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Richard Christen - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Pseudoalteromonas distincta-like sea-water isolates and description of Pseudoalteromonas aliena sp. nov.
International journal of systematic and evolutionary microbiology, 2004Co-Authors: Elena P. Ivanova, Natalia V Zhukova, Anatolii M Lysenko, Nataliya M Gorshkova, Valery V Mikhailov, Elena A Zelepuga, Nina G Prokof'eva, Dan V Nicolau, Richard ChristenAbstract:Seven melanogenic Pseudoalteromonas distincta-like strains, KMM 3562T, KMM 3536, KMM 3537, KMM 3538, KMM 3539, KMM 3615 and KMM 3629, which expressed tyrosinases were isolated from sea-water samples collected from different locations in Amursky Bay (Sea of Japan, Pacific Ocean) and characterized to clarify their taxonomic position. By 16S rRNA gene sequence analysis, the bacteria were shown to belong to the genus Pseudoalteromonas. The G + C content of the DNAs of the strains was 41-43 mol%. The level of DNA similarity among these strains was conspecific (92-97 %), indicating that they represented a single genospecies. However, DNA from the strains isolated from sea water showed only 63-65 % genetic relatedness with the DNA of the type strain P. distincta. The novel organisms grew mainly between 4 and 30 degrees C, were neutrophilic and slightly halophilic (four strains had a narrow range of growth between 3 and 6 % NaCl, w/v), were haemolytic and cytotoxic and were able to degrade starch, gelatin and Tween 80. The predominant fatty acids, including 16 : 0, 16 : 1omega7, 17 : 1omega7 and 18 : 1omega7, were typical of the genus Pseudolateromonas. The phylogenetic, genetic and physiological properties of the seven strains placed them within a novel species, Pseudoalteromonas aliena sp. nov., the type strain of which is SW19T (= KMM 3562T = LMG 22059T).
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Pseudoalteromonas translucida sp. nov. and Pseudoalteromonas paragorgicola sp. nov., and emended description of the genus.
International Journal of Systematic and Evolutionary Microbiology, 2002Co-Authors: Elena P. Ivanova, Natalia V Zhukova, Anatolii M Lysenko, Nataliya M Gorshkova, Richard Christen, Tomoo Sawabe, Dan V Nicolau, Kenji Hayashi, Valery V MikhailovAbstract:On the basis of phenotypic and genotypic characteristics and analysis of 16S rRNA sequences, two novel species belonging to the genus Pseudoalteromonas are described. A pale-orange-pigmented strain, KMM 3548T, isolated from a sponge and a non-pigmented strain, KMM 520T, isolated from sea water are marine, gram-negative, aerobic, rod-shaped organisms. One of the strains, KMM 520T, had bipolar flagella. Both strains had the ability to degrade gelatin, DNA and Tween 80 but not chitin or agar. Strain KMM 520T decomposed elastin and grew at NaCl concentrations of 1-8%, while strain KMM 3548T grew at 1-6% NaCl. The temperature range for both strains was 4-30 degrees C. The DNA G+C contents were 46.3 (KMM 520T) and 41.1 mol% (KMM 3548T). The level of DNA relatedness between the two strains was 20%. DNA from strain KMM 520T showed 8-34% genetic relatedness and that of KMM 3548T showed 17-53% relatedness to the DNA of other type strains of the genus Pseudoalteromonas. 16S rRNA analysis indicated a clear affiliation of these novel bacteria with the genus Pseudoalteromonas. The type strains of the novel species are Pseudoalteromonas translucida sp. nov. KMM 520T (= LMG 19696T = ATCC BAA-3157T) and Pseudoalteromonas paragorgicola sp. nov. KMM 3548T (= LMG 19694T = ATCC BAA-322T).
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Pseudoalteromonas maricaloris sp. nov., isolated from an Australian sponge, and reclassification of [Pseudoalteromonas aurantia] NCIMB 2033 as Pseudoalteromonas flavipulchra sp. nov.
International journal of systematic and evolutionary microbiology, 2002Co-Authors: Elena P. Ivanova, Vassilii I. Svetashev, Anatolii M Lysenko, Nataliya M Gorshkova, Richard Christen, Tomoo Sawabe, Ludmila S Shevchenko, Masataka Satomi, Valery V MikhailovAbstract:A marine, gram-negative, aerobic bacterium that produced cytotoxic, lemon-yellow, chromopeptide pigments that inhibited the development of sea urchin eggs has been isolated from the Australian sponge Fascaplysinopsis reticulata Hentschel. The cells of the organism were rod-shaped with a single polar flagellum and they required NaCl for growth (0.5-10%) with optimum growth at 1-3% NaCl. The temperature for growth was 10-37 degrees C, with optimum growth at 25-30 degrees C. Growth occurred at pH values from 6.0 to 10.0, with optimum growth at pH 6.0-8.0. Major phospholipids were phosphatidylethanolamine, phosphatidylglycerol and lyso-phosphatidylethanolamine. Of 26 fatty acids with 11-19 carbon atoms that were detected, 16:1omega7, 16:0, 17:1omega8 and 18:1omega7 were predominant. The DNA G+C content was 38.9 mol%. All of these phenotypic and chemotaxonomic characters place the organism in the genus Pseudoalteromonas (Gauthier et al, 1995). These data are consistent with the phylogenetic analyses that confirmed that strain KMM 636T is a member of the Pseudoalteromonas cluster in the gamma-subclass of the Proteobacteria. DNA-DNA hybridization experiments revealed that the levels of relatedness between the DNA of the strain studied and DNAs of type strains of the species that clustered together (on the basis of 16S rDNA sequences) and [Pseudoalteromonas aurantia] NCIMB 2033 ranged from 19 to 35%, and that the DNA-DNA homology between [P. aurantia] NCIMB 2033 and other phylogenetically and/or phenotypically similar type strains ranged from 32 to 52%. According to the polyphasic evidence presented in this study, it is proposed that strain KMM 636T (= LMG 19692T = CIP 106859T) be classified as Pseudoalteromonas maricaloris sp. nov. and [P. aurantia] NCIMB 2033 be reclassified as Pseudoalteromonas flavipulchra NCIMB 2033T (= KMM 3630T = LMG 20361T) sp. nov.
