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Sample records for marine antagonistic bacterium

  1. Isolation, identification, and optimal cultivation of a marine bacterium antagonistic to Magnaporthe grisea.

    PubMed

    Zhang, W J; Guo, P; Liu, M; Yang, B L; Wang, J H; Jiang, J

    2016-01-01

    In this paper, a plate confrontation method was used to isolate bacteria antagonistic to the rice blast fungus Magnaporthe grisea from samples collected from China's Dalian Bay. The antagonist strain LM-031 was obtained. We studied this strain's morphological, physiological and biochemical characteristics and analyzed its 16S rDNA sequence. We compared the effects of different culture conditions (type of media, carbon and nitrogen source, incubation temperature and time, and initial pH value) on the inhibitory effect against M. grisea. Strain LM-031 was preliminarily identified as Bacillus pumilus and was found to strongly inhibit M. grisea, especially when grown on BPY medium at an initial pH 7 for 72 h at 30°C. The optimum carbon and nitrogen sources for growth were lactose and peptone, respectively. The most suitable carbon and nitrogen sources for production of active substances were glucose and NH4Cl, respectively. Our results show that development and utilization of B. pumilus LM-031 has great potential for biological control of M. grisea. PMID:27323038

  2. Chitoporin from the Marine Bacterium Vibrio harveyi

    PubMed Central

    Chumjan, Watcharin; Winterhalter, Mathias; Schulte, Albert; Benz, Roland; Suginta, Wipa

    2015-01-01

    VhChiP is a sugar-specific porin present in the outer membrane of the marine bacterium Vibrio harveyi. VhChiP is responsible for the uptake of chitin oligosaccharides, with particular selectivity for chitohexaose. In this study, we employed electrophysiological and biochemical approaches to demonstrate that Trp136, located at the mouth of the VhChiP pore, plays an essential role in controlling the channel's ion conductivity, chitin affinity, and permeability. Kinetic analysis of sugar translocation obtained from single channel recordings indicated that the Trp136 mutations W136A, W136D, W136R, and W136F considerably reduce the binding affinity of the protein channel for its best substrate, chitohexaose. Liposome swelling assays confirmed that the Trp136 mutations decreased the rate of bulk chitohexaose permeation through the VhChiP channel. Notably, all of the mutants show increases in the off-rate for chitohexaose of up to 20-fold compared with that of the native channel. Furthermore, the cation/anion permeability ratio Pc/Pa is decreased in the W136R mutant and increased in the W136D mutant. This demonstrates that the negatively charged surface at the interior of the protein lumen preferentially attracts cationic species, leading to the cation selectivity of this trimeric channel. PMID:26082491

  3. Pangenome Evolution in the Marine Bacterium Alteromonas

    PubMed Central

    López-Pérez, Mario; Rodriguez-Valera, Francisco

    2016-01-01

    We have examined a collection of the free-living marine bacterium Alteromonas genomes with cores diverging in average nucleotide identities ranging from 99.98% to 73.35%, i.e., from microbes that can be considered members of a natural clone (like in a clinical epidemiological outbreak) to borderline genus level. The genomes were largely syntenic allowing a precise delimitation of the core and flexible regions in each. The core was 1.4 Mb (ca. 30% of the typical strain genome size). Recombination rates along the core were high among strains belonging to the same species (37.7–83.7% of all nucleotide polymorphisms) but they decreased sharply between species (18.9–5.1%). Regarding the flexible genome, its main expansion occurred within the boundaries of the species, i.e., strains of the same species already have a large and diverse flexible genome. Flexible regions occupy mostly fixed genomic locations. Four large genomic islands are involved in the synthesis of strain-specific glycosydic receptors that we have called glycotypes. These genomic regions are exchanged by homologous recombination within and between species and there is evidence for their import from distant taxonomic units (other genera within the family). In addition, several hotspots for integration of gene cassettes by illegitimate recombination are distributed throughout the genome. They code for features that give each clone specific properties to interact with their ecological niche and must flow fast throughout the whole genus as they are found, with nearly identical sequences, in different species. Models for the generation of this genomic diversity involving phage predation are discussed. PMID:27189983

  4. Pangenome Evolution in the Marine Bacterium Alteromonas.

    PubMed

    López-Pérez, Mario; Rodriguez-Valera, Francisco

    2016-01-01

    We have examined a collection of the free-living marine bacterium Alteromonas genomes with cores diverging in average nucleotide identities ranging from 99.98% to 73.35%, i.e., from microbes that can be considered members of a natural clone (like in a clinical epidemiological outbreak) to borderline genus level. The genomes were largely syntenic allowing a precise delimitation of the core and flexible regions in each. The core was 1.4 Mb (ca. 30% of the typical strain genome size). Recombination rates along the core were high among strains belonging to the same species (37.7-83.7% of all nucleotide polymorphisms) but they decreased sharply between species (18.9-5.1%). Regarding the flexible genome, its main expansion occurred within the boundaries of the species, i.e., strains of the same species already have a large and diverse flexible genome. Flexible regions occupy mostly fixed genomic locations. Four large genomic islands are involved in the synthesis of strain-specific glycosydic receptors that we have called glycotypes. These genomic regions are exchanged by homologous recombination within and between species and there is evidence for their import from distant taxonomic units (other genera within the family). In addition, several hotspots for integration of gene cassettes by illegitimate recombination are distributed throughout the genome. They code for features that give each clone specific properties to interact with their ecological niche and must flow fast throughout the whole genus as they are found, with nearly identical sequences, in different species. Models for the generation of this genomic diversity involving phage predation are discussed. PMID:27189983

  5. Microcalorimetric Measurements of Glucose Metabolism by Marine Bacterium Vibrio alginolyticus

    PubMed Central

    Gordon, Andrew S.; Millero, Frank J.; Gerchakov, Sol M.

    1982-01-01

    Microcalorimetric measurements of heat production from glucose by Vibrio alginolyticus were made to assess the viability of calorimetry as a technique for studying the metabolism of marine bacteria at organic nutrient concentrations found in marine waters. The results show that the metabolism of glucose by this bacterium can be measured by calorimetry at submicromolar concentrations. A linear correlation between glucose concentration and total heat production was observed over a concentration range of 8 mM to 0.35 μM. It is suggested that these data indicate a constant efficiency of metabolism for this bacterium over the wide range of glucose concentrations studied. PMID:16346131

  6. Isolation from the Sorghum bicolor Mycorrhizosphere of a Bacterium Compatible with Arbuscular Mycorrhiza Development and Antagonistic towards Soilborne Fungal Pathogens

    PubMed Central

    Budi, S. W.; van Tuinen, D.; Martinotti, G.; Gianinazzi, S.

    1999-01-01

    A gram-positive bacterium with antagonistic activity towards soilborne fungal pathogens has been isolated from the mycorrhizosphere of Sorghum bicolor inoculated with Glomus mosseae. It has been identified as Paenibacillus sp. strain B2 based on its analytical profile index and on 16S ribosomal DNA analysis. Besides having antagonistic activity, this bacterium stimulates mycorrhization. PMID:10543835

  7. Antagonistic interactions among marine bacteria impede the proliferation of Vibrio cholerae.

    PubMed

    Long, Richard A; Rowley, David C; Zamora, Eric; Liu, Jiayuan; Bartlett, Douglas H; Azam, Farooq

    2005-12-01

    Changes in global climate have raised concerns about the emergence and resurgence of infectious diseases. Vibrio cholerae is a reemerging pathogen that proliferates and is transported on marine particles. Patterns of cholera outbreaks correlate with sea surface temperature increases, but the underlying mechanisms for rapid proliferation of V. cholerae during ocean warming events have yet to be fully elucidated. In this study, we tested the hypothesis that autochthonous marine bacteria impede the spread of V. cholerae in the marine environment. It was found that some marine bacteria are capable of inhibiting the growth of V. cholerae on surfaces and that bacterial isolates derived from pelagic particles show a greater frequency of V. cholerae inhibition than free-living bacteria. Vibrio cholerae was less susceptible to antagonism at higher temperatures, such as those measured during El Niño-Southern Oscilliation and monsoonal events. Using a model system employing green fluorescent protein-labeled bacteria, we found that marine bacteria can directly inhibit V. cholerae colonization of particles. The mechanism of inhibition in our model system was linked to the biosynthesis of andrimid, an antibacterial agent. Antibiotic production by the model antagonistic strain decreased at higher temperatures, thereby explaining the increased competitiveness of V. cholerae under warmer conditions. These findings suggest that bacterium-bacterium antagonism is a contributing mechanism in regulating the proliferation of V. cholerae on marine particles.

  8. Antagonistic Coevolution of Marine Planktonic Viruses and Their Hosts

    NASA Astrophysics Data System (ADS)

    Martiny, Jennifer B. H.; Riemann, Lasse; Marston, Marcia F.; Middelboe, Mathias

    2014-01-01

    The potential for antagonistic coevolution between marine viruses and their (primarily bacterial) hosts is well documented, but our understanding of the consequences of this rapid evolution is in its infancy. Acquisition of resistance against co-occurring viruses and the subsequent evolution of virus host range in response have implications for bacterial mortality rates as well as for community composition and diversity. Drawing on examples from a range of environments, we consider the potential dynamics, underlying genetic mechanisms and fitness costs, and ecological impacts of virus-host coevolution in marine waters. Given that much of our knowledge is derived from laboratory experiments, we also discuss potential challenges and approaches in scaling up to diverse, complex networks of virus-host interactions. Finally, we note that a variety of novel approaches for characterizing virus-host interactions offer new hope for a mechanistic understanding of antagonistic coevolution in marine plankton.

  9. Energy coupling to K+ transport in a marine bacterium.

    PubMed

    Sedgwick, E G; MacLeod, R A

    1980-10-01

    Cells of the marine bacterium Alteromonas haloplanktis 214 ATCC 19855 (previously referred to as marine pseudomonad B-16) were depleted of K+ by washing with 0.1 M MgSO4. Washing with 0.05 M MgSO4 lowered the Vmax for K+ transport compared with washing with 0.1 M with 0.05 but did not change the Km, while washing with lower concentrations of MgSO4 caused loss of ultraviolet-absorbing material from the cells. K+ uptake was a strictly aerobic process and was accompanied by proton release. When an anaerobic suspension of cells was added to incubation mixtures containing increasing amounts of O2, intracellular ATP concentrations increased as the O2 concentration increased and reached near maximum values before K+ transport began. The O2 concentration initiating K+ transport caused transport to proceed at its maximum rate. For these experiments A. haloplanktis was depleted of ATP by incubating under anaerobic conditions. Incubating with either N,N'-dicyclohexyl carbodiimide (DCCD) or arsenate failed to deplete intact cells of ATP or prevent K+ transport. The inhibitory activity of DCCD for ATPase in membrane preparations was higher at 5 mM than at other MgSO4 concentrations and increased with time. Cyanide and the uncoupling agents tetrachloro-salicylanide (TCS) and carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP) prevented K+ uptake while TSC and FCCP though not cyanide caused K+ to be released from K+-containing cells. It is concluded that the driving force for K+ transport in these cells is likely to be the membrane potential and that K+ transport may be gated.

