduced to ammonium. Phylogenetic studies indicated that strain DSM 1925T was distantly related to the type strain of Desulfovibrio vulgaris (95.4 % similarity of the small-subunit rRNA gene) and had as its closest phylogenetic relatives two other nitrate- and sulfate-reducing bacteria, namely Desulfovibrio termitidis (99.4 % similarity) and Desulfovibrio longreachensis (98.4 % similarity). Additional experiments were conducted to characterize better strain DSM 1925T. This strain incompletely oxidized lactate and ethanol to acetate. It also oxidized butanol, pyruvate and citrate, but not glucose, fructose, acetate, propionate, butyrate, methanol, glycerol or peptone. The optimum temperature for growth was 37 °C (range 16–50 °C) and the optimum NaCl concentration for growth was 0.1 % (range 0–5 %). Because of significant genotypic and phenotypic differences from Desulfovibrio termitidis and Desulfovibrio longreachensis, reclassification of Desulfovibrio vulgaris subsp. oxamicus as Desulfovibrio oxamicus sp. nov., comb. nov., is proposed. The type strain is strain Monticello 2T (=DSM 1925T=NCIMB 9442T=ATCC 33405T).
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Reclassification of the sulfate- and nitrate-reducing bacterium Desulfovibrio vulgaris subsp. oxamicus as Desulfovibrio oxamicus sp. nov., comb. nov.
International journal of systematic and evolutionary microbiology, 2006Co-Authors: Alejandro López-cortés, Guy Fauque, Marie-laure Fardeau, Catherine Joulian, Bernard OllivierAbstract:Desulfovibrio vulgaris subsp. oxamicus (type strain, DSM 1925(T)) was found to use nitrate as a terminal electron acceptor, the latter being reduced to ammonium. Phylogenetic studies indicated that strain DSM 1925(T) was distantly related to the type strain of Desulfovibrio vulgaris (95.4 % similarity of the small-subunit rRNA gene) and had as its closest phylogenetic relatives two other nitrate- and sulfate-reducing bacteria, namely Desulfovibrio termitidis (99.4 % similarity) and Desulfovibrio longreachensis (98.4 % similarity). Additional experiments were conducted to characterize better strain DSM 1925(T). This strain incompletely oxidized lactate and ethanol to acetate. It also oxidized butanol, pyruvate and citrate, but not glucose, fructose, acetate, propionate, butyrate, methanol, glycerol or peptone. The optimum temperature for growth was 37 degrees C (range 16-50 degrees C) and the optimum NaCl concentration for growth was 0.1 % (range 0-5 %). Because of significant genotypic and phenotypic differences from Desulfovibrio termitidis and Desulfovibrio longreachensis, reclassification of Desulfovibrio vulgaris subsp. oxamicus as Desulfovibrio oxamicus sp. nov., comb. nov., is proposed. The type strain is strain Monticello 2(T) (=DSM 1925(T)=NCIMB 9442(T)=ATCC 33405(T)).
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Biochemical and spectroscopic characterization of an aldehyde oxidoreductase isolated from Desulfovibrio aminophilus.
Journal of inorganic biochemistry, 2005Co-Authors: Anders Thapper, Guy Fauque, Isabel Moura, Bernard Ollivier, Maria G. Rivas, Carlos D. Brondino, José J. G. MouraAbstract:Aldehyde oxidoreductase (AOR) activity has been found in a number of sulfate-reducing bacteria. The enzyme that is responsible for the conversion of aldehydes to carboxylic acids is a mononuclear molybdenum enzyme belonging to the xanthine oxidase family. We report here the purification and characterization of AOR isolated from the sulfate-reducing bacterium Desulfovibrio (D.) aminophilus DSM 12254, an aminolytic strain performing thiosulfate dismutation. The enzyme is a homodimer (ca. 200 kDa), containing a molybdenum centre and two [2Fe-2S] clusters per monomer. UV/Visible and electron paramagnetic resonance (EPR) spectra of D. aminophilus AOR recorded in as-prepared and reduced states are similar to those obtained in AORs from Desulfovibrio gigas, Desulfovibrio desulfuricans and Desulfovibrio alaskensis. Despite AOR from D. aminophilus is closely related to other AORs, it presents lower activity towards aldehydes and no activity towards N-heterocyclic compounds, which suggests another possible role for this enzyme in vivo. A comparison of the molecular and EPR properties of AORs from different Desulfovibrio species is also included.