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assignment of alteromonas elyakovii kmm 162t and five strains isolated from spot wounded fronds of laminaria japonica to Pseudoalteromonas elyakovii comb nov and the extended description of the species
International Journal of Systematic and Evolutionary Microbiology, 2000Co-Authors: Tomoo Sawabe, Mohamed Mahabubu Iqbal, Reiji Tanaka, Kenichi Tajima, Yoshio Ezura, Elena P. Ivanova, Richard ChristenAbstract:A marine bacterium, Alteromonas elyakovii KMM 162T, which was described recently, and five strains isolated from spot-wounded fronds of Laminaria japonica have been subjected to phylogenetic analysis, and geno- and phenotypic characterization. The phenotypic features of Pseudoalteromonas elyakovii strains were closely related to that of Pseudoalteromonas espejiana IAM 12640T, but utilization of three carbon compounds (D-mannose, L-tyrosine and trehalose) distinguished both species. The G+C content of Pseudoalteromonas elyakovii was between 38.5 and 38.9 mol%. Pseudoalteromonas elyakovii KMM 162T and the five Laminaria isolates constitute a single species different from any other Alteromonas and Pseudoalteromonas species as revealed by DNA-DNA hybridization data, especially Pseudoalteromonas distincta KMM 638T (52.4%), Pseudoalteromonas citrea KMM 216 (49.5%), Pseudoalteromonas carrageenovora NCIMB 302T (46.9%) and Pseudoalteromonas espejiana IAM 12640T (29.9%). All the data indicated that Alteromonas elyakovii KMM 162T should be reclassified as Pseudoalteromonas elyakovii and five strains isolated from Laminaria japonica have to be included in the species. Pseudoalteromonas elyakovii comb. nov. (type strain, KMM 162T = ATCC 700519T) is proposed and a set of phenotypic features which differentiate the Pseudoalteromonas species is described.
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Pseudoalteromonas bacteriolytica sp nov a marine bacterium that is the causative agent of red spot disease of laminaria japonica
International Journal of Systematic and Evolutionary Microbiology, 1998Co-Authors: Tomoo Sawabe, Hideyuki Makino, Mohammed Mahbub Iqbal, Masahiro Tatsumi, Isao Yumoto, Kenichi Tajima, Yoshio Ezura, Kazuaki Nakano, Richard ChristenAbstract:An aerobic, polarly flagellated marine bacterium that produces a prodigiosinlike pigment was isolated from the red-spotted culture beds of Laminaria japonica. Five isolates had unique bacteriolytic activity for both Gram-positive and -negative bacteria, which had never been observed among Alteromonas or related species. The isolates were identified as the causative agent of red spot disease of L. japonica seeds. The phenotypic features of the isolates were similar to these of Pseudoalteromonas rubra ATCC 29570T, but they could be differentiated using 10 traits (growth at 37°C, requirement for organic growth factors, bacteriolytic activity, utilization of sucrose, N-acetylglucosamine, fumarate, succinate, d-galactose, l-proline and acetate). The G+C content of DNAs from the isolates was 44–46 mol%. The isolates constitute a new species, distinct from the other Alteromonas and Pseudoalteromonas species, as shown by DNA-DNA hybridization experiments and phylogenetic clustering of 16S rRNA gene sequences, for which the name Pseudoalteromonas bacteriolytica sp. nov. (type strain = IAM 14595T) is proposed. A set of phenotypic features which differentiate this new species from closely related Pseudoalteromonas and Alteromonas species is provided.
Elena P. Ivanova - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Pseudoalteromonas distincta-like sea-water isolates and description of Pseudoalteromonas aliena sp. nov.
International journal of systematic and evolutionary microbiology, 2004Co-Authors: Elena P. Ivanova, Natalia V Zhukova, Anatolii M Lysenko, Nataliya M Gorshkova, Valery V Mikhailov, Elena A Zelepuga, Nina G Prokof'eva, Dan V Nicolau, Richard ChristenAbstract:Seven melanogenic Pseudoalteromonas distincta-like strains, KMM 3562T, KMM 3536, KMM 3537, KMM 3538, KMM 3539, KMM 3615 and KMM 3629, which expressed tyrosinases were isolated from sea-water samples collected from different locations in Amursky Bay (Sea of Japan, Pacific Ocean) and characterized to clarify their taxonomic position. By 16S rRNA gene sequence analysis, the bacteria were shown to belong to the genus Pseudoalteromonas. The G + C content of the DNAs of the strains was 41-43 mol%. The level of DNA similarity among these strains was conspecific (92-97 %), indicating that they represented a single genospecies. However, DNA from the strains isolated from sea water showed only 63-65 % genetic relatedness with the DNA of the type strain P. distincta. The novel organisms grew mainly between 4 and 30 degrees C, were neutrophilic and slightly halophilic (four strains had a narrow range of growth between 3 and 6 % NaCl, w/v), were haemolytic and cytotoxic and were able to degrade starch, gelatin and Tween 80. The predominant fatty acids, including 16 : 0, 16 : 1omega7, 17 : 1omega7 and 18 : 1omega7, were typical of the genus Pseudolateromonas. The phylogenetic, genetic and physiological properties of the seven strains placed them within a novel species, Pseudoalteromonas aliena sp. nov., the type strain of which is SW19T (= KMM 3562T = LMG 22059T).