  10. Idiomarina maris sp. nov., a marine bacterium isolated from sediment.

    PubMed

    Zhang, Yan-Jiao; Zhang, Xi-Ying; Zhao, Hui-Lin; Zhou, Ming-Yang; Li, Hui-Juan; Gao, Zhao-Ming; Chen, Xiu-Lan; Dang, Hong-Yue; Zhang, Yu-Zhong

    2012-02-01

    A protease-producing marine bacterium, designated CF12-14(T), was isolated from sediment of the South China Sea. Phylogenetic analysis of the 16S rRNA gene sequence revealed that strain CF12-14(T) formed a separate lineage within the genus Idiomarina (Gammaproteobacteria). The isolate showed the highest 16S rRNA gene sequence similarity with Idiomarina salinarum ISL-52(T) (94.7 %), Idiomarina seosinensis CL-SP19(T) (94.6 %) and other members of the genus Idiomarina (91.9-94.6 %). Cells were gram-negative, aerobic, flagellated, straight or slightly curved, and often formed buds and prosthecae. Strain CF12-14(T) grew at 4-42 °C (optimum 30-35 °C) and with 0.1-15 % (w/v) NaCl (optimum 2-3 %). The isolate reduced nitrate to nitrite and hydrolysed DNA, but did not produce acids from sugars. The predominant cellular fatty acids were iso-C(15 : 0) (27.4 %), iso-C(17 : 0) (16.0 %) and iso-C(17 : 1)ω9c (15.8 %). The major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol. The major respiratory quinone was ubiquinone 8. The DNA G+C content was 50.4 mol%. The phylogenetic, phenotypic and chemotaxonomic data supported the conclusion that CF12-14(T) represents a novel species of the genus Idiomarina, for which the name Idiomarina maris sp. nov. is proposed. The type strain is CF12-14(T) ( = CCTCC AB 208166(T) = KACC 13974(T)).

  11. Bacillus amyloliquefaciens G1: A Potential Antagonistic Bacterium against Eel-Pathogenic Aeromonas hydrophila

    PubMed Central

    Cao, Haipeng; He, Shan; Wei, Ruopeng; Diong, Marek; Lu, Liqun

    2011-01-01

    Recent studies have revealed that the use of probiotics is an alternative to control marine aeromonas. However, few probiotics are available against Aeromonas hydrophila infections in eels. In the present study, a potential antagonistic strain G1 against the eel-pathogenic A. hydrophila was isolated from sediment underlying brackish water. Its extracellular products with antibacterial activities were shown to be stable under wide range of pH, temperature, and proteinase K. It was initially identified as Bacillus amyloliquefaciens using API identification kits and confirmed to be B. amyloliquefaciens strain (GenBank accession number DQ422953) by phylogenetic analysis. In addition, it was shown to be safe for mammalians, had a wide anti-A. hydrophila spectrum, and exhibited significant effects on inhibiting the growth of the eel-pathogenic A. hydrophila both in vitro and in vivo. To the best of our knowledge, this is the first report on a promising antagonistic Bacillus amyloliquefaciens strain from brackish water sediment against eel-pathogenic A. hydrophila. PMID:21754944

  12. Exploring antagonistic metabolites of established biocontrol agent of marine origin.

    PubMed

    Rane, Makarand Ramesh; Sarode, Prashant Diwakar; Chaudhari, Bhushan Liladhar; Chincholkar, Sudhir Bhaskarrao

    2008-12-01

    Biocontrol ability of Pseudomonas aeruginosa ID 4365, a biocontrol agent of groundnut phytopathogens from marine origin, was previously attributed to the production of pyoverdin type of siderophores. However, pyoverdin-rich supernatants of this organism showed better antifungal activity compared to equivalent amount of purified pyoverdin indicating presence of undetected metabolite(s) in pyoverdin rich supernatants. On the basis of observation that antagonistic activity was iron-dependent and iron-independent, an attempt was made to detect the presence of additional metabolites. In addition to pyoverdin, strain produced additional siderophores, viz. pyochelin and salicylic acid. Two broad spectrum antifungal compounds, viz. pyocyanin and phenazine-1-carboxylic acid, were detected, characterized, and activity against phytopathogens was demonstrated. Iron- and phosphate-dependent co-production of siderophores and phenazines was confirmed. Strain showed additional features like production of hydrogen cyanide, indol-3-acetic acid, and phosphate solubilization. PMID:18626581

  13. Role of prodigiosin and chitinases in antagonistic activity of the bacterium Serratia marcescens against the fungus Didymella applanata.

    PubMed

    Duzhak, A B; Panfilova, Z I; Duzhak, T G; Vasyunina, E A; Shternshis, M V

    2012-08-01

    The molecular features of antagonism of the bacterium Serratia marcescens against the plant pathogenic fungus Didymella applanata have been studied. The chitinases and the red pigment prodigiosin (PG) of S. marcescens were isolated and characterized. Specific antifungal activity of the purified PG and chitinases against D. applanata was tested in vitro. The antagonistic properties of several S. marcescens strains exhibiting different levels of PG and chitinase production were analyzed in vitro with regard to D. applanata. It was found that the ability of S. marcescens to suppress the vital functions of D. applanata depends mainly on the level of PG production, whereas chitinase production does not provide the bacterium with any competitive advantage over the fungus.

  14. PSEUDOMONAS NATRIEGENS, A MARINE BACTERIUM WITH A GENERATION TIME OF LESS THAN 10 MINUTES

    PubMed Central

    Eagon, R. G.

    1962-01-01

    Eagon, R. G. (University of Georgia, Athens). Pseudomonas natriegens, a marine bacterium with a generation time of less than 10 minutes. J. Bacteriol. 83:736–737. 1962.—Pseudomonas natriegens, a marine microorganism, was demonstrated to have a generation time of 9.8 min. This is the shortest generation time reported to date. Optimal growth occurred at 37 C in brain heart infusion broth supplemented with 1.5% sea salt. PMID:13888946

  15. Draft Genome Sequence of the Novel Agar-Digesting Marine Bacterium HQM9▿

    PubMed Central

    Du, Zongjun; Zhang, Zhewen; Miao, Tingting; Wu, Jiayan; Lü, Guoqiang; Yu, Jun; Xiao, Jingfa; Chen, Guanjun

    2011-01-01

    Strain HQM9, an aerobic, rod-shaped marine bacterium from red algae, can produce agarases and liquefy solid plating media efficiently when agar is used as a coagulant. Here we report the draft genome sequence and the initial findings from a preliminary analysis of strain HQM9, which should be a novel species of Flavobacteriaceae. PMID:21725015

  16. Cold adaptation in the marine bacterium, Sphingopyxis alaskensis, assessed using quantitative proteomics.

    PubMed

    Ting, Lily; Williams, Timothy J; Cowley, Mark J; Lauro, Federico M; Guilhaus, Michael; Raftery, Mark J; Cavicchioli, Ricardo

    2010-10-01

    The cold marine environment constitutes a large proportion of the Earth's biosphere. Sphingopyxis alaskensis was isolated as a numerically abundant bacterium from several cold marine locations, and has been extensively studied as a model marine bacterium. Recently, a metabolic labelling platform was developed to comprehensively identify and quantify proteins from S. alaskensis. The approach incorporated data normalization and statistical validation for the purpose of generating highly confident quantitative proteomics data. Using this approach, we determined quantitative differences between cells grown at 10°C (low temperature) and 30°C (high temperature). Cold adaptation was linked to specific aspects of gene expression: a dedicated protein-folding system using GroESL, DnaK, DnaJ, GrpE, SecB, ClpB and PPIase; polyhydroxyalkanoate-associated storage materials; a link between enzymes in fatty acid metabolism and energy generation; de novo synthesis of polyunsaturated fatty acids in the membrane and cell wall; inorganic phosphate ion transport by a phosphate import PstB homologue; TonB-dependent receptor and bacterioferritin in iron homeostasis; histidine, tryptophan and proline amino acid metabolism; and a large number of proteins without annotated functions. This study provides a new level of understanding on how important marine bacteria can adapt to compete effectively in cold marine environments. This study is also a benchmark for comparative proteomic analyses with other important marine bacteria and other cold-adapted organisms. PMID:20482592

  17. Cadherin Domains in the Polysaccharide-Degrading Marine Bacterium Saccharophagus degradans 2-40 Are Carbohydrate-Binding Modules▿

    PubMed Central

    Fraiberg, Milana; Borovok, Ilya; Bayer, Edward A.; Weiner, Ronald M.; Lamed, Raphael

    2011-01-01

    The complex polysaccharide-degrading marine bacterium Saccharophagus degradans strain 2-40 produces putative proteins that contain numerous cadherin and cadherin-like domains involved in intercellular contact interactions. The current study reveals that both domain types exhibit reversible calcium-dependent binding to different complex polysaccharides which serve as growth substrates for the bacterium. PMID:21036994

  18. Complete Genome Sequence of Pseudomonas brassicacearum LBUM300, a Disease-Suppressive Bacterium with Antagonistic Activity toward Fungal, Oomycete, and Bacterial Plant Pathogens

    PubMed Central

    Novinscak, Amy; Gadkar, Vijay J.; Joly, David L.

    2016-01-01

    Pseudomonas brassicacearum LBUM300, a plant rhizosphere-inhabiting bacterium, produces 2,4-diacetylphloroglucinol and hydrogen cyanide and has shown antagonistic activity against the plant pathogens Verticillium dahliae, Phytophthora cactorum, and Clavibacter michiganensis subsp. michiganensis. Here, we report the complete genome sequence of P. brassicacearum LBUM300. PMID:26823582

  19. Development of a gene cloning system for the hydrogen-producing marine photosynthetic bacterium Rhodopseudomonas sp

    SciTech Connect

    Matsunaga, T.; Matsunaga, N.; Tsubaki, K.; Tanaka, T.

    1986-10-01

    Seventy-six strains of marine photosynthetic bacteria were analyzed by agarose gel electrophoresis for plasmid DNA content. Among these strains, 12 carried two to four different plasmids with sizes ranging from 3.1 to 11.0 megadaltons. The marine photosynthetic bacterium Rhodopseudomonas sp. NKPB002106 had two plasmids, pRD06S and pRD06L. The smaller plasmid, pRD06S, had a molecular weight of 3.8 megadaltons and was cut at a single site by restriction endonucleases SalI, SmaI, PstI, XhoI, and BglII. Moreover, the marine photosynthetic bacterium Rhodopseudomonas sp. NKPB002106 containing plasmid pRD06 had a satisfactory growth rate (doubling time, 7.5 h), a hydrogen-producing rate of 0.96 ..mu..mol/mg (dry weight) of cells per h, and nitrogen fixation capability. Plasmid pRD06S, however, had neither drug resistance nor heavy-metal resistance, and its copy number was less than 10. Therefore, a recombinant plasmid consisting of pRD06S and Escherichia coli cloning vector pUC13 was constructed and cloned in E. coli. The recombinant plasmid was transformed into Rhodopseudomonas sp. NKPB002106. As a result, Rhodopseudomonas sp. NKPB002106 developed ampicillin resistance. Thus, a shuttle vector for gene transfer was constructed for marine photosynthetic bacteria.

  20. Development of a gene cloning system for the hydrogen-producing marine photosynthetic bacterium Rhodopseudomonas sp.

    PubMed Central

    Matsunaga, T; Matsunaga, N; Tsubaki, K; Tanaka, T

    1986-01-01

    Seventy-six strains of marine photosynthetic bacteria were analyzed by agarose gel electrophoresis for plasmid DNA content. Among these strains, 12 carried two to four different plasmids with sizes ranging from 3.1 to 11.0 megadaltons. The marine photosynthetic bacterium Rhodopseudomonas sp. NKPB002106 had two plasmids, pRD06S and pRD06L. The smaller plasmid, pRD06S, had a molecular weight of 3.8 megadaltons and was cut at a single site by restriction endonucleases SalI, SmaI, PstI, XhoI, and BglII. Moreover, the marine photosynthetic bacterium Rhodopseudomonas sp. NKPB002106 containing plasmid pRD06 had a satisfactory growth rate (doubling time, 7.5 h), a hydrogen-producing rate of 0.96 mumol/mg (dry weight) of cells per h, and nitrogen fixation capability. Plasmid pRD06S, however, had neither drug resistance nor heavy-metal resistance, and its copy number was less than 10. Therefore, a recombinant plasmid consisting of pRD06S and Escherichia coli cloning vector pUC13 was constructed and cloned in E. coli. The recombinant plasmid was transformed into Rhodopseudomonas sp. NKPB002106. As a result, Rhodopseudomonas sp. NKPB002106 developed ampicillin resistance. Thus, a shuttle vector for gene transfer was constructed for marine photosynthetic bacteria. PMID:3020006

  1. Biomass yield efficiency of the marine anammox bacterium, "Candidatus Scalindua sp.," is affected by salinity.

    PubMed

    Awata, Takanori; Kindaichi, Tomonori; Ozaki, Noriatsu; Ohashi, Akiyoshi

    2015-01-01

    The growth rate and biomass yield efficiency of anaerobic ammonium oxidation (anammox) bacteria are markedly lower than those of most other autotrophic bacteria. Among the anammox bacterial genera, the growth rate and biomass yield of the marine anammox bacterium "Candidatus Scalindua sp." is still lower than those of other anammox bacteria enriched from freshwater environments. The activity and growth of marine anammox bacteria are generally considered to be affected by the presence of salinity and organic compounds. Therefore, in the present study, the effects of salinity and volatile fatty acids (VFAs) on the anammox activity, inorganic carbon uptake, and biomass yield efficiency of "Ca. Scalindua sp." enriched from the marine sediments of Hiroshima Bay, Japan, were investigated in batch experiments. Differences in VFA concentrations (0-10 mM) were observed under varying salinities (0.5%-4%). Anammox activity was high at 0.5%-3.5% salinity, but was 30% lower at 4% salinity. In addition, carbon uptake was higher at 1.5%-3.5% salinity. The results of the present study clearly demonstrated that the biomass yield efficiency of the marine anammox bacterium "Ca. Scalindua sp." was significantly affected by salinity. On the other hand, the presence of VFAs up to 10 mM did not affect anammox activity, carbon uptake, or biomass yield efficiency.