Luciana Marcia Oliveira - One of the best experts on this subject based on the ideXlab platform.
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genome sequence of the model sulfate reducer Desulfovibrio gigas a comparative analysis within the Desulfovibrio genus
MicrobiologyOpen, 2014Co-Authors: Fabio O Moraissilva, Antonio Mauro Rezende, Catia I Santos, Carla Clemente, Ana Varela Raposo, Daniela M Resende, Luciana Marcia Oliveira, Catarina Pimentel, Sofia M. SilvaAbstract:Desulfovibrio gigas is a model organism of sulfate-reducing bacteria of which energy metabolism and stress response have been extensively studied. The complete genomic context of this organism was however, not yet available. The sequencing of the D. gigas genome provides insights into the integrated network of energy conserving complexes and structures present in this bacterium. Comparison with genomes of other Desulfovibrio spp. reveals the presence of two different CRISPR/Cas systems in D. gigas. Phylogenetic analysis using conserved protein sequences (encoded by rpoB and gyrB) indicates two main groups of Desulfovibrio spp, being D. gigas more closely related to D. vulgaris and D. desulfuricans strains. Gene duplications were found such as those encoding fumarate reductase, formate dehydrogenase, and superoxide dismutase. Complexes not yet described within Desulfovibrio genus were identified: Mnh complex, a v-type ATP-synthase as well as genes encoding the MinCDE system that could be responsible for the larger size of D. gigas when compared to other members of the genus. A low number of hydrogenases and the absence of the codh/acs and pfl genes, both present in D. vulgaris strains, indicate that intermediate cycling mechanisms may contribute substantially less to the energy gain in D. gigas compared to other Desulfovibrio spp. This might be compensated by the presence of other unique genomic arrangements of complexes such as the Rnf and the Hdr/Flox, or by the presence of NAD(P)H related complexes, like the Nuo, NfnAB or Mnh.
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genome sequence of the model sulfate reducer Desulfovibrio gigas a comparative analysis within the Desulfovibrio genus
MicrobiologyOpen, 2014Co-Authors: Fabio O Moraissilva, Antonio Mauro Rezende, Catia I Santos, Carla Clemente, Ana Varela Raposo, Daniela M Resende, Luciana Marcia Oliveira, Catarina Pimentel, Sofia M. SilvaAbstract:Desulfovibrio gigas is a model organism of sulfate-reducing bacteria of which energy metabolism and stress response have been extensively studied. The complete genomic context of this organism was however, not yet available. The sequencing of the D. gigas genome provides insights into the integrated network of energy conserving complexes and structures present in this bacterium. Comparison with genomes of other Desulfovibrio spp. reveals the presence of two different CRISPR/Cas systems in D. gigas. Phylogenetic analysis using conserved protein sequences (encoded by rpoB and gyrB) indicates two main groups of Desulfovibrio spp, being D. gigas more closely related to D. vulgaris and D. desulfuricans strains. Gene duplications were found such as those encoding fumarate reductase, formate dehydrogenase, and superoxide dismutase. Complexes not yet described within Desulfovibrio genus were identified: Mnh complex, a v-type ATP-synthase as well as genes encoding the MinCDE system that could be responsible for the larger size of D. gigas when compared to other members of the genus. A low number of hydrogenases and the absence of the codh/acs and pfl genes, both present in D. vulgaris strains, indicate that intermediate cycling mechanisms may contribute substantially less to the energy gain in D. gigas compared to other Desulfovibrio spp. This might be compensated by the presence of other unique genomic arrangements of complexes such as the Rnf and the Hdr/Flox, or by the presence of NAD(P)H related complexes, like the Nuo, NfnAB or Mnh.
José J. G. Moura - One of the best experts on this subject based on the ideXlab platform.