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Pseudoalteromonas translucida sp. nov. and Pseudoalteromonas paragorgicola sp. nov., and emended description of the genus.
International Journal of Systematic and Evolutionary Microbiology, 2002Co-Authors: Elena P. Ivanova, Natalia V Zhukova, Anatolii M Lysenko, Nataliya M Gorshkova, Richard Christen, Tomoo Sawabe, Dan V Nicolau, Kenji Hayashi, Valery V MikhailovAbstract:On the basis of phenotypic and genotypic characteristics and analysis of 16S rRNA sequences, two novel species belonging to the genus Pseudoalteromonas are described. A pale-orange-pigmented strain, KMM 3548T, isolated from a sponge and a non-pigmented strain, KMM 520T, isolated from sea water are marine, gram-negative, aerobic, rod-shaped organisms. One of the strains, KMM 520T, had bipolar flagella. Both strains had the ability to degrade gelatin, DNA and Tween 80 but not chitin or agar. Strain KMM 520T decomposed elastin and grew at NaCl concentrations of 1-8%, while strain KMM 3548T grew at 1-6% NaCl. The temperature range for both strains was 4-30 degrees C. The DNA G+C contents were 46.3 (KMM 520T) and 41.1 mol% (KMM 3548T). The level of DNA relatedness between the two strains was 20%. DNA from strain KMM 520T showed 8-34% genetic relatedness and that of KMM 3548T showed 17-53% relatedness to the DNA of other type strains of the genus Pseudoalteromonas. 16S rRNA analysis indicated a clear affiliation of these novel bacteria with the genus Pseudoalteromonas. The type strains of the novel species are Pseudoalteromonas translucida sp. nov. KMM 520T (= LMG 19696T = ATCC BAA-3157T) and Pseudoalteromonas paragorgicola sp. nov. KMM 3548T (= LMG 19694T = ATCC BAA-322T).
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Pseudoalteromonas maricaloris sp. nov., isolated from an Australian sponge, and reclassification of [Pseudoalteromonas aurantia] NCIMB 2033 as Pseudoalteromonas flavipulchra sp. nov.
International journal of systematic and evolutionary microbiology, 2002Co-Authors: Elena P. Ivanova, Vassilii I. Svetashev, Anatolii M Lysenko, Nataliya M Gorshkova, Richard Christen, Tomoo Sawabe, Ludmila S Shevchenko, Masataka Satomi, Valery V MikhailovAbstract:A marine, gram-negative, aerobic bacterium that produced cytotoxic, lemon-yellow, chromopeptide pigments that inhibited the development of sea urchin eggs has been isolated from the Australian sponge Fascaplysinopsis reticulata Hentschel. The cells of the organism were rod-shaped with a single polar flagellum and they required NaCl for growth (0.5-10%) with optimum growth at 1-3% NaCl. The temperature for growth was 10-37 degrees C, with optimum growth at 25-30 degrees C. Growth occurred at pH values from 6.0 to 10.0, with optimum growth at pH 6.0-8.0. Major phospholipids were phosphatidylethanolamine, phosphatidylglycerol and lyso-phosphatidylethanolamine. Of 26 fatty acids with 11-19 carbon atoms that were detected, 16:1omega7, 16:0, 17:1omega8 and 18:1omega7 were predominant. The DNA G+C content was 38.9 mol%. All of these phenotypic and chemotaxonomic characters place the organism in the genus Pseudoalteromonas (Gauthier et al, 1995). These data are consistent with the phylogenetic analyses that confirmed that strain KMM 636T is a member of the Pseudoalteromonas cluster in the gamma-subclass of the Proteobacteria. DNA-DNA hybridization experiments revealed that the levels of relatedness between the DNA of the strain studied and DNAs of type strains of the species that clustered together (on the basis of 16S rDNA sequences) and [Pseudoalteromonas aurantia] NCIMB 2033 ranged from 19 to 35%, and that the DNA-DNA homology between [P. aurantia] NCIMB 2033 and other phylogenetically and/or phenotypically similar type strains ranged from 32 to 52%. According to the polyphasic evidence presented in this study, it is proposed that strain KMM 636T (= LMG 19692T = CIP 106859T) be classified as Pseudoalteromonas maricaloris sp. nov. and [P. aurantia] NCIMB 2033 be reclassified as Pseudoalteromonas flavipulchra NCIMB 2033T (= KMM 3630T = LMG 20361T) sp. nov.
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retrieval of the species alteromonas tetraodonis simidu et al 1990 as Pseudoalteromonas tetraodonis comb nov and emendation of description
International Journal of Systematic and Evolutionary Microbiology, 2001Co-Authors: Elena P. Ivanova, Maria E Matte, Glavur Rogerio Matte, Anatolii M Lysenko, Usio Simidu, Lyudmila A Romanenko, Kumiko Kitatsukamoto, Mikhail V Vysotskii, Tomoo Sawabe, Galina M. FrolovaAbstract:A polyphasic taxonomy study was undertaken of three strains of Pseudoalteromonas haloplanktis subsp. tetraodonis (Simidu et al. 1990) Gauthier et al. 1995. DNA was prepared from each of the strains and genomic relatedness was measured by DNA-DNA hybridization. Strains KMM 458T and IAM 14160T shared 99% genetic relatedness, but were only 48-49% related to the type strain of Pseudoalteromonas haloplanktis subsp. haloplanktis, IAM 12915T. The third strain, P. haloplanktis subsp. tetraodonis A-M, showed 83% genetic similarity with P. haloplanktis subsp. haloplanktis IAM 12915T and 32% with KMM 458T. From these results, it is concluded that strains KMM 458T and IAM 14160T comprise a separate species, originally described as Alteromonas tetraodonis, whereas strain A-M belongs to the species Pseudoalteromonas haloplanktis. Based on phenotypic and chemotaxonomic data, genomic fingerprint patterns, DNA-DNA hybridization data and phylogenetic analysis of 16S rRNA, it is proposed that the species Alteromonas tetraodonis be retrieved and recognized as Pseudoalteromonas tetraodonis comb. nov. (type strain IAM 14160T = KMM 458T).