  2. Enzymatic properties of chitinase-producing antagonistic bacterium Paenibacillus chitinolyticus with various substrates.

    PubMed

    Song, Yong-Su; Seo, Dong-Jun; Ju, Wan-Taek; Lee, Yong-Seong; Jung, Woo-Jin

    2015-12-01

    Various chitin substrates were used to investigate the properties of enzymes produced from the chitinase-producing bacterium Paenibacillus chitinolyticus MP-306 against phytopathogens. The MP-306 bacterium was incubated in nine culture media [crab shell powder chitin (CRS), chitin-protein complex powder (CPC), carboxymethyl-chitin powder (CMC), yeast extract only (YE), LB (Trypton, NaCl, and yeast extract), GT (Trypton, NaCl, and glucose), crab shell colloidal chitin (CSC), squid pen powder chitin (SPC), and cicada slough powder chitin (CSP)] at 30 °C for 3 days. Chitinase isozymes in CPC medium were expressed strongly as CN1, CN2, CN3, CN4, CN5, and CN6 bands on native-PAGE gels. Chitinase isozymes in CPC and CMC medium were expressed as 13 bands (CS1-CS13) on SDS-PAGE gels. Chitinase isozymes were expressed strongly on SDS-PAGE gels as two bands (CS6 and CS8) on YE and LB medium and 13 bands (CS1-CS13) on SPC medium. In crude enzyme, chitinase isozymes at pH 7 and pH 9 in chitin media appeared strongly on SDS-PAGE gels. Partial purified enzyme indicated high stability of enzyme activity at various temperatures and pHs in chitin medium, while these enzymes indicated low activity staining of enzyme on electrophoresis gels at various temperatures and pHs condition of chitin medium.

  3. The structure of ferricytochrome c552 from the psychrophilic marine bacterium Colwellia psychrerythraea 34H

    PubMed Central

    Harvilla, Paul B.; Wolcott, Holly N.

    2014-01-01

    Approximately 40% of all proteins are metalloproteins, and approximately 80% of Earth’s ecosystems are at temperatures ≤ 5 °C, including 90% of the global ocean. Thus, an essential aspect of marine metallobiochemistry is an understanding of the structure, dynamics, and mechanisms of cold adaptation of metalloproteins from marine microorganisms. Here, the molecular structure of the electron-transfer protein cytochrome c552 from the psychrophilic marine bacterium Colwellia psychrerythraea 34H has been determined by X-ray crystallography (PDB: 4O1W). The structure is highly superimposable with that of the homologous cytochrome from the mesophile Marinobacter hydrocarbonoclasticus. Based on structural analysis and comparison of psychrophilic, psychrotolerant, and mesophilic sequences, a methionine-based ligand-substitution mechanism for psychrophilic protein stabilization is proposed. PMID:24727932

  4. Isolation and biological characteristics of aerobic marine magnetotactic bacterium YSC-1

    NASA Astrophysics Data System (ADS)

    Gao, Jun; Pan, Hongmiao; Yue, Haidong; Song, Tao; Zhao, Yong; Chen, Guanjun; Wu, Longfei; Xiao, Tian

    2006-12-01

    Magnetotactic bacteria have become a hot spot of research in microbiology attracting intensive interest of researchers in multiple disciplinary fields. However, the studies were limited in few fastidious bacteria. The objective of this study aims at isolating new marine magnetic bacteria and better comprehension of magnetotactic bacteria. In this study, an aerobic magnetotactic bacterium YSC-1 was isolated from sediments in the Yellow Sea Cold Water Mass (YSCWM). In TEM, magnetic cells have one or several circular magnetosomes in diameter of 100nm, and consist of Fe and Co shown on energy dispersive X-ray spectrum. The biological and physiological characteristics of this bacterium were also described. The colour of YSC-1 colony is white in small rod. The gram stain is negative. Results showed that Strain YSC-1 differs from microaerophile magnetotactic bacteria MS-1 and WD-1 in biology.

  5. Quorum-sensing effects in the antagonistic rhizosphere bacterium Serratia plymuthica HRO-C48.

    PubMed

    Müller, Henry; Westendorf, Christian; Leitner, Erich; Chernin, Leonid; Riedel, Kathrin; Schmidt, Silvia; Eberl, Leo; Berg, Gabriele

    2009-03-01

    The rhizosphere-associated bacterium Serratia plymuthica HRO-C48 is not only able to suppress symptoms caused by soil-borne pathogens but is also able to stimulate growth of plants. Detailed knowledge about the underlying mechanisms and regulation are crucial for the application in biocontrol strategies. To analyse the influence of N-acyl homoserine lactone (AHL)-mediated communication on the biocontrol activity, the AHL-degrading lactonase AiiA was heterologously expressed in the strain, resulting in abolished AHL production. The comparative analysis of the wild type and AHL negative mutants led to the identification of new AHL-regulated phenotypes. In the pathosystem Verticillium dahliae-oilseed rape, the essential role of AHL-mediated signaling for disease suppression was demonstrated. In vitro, the regulatory function of AHLs in the synthesis of the plant growth hormone indole-3-acetic acid is shown for the first time. Additionally, swimming motility was found to be negatively AHL regulated. In contrast, production of extracellular hydrolytic enzymes is shown to be positively AHL-regulated. HRO-C48 emits a broad spectrum of volatile organic compounds that are involved in antifungal activity and, interestingly, whose relative abundances are influenced by quorum sensing (QS). This study shows that QS is crucial for biocontrol activity of S. plymuthica and discusses the impact for the application of the strain as a biocontrol agent. PMID:19220861

  6. Antagonistic action of the bacterium Bacillus licheniformis M-4 toward the amoeba Naegleria fowleri.

    PubMed

    Cordovilla, P; Valdivia, E; Gonzalez-Segura, A; Galvez, A; Martinez-Bueno, M; Maqueda, M

    1993-01-01

    Free-living amoebae belonging to the species Naegleria fowleri are known to be the etiological agents for a form of fulminant meningoencephalitis that is generally fatal (primary amoebic meningoencephalitis). In a broad bacterial screening from soil and water we have isolated three strains (M-4, D-13 and A-12) belonging to the species Bacillus licheniformis that have remarkable amoebicidal activity against Naegleria sp. and also against different Gram-positive and Gram-negative bacteria. Physical-chemical characteristics, partial purification and biological activities of a substance produced by the M-4 strain have been investigated. This substance (m-4) is stable at high temperature (up to 100 degrees C) and extremes of pH (2.5-9.5) and also at -20 degrees C for months. Its production is greatly influenced by oxygenation of the cultures and is probably related to the sporulation process of the bacterium. Scanning electron microscope observations reveal that amoebae are lysed after a few minutes contact with m-4.

  7. An Updated genome annotation for the model marine bacterium Ruegeria pomeroyi DSS-3

    PubMed Central

    2014-01-01

    When the genome of Ruegeria pomeroyi DSS-3 was published in 2004, it represented the first sequence from a heterotrophic marine bacterium. Over the last ten years, the strain has become a valuable model for understanding the cycling of sulfur and carbon in the ocean. To ensure that this genome remains useful, we have updated 69 genes to incorporate functional annotations based on new experimental data, and improved the identification of 120 protein-coding regions based on proteomic and transcriptomic data. We review the progress made in understanding the biology of R. pomeroyi DSS-3 and list the changes made to the genome. PMID:25780504

  8. An Updated genome annotation for the model marine bacterium Ruegeria pomeroyi DSS-3.

    PubMed

    Rivers, Adam R; Smith, Christa B; Moran, Mary Ann

    2014-01-01

    When the genome of Ruegeria pomeroyi DSS-3 was published in 2004, it represented the first sequence from a heterotrophic marine bacterium. Over the last ten years, the strain has become a valuable model for understanding the cycling of sulfur and carbon in the ocean. To ensure that this genome remains useful, we have updated 69 genes to incorporate functional annotations based on new experimental data, and improved the identification of 120 protein-coding regions based on proteomic and transcriptomic data. We review the progress made in understanding the biology of R. pomeroyi DSS-3 and list the changes made to the genome.

  9. Purine catabolic pathway revealed by transcriptomics in the model marine bacterium Ruegeria pomeroyi DSS-3.

    PubMed

    Cunliffe, Michael

    2016-01-01

    Purines are nitrogen-rich compounds that are widely distributed in the marine environment and are an important component of the dissolved organic nitrogen (DON) pool. Even though purines have been shown to be degraded by bacterioplankton, the identities of marine bacteria capable of purine degradation and their underlying catabolic mechanisms are currently unknown. This study shows that Ruegeria pomeroyi, a model marine bacterium and Marine Roseobacter Clade (MRC) representative, utilizes xanthine as a source of carbon and nitrogen. The R. pomeroyi genome contains putative genes that encode xanthine dehydrogenase (XDH), which is expressed during growth with xanthine. RNAseq-based analysis of the R. pomeroyi transcriptome revealed that the transcription of an XDH-initiated catabolic pathway is up-regulated during growth with xanthine, with transcription greatest when xanthine was the only available carbon source. The RNAseq-deduced pathway indicates that glyoxylate and ammonia are the key intermediates from xanthine degradation. Utilising a laboratory model, this study has identified the potential genes and catabolic pathway active during xanthine degradation. The ability of R. pomeroyi to utilize xanthine provides novel insights into the capabilities of the MRC that may contribute to their success in marine ecosystems and the potential biogeochemical importance of the group in processing DON.

  10. Complete genome sequencing and analysis of Saprospira grandis str. Lewin, a predatory marine bacterium.

    PubMed

    Saw, Jimmy H W; Yuryev, Anton; Kanbe, Masaomi; Hou, Shaobin; Young, Aaron G; Aizawa, Shin-Ichi; Alam, Maqsudul

    2012-03-19

    Saprospira grandis is a coastal marine bacterium that can capture and prey upon other marine bacteria using a mechanism known as 'ixotrophy'. Here, we present the complete genome sequence of Saprospira grandis str. Lewin isolated from La Jolla beach in San Diego, California. The complete genome sequence comprises a chromosome of 4.35 Mbp and a plasmid of 54.9 Kbp. Genome analysis revealed incomplete pathways for the biosynthesis of nine essential amino acids but presence of a large number of peptidases. The genome encodes multiple copies of sensor globin-coupled rsbR genes thought to be essential for stress response and the presence of such sensor globins in Bacteroidetes is unprecedented. A total of 429 spacer sequences within the three CRISPR repeat regions were identified in the genome and this number is the largest among all the Bacteroidetes sequenced to date.