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Orange protein from Desulfovibrio alaskensis G20: insights into the Mo–Cu cluster protein-assisted synthesis
JBIC Journal of Biological Inorganic Chemistry, 2016Co-Authors: Marta S. P. Carepo, José J. G. Moura, Corinne Aubert, Alain Dolla, Cíntia Carreira, Raquel Grazina, Małgorzata E. Zakrzewska, Sofia R. Pauleta, Isabel MouraAbstract:A novel metalloprotein containing a unique [S_2MoS_2CuS_2MoS_2]^3− cluster, designated as Orange Protein (ORP), was isolated for the first time from Desulfovibrio gigas , a sulphate reducer. The orp operon is conserved in almost all sequenced Desulfovibrio genomes and in other anaerobic bacteria, however, so far D. gigas ORP had been the only ORP characterized in the literature. In this work, the purification of another ORP isolated form Desulfovibrio alaskensis G20 is reported. The native protein is monomeric (12443.8 ± 0.1 Da by ESI–MS) and contains also a MoCu cluster with characteristic absorption bands at 337 and 480 nm, assigned to S–Mo charge transfer bands. Desulfovibrio alaskensis G20 recombinant protein was obtained in the apo-form from E. coli . Cluster reconstitution studies and UV–visible titrations with tetrathiomolybdate of the apo-ORP incubated with Cu ions indicate that the cluster is incorporated in a protein metal-assisted synthetic mode and the protein favors the 2Mo:1Cu stoichiometry. In Desulfovibrio alaskensis G20, the orp genes are encoded by a polycistronic unit composed of six genes whereas in Desulfovibrio vulgaris Hildenborough the same genes are organized into two divergent operons, although the composition in genes is similar. The gene expression of ORP ( Dde_3198 ) increased 6.6 ± 0.5 times when molybdate was added to the growth medium but was not affected by Cu(II) addition, suggesting an involvement in molybdenum metabolism directly or indirectly in these anaerobic bacteria.
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Biochemical and spectroscopic characterization of an aldehyde oxidoreductase isolated from Desulfovibrio aminophilus.
Journal of inorganic biochemistry, 2005Co-Authors: Anders Thapper, Guy Fauque, Isabel Moura, Bernard Ollivier, Maria G. Rivas, Carlos D. Brondino, José J. G. MouraAbstract:Aldehyde oxidoreductase (AOR) activity has been found in a number of sulfate-reducing bacteria. The enzyme that is responsible for the conversion of aldehydes to carboxylic acids is a mononuclear molybdenum enzyme belonging to the xanthine oxidase family. We report here the purification and characterization of AOR isolated from the sulfate-reducing bacterium Desulfovibrio (D.) aminophilus DSM 12254, an aminolytic strain performing thiosulfate dismutation. The enzyme is a homodimer (ca. 200 kDa), containing a molybdenum centre and two [2Fe-2S] clusters per monomer. UV/Visible and electron paramagnetic resonance (EPR) spectra of D. aminophilus AOR recorded in as-prepared and reduced states are similar to those obtained in AORs from Desulfovibrio gigas, Desulfovibrio desulfuricans and Desulfovibrio alaskensis. Despite AOR from D. aminophilus is closely related to other AORs, it presents lower activity towards aldehydes and no activity towards N-heterocyclic compounds, which suggests another possible role for this enzyme in vivo. A comparison of the molecular and EPR properties of AORs from different Desulfovibrio species is also included.
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Isolation and characterisation of a novel sulphate-reducing bacterium of the Desulfovibrio genus
Anaerobe, 1998Co-Authors: Maria J. Feio, Ricardo Franco, Marta S. P. Carepo, Iwona B. Beech, João Madeira Lopes, C.w.s Cheung, Jean Guezennec, James R. Smith, Julian Mitchell, José J. G. MouraAbstract:Abstract A novel sulphate-reducing bacterium (Ind 1) was isolated from a biofilm removed from a severely corroded carbon steel structure in a marine environment. Light microscopy observations revealed that cells were Gram-negative, rod shaped and very motile. Partial 16S rRNA gene sequencing and analysis of the fatty acid profile demonstrated a strong similarity between the new species and members from the Desulfovibrio genus. This was confirmed by the results obtained following purification and characterisation of the key proteins involved in the sulphate-reduction pathway. Several metal-containing proteins, such as two periplasmic proteins: hydrogenase and cytochrome c 3 , and two cytoplasmic proteins: ferredoxin and sulphite reductase, were isolated and purified. The latter proved to be of the desulfoviridin type which is typical of the Desulfovibrio genus. The study of the remaining proteins revealed a high degree of similarity with the homologous proteins isolated from Desulfovibrio gigas . However, the position of the strain within the phylogenetic tree clearly indicates that the bacterium is closely related to Desulfovibrio gabonensis , and these three strains form a separate cluster in the delta subdivision of the Proteobacteria. On the basis of the results obtained, it is suggested that Ind 1 belongs to a new species of the genus Desulfovibrio , and the name Desulfovibrio indonensis is proposed.