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A new family of Alteromonadaceae fam. nov., including the marine proteobacteria species Alteromonas, Pseudoalteromonas, Idiomarina i Colwellia
Mikrobiologiia, 2001Co-Authors: Elena P. IvanovaAbstract:The taxonomic position of the marine genera Alteromonas, Pseudoalteromonas, Idiomarina, and Colwellia within the gamma subclass of the class Proteobacteria were specified on the basis of their phenotypic, genotypic, and phylogenetic characteristics. Gram-negative aerobic bacteria of the genera Alteromonas, Pseudoalteromonas, and Idiomarina and facultatively anaerobic bacteria of the genus Colwellia were found to form a phylogenetic cluster with a 16S rRNA sequence homology of 90% or higher. The characteristics of these genera presented in this paper allow their reliable taxonomic identification. Based on the analysis of our experimental data and analyses available in the literature, we propose to combine the genera Alteromonas, Pseudoalteromonas, Idiomarina, and Colwellia into a new family, Alteromonadaceae fam. nov., with the type genus Alteromonas.
Staffan Kjelleberg - One of the best experts on this subject based on the ideXlab platform.
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marine bacteria from danish coastal waters show antifouling activity against the marine fouling bacterium Pseudoalteromonas sp strain s91 and zoospores of the green alga ulva australis independent of bacteriocidal activity
Applied and Environmental Microbiology, 2011Co-Authors: Staffan Kjelleberg, Nete Bernbom, Tilmann Harder, Lone GramAbstract:The aims of this study were to determine if marine bacteria from Danish coastal waters produce antifouling compounds and if antifouling bacteria could be ascribed to specific niches or seasons. We further assess if antibacterial effect is a good proxy for antifouling activity. We isolated 110 bacteria with anti-Vibrio activity from different sample types and locations during a 1-year sampling from Danish coastal waters. The strains were identified as Pseudoalteromonas, Phaeobacter, and Vibrionaceae based on phenotypic tests and partial 16S rRNA gene sequence similarity. The numbers of bioactive bacteria were significantly higher in warmer than in colder months. While some species were isolated at all sampling locations, others were niche specific. We repeatedly isolated Phaeobacter gallaeciensis at surfaces from one site and Pseudoalteromonas tunicata at two others. Twenty-two strains, representing the major taxonomic groups, different seasons, and isolation strategies, were tested for antiadhesive effect against the marine biofilm-forming bacterium Pseudoalteromonas sp. strain S91 and zoospores of the green alga Ulva australis. The antiadhesive effects were assessed by quantifying the number of strain S91 or Ulva spores attaching to a preformed biofilm of each of the 22 strains. The strongest antifouling activity was found in Pseudoalteromonas strains. Biofilms of Pseudoalteromonas piscicida, Pseudoalteromonas tunicata, and Pseudoalteromonas ulvae prevented Pseudoalteromonas S91 from attaching to steel surfaces. P. piscicida killed S91 bacteria in the suspension cultures, whereas P. tunicata and P. ulvae did not; however, they did prevent adhesion by nonbactericidal mechanism(s). Seven Pseudoalteromonas species, including P. piscicida and P. tunicata, reduced the number of settling Ulva zoospores to less than 10% of the number settling on control surfaces. The antifouling alpP gene was detected only in P. tunicata strains (with purple and yellow pigmentation), so other compounds/mechanisms must be present in the other Pseudoalteromonas strains with antifouling activity.
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Molecular investigation of the distribution, abundance and diversity of the genus Pseudoalteromonas in marine samples.
FEMS microbiology ecology, 2007Co-Authors: Torben L. Skovhus, Carola Holmstrom, Staffan Kjelleberg, Ingela DahllöfAbstract:The genus Pseudoalteromonas has attracted interest because it has frequently been found in association with eukaryotic hosts, and because many Pseudoalteromonas species produce biologically active compounds. One distinct group of Pseudoalteromonas species is the antifouling subgroup containing Pseudoalteromonas tunicata and Ps. ulvae, which both produce extracellular compounds that inhibit growth and colonization by different marine organisms. PCR primers targeting the 16S rRNA gene of the genus Pseudoalteromonas and the antifouling subgroup were developed and applied in this study. Real-time quantitative PCR (qPCR) was applied to determine the relative bacterial abundance of the genus and the antifouling subgroup, and denaturing gradient gel electrophoresis (DGGE) was applied to study the diversity of the genus in 11 different types of marine samples from Danish coastal waters. The detection of Ps. tunicata that contain the antifouling subgroup was achieved through specific PCR amplification of the antibacterial protein gene (alpP). The Pseudoalteromonas species accounted for 1.6% of the total bacterial abundance across all samples. The Pseudoalteromonas diversity on the three unfouled marine organisms Ciona intestinalis, Ulva lactuca and Ulvaria fusca was found to be low, and Ps. tunicata was only detected on these three hosts, which all contain accessible cellulose polymers in their cell walls.