  11. Complete Genome Sequence of the Complex Carbohydrate-Degrading Marine Bacterium, Saccharophagus degradans Strain 2-40T

    PubMed Central

    Weiner, Ronald M.; Taylor, Larry E.; Henrissat, Bernard; Hauser, Loren; Land, Miriam; Coutinho, Pedro M.; Rancurel, Corinne; Saunders, Elizabeth H.; Longmire, Atkinson G.; Zhang, Haitao; Bayer, Edward A.; Gilbert, Harry J.; Larimer, Frank; Zhulin, Igor B.; Ekborg, Nathan A.; Lamed, Raphael; Richardson, Paul M.; Borovok, Ilya; Hutcheson, Steven

    2008-01-01

    The marine bacterium Saccharophagus degradans strain 2-40 (Sde 2-40) is emerging as a vanguard of a recently discovered group of marine and estuarine bacteria that recycles complex polysaccharides. We report its complete genome sequence, analysis of which identifies an unusually large number of enzymes that degrade >10 complex polysaccharides. Not only is this an extraordinary range of catabolic capability, many of the enzymes exhibit unusual architecture including novel combinations of catalytic and substrate-binding modules. We hypothesize that many of these features are adaptations that facilitate depolymerization of complex polysaccharides in the marine environment. This is the first sequenced genome of a marine bacterium that can degrade plant cell walls, an important component of the carbon cycle that is not well-characterized in the marine environment. PMID:18516288

  12. Data supporting functional diversity of the marine bacterium Cobetia amphilecti KMM 296.

    PubMed

    Balabanova, Larissa; Nedashkovskaya, Olga; Podvolotskaya, Anna; Slepchenko, Lubov; Golotin, Vasily; Belik, Alexey; Shevchenko, Ludmila; Son, Oksana; Rasskazov, Valery

    2016-09-01

    Data is presented in support of functionality of hyper-diverse protein families encoded by the Cobetia amphilecti KMM 296 (formerly Cobetia marina KMM 296) genome ("The genome of the marine bacterium Cobetia marina KMM 296 isolated from the mussel Crenomytilus grayanus (Dunker, 1853)" [1]) providing its nutritional versatility, adaptability and biocontrol that could be the basis of the marine bacterium evolutionary and application potential. Presented data include the information of growth and biofilm-forming properties of the food-associated isolates of Pseudomonas, Bacillus, Listeria, Salmonella and Staphylococcus under the conditions of their co-culturing with C. amphilecti KMM 296 to confirm its high inter-species communication and anti-microbial activity. Also included are the experiments on the crude petroleum consumption by C. amphilecti KMM 296 as the sole source of carbon in the presence of sulfate or nitrate to ensure its bioremediation capacity. The multifunctional C. amphilecti KMM 296 genome is a promising source for the beneficial psychrophilic enzymes and essential secondary metabolites. PMID:27508225

  13. Transcriptional Changes Underlying Elemental Stoichiometry Shifts in a Marine Heterotrophic Bacterium

    PubMed Central

    Chan, Leong-Keat; Newton, Ryan J.; Sharma, Shalabh; Smith, Christa B.; Rayapati, Pratibha; Limardo, Alexander J.; Meile, Christof; Moran, Mary Ann

    2012-01-01

    Marine bacteria drive the biogeochemical processing of oceanic dissolved organic carbon (DOC), a 750-Tg C reservoir that is a critical component of the global C cycle. Catabolism of DOC is thought to be regulated by the biomass composition of heterotrophic bacteria, as cells maintain a C:N:P ratio of ∼50:10:1 during DOC processing. Yet a complicating factor in stoichiometry-based analyses is that bacteria can change the C:N:P ratio of their biomass in response to resource composition. We investigated the physiological mechanisms of resource-driven shifts in biomass stoichiometry in continuous cultures of the marine heterotrophic bacterium Ruegeria pomeroyi (a member of the Roseobacter clade) under four element limitation regimes (C, N, P, and S). Microarray analysis indicated that the bacterium scavenged for alternate sources of the scarce element when cells were C-, N-, or P-limited; reworked the ratios of biomolecules when C- and P- limited; and exerted tighter control over import/export and cytoplasmic pools when N-limited. Under S limitation, a scenario not existing naturally for surface ocean microbes, stress responses dominated transcriptional changes. Resource-driven changes in C:N ratios of up to 2.5-fold and in C:P ratios of up to sixfold were measured in R. pomeroyi biomass. These changes were best explained if the C and P content of the cells was flexible in the face of shifting resources but N content was not, achieved through the net balance of different transcriptional strategies. The cellular-level metabolic trade-offs that govern biomass stoichiometry in R. pomeroyi may have implications for global carbon cycling if extendable to other heterotrophic bacteria. Strong homeostatic responses to N limitation by marine bacteria would intensify competition with autotrophs. Modification of cellular inventories in C- and P-limited heterotrophs would vary the elemental ratio of particulate organic matter sequestered in the deep ocean. PMID:22783226

  14. Fabivirga thermotolerans gen. nov., sp. nov., a novel marine bacterium isolated from culture broth of a marine cyanobacterium.

    PubMed

    Tang, M; Chen, C; Li, J; Xiang, W; Wu, H; Wu, J; Dai, S; Wu, H; Li, T; Wang, G

    2016-02-01

    A Gram-stain-negative, red, non-spore-forming, strictly aerobic bacterium, designated strain A4T, was isolated from culture broth of a marine cyanobacterium. Cells were flexible rods with gliding motility. Phylogenetic analysis, based on 16S rRNA gene sequences, revealed that strain A4T formed a coherent cluster with members of the genera Roseivirga and Fabibacter, and represents a distinct lineage in the family Flammeovirgaceae. Thermotolerance and a distinctive cellular fatty acid profile could readily distinguish this isolate from any bacteria of the genera Roseivirga and Fabibacter with a validly published name. On the basis of the phenotypic, chemotaxonomic and phylogenetic characteristics, strain A4T is suggested to represent a novel species in a novel genus, for which the name Fabivirga thermotolerans gen. nov., sp. nov. is proposed. The type strain is A4T ( = KCTC 42507T = CGMCC 1.15111T).

  15. Discovery of a novel iota carrageenan sulfatase isolated from the marine bacterium Pseudoalteromonas carrageenovora

    NASA Astrophysics Data System (ADS)

    Genicot, Sabine; Groisillier, Agnès; Rogniaux, Hélène; Meslet-Cladière, Laurence; Barbeyron, Tristan; Helbert, William

    2014-08-01

    Carrageenans are sulfated polysaccharides extracted from the cell wall of some marine red algae. These polysaccharides are widely used as gelling, stabilizing, and viscosifying agents in the food and pharmaceutical industries. Since the rheological properties of these polysaccharides depend on their sulfate content, we screened several isolated marine bacteria for carrageenan specific sulfatase activity, in the aim of developing enzymatic bioconversion of carrageenans. As a result of the screening, an iota-carrageenan sulfatase was detected in the cell-free lysate of the marine bacterium Pseudoalteromonas carrageenovora strain PscT. It was purified through Phenyl Sepharose and Diethylaminoethyl Sepharose chromatography. The pure enzyme, Psc ?-CgsA, was characterized. It had a molecular weight of 115.9 kDaltons and exhibited an optimal activity/stability at pH ~8.3 and at 40°C ± 5°C. It was inactivated by phenylmethylsulfonyl fluoride but not by ethylene diamine tetraacetic acid. Psc ?-CgsA specifically catalyzes the hydrolysis of the 4-S sulfate of iota-carrageenan. The purified enzyme could transform iota-carrageenan into hybrid iota-/alpha- or pure alpha-carrageenan under controlled conditions. The gene encoding Psc ?-CgsA, a protein of 1038 amino acids, was cloned into Escherichia coli, and the sequence analysis revealed that Psc ?-CgsA has more than 90% sequence identity with a putative uncharacterized protein Q3IKL4 from the marine strain Pseudoalteromonas haloplanktis TAC 125, but besides this did not share any homology to characterized sulfatases. Phylogenetic studies show that P. carrageenovora sulfatase thus represents the first characterized member of a new sulfatase family, with a C-terminal domain having strong similarity with the superfamily of amidohydrolases, highlighting the still unexplored diversity of marine polysaccharide modifying enzymes.

  16. Discovery of a novel iota carrageenan sulfatase isolated from the marine bacterium Pseudoalteromonas carrageenovora

    PubMed Central

    Genicot, Sabine M.; Groisillier, Agnès; Rogniaux, Hélène; Meslet-Cladière, Laurence; Barbeyron, Tristan; Helbert, William

    2014-01-01

    Carrageenans are sulfated polysaccharides extracted from the cell wall of some marine red algae. These polysaccharides are widely used as gelling, stabilizing, and viscosifying agents in the food and pharmaceutical industries. Since the rheological properties of these polysaccharides depend on their sulfate content, we screened several isolated marine bacteria for carrageenan specific sulfatase activity, in the aim of developing enzymatic bioconversion of carrageenans. As a result of the screening, an iota-carrageenan sulfatase was detected in the cell-free lysate of the marine bacterium Pseudoalteromonas carrageenovora strain PscT. It was purified through Phenyl Sepharose and Diethylaminoethyl Sepharose chromatography. The pure enzyme, Psc ι-CgsA, was characterized. It had a molecular weight of 115.9 kDaltons and exhibited an optimal activity/stability at pH ~8.3 and at 40 ± 5°C. It was inactivated by phenylmethylsulfonyl fluoride but not by ethylene diamine tetraacetic acid. Psc ι-CgsA specifically catalyzes the hydrolysis of the 4-S sulfate of iota-carrageenan. The purified enzyme could transform iota-carrageenan into hybrid iota-/alpha- or pure alpha-carrageenan under controlled conditions. The gene encoding Psc ι-CgsA, a protein of 1038 amino acids, was cloned into Escherichia coli, and the sequence analysis revealed that Psc ι-CgsA has more than 90% sequence identity with a putative uncharacterized protein Q3IKL4 from the marine strain Pseudoalteromonas haloplanktis TAC 125, but besides this did not share any homology to characterized sulfatases. Phylogenetic studies show that P. carrageenovora sulfatase thus represents the first characterized member of a new sulfatase family, with a C-terminal domain having strong similarity with the superfamily of amidohydrolases, highlighting the still unexplored diversity of marine polysaccharide modifying enzymes. PMID:25207269

  17. RecA Expression in Response to Solar UVR in the Marine Bacterium Vibrio natriegens.

    PubMed

    Booth, M.G.; Jeffrey, W.H.; Miller, R.V.

    2001-12-01

    Solar ultraviolet radiation may produce daily stress on marine and estuarine communities as cells are damaged and repair that damage. Reduction in the earth's stratospheric ozone layer has increased awareness of the potential effects that ultraviolet radiation may have in the environment, including how marine bacteria respond to changes in solar radiation. We examined the use of the bacterial RecA protein as an indicator of the potential of bacteria to repair DNA damage caused by solar UV irradiation using the marine bacterium Vibrio natriegens as a model. RecA is universally present in bacteria and is a regulator protein for the so-called Dark Repair Systems, which include excision repair, postreplication recombinational repair, and mutagenic or SOS repair. Solar UVB and UVA both reduced V. natriegens viability in seawater microcosms. After exposure to unfiltered solar radiation or radiation in which UVB was blocked, survival dropped below 1%, whereas visible light from which UVA and UVB had been filtered had no effect on survival. Using a RecA-specific antibody for detection, RecA protein was induced by solar radiation in a diel pattern in marine microcosms conducted in the Gulf of Mexico. Peak induction was observed at dusk each day. Although RecA expression was correlated with the formation of UVB-induced cyclobutyl pyrimidine dimers, longer wavelength UVA radiation also induced recA gene expression. Our results demonstrate that RecA-regulated, light-independent repair is an important component in the ability of marine bacteria to survive exposure to solar ultraviolet radiation and that RecA expression is a useful monitor of bacterial repair after exposure to solar UVR.

  18. Evidence for quorum sensing and differential metabolite production by a marine bacterium in response to DMSP.

    PubMed

    Johnson, Winifred M; Kido Soule, Melissa C; Kujawinski, Elizabeth B

    2016-09-01

    Microbes, the foundation of the marine foodweb, do not function in isolation, but rather rely on molecular level interactions among species to thrive. Although certain types of interactions between autotrophic and heterotrophic microorganisms have been well documented, the role of specific organic molecules in regulating inter-species relationships and supporting growth are only beginning to be understood. Here, we examine one such interaction by characterizing the metabolic response of a heterotrophic marine bacterium, Ruegeria pomeroyi DSS-3, to growth on dimethylsulfoniopropionate (DMSP), an abundant organosulfur metabolite produced by phytoplankton. When cultivated on DMSP, R. pomeroyi synthesized a quorum-sensing molecule, N-(3-oxotetradecanoyl)-l-homoserine lactone, at significantly higher levels than during growth on propionate. Concomitant with the production of a quorum-sensing molecule, we observed differential production of intra- and extracellular metabolites including glutamine, vitamin B2 and biosynthetic intermediates of cyclic amino acids. Our metabolomics data indicate that R. pomeroyi changes regulation of its biochemical pathways in a manner that is adaptive for a cooperative lifestyle in the presence of DMSP, in anticipation of phytoplankton-derived nutrients and higher microbial density. This behavior is likely to occur on sinking marine particles, indicating that this response may impact the fate of organic matter. PMID:26882264

  19. Evidence for quorum sensing and differential metabolite production by a marine bacterium in response to DMSP

    PubMed Central

    Johnson, Winifred M; Kido Soule, Melissa C; Kujawinski, Elizabeth B

    2016-01-01

    Microbes, the foundation of the marine foodweb, do not function in isolation, but rather rely on molecular level interactions among species to thrive. Although certain types of interactions between autotrophic and heterotrophic microorganisms have been well documented, the role of specific organic molecules in regulating inter-species relationships and supporting growth are only beginning to be understood. Here, we examine one such interaction by characterizing the metabolic response of a heterotrophic marine bacterium, Ruegeria pomeroyi DSS-3, to growth on dimethylsulfoniopropionate (DMSP), an abundant organosulfur metabolite produced by phytoplankton. When cultivated on DMSP, R. pomeroyi synthesized a quorum-sensing molecule, N-(3-oxotetradecanoyl)-l-homoserine lactone, at significantly higher levels than during growth on propionate. Concomitant with the production of a quorum-sensing molecule, we observed differential production of intra- and extracellular metabolites including glutamine, vitamin B2 and biosynthetic intermediates of cyclic amino acids. Our metabolomics data indicate that R. pomeroyi changes regulation of its biochemical pathways in a manner that is adaptive for a cooperative lifestyle in the presence of DMSP, in anticipation of phytoplankton-derived nutrients and higher microbial density. This behavior is likely to occur on sinking marine particles, indicating that this response may impact the fate of organic matter. PMID:26882264

  20. Adhesive properties of a symbolic bacterium from a wood-boreing marine shipworm

    SciTech Connect

    Imam, S.H.; Greene, R.V.; Griffin, H.L. )

    1990-05-01

    Adhesive properties of cellulolytic, nitrogen-fixing bacterium isolated from a marine shipworm are described. {sup 35}S-labeled cells of the shipworm bacterium bound preferentially Whatman no.1 cellulose filter paper, compared with its binding to other cellulose substrata or substrata lacking cellulose. The ability of the bacteria to bind to Whatman no. 1 filter paper was significantly reduced by glutaraldehyde or heat treatment of cells. Pretreatment of cells with azide, valinomycin, gramicidin-D, bis-hexafluoroacetylacetone (1799), or carbonyl cyanide-p-trifluoromethoxyphenylhydrazone inhibited adhesion activity. Cells pretreated with pronase or trypsin also exhibited reduced binding activity, but chymotrypsin and peptidase had no effect on adhesion activity. Cellodextrins and methyl cellulose 15 inhibited the adhesion of the shipworm bacteria to filter paper, whereas glucose, cellobiose, and soluble carboxymethyl cellulose had no significant effect. The divalent cation chelators EDTA and EGTA (ethylene hlycol-bis({beta}-aminoethyl ether)-N,N,N{prime}N{prime}-tetraacetic acid) had little or no effect on adhesive properties of shipworm bacteria. Also, preabsorbing the substratum with extracellular endoglucanase isolated from the ship worm bacterium or 1% bovine serum albumin had no apparent effect on bacterial binding. Low concentration (0.01%) of sodium dodecyl sulfate solubilized a fraction from whole cells, which appeared to be involved in cellular binding activity. After removal of sodium dodecyl, sulfate, several proteins in this fraction associated with intact cells. These cells exhibited up to 50% enhanced binding to filter paper in comparison to cells which had not been exposed to the sodium dodecyl sulfate-solubilized fraction.

  1. Marine bacterium strain screening and pyrethroid insecticide-degrading efficiency analysis

    NASA Astrophysics Data System (ADS)

    Sun, Aili; Liu, Jinghua; Shi, Xizhi; Li, Dexiang; Chen, Jiong; Tang, Daojun

    2014-09-01

    A pyrethroid insecticide-degrading bacterium, strain HS-24, was isolated from an offshore seawater environment. The strain, which can degrade cypermethrin (CYP) and deltamethrin (DEL), was identified as Methylophaga sp. The optimal culture and degradation conditions for CYP and DEL by strain HS-24 is pH 7 at 28°C. Under optimum culture conditions, strain HS-24 exhibited a broad degradation concentration range of 100, 200, 400, 600, and 800 mg/L for CYP and DEL. The metabolic intermediates were analyzed by NMR, which provided strong evidence that CYP and DEL removal occurred mainly because of a biological process. The toxicity of the degradation products of strain HS-24 was studied simultaneously by measuring the light output of the luminescence bacterium. This demonstrated that the biodegradation ability of strain HS-24 significantly decreased the toxicity of CYP- and DEL-contaminated aquaculture seawater. Finally, the findings of this paper indicate that strain HS-24 is thus revealed as a biological agent for the remediation of marine aquatic environments.

  2. Photobacterium damselae subsp. damselae, a bacterium pathogenic for marine animals and humans

    PubMed Central

    Rivas, Amable J.; Lemos, Manuel L.; Osorio, Carlos R.

    2013-01-01

    Photobacterium damselae subsp. damselae (formerly Vibrio damsela) is a pathogen of a variety of marine animals including fish, crustaceans, molluscs, and cetaceans. In humans, it can cause opportunistic infections that may evolve into necrotizing fasciitis with fatal outcome. Although the genetic basis of virulence in this bacterium is not completely elucidated, recent findings demonstrate that the phospholipase-D Dly (damselysin) and the pore-forming toxins HlyApl and HlyAch play a main role in virulence for homeotherms and poikilotherms. The acquisition of the virulence plasmid pPHDD1 that encodes Dly and HlyApl has likely constituted a main driving force in the evolution of a highly hemolytic lineage within the subspecies. Interestingly, strains that naturally lack pPHDD1 show a strong pathogenic potential for a variety of fish species, indicating the existence of yet uncharacterized virulence factors. Future and deep analysis of the complete genome sequence of Photobacterium damselae subsp. damselae will surely provide a clearer picture of the virulence factors employed by this bacterium to cause disease in such a varied range of hosts. PMID:24093021

  3. Characterization of a Marine Bacterium Associated with Crassostrea virginica (the Eastern Oyster)

    PubMed Central

    Weiner, Ronald M.; Segall, Anca M.; Colwell, Rita R.

    1985-01-01

    A gram-negative bacterium found to be closely associated with oysters has been isolated and characterized. The organism, designated LST, has a generation time of 106 min in Marine broth under optimal growth conditions at 25°C. During the decline phase of growth, it exhibits a morphological transition from a motile rod (ca. 1 μm in length) to an elongated, 3- to 40-μm, nonmotile, tightly coiled helix. LST synthesizes and releases a pigment in the stationary and decline phases of growth. Identified as melanin on the basis of chemical properties and UV absorbance maxima, the pigment comprises polymers of heterogeneous molecular weights, ranging from 12,000 to 120,000. The guanosine-plus-cytosine content of the LST DNA is 46%, and results of phenetic analysis and DNA-DNA hybridization indicate that this bacterium represents a new species. LST adheres to a variety of surfaces, including glass, plastics, and oyster shell, and has been shown to promote the settlement of oyster larvae. Images PMID:16346712

  4. Draft Genome of Shewanella frigidimarina Ag06-30, a Marine Bacterium Isolated from Potter Peninsula, King George Island, Antarctica

    PubMed Central

    Parmeciano Di Noto, Gisela; Vázquez, Susana C.; MacCormack, Walter P.; Iriarte, Andrés

    2016-01-01

    We present the draft genome of Shewanella frigidimarina Ag06-30, a marine bacterium from King George Island, Antarctica, which encodes the carbapenemase SFP-1. The assembly contains 4,799,218 bp (G+C content 41.24%). This strain harbors several mobile genetic elements that provide insight into lateral gene transfer and bacterial plasticity and evolution. PMID:27151790

  5. Draft Genome of Shewanella frigidimarina Ag06-30, a Marine Bacterium Isolated from Potter Peninsula, King George Island, Antarctica.

    PubMed

    Parmeciano Di Noto, Gisela; Vázquez, Susana C; MacCormack, Walter P; Iriarte, Andrés; Quiroga, Cecilia

    2016-05-05

    We present the draft genome of Shewanella frigidimarina Ag06-30, a marine bacterium from King George Island, Antarctica, which encodes the carbapenemase SFP-1. The assembly contains 4,799,218 bp (G+C content 41.24%). This strain harbors several mobile genetic elements that provide insight into lateral gene transfer and bacterial plasticity and evolution.

  6. The nucleotide sequence of Beneckea harveyi 5S rRNA. [bioluminescent marine bacterium

    NASA Technical Reports Server (NTRS)

    Luehrsen, K. R.; Fox, G. E.

    1981-01-01

    The primary sequence of the 5S ribosomal RNA isolated from the free-living bioluminescent marine bacterium Beneckea harveyi is reported and discussed in regard to indications of phylogenetic relationships with the bacteria Escherichia coli and Photobacterium phosphoreum. Sequences were determined for oligonucleotide products generated by digestion with ribonuclease T1, pancreatic ribonuclease and ribonuclease T2. The presence of heterogeneity is indicated for two sites. The B. harveyi sequence can be arranged into the same four helix secondary structures as E. coli and other prokaryotic 5S rRNAs. Examination of the 5S-RNS sequences of the three bacteria indicates that B. harveyi and P. phosphoreum are specifically related and share a common ancestor which diverged from an ancestor of E. coli at a somewhat earlier time, consistent with previous studies.

  7. Identification of bisphosphatidic acid and its plasmalogen analogues in the phospholipids of a marine bacterium.

    PubMed

    McAllister, D J; De Siervo, A J

    1975-07-01

    A relatively nonpolar unidentified phospholipid (phospholipid X) , isolated from the gram-negative marine bacterium MB 45, was characterized both chromatographically and by chemical analysis. Phospholipid X was shown to be an acidic phospholipid without vicinal hydroxyl, free-amino, or amide groups. The presence of O-alkenyl groups was indicated by a positive reaction for plasmalogen. Mild alkaline methanolysis of phospholipid X yielded only glycerophosphoryglycerol as the derivative. Acetolysis produced only diacyl-glycerol monoacetate. Clevage of O-alkenyl chains by methanolic hydrochloride resulted in the formation of three lyso derivatives. It was estimated that 18.2% of phospholipid X was plasmalogen. From these data, together with chromatographic comparisons with standards, infrared spectra, a molecular weight estimation, and the determination of the glycerol-phosphate-acyl ester ratio, it was concluded that phospholipid X was bisphosphatidic acid mixed with its plasmalogen analogues. PMID:1141198

  8. A novel eliminase from a marine bacterium that degrades hyaluronan and chondroitin sulfate.

    PubMed

    Han, Wenjun; Wang, Wenshuang; Zhao, Mei; Sugahara, Kazuyuki; Li, Fuchuan

    2014-10-01

    Lyases cleave glycosaminoglycans (GAGs) in an eliminative mechanism and are important tools for the structural analysis and oligosaccharide preparation of GAGs. Various GAG lyases have been identified from terrestrial but not marine organisms even though marine animals are rich in GAGs with unique structures and functions. Herein we isolated a novel GAG lyase for the first time from the marine bacterium Vibrio sp. FC509 and then recombinantly expressed and characterized it. It showed strong lyase activity toward hyaluronan (HA) and chondroitin sulfate (CS) and was designated as HA and CS lyase (HCLase). It exhibited the highest activities to both substrates at pH 8.0 and 0.5 m NaCl at 30 °C. Its activity toward HA was less sensitive to pH than its CS lyase activity. As with most other marine enzymes, HCLase is a halophilic enzyme and very stable at temperatures from 0 to 40 °C for up to 24 h, but its activity is independent of divalent metal ions. The specific activity of HCLase against HA and CS reached a markedly high level of hundreds of thousands units/mg of protein under optimum conditions. The HCLase-resistant tetrasaccharide Δ(4,5)HexUAα1-3GalNAc(6-O-sulfate)β1-4GlcUA(2-O-sulfate)β1-3GalNAc(6-O-sulfate) was isolated from CS-D, the structure of which indicated that HCLase could not cleave the galactosaminidic linkage bound to 2-O-sulfated d-glucuronic acid (GlcUA) in CS chains. Site-directed mutagenesis indicated that HCLase may work via a catalytic mechanism in which Tyr-His acts as the Brønsted base and acid. Thus, the identification of HCLase provides a useful tool for HA- and CS-related research and applications.

  9. A Novel Eliminase from a Marine Bacterium That Degrades Hyaluronan and Chondroitin Sulfate*

    PubMed Central

    Han, Wenjun; Wang, Wenshuang; Zhao, Mei; Sugahara, Kazuyuki; Li, Fuchuan

    2014-01-01

    Lyases cleave glycosaminoglycans (GAGs) in an eliminative mechanism and are important tools for the structural analysis and oligosaccharide preparation of GAGs. Various GAG lyases have been identified from terrestrial but not marine organisms even though marine animals are rich in GAGs with unique structures and functions. Herein we isolated a novel GAG lyase for the first time from the marine bacterium Vibrio sp. FC509 and then recombinantly expressed and characterized it. It showed strong lyase activity toward hyaluronan (HA) and chondroitin sulfate (CS) and was designated as HA and CS lyase (HCLase). It exhibited the highest activities to both substrates at pH 8.0 and 0.5 m NaCl at 30 °C. Its activity toward HA was less sensitive to pH than its CS lyase activity. As with most other marine enzymes, HCLase is a halophilic enzyme and very stable at temperatures from 0 to 40 °C for up to 24 h, but its activity is independent of divalent metal ions. The specific activity of HCLase against HA and CS reached a markedly high level of hundreds of thousands units/mg of protein under optimum conditions. The HCLase-resistant tetrasaccharide Δ4,5HexUAα1-3GalNAc(6-O-sulfate)β1-4GlcUA(2-O-sulfate)β1-3GalNAc(6-O-sulfate) was isolated from CS-D, the structure of which indicated that HCLase could not cleave the galactosaminidic linkage bound to 2-O-sulfated d-glucuronic acid (GlcUA) in CS chains. Site-directed mutagenesis indicated that HCLase may work via a catalytic mechanism in which Tyr-His acts as the Brønsted base and acid. Thus, the identification of HCLase provides a useful tool for HA- and CS-related research and applications. PMID:25122756

  10. Calcium ion-mediated assembly and function of glycosylated flagellar sheath of marine magnetotactic bacterium.

    PubMed

    Lefèvre, Christopher T; Santini, Claire-Lise; Bernadac, Alain; Zhang, Wei-Jia; Li, Ying; Wu, Long-Fei

    2010-12-01

    Flagella of some pathogens or marine microbes are sheathed by an apparent extension of the outer cell membrane. Although flagellar sheath has been reported for almost 60 years, little is known about its function and the mechanism of its assembly. Recently, we have observed a novel type of sheath that encloses a flagellar bundle, instead of a single flagellum, in a marine magnetotactic bacterium MO-1. Here, we reported isolation and characterization of the sheath which can be described as a six-start, right-handed helical tubular structure with a diameter of about 100 nm, and a pitch of helix of about 260 nm. By proteomic, microscopic and immunolabelling analyses, we showed that the sheath of MO-1 consists of glycoprotein with an apparent molecular mass > 350 kDa. This protein, named sheath-associated protein (Sap), shows homology with bacterial adhesins and eukaryotic calcium-dependent adherent proteins (cadherin). Most importantly, we showed that calcium ions mediate the assembly of the tubular-shaped sheath and disintegration of the sheath was deleterious for smooth swimming of MO-1 cells. The disintegrated sheath was efficiently reconstituted in vitro by adding calcium ions. Altogether, these results demonstrate a novel bacterial Ca(2+) -dependent surface architecture, which is essential for bacterial swimming. PMID:21091512

  11. Complete Cellulase System in the Marine Bacterium Saccharophagus degradans Strain 2-40T

    PubMed Central

    Taylor, Larry E.; Henrissat, Bernard; Coutinho, Pedro M.; Ekborg, Nathan A.; Hutcheson, Steven W.; Weiner, Ronald M.

    2006-01-01

    Saccharophagus degradans strain 2-40 is a representative of an emerging group of marine complex polysaccharide (CP)-degrading bacteria. It is unique in its metabolic versatility, being able to degrade at least 10 distinct CPs from diverse algal, plant and invertebrate sources. The S. degradans genome has been sequenced to completion, and more than 180 open reading frames have been identified that encode carbohydrases. Over half of these are likely to act on plant cell wall polymers. In fact, there appears to be a full array of enzymes that degrade and metabolize plant cell walls. Genomic and proteomic analyses reveal 13 cellulose depolymerases complemented by seven accessory enzymes, including two cellodextrinases, three cellobiases, a cellodextrin phosphorylase, and a cellobiose phosphorylase. Most of these enzymes exhibit modular architecture, and some contain novel combinations of catalytic and/or substrate binding modules. This is exemplified by endoglucanase Cel5A, which has three internal family 6 carbohydrate binding modules (CBM6) and two catalytic modules from family five of glycosyl hydrolases (GH5) and by Cel6A, a nonreducing-end cellobiohydrolase from family GH6 with tandem CBM2s. This is the first report of a complete and functional cellulase system in a marine bacterium with a sequenced genome. PMID:16707677

  12. Hydrogen peroxide-dependent uptake of iodine by marine Flavobacteriaceae bacterium strain C-21.

    PubMed

    Amachi, Seigo; Kimura, Koh; Muramatsu, Yasuyuki; Shinoyama, Hirofumi; Fujii, Takaaki

    2007-12-01

    The cells of the marine bacterium strain C-21, which is phylogenetically closely related to Arenibacter troitsensis, accumulate iodine in the presence of glucose and iodide (I-). In this study, the detailed mechanism of iodine uptake by C-21 was determined using a radioactive iodide tracer, 125I-. In addition to glucose, oxygen and calcium ions were also required for the uptake of iodine. The uptake was not inhibited or was only partially inhibited by various metabolic inhibitors, whereas reducing agents and catalase strongly inhibited the uptake. When exogenous glucose oxidase was added to the cell suspension, enhanced uptake of iodine was observed. The uptake occurred even in the absence of glucose and oxygen if hydrogen peroxide was added to the cell suspension. Significant activity of glucose oxidase was found in the crude extracts of C-21, and it was located mainly in the membrane fraction. These findings indicate that hydrogen peroxide produced by glucose oxidase plays a key role in the uptake of iodine. Furthermore, enzymatic oxidation of iodide strongly stimulated iodine uptake in the absence of glucose. Based on these results, the mechanism was considered to consist of oxidation of iodide to hypoiodous acid by hydrogen peroxide, followed by passive translocation of this uncharged iodine species across the cell membrane. Interestingly, such a mechanism of iodine uptake is similar to that observed in iodine-accumulating marine algae.

  13. Structure and morphology of magnetite anaerobically-produced by a marine magnetotactic bacterium and a dissimilatory iron-reducing bacterium

    NASA Astrophysics Data System (ADS)

    Sparks, N. H. C.; Mann, S.; Bazylinski, D. A.; Lovley, D. R.; Jannasch, H. W.; Frankel, R. B.

    1990-04-01

    Intracellular crystals of magnetite synthesized by cells of the magnetotactic vibroid organism, MV-1, and extracellular crystals of magnetite produced by the non-magnetotactic dissimilatory iron-reducing bacterium strain GS-15, were examined using high-resolution transmission electron microscopy, electron diffraction and 57Fe Mo¨ssbauer spectroscopy. The magnetotactic bacterium contained a single chain of approximately 10 crystals aligned along the long axis of the cell. The crystals were essentially pure stoichiometric magnetite. When viewed along the crystal long axis the particles had a hexagonal cross-section whereas side-on they appeared as rectangules or truncated rectangles of average dimension, 53 × 35 nm. These findings are explained in terms of a three-dimensional morphology comprising a hexagonal prism of 110 faces which are capped and truncated by 111 end faces. Electron diffraction and lattice imaging studies indicated that the particles were structurally well-defined single crystals. In contrast, magnetite particles produced by the strain, GS-15 were irregular in shape and had smaller mean dimensions (14 nm). Single crystals were imaged but these were not of high structural perfection. These results highlight the influence of intracellular control on the crystallochemical specificity of bacterial magnetites. The characterization of these crystals is important in aiding the identification of biogenic magnetic materials in paleomagnetism and in studies of sediment magnetization.

  14. Structure and morphology of magnetite anaerobically-produced by a marine magnetotactic bacterium and a dissimilatory iron-reducing bacterium

    USGS Publications Warehouse

    Sparks, N.H.C.; Mann, S.; Bazylinski, D.A.; Lovley, D.R.; Jannasch, H.W.; Frankel, R.B.

    1990-01-01

    Intracellular crystals of magnetite synthesized by cells of the magnetotactic vibroid organism, MV-1, and extracellular crystals of magnetite produced by the non-magnetotactic dissimilatory iron-reducing bacterium strain GS-15, were examined using high-resolution transmission electron microscopy, electron diffraction and 57Fe Mo??ssbauer spectroscopy. The magnetotactic bacterium contained a single chain of approximately 10 crystals aligned along the long axis of the cell. The crystals were essentially pure stoichiometric magnetite. When viewed along the crystal long axis the particles had a hexagonal cross-section whereas side-on they appeared as rectangules or truncated rectangles of average dimension, 53 ?? 35 nm. These findings are explained in terms of a three-dimensional morphology comprising a hexagonal prism of {110} faces which are capped and truncated by {111} end faces. Electron diffraction and lattice imaging studies indicated that the particles were structurally well-defined single crystals. In contrast, magnetite particles produced by the strain, GS-15 were irregular in shape and had smaller mean dimensions (14 nm). Single crystals were imaged but these were not of high structural perfection. These results highlight the influence of intracellular control on the crystallochemical specificity of bacterial magnetites. The characterization of these crystals is important in aiding the identification of biogenic magnetic materials in paleomagnetism and in studies of sediment magnetization. ?? 1990.

  15. Draft Genome Sequence of Providencia sneebia Strain ST1, a Quorum Sensing Bacterium Associated with Marine Microalgae

    PubMed Central

    Zhou, Jin; Lao, Yong-Min; Cai, Zhong-Hua

    2016-01-01

    Providencia sneebia strain ST1 is a symbiotic bacterium (belonging to phylum gammaproteobacteria) with marine microalgae. This bacterium exhibits the ability to produce N-Acyl homoserine lactone signal molecule. To date, no genome that originates from marine Providencia spp. has been reported. In this study, we present the genome sequence of this strain. It has a genome size of 4.89 M, with 19 contigs and an average G+C of 51.97%. The function of 4,631 proteins was predicted, and 3,652 proteins were assigned to COG functional categories. Among them, 407 genes are involved in carbohydrate metabolism, 306 genes participate in nitrogen utilization and energy conversion, and 185 genes related to signal transduction process. Thus, this strain plays an active role in the biogeochemical cycle in algal life history. The whole-genome of this isolate and annotation will help enhance understanding of bacterial ecological behavior in the phycosphere. PMID:27026792

  16. Stereochemical course of hydrolytic reaction catalyzed by alpha-galactosidase from cold adaptable marine bacterium of genus Pseudoalteromonas

    NASA Astrophysics Data System (ADS)

    Bakunina, Irina; Balabanova, Larissa; Golotin, Vasiliy; Slepchenko, Lyubov; Isakov, Vladimir; Rasskazov, Valeriy

    2014-10-01

    The recombinant α-galactosidase of the marine bacterium (α-PsGal) was synthesized with the use of the plasmid 40Gal, consisting of plasmid pET-40b (+) (Novagen) and the gene corresponding to the open reading frame of the mature α-galactosidase of marine bacterium Pseudoalteromonas sp. KMM 701, transformed into the E. coli Rosetta(DE3) cells. In order to understand the mechanism of action, the stereochemistry of hydrolysis of 4-nitrophenyl α-D-galactopyranoside (4-NPGP) by α-PsGal was measured by 1H NMR spectroscopy. The kinetics of formation of α- and β-anomer of galactose showed that α-anomer initially formed and accumulated, and then an appreciable amount of β-anomer appeared as a result of mutarotation. The data clearly show that the enzymatic hydrolysis of 4-NPGP proceeds with the retention of anomeric configuration, probably, due to a double displacement mechanism of reaction.

  17. Methanosarcina acetivorans sp. nov., an Acetotrophic Methane-Producing Bacterium Isolated from Marine Sediments

    PubMed Central

    Sowers, Kevin R.; Baron, Stephen F.; Ferry, James G.

    1984-01-01

    A new acetotrophic marine methane-producing bacterium that was isolated from the methane-evolving sediments of a marine canyon is described. Exponential phase cultures grown with sodium acetate contained irregularly shaped cocci that aggregated in the early stationary phase and finally differentiated into communal cysts that released individual cocci when ruptured or transferred to fresh medium. The irregularly shaped cocci (1.9 ± 0.2 mm in diameter) were gram negative and occurred singly or in pairs. Cells were nonmotile, but possessed a single fimbria-like structure. Micrographs of thin sections showed a monolayered cell wall approximately 10 nm thick that consisted of protein subunits. The cells in aggregates were separated by visible septation. The communal cysts contained several single cocci encased in a common envelope. An amorphous form of the communal cyst that had incomplete septation and internal membrane-like vesicles was also present in late exponential phase cultures. Sodium acetate, methanol, methylamine, dimethylamine, and trimethylamine were substrates for growth and methanogenesis; H2-CO2 (80:20) and sodium formate were not. The optimal growth temperature was 35 to 40°C. The optimal pH range was 6.5 to 7.0. Both NaCl and Mg2+ were required for growth, with maximum growth rates at 0.2 M NaCl and 0.05 M MgSO4. The DNA base composition was 41 ± 1% guanine plus cytosine. Methanosarcina acetivorans is the proposed species. C2A is the type strain (DSM 2834, ATCC 35395). Images PMID:16346552

  18. Purification and Characterization of a Fucoidanase (FNase S) from a Marine Bacterium Sphingomonas paucimobilis PF-1

    PubMed Central

    Kim, Woo Jung; Park, Joo Woong; Park, Jae Kweon; Choi, Doo Jin; Park, Yong Il

    2015-01-01

    The Search for enzyme activities that efficiently degrade marine polysaccharides is becoming an increasingly important area for both structural analysis and production of lower-molecular weight oligosaccharides. In this study, an endo-acting fucoidanase that degrades Miyeokgui fucoidan (MF), a sulfated galactofucan isolated from the sporophyll (called Miyeokgui in Korean) of Undaria pinnatifida, into smaller-sized galactofuco-oligosaccharides (1000–4000 Da) was purified from a marine bacterium, Sphingomonas paucimobilis PF-1, by ammonium sulfate precipitation, diethylaminoethyl (DEAE)-Sepharose column chromatography, and chromatofocusing. The specific activity of this enzyme was approximately 112-fold higher than that of the crude enzyme, and its molecular weight was approximately 130 kDa (FNase S), as determined by native gel electrophoresis and 130 (S1), 70 (S2) and 60 (S3) kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature of FNase S were pH 6.0–7.0 and 40–45 °C, respectively. FNase S activity was enhanced by Mn2+ and Na+ (115.7% and 131.2%), but it was inhibited by Ca2+, K+, Ba2+, Cu2+ (96%, 83.7%, 84.3%, and 89.3%, respectively), each at 1 mM. The Km, Vmax and Kcat values of FNase S on MF were 1.7 mM, 0.62 mg·min−1, and 0.38·S−1, respectively. This enzyme could be a valuable tool for the structural analysis of fucoidans and production of bioactive fuco-oligosaccharides. PMID:26193285

  19. Purification and Characterization of a Fucoidanase (FNase S) from a Marine Bacterium Sphingomonas paucimobilis PF-1.

    PubMed

    Kim, Woo Jung; Park, Joo Woong; Park, Jae Kweon; Choi, Doo Jin; Park, Yong Il

    2015-07-16

    The Search for enzyme activities that efficiently degrade marine polysaccharides is becoming an increasingly important area for both structural analysis and production of lower-molecular weight oligosaccharides. In this study, an endo-acting fucoidanase that degrades Miyeokgui fucoidan (MF), a sulfated galactofucan isolated from the sporophyll (called Miyeokgui in Korean) of Undaria pinnatifida, into smaller-sized galactofuco-oligosaccharides (1000-4000 Da) was purified from a marine bacterium, Sphingomonas paucimobilis PF-1, by ammonium sulfate precipitation, diethylaminoethyl (DEAE)-Sepharose column chromatography, and chromatofocusing. The specific activity of this enzyme was approximately 112-fold higher than that of the crude enzyme, and its molecular weight was approximately 130 kDa (FNase S), as determined by native gel electrophoresis and 130 (S1), 70 (S2) and 60 (S3) kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature of FNase S were pH 6.0-7.0 and 40-45 °C, respectively. FNase S activity was enhanced by Mn2+ and Na+ (115.7% and 131.2%), but it was inhibited by Ca2+, K+, Ba2+, Cu2+ (96%, 83.7%, 84.3%, and 89.3%, respectively), each at 1 mM. The Km, Vmax and Kcat values of FNase S on MF were 1.7 mM, 0.62 mg·min-1, and 0.38·S-1, respectively. This enzyme could be a valuable tool for the structural analysis of fucoidans and production of bioactive fuco-oligosaccharides.

  20. Comprehensive insights into the response of Alexandrium tamarense to algicidal component secreted by a marine bacterium

    PubMed Central

    Lei, Xueqian; Li, Dong; Li, Yi; Chen, Zhangran; Chen, Yao; Cai, Guanjing; Yang, Xujun; Zheng, Wei; Zheng, Tianling

    2015-01-01

    Harmful algal blooms occur throughout the world, threatening human health, and destroying marine ecosystems. Alexandrium tamarense is a globally distributed and notoriously toxic dinoflagellate that is responsible for most paralytic shellfish poisoning incidents. The culture supernatant of the marine algicidal bacterium BS02 showed potent algicidal effects on A. tamarense ATGD98-006. In this study, we investigated the effects of this supernatant on A. tamarense at physiological and biochemical levels to elucidate the mechanism involved in the inhibition of algal growth by the supernatant of the strain BS02. Reactive oxygen species (ROS) levels increased following exposure to the BS02 supernatant, indicating that the algal cells had suffered from oxidative damage. The levels of cellular pigments, including chlorophyll a and carotenoids, were significantly decreased, which indicated that the accumulation of ROS destroyed pigment synthesis. The decline of the maximum photochemical quantum yield (Fv/Fm) and relative electron transport rate (rETR) suggested that the photosynthesis systems of algal cells were attacked by the BS02 supernatant. To eliminate the ROS, the activities of antioxidant enzymes, including superoxide dismutase (SOD) and catalase (CAT), increased significantly within a short period of time. Real-time PCR revealed changes in the transcript abundances of two target photosynthesis-related genes (psbA and psbD) and two target respiration-related genes (cob and cox). The transcription of the respiration-related genes was significantly inhibited by the treatments, which indicated that the respiratory system was disturbed. Our results demonstrate that the BS02 supernatant can affect the photosynthesis process and might block the PS II electron transport chain, leading to the production of excessive ROS. The increased ROS can further destroy membrane integrity and pigments, ultimately inducing algal cell death. PMID:25667582

  1. Genome shuffling of marine derived bacterium Nocardia sp. ALAA 2000 for improved ayamycin production.

    PubMed

    El-Gendy, Mervat M A; El-Bondkly, Ahmed M A

    2011-05-01

    Genome shuffling is a recent development in microbiology. The advantage of this technique is that genetic changes can be made in a microorganism without knowing its genetic background. Genome shuffling was applied to the marine derived bacterium Nocardia sp. ALAA 2000 to achieve rapid improvement of ayamycin production. The initial mutant population was generated by treatment with ethyl methane sulfonate (EMS) combined with UV irradiation of the spores, resulting in an improved population (AL/11, AL/136, AL/213 and AL/277) producing tenfold (150 μg/ml) more ayamycin than the original strain. These mutants were used as the starting strains for three rounds of genome shuffling and after each round improved strains were screened and selected based on their ayamycin productivity. The population after three rounds of genome shuffling exhibited an improved ayamycin yield. Strain F3/22 yielded 285 μg/ml of ayamycin, which was 19-fold higher than that of the initial strain and 1.9-fold higher than the mutants used as the starting point for genome shuffling. We evaluated the genetic effect of UV + EMS-mutagenesis and three rounds of genome shuffling on the nucleotide sequence by random amplified polymorphic DNA (RAPD) analysis. Many differences were noticed in mutant and recombinant strains compared to the wild type strain. These differences in RAPD profiles confirmed the presence of genetic variations in the Nocardia genome after mutagenesis and genome shuffling. PMID:21240675

  2. A cold-adapted, solvent and salt tolerant esterase from marine bacterium Psychrobacter pacificensis.

    PubMed

    Wu, Gaobing; Zhang, Xiangnan; Wei, Lu; Wu, Guojie; Kumar, Ashok; Mao, Tao; Liu, Ziduo

    2015-11-01

    Lipolytic enzymes with unique physico-chemical characteristics are gaining more attention for their immense industrial importance. In this study, a novel lipolytic enzyme (Est11) was cloned from the genomic library of a marine bacterium Psychrobacter pacificensis. The enzyme was expressed in Escherichia coli and purified to homogeneity with molecular mass of 32.9kDa. The recombinant Est11 was able to hydrolyze short chain esters (C2-C8) and displayed an optimum activity against butyrate ester (C4). The optimal temperature and pH were 25°C and 7.5, respectively. Est11 retained more than 70% of its original activity at 10°C, suggesting that it was a cold-active esterase. The enzyme was highly active and stable at high concentration of NaCl (5M). Further, incubation with ethanol, isopropanol, propanediol, DMSO, acetonitrile, and glycerol rendered remarkable positive effects on Est11 activity. Typically, even at the concentration of 30% (v/v), ethanol, DMSO, and propanediol increased Est11 activity by 1.3, 2.0, and 2.4-folds, respectively. This new robust enzyme with remarkable properties like cold-adaptability, exceptional tolerance to salt and organic solvents provides us a promising candidate to meet the needs of some harsh industrial processes. PMID:26231332

  3. Three Alginate Lyases from Marine Bacterium Pseudomonas fluorescens HZJ216: Purification and Characterization

    SciTech Connect

    Liyan, Li; Jiang, Xiaolu; Wang, Peng; Guan, Huashi; Guo, Hong

    2010-01-01

    Three alginate lyases (A, B, and C) from an alginate-degrading marine bacterium strain HZJ216 isolated from brown seaweed in the Yellow Sea of China and identified preliminarily as Pseudomonas fluorescens are purified, and their biochemical properties are described. Molecular masses of the three enzymes are determined by SDS-PAGE to be 60.25, 36, and 23 kDa with isoelectric points of 4, 4.36, and 4.59, respectively. Investigations of these enzymes at different pH and temperatures show that they are most active at pH 7.0 and 35 C. Alginate lyases A and B are stable in the pH range of 5.0 9.0, while alginate lyase C is stable in the pH range of 5.0 7.0. Among the metal ions tested, additions of Na+, K+, and Mg2+ ions can enhance the enzyme activities while Fe2+, Fe3+, Ba2+, and Zn2+ ions show inhibitory effects. The substrate specificity results demonstrate that alginate lyase C has the specificity for G block while alginate lyases A and B have the activities for both M and G blocks. It is the first report about extracellular alginate lyases with high alginate-degrading activity from P. fluorescens.