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Voltammetric studies of the catalytic electron-transfer process between the Desulfovibrio gigas hydrogenase and small proteins isolated from the same genus
FEBS Journal, 1993Co-Authors: Cristina Moreno, Jean Le Gall, Ricardo Franco, Isabel Moura, José J. G. MouraAbstract:The kinetics of electron transfer between the Desulfovibrio gigas hydrogenase and several electron-transfer proteins from Desulfovibrio species were investigated by cyclic voltammetry, square-wave voltammetry and chronoamperometry. The cytochrome c3 from Desulfovibrio vulgaris (Hildenborough), Desulfovibrio desulfuricans (Norway 4), Desulfovibrio desulfuricans (American Type Culture Collection 27774) and D. gigas (NCIB 9332) were used as redox carriers. They differ in their redox potentials and isoelectric point. Depending on the pH, all the reduced forms of these cytochromes were effective in electron exchange with hydrogenase. Other small electron-transfer proteins such as ferredoxin I, ferredoxin II and rubredoxin from D. gigas were tentatively used as redox carriers. Only ferredoxin II was effective in mediating electron exchange between hydrogenase and the working electrode. The second-order rate constants k for the reaction between reduced proteins and hydrogenase were calculated based on the theory of the simplest electrocatalytic mechanism [Moreno, C., Costa, C., Moura, I., Le Gall, J., Liu, M. Y., Payne, W. J., van Dijk, C. & Moura, J. J. G. (1993) Eur. J. Biochem. 212, 79-86] and the results obtained by cyclic voltammetry were compared with those obtained by chronoamperometry. Values for k of 10(5)-10(6) M-1 s-1 (cytochrome c3 as electron carrier) and 10(4) M-1 s-1 (ferredoxin II as the electron carrier) were determined. The rate-constant values are discussed in terms of the existence of an electrostatic interaction between the electrode surface and the redox carrier and between the redox carrier and a positively charged part of the enzyme.
Marc Labat - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Desulfovibrio salinus sp. nov., a slightly halophilic sulfate-reducing bacterium isolated from a saline lake in Tunisia
International Journal of Systematic and Evolutionary Microbiology, 2018Co-Authors: Zouhaier Ben Ali Gam, Guy Fauque, Jean-luc Cayol, Abdoulaye Thioye, Manon Joseph, Marc LabatAbstract:A novel slightly halophilic sulfate-reducing bacterium, designated strain P1BSR T , was isolated from water of a saline lake in Tunisia. Strain P1BSR T had motile (single polar flagellum), Gram-negative, rod-shaped, non-spore-forming cells, occurring singly or in pairs. Strain P1BSR T grew at temperatures between 15 and 45 C (optimum 40 C), and in a pH range between 6 and 8.5 (optimum pH 6.7). The strain required NaCl for growth (1 % w/v), and tolerated high NaCl concentration (up to 12 % w/v) with an optimum of 3 % (w/v). Sulfate, thiosulfate and sulfite served as terminal electron acceptors, but not elemental sulfur, fumarate, nitrate and nitrite. Strain P1BSR T utilized lactate, pyruvate, formate, D-fructose and glycerol as carbon and energy sources. The main cellular fatty acid was C 16 : 0 (50.8 %). The genomic DNA G+C content was 47.7 mol%. Phylogenetic analysis of 16S rRNA gene sequence similarity indicated that strain P1BSR T was affiliated to the genus Desulfovibrio, with the type strains Desulfovibrio salexigens (96.51 %), Desulfovibrio zosterae (95.68 %), Desulfovibrio hydrothermalis (94.81 %) and Desulfovibrio ferrireducens (94.73 %) as its closest phylogenetic relatives. On the basis of genotypic, phenotypic and phylogenetic characteristics, it is proposed to assign strain P1BSR T to a novel species of the genus Desulfovibrio, Desulfovibrio salinus sp. nov. The type strain is P1BSR T (=DSM 101510 T =JCM 31065 T). Sulfate-reducing prokaryotes (SRPs) are mainly chemohe-terotrophs, both Bacteria and Archaea (250 species of 65 