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Real-Time Quantitative PCR for Assessment of Abundance of Pseudoalteromonas Species in Marine Samples
Applied and environmental microbiology, 2004Co-Authors: Torben L. Skovhus, Carola Holmstrom, Staffan Kjelleberg, Niels B. Ramsing, Ingela DahllöfAbstract:A real-time quantitative PCR (RTQ-PCR) method for measuring the abundance of Pseudoalteromonas species in marine samples is presented. PCR primers targeting a Pseudoalteromonas-specific region of the 16S rRNA gene were tested at three different levels using database searches (in silico), a selection of pure cultures (in vitro), and a combined denaturing gradient gel electrophoresis and cloning approach on environmental DNA (in situ). The RTQ-PCR method allowed for the detection of SYBR Green fluorescence from double-stranded DNA over a linear range spanning six orders of magnitude. The detection limit was determined as 1.4 fg of target DNA (1,000 gene copies) measured in the presence of 20 ng of nontarget DNA from salmon testes. In this study, we discuss the importance of robust post-PCR analyses to overcome pitfalls in RTQ-PCR when samples from different complex marine habitats are analyzed and compared on a nonroutine basis. Representatives of the genus Pseudoalteromonas were detected in samples from all investigated habitats, suggesting a widespread distribution of this genus across many marine habitats (e.g., seawater, rocks, macroalgae, and marine animals). Three sample types were analyzed by RTQ-PCR to determine the relative abundance of Pseudoalteromonas ribosomal DNA (rDNA) compared to the total abundance of eubacterial rDNA. The rDNA fractions of Pseudoalteromonas compared to all Eubacteria were 1.55% on the green alga Ulva lactuca, 0.10% on the tunicate Ciona intestinalis, and 0.06% on the green alga Ulvaria fusca.
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antifouling activities expressed by marine surface associated Pseudoalteromonas species
FEMS Microbiology Ecology, 2002Co-Authors: Carola Holmstrom, Suhelen Egan, Ashley E Franks, Sophie Mccloy, Staffan KjellebergAbstract:Members of the marine bacterial genus Pseudoalteromonas have been found in association with living surfaces and are suggested to produce bioactive compounds against settlement of algal spores, invertebrate larvae, bacteria and fungi. To determine the extent by which these antifouling activities and the production of bioactive compounds are distributed amongst the members of the genus Pseudoalteromonas, 10 different Pseudoalteromonas species mostly derived from different host organisms were tested in a broad range of biofouling bioassays. These assays included the settlement of larvae of two ubiquitous invertebrates Hydroides elegans and Balanus amphitrite as well as the settlement of spores of the common fouling algae Ulva lactuca and Polysiphonia sp. The growth of bacteria and fungi, which are the initial fouling organisms on marine surfaces, was also assayed in the presence of each of the 10 Pseudoalteromonas species. It was found that most members of this genus produced a variety of bioactive compounds. The broadest range of inhibitory activities was expressed by Pseudoalteromonas tunicata which inhibited all target fouling organisms. Only two species, Pseudoalteromonas haloplanktis and Pseudoalteromonas nigrifaciens, displayed negligible activity in the bioassays. These were also the only two non-pigmented species tested in this study which indicates a correlation between production of bioactive compounds and expression of pigment. Three members, P. tunicata, Pseudoalteromonas citrea and Pseudoalteromonas rubra, were demonstrated to express autoinhibitory activity. It is suggested that most Pseudoalteromonas species are efficient producers of antifouling agents and that the production of inhibitory compounds by surface associated Pseudoalteromonas species may aid the host against colonisation of its surface.
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Pseudoalteromonas ulvae sp. nov., a bacterium with antifouling activities isolated from the surface of a marine alga.
International journal of systematic and evolutionary microbiology, 2001Co-Authors: Suhelen Egan, Carola Holmstrom, Staffan KjellebergAbstract:A dark-purple marine bacterium that inhibits the germination of marine algal spores and the settlement of invertebrate larvae has been characterized and assessed for taxonomic assignment. Two strains, designated UL12T and UL13, were isolated from the surface of the common marine alga Ulva lactuca. Based on 16S rDNA sequencing, UL12T and UL13 were found to show the highest similarity (97%) to members of the genus Pseudoalteromonas. DNA-DNA hybridization studies demonstrated less than 28% genomic DNA relatedness between these isolates and closely related Pseudoalteromonas species and greater than 65% homology between UL12T and UL13. The two isolates were found to display identical characteristics and are strict aerobes, motile by means of single polar flagella, exhibit non-fermentative metabolism and require sodium ions for growth. The isolates hydrolyse gelatin and can utilize citrate, maltose, mannose and glucose but not trehalose, sucrose, fructose, lactose or glycerol as sole carbon sources. The molecular evidence together with the phenotypic characteristics show that this bacterium constitutes a new species within the genus Pseudoalteromonas. The name Pseudoalteromonas ulvae sp. nov. is proposed for this bacterium and the type strain is UL12T (= UNSW 095600T = NCIMB 13762T).
Valery V Mikhailov - One of the best experts on this subject based on the ideXlab platform.
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Characterization of Pseudoalteromonas distincta-like sea-water isolates and description of Pseudoalteromonas aliena sp. nov.
International journal of systematic and evolutionary microbiology, 2004Co-Authors: Elena P. Ivanova, Natalia V Zhukova, Anatolii M Lysenko, Nataliya M Gorshkova, Valery V Mikhailov, Elena A Zelepuga, Nina G Prokof'eva, Dan V Nicolau, Richard ChristenAbstract:Seven melanogenic Pseudoalteromonas distincta-like strains, KMM 3562T, KMM 3536, KMM 3537, KMM 3538, KMM 3539, KMM 3615 and KMM 3629, which expressed tyrosinases were isolated from sea-water samples collected from different locations in Amursky Bay (Sea of Japan, Pacific Ocean) and characterized to clarify their taxonomic position. By 16S rRNA gene sequence analysis, the bacteria were shown to belong to the genus Pseudoalteromonas. The G + C content of the DNAs of the strains was 41-43 mol%. The level of DNA similarity among these strains was conspecific (92-97 %), indicating that they represented a single genospecies. However, DNA from the strains isolated from sea water showed only 63-65 % genetic relatedness with the DNA of the type strain P. distincta. The novel organisms grew mainly between 4 and 30 degrees C, were neutrophilic and slightly halophilic (four strains had a narrow range of growth between 3 and 6 % NaCl, w/v), were haemolytic and cytotoxic and were able to degrade starch, gelatin and Tween 80. The predominant fatty acids, including 16 : 0, 16 : 1omega7, 17 : 1omega7 and 18 : 1omega7, were typical of the genus Pseudolateromonas. The phylogenetic, genetic and physiological properties of the seven strains placed them within a novel species, Pseudoalteromonas aliena sp. nov., the type strain of which is SW19T (= KMM 3562T = LMG 22059T).
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assignment of alteromonas marinoglutinosa ncimb 1770 to Pseudoalteromonas mariniglutinosa sp nov nom rev comb nov
International Journal of Systematic and Evolutionary Microbiology, 2003Co-Authors: Lyudmila A Romanenko, Natalia V Zhukova, Valery V Mikhailov, A M Lysenko, Erko StackebrandtAbstract:The taxonomic position of the marine bacterium ‘Alteromonas marinoglutinosa’ NCIMB 1770 was investigated in a polyphasic study. Analysis of 16S rDNA sequence and DNA–DNA reassociation values confirmed the phylogenetic position of strain NCIMB 1770 within the genus Pseudoalteromonas as a separate species, distinct from all Pseudoalteromonas species with validly described names. On the basis of physiological and molecular properties, it is proposed that strain NCIMB 1770 is classified as Pseudoalteromonas mariniglutinosa sp. nov., nom. rev., comb. nov., with the type strain NCIMB 1770T (=KMM 3635T).
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Pseudoalteromonas agarivorans sp. nov., a novel marine agarolytic bacterium.
International journal of systematic and evolutionary microbiology, 2003Co-Authors: Lyudmila A Romanenko, Natalia V Zhukova, Valery V Mikhailov, Manfred Rohde, Anatoly M Lysenko, Erko StackebrandtAbstract:The phenotypic, genomic and phylogenetic characteristics of four aerobic, Gram-negative, non-fermentative, motile, non-pigmented, agarolytic Pseudoalteromonas-like bacteria, isolated from marine environments, have been investigated. These bacteria share DNA-DNA similarities above 86%. Comparative 16S rDNA sequence analysis of strain KMM 255T revealed its membership of the genus Pseudoalteromonas; it shares 99.9% sequence similarity with Pseudoalteromonas distincta, Pseudoalteromonas elyakovii, Pseudoalteromonas atlantica and Pseudoalteromonas espejiana. DNA-DNA reassociation levels obtained for strain KMM 255T and type strains of these four species and other Pseudoalteromonas species were below 45%. The marine isolates differed from known species of the genus by the fact that the cells are motile by means of a single flagellum or two to four polar unsheathed flagella and by an inability to utilize most organic compounds. On the basis of phenotypic, DNA-DNA hybridization and phylogenetic data, it is concluded that the isolates represent a novel species within the genus Pseudoalteromonas, for which the name Pseudoalteromonas agarivorans sp. nov. is proposed. The type strain is strain KMM 255T (= DSM 14585T).
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Pseudoalteromonas translucida sp. nov. and Pseudoalteromonas paragorgicola sp. nov., and emended description of the genus.
International Journal of Systematic and Evolutionary Microbiology, 2002Co-Authors: Elena P. Ivanova, Natalia V Zhukova, Anatolii M Lysenko, Nataliya M Gorshkova, Richard Christen, Tomoo Sawabe, Dan V Nicolau, Kenji Hayashi, Valery V MikhailovAbstract:On the basis of phenotypic and genotypic characteristics and analysis of 16S rRNA sequences, two novel species belonging to the genus Pseudoalteromonas are described. A pale-orange-pigmented strain, KMM 3548T, isolated from a sponge and a non-pigmented strain, KMM 520T, isolated from sea water are marine, gram-negative, aerobic, rod-shaped organisms. One of the strains, KMM 520T, had bipolar flagella. Both strains had the ability to degrade gelatin, DNA and Tween 80 but not chitin or agar. Strain KMM 520T decomposed elastin and grew at NaCl concentrations of 1-8%, while strain KMM 3548T grew at 1-6% NaCl. The temperature range for both strains was 4-30 degrees C. The DNA G+C contents were 46.3 (KMM 520T) and 41.1 mol% (KMM 3548T). The level of DNA relatedness between the two strains was 20%. DNA from strain KMM 520T showed 8-34% genetic relatedness and that of KMM 3548T showed 17-53% relatedness to the DNA of other type strains of the genus Pseudoalteromonas. 16S rRNA analysis indicated a clear affiliation of these novel bacteria with the genus Pseudoalteromonas. The type strains of the novel species are Pseudoalteromonas translucida sp. nov. KMM 520T (= LMG 19696T = ATCC BAA-3157T) and Pseudoalteromonas paragorgicola sp. nov. KMM 3548T (= LMG 19694T = ATCC BAA-322T).
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Pseudoalteromonas maricaloris sp. nov., isolated from an Australian sponge, and reclassification of [Pseudoalteromonas aurantia] NCIMB 2033 as Pseudoalteromonas flavipulchra sp. nov.
International journal of systematic and evolutionary microbiology, 2002Co-Authors: Elena P. Ivanova, Vassilii I. Svetashev, Anatolii M Lysenko, Nataliya M Gorshkova, Richard Christen, Tomoo Sawabe, Ludmila S Shevchenko, Masataka Satomi, Valery V MikhailovAbstract:A marine, gram-negative, aerobic bacterium that produced cytotoxic, lemon-yellow, chromopeptide pigments that inhibited the development of sea urchin eggs has been isolated from the Australian sponge Fascaplysinopsis reticulata Hentschel. The cells of the organism were rod-shaped with a single polar flagellum and they required NaCl for growth (0.5-10%) with optimum growth at 1-3% NaCl. The temperature for growth was 10-37 degrees C, with optimum growth at 25-30 degrees C. Growth occurred at pH values from 6.0 to 10.0, with optimum growth at pH 6.0-8.0. Major phospholipids were phosphatidylethanolamine, phosphatidylglycerol and lyso-phosphatidylethanolamine. Of 26 fatty acids with 11-19 carbon atoms that were detected, 16:1omega7, 16:0, 17:1omega8 and 18:1omega7 were predominant. The DNA G+C content was 38.9 mol%. All of these phenotypic and chemotaxonomic characters place the organism in the genus Pseudoalteromonas (Gauthier et al, 1995). These data are consistent with the phylogenetic analyses that confirmed that strain KMM 636T is a member of the Pseudoalteromonas cluster in the gamma-subclass of the Proteobacteria. DNA-DNA hybridization experiments revealed that the levels of relatedness between the DNA of the strain studied and DNAs of type strains of the species that clustered together (on the basis of 16S rDNA sequences) and [Pseudoalteromonas aurantia] NCIMB 2033 ranged from 19 to 35%, and that the DNA-DNA homology between [P. aurantia] NCIMB 2033 and other phylogenetically and/or phenotypically similar type strains ranged from 32 to 52%. According to the polyphasic evidence presented in this study, it is proposed that strain KMM 636T (= LMG 19692T = CIP 106859T) be classified as Pseudoalteromonas maricaloris sp. nov. and [P. aurantia] NCIMB 2033 be reclassified as Pseudoalteromonas flavipulchra NCIMB 2033T (= KMM 3630T = LMG 20361T) sp. nov.
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Marine Chitinolytic Pseudoalteromonas Represents an Untapped Reservoir of Bioactive Potential.
mSystems, 2019Co-Authors: Sara Skøtt Paulsen, Lone Gram, Mikael Lenz Strube, Pernille Kjersgaard Bech, Eva C. SonnenscheinAbstract:ABSTRACT Chitin is the most abundant polymer in the marine environment and a nutrient-rich surface for adhering marine bacteria. We have previously shown that chitin can induce the production of antibiotic compounds in Vibrionaceae, suggesting that the discovery of novel bioactive molecules from bacteria can be facilitated by mimicking their natural habitat. The purpose of this study was to determine the glycosyl hydrolase (GH) profiles of strains of the genus Pseudoalteromonas to enable selection of presumed growth substrates and explore possible links to secondary metabolism. Genomic analyses were conducted on 62 pigmented and 95 nonpigmented strains. Analysis of the total GH profiles and multidimensional scaling suggested that the degradation of chitin is a significant trait of pigmented strains, whereas nonpigmented strains seem to be driven toward the degradation of alga-derived carbohydrates. The genomes of all pigmented strains and 40 nonpigmented strains encoded at least one conserved chitin degradation cluster, and chitinolytic activity was phenotypically confirmed. Additionally, the genomes of all pigmented and a few nonpigmented strains encoded chitinases of the rare GH family 19. Pigmented strains devote up to 15% of their genome to secondary metabolism, while for nonpigmented species it was 3% at most. Thus, pigmented Pseudoalteromonas strains have a bioactive potential similar to that of well-known antibiotic producers of the Actinobacteria phylum. Growth on chitin did not measurably enhance the antibacterial activity of the strains; however, we demonstrated a remarkable co-occurrence of chitin degradation and the potential for secondary metabolite production in pigmented Pseudoalteromonas strains. This indicates that chitin and its colonizers of the Pseudoalteromonas genus represent a so far underexplored niche for novel enzymes and bioactive compounds. IMPORTANCE Infectious bacteria are developing and spreading resistance to conventional treatments at a rapid pace. To provide novel potent antimicrobials, we must develop new bioprospecting strategies. Here, we combined in silico and phenotypic approaches to explore the bioactive potential of the marine bacterial genus Pseudoalteromonas. We found that pigmented strains in particular represent an untapped resource of secondary metabolites and that they also harbor an elaborate chitinolytic machinery. Furthermore, our analysis showed that chitin is likely a preferred substrate for pigmented species, in contrast to nonpigmented species. Potentially, chitin could facilitate the production of new secondary metabolites in pigmented Pseudoalteromonas strains.
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Diversity and distribution of the bmp gene cluster and its Polybrominated products in the genus Pseudoalteromonas
Environmental microbiology, 2019Co-Authors: Julia Busch, Bradley S Moore, Lone Gram, Vinayak Agarwal, Michelle A. Schorn, Henrique Machado, Greg W. Rouse, Paul R. JensenAbstract:The production of pentabromopseudilin and related brominated compounds by Pseudoalteromonas spp. has recently been linked to the bmp biosynthetic gene cluster. This study explored the distribution and evolutionary history of this gene cluster in the genus Pseudoalteromonas. A phylogeny of the genus revealed numerous clades that do not contain type strains, suggesting considerable species level diversity has yet to be described. Comparative genomics revealed four distinct versions of the gene cluster distributed among 19 of the 101 Pseudoalteromonas genomes examined. These were largely localized to the least inclusive clades containing the Pseudoalteromonas luteoviolacea and Pseudoalteromonas phenolica type strains and show clear evidence of gene and gene cluster loss in certain lineages. Bmp gene phylogeny is largely congruent with the Pseudoalteromonas species phylogeny, suggesting vertical inheritance within the genus. However, the gene cluster is found in three different genomic environments suggesting either chromosomal rearrangement or multiple acquisition events. Bmp conservation within certain lineages suggests the encoded products are highly relevant to the ecology of these bacteria.
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Reclassification of Alteromonas fuliginea (Romanenko et al. 1995) as Pseudoalteromonas fuliginea comb. nov. and an emended description.
International journal of systematic and evolutionary microbiology, 2016Co-Authors: Henrique Machado, Nikolaj Grønnegaard Vynne, Gunna Christiansen, Lone GramAbstract:A new aerobic marine bacterium, strain S3431, was isolated from swab samples of an unidentified polychaete near Canal Concepcion, Chile. This strain was thought to represent a new taxon within the genus Pseudoalteromonas. Although DNA-DNA reassociation values showed less than 70 % genomic DNA relatedness to established Pseudoalteromonas type strains, it shared 78 % DNA-DNA relatedness with Alteromonas fuliginea DSM 15748 (=KMM 216) (Romanenko et al., 1994). A. fuliginea has later been considered a heterotypic synonym of Pseudoalteromonas citrea(Ivanova et al., 1998). Relatedness between strains S3431, A. fuliginea DSM 15748 and the type strain P. citrea LMG 12323T was therefore studied. Physiological traits and genomic information were shared at a high level by strains S3431 and DSM 15748, but not between these and P. citrea LMG 12323T. There was only approximately 20 % DNA-DNA relatedness between P. citrea LMG 12323T and strains S3431 and DSM 15748. Based on the available phylogenetic and phenotypic data, the reclassification of A. fuliginea DSM 15748 (Romanenko et al., 1995) → Pseudoalteromonas citrea(Ivanova et al., 1998) as Pseudoalteromonas fuligineacomb. nov. is proposed, and strain S3431 should be assigned to this new species. The name Pseudoalteromonas fuliginea is proposed with KMM 216T (=DSM 15748T=CIP 105339T) as the type strain.
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Pseudoalteromonas strains are potent immunomodulators owing to low-stimulatory LPS
Innate immunity, 2012Co-Authors: Kristina Maaetoft-udsen, Lone Gram, Nikolaj Grønnegaard Vynne, Peter M. H. Heegaard, Hanne FrøkiærAbstract:Many species of marine bacteria elicit a weak immune response. In this study, the aim was to assess the immunomodulatory properties of Gram-negative Pseudoalteromonas strains compared with other marine Gram-negative bacteria and to identify the molecular cause of the immunomodulation. Using murine bone-marrow derived dendritic cells (DCs), it was found that Pseudoalteromonas strains induced low cytokine production and modest up-regulation of surface markers CD40 and CD86 compared with other marine bacteria and Escherichia coli LPS. Two strains, Ps. luteoviolacea and Ps. ruthenica, were further investigated with respect to their immunomodulatory properties in DCs. Both inhibited IL-12 and increased IL-10 production induced by E. coli LPS. LPS isolated from the two Pseudoalteromonas strains had characteristic lipid A bands in SDS-PAGE. Stimulation of HEK293 TLR4/MD2 cells with the isolated LPS confirmed the involvement of LPS and TLR4 and established Pseudoalteromonas LPS as TLR4 antagonists. The isolated LPS was active in the endotoxin limulus amoebocyte lysate assay and capable of inducing increased endocytosis in DCs. This study highlights that antagonistic LPS from Pseudoalteromonas strains has potential as a new candidate of therapeutic agent capable of modulating immune responses.
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marine bacteria from danish coastal waters show antifouling activity against the marine fouling bacterium Pseudoalteromonas sp strain s91 and zoospores of the green alga ulva australis independent of bacteriocidal activity
Applied and Environmental Microbiology, 2011Co-Authors: Staffan Kjelleberg, Nete Bernbom, Tilmann Harder, Lone GramAbstract:The aims of this study were to determine if marine bacteria from Danish coastal waters produce antifouling compounds and if antifouling bacteria could be ascribed to specific niches or seasons. We further assess if antibacterial effect is a good proxy for antifouling activity. We isolated 110 bacteria with anti-Vibrio activity from different sample types and locations during a 1-year sampling from Danish coastal waters. The strains were identified as Pseudoalteromonas, Phaeobacter, and Vibrionaceae based on phenotypic tests and partial 16S rRNA gene sequence similarity. The numbers of bioactive bacteria were significantly higher in warmer than in colder months. While some species were isolated at all sampling locations, others were niche specific. We repeatedly isolated Phaeobacter gallaeciensis at surfaces from one site and Pseudoalteromonas tunicata at two others. Twenty-two strains, representing the major taxonomic groups, different seasons, and isolation strategies, were tested for antiadhesive effect against the marine biofilm-forming bacterium Pseudoalteromonas sp. strain S91 and zoospores of the green alga Ulva australis. The antiadhesive effects were assessed by quantifying the number of strain S91 or Ulva spores attaching to a preformed biofilm of each of the 22 strains. The strongest antifouling activity was found in Pseudoalteromonas strains. Biofilms of Pseudoalteromonas piscicida, Pseudoalteromonas tunicata, and Pseudoalteromonas ulvae prevented Pseudoalteromonas S91 from attaching to steel surfaces. P. piscicida killed S91 bacteria in the suspension cultures, whereas P. tunicata and P. ulvae did not; however, they did prevent adhesion by nonbactericidal mechanism(s). Seven Pseudoalteromonas species, including P. piscicida and P. tunicata, reduced the number of settling Ulva zoospores to less than 10% of the number settling on control surfaces. The antifouling alpP gene was detected only in P. tunicata strains (with purple and yellow pigmentation), so other compounds/mechanisms must be present in the other Pseudoalteromonas strains with antifouling activity.