  4. Aerobic and anaerobic degradation of a range of alkyl sulfides by a denitrifying marine bacterium

    USGS Publications Warehouse

    Visscher, P.T.; Taylor, B.F.

    1993-01-01

    A pure culture of a bacterium was obtained from a marine microbial mat by using an anoxic medium containing dimethyl sulfide (DMS) and nitrate. The isolate grew aerobically or anaerobically as a denitrifier on alkyl sulfides, including DMS, dimethyl disulfide, diethyl sulfide (DES), ethyl methyl sulfide, dipropyl sulfide, dibutyl sulfide, and dibutyl disulfide. Cells grown on an alkyl sulfide or disulfide also oxidized the corresponding thiols, namely, methanethiol, ethanethiol, propanethiol, or butanethiol. Alkyl sulfides were metabolized by induced or derepressed cells with oxygen, nitrate, or nitrite as electron acceptor. Cells grown on DMS immediately metabolized DMS, but there was a lag before DES was consumed; with DES-grown cells, DES was immediately used but DMS was used only after a lag. Chloramphenicol prevented the eventual use of DES by DMS-grown cells and DMS use by DES-grown cells, respectively, indicating separate enzymes for the metabolism of methyl and ethyl groups. Growth was rapid on formate, acetate, propionate, and butyrate but slow on methanol. The organism also grew chemolithotrophically on thiosulfate with a decrease in pH; growth required carbonate in the medium. Growth on sulfide was also carbonate dependent but slow. The isolate was identified as a Thiobacillus sp. and designated strain ASN-1. It may have utility for removing alkyl sulfides, and also nitrate, nitrite, and sulfide, from wastewaters.

  5. Aerobic and anaerobic degradation of a range of alkyl sulfides by a denitrifying marine bacterium.

    PubMed Central

    Visscher, P T; Taylor, B F

    1993-01-01

    A pure culture of a bacterium was obtained from a marine microbial mat by using an anoxic medium containing dimethyl sulfide (DMS) and nitrate. The isolate grew aerobically or anaerobically as a denitrifier on alkyl sulfides, including DMS, dimethyl disulfide, diethyl sulfide (DES), ethyl methyl sulfide, dipropyl sulfide, dibutyl sulfide, and dibutyl disulfide. Cells grown on an alkyl sulfide or disulfide also oxidized the corresponding thiols, namely, methanethiol, ethanethiol, propanethiol, or butanethiol. Alkyl sulfides were metabolized by induced or derepressed cells with oxygen, nitrate, or nitrite as electron acceptor. Cells grown on DMS immediately metabolized DMS, but there was a lag before DES was consumed; with DES-grown cells, DES was immediately used but DMS was used only after a lag. Chloramphenicol prevented the eventual use of DES by DMS-grown cells and DMS use by DES-grown cells, respectively, indicating separate enzymes for the metabolism of methyl and ethyl groups. Growth was rapid on formate, acetate, propionate, and butyrate but slow on methanol. The organism also grew chemolithotrophically on thiosulfate with a decrease in pH; growth required carbonate in the medium. Growth on sulfide was also carbonate dependent but slow. The isolate was identified as a Thiobacillus sp. and designated strain ASN-1. It may have utility for removing alkyl sulfides, and also nitrate, nitrite, and sulfide, from wastewaters. PMID:8285707

  6. Purification and characterization of catalase from marine bacterium Acinetobacter sp. YS0810.

    PubMed

    Fu, Xinhua; Wang, Wei; Hao, Jianhua; Zhu, Xianglin; Sun, Mi

    2014-01-01

    The catalase from marine bacterium Acinetobacter sp. YS0810 (YS0810CAT) was purified and characterized. Consecutive steps were used to achieve the purified enzyme as follows: ethanol precipitation, DEAE Sepharose ion exchange, Superdex 200 gel filtration, and Resource Q ion exchange. The active enzyme consisted of four identical subunits of 57.256 kDa. It showed a Soret peak at 405 nm, indicating the presence of iron protoporphyrin IX. The catalase was not apparently reduced by sodium dithionite but was inhibited by 3-amino-1,2,4-triazole, hydroxylamine hydrochloride, and sodium azide. Peroxidase-like activity was not found with the substrate o-phenylenediamine. So the catalase was determined to be a monofunctional catalase. N-terminal amino acid of the catalase analysis gave the sequence SQDPKKCPVTHLTTE, which showed high degree of homology with those of known catalases from bacteria. The analysis of amino acid sequence of the purified catalase by matrix-assisted laser desorption ionization time-of-flight mass spectrometry showed that it was a new catalase, in spite of its high homology with those of known catalases from other bacteria. The catalase showed high alkali stability and thermostability.

  7. A new κ-carrageenase CgkS from marine bacterium Shewanella sp. Kz7

    NASA Astrophysics Data System (ADS)

    Wang, Linna; Li, Shangyong; Zhang, Shilong; Li, Jiejing; Yu, Wengong; Gong, Qianhong

    2015-08-01

    A new κ-carrageenase gene cgkS was cloned from marine bacterium Shewanella sp. Kz7 by using degenerate and site-finding PCR. The gene was comprised of an open reading frame of 1224 bp, encoding 407 amino acid residues, with a signal peptide of 24 residues. Based on the deduced amino acid sequence, the κ-carrageenase CgkS was classified into the Glycoside Hydrolase family 16. The cgkS gene was expressed in Escherichia coli, and the recombinant enzyme was purified to homogeneity with a specific activity of 716.8 U mg-1 and a yield of 69%. Recombinant CgkS was most active at 45°C and pH 8.0. It was stable at pH 6.0-9.0 and below 30°C. The enzyme did not require NaCl for activity, although its activity was enhanced by NaCl. CgkS degraded κ-carrageenan in an endo-fashion releasing tetrasaccharides and disaccharides as main hydrolysis products.

  8. A serine hydroxymethyltransferase from marine bacterium Shewanella algae: Isolation, purification, characterization and l-serine production.

    PubMed

    Jiang, Wei; Xia, Bingzhao; Liu, Ziduo

    2013-10-01

    Currently, l-serine is mainly produced by enzymatic conversion, in which serine hydroxymethyltransferase (SHMT) is the key enzyme, suggesting the importance of searching for a SHMT with high activity. Shewanella algae, a methanol-utilizing marine bacterium showing high SHMT activity, was selected based on screening bacterial strains and comparison of the activities of SHMTs. A glyA was isolated from the S. algae through thermal asymmetric interlaced PCR (TAIL-PCR) and it encoded a 417 amino acid polypeptide. The SaSHMT, encoded by the glyA, showed the optimal activity at 50°C and pH 7.0, and retained over 45% of its maximal activity after incubation at 40°C for 3h. The enzyme showed better stability under alkaline environment (pH 6.5-9.0) than Hyphomicrobium methylovorum GM2's SHMT (pH 6.0-7.5). The SaSHMT can produce 77.76mM of l-serine by enzymatic conversion, with the molecular conversion rate in catalyzing glycine to l-serine being 1.41-fold higher than that of Escherichia coli. Therefore, the SaSHMT has the potential for industrial applications due to its tolerance of alkaline environment and a relatively high enzymatic conversion rate. PMID:23632047

  9. An expansin from the marine bacterium Hahella chejuensis acts synergistically with xylanase and enhances xylan hydrolysis.

    PubMed

    Lee, Hee Jin; Kim, In Jung; Kim, Jihyun F; Choi, In-Geol; Kim, Kyoung Heon

    2013-12-01

    HcEXLX2 is a bacterial expansin found in a marine bacterium, Hahella chejuensis. Previously, HcEXLX2 was reported to act synergistically with a commercial cellulase preparation on the cellulose hydrolysis. The aim of the present study was to investigate the possible synergistic activity of HcEXLX2 with an endo-type xylanase from Saccharophagus degradans 2-40(T) (Xyn10C) in the hydrolysis of xylan. When 160 μg of HcEXLX2 was incubated with 12 μg of Xyn10C, the yield of reducing sugar increased 3.1 times when compared to that without HcEXLX2. The optimal temperature and pH for the synergism of HcEXLX2 with Xyn10C were 30°C and pH 7, respectively. In addition, binding experiments revealed that HcEXLX2 binds to xylan more preferentially than to Avicel. These results imply that HcEXLX2 could be used as an accessory protein to boost the activity of xylanase if its synergistic effect is strengthened at lower dosages.

  10. A polysaccharide-degrading marine bacterium Flammeovirga sp. MY04 and its extracellular agarase system

    NASA Astrophysics Data System (ADS)

    Han, Wenjun; Gu, Jingyan; Yan, Qiujie; Li, Jungang; Wu, Zhihong; Gu, Qianqun; Li, Yuezhong

    2012-09-01

    Bacteria of the genus Flammeovirga can digest complex polysaccharides (CPs), but no details have been reported regarding the CP depolymerases of these bacteria. MY04, an agarolytic marine bacterium isolated from coastal sediments, has been identified as a new member of the genus Flammeovirga. The MY04 strain is able to utilize multiple CPs as a sole carbon source and grows well on agarose, mannan, or xylan. This strain produces high concentrations of extracellular proteins (490 mg L-1 ± 18.2 mg L-1 liquid culture) that exhibit efficient and extensive degradation activities on various polysaccharides, especially agarose. These proteins have an activity of 310 U mg-1 ± 9.6 U mg-1 proteins. The extracellular agarase system (EAS) in the crude extracellular enzymes contains at least four agarose depolymerases, which are with molecular masses of approximately 30-70 kDa. The EAS is stable at a wide range of pH values (6.0-11.0), temperatures (0-50°C), and sodium chloride (NaCl) concentrations (0-0.9 mol L-1). Two major degradation products generated from agarose by the EAS are identified to be neoagarotetraose and neoagarohexaose, suggesting that β-agarases are the major constituents of the MY04 EAS. These results suggest that the Flammeovirga strain MY04 and its polysaccharide-degradation system hold great promise in industrial applications.

  11. Iridescence of a Marine Bacterium and Classification of Prokaryotic Structural Colors

    PubMed Central

    Vukusic, Peter; Luke, Stephen

    2012-01-01

    Iridescence is a property of structural color that is occasionally encountered in higher eukaryotes but that has been poorly documented in the prokaryotic kingdom. In the present work, we describe a marine bacterium, identified as Cellulophaga lytica, isolated from the surface of an anemone, that exhibits bright green iridescent colonies under direct epi-illumination. This phenomenon