genera), that can use sulfate as a terminal electron acceptor in their energy metabolism [1, 2]. Owing to their broad metabolic capacities, sulfate-reducing bacteria (SRB) are important in the mineralization of organic matter in anoxic marine sediments. Dissimilatory sulfate reduction has been observed in various hypersaline environments such as salt-erns, the Dead Sea and the Great Salt Lake [3]. However, most of the halophilic SRPs isolated so far are marine or slightly halophilic microorganisms [with optimum salinity ranging from 1 to 4 % (w/v) NaCl] belonging to several gen-era of SRPs, including Desulfovibrio, Desulfonatronovibrio and Desulfonatronobacter species [3-6]. The first SRB species belonging to the genus Desulfovibrio isolated from a hypersaline environment was Desulfovibrio salexigens, which did not grow at NaCl concentrations higher than 12 % (w/v) [7]. Cord-Ruwish [8] then isolated several strains of SRBs from hypersaline oilfield water containing about 10 % (w/v) NaCl. One isolate grew slowly up to 27 % (w/v) NaCl but has not been described in more detail since. One year later, Trüper and Galinski [9] isolated a few SRB strains from hot brines in the Red Sea that were similar to Desulfovibrio halophilus, a moderately halophilic sulfate reducer isolated by Caumette et al. [10] from the hypersa-line Solar Lake in Sinai. The latter isolate grew in salinity ranging from 3 to 18 % (w/v), and optimally at 6-7 % (w/v) NaCl. However, since 1991, no novel SRB species belonging to the genus Desulfovibrio has been characterized that grows in salt concentrations above 10 % NaCl (w/v). No pure culture of extreme halophilic SRB (i.e. growing under saturating salt conditions) has been isolated until now. In this study, we report the isolation and characterization of a mesophilic, slightly halophilic SRB isolated from water samples of a Tunisian saline lake that is able to grow in up to 12 % NaCl (w/v), but grows optimally at 3 % (w/v). This SRB isolate is proposed to represent a novel species of the genus Desulfovibrio. Water samples were collected from a continental saline lake located in the middle-east of Tunisia and transported to the laboratory at ambient temperature. Bacteria were
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Desulfovibrio marrakechensis sp nov., a 1,4-tyrosol-oxidizing, sulfate-reducing bacterium isolated from olive mill wastewater
International Journal of Systematic and Evolutionary Microbiology, 2009Co-Authors: Fatima Chamkh, Cathrin Sproeer, Paulo Costa Lemos, Stephane Besson, Abdel-ghani El Asli, Rhizlane Bennisse, Marc Labat, Maria Reis, Abdel-illah QatibiAbstract:A novel mesophilic sulfate-reducing bacterium, EMSSDQ(4)(T), was isolated from olive mill wastewater in the semi-arid region of Morocco (Marrakech). Cells were Gram-negative, catalase-positive, straight rods that were non-motile and non-spore-forming and contained cytochrome c(3) and desulfoviridin. The DNA G + C content was 65.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the isolate was a member of the genus Desulfovibrio with Desulfovibrio carbinoliphilus D41(T), Desulfovibrio alcoholivorans SPSNT, Desulfovibrio fructosivorans JJ(T) and Desulfovibrio carbinolicus EDK82(T) as the most closely related strains with validly published names. In addition to the classical substrates used by Desulfovibrio species, the isolate oxidized 1,4-tyrosol, one of the most abundant phenolic compounds occurring in olive mill wastewater, to 4-hydroxyphenylacetate without ring cleavage. D. alcoholivorans SPSNT was also found to carry out this reaction. Under air, strain EMSSDQ(4)(T) exhibited limited growth on lactate and yeast extract in the absence of sulfate. On the basis of genotypic and phenotypic characteristics, it is proposed that the isolate represents a novel species, Desulfovibrio marrakechensis sp. nov. The type strain is EMSSDQ(4)(T) (=DSM 19337(T) =ATCC BAA-1562(T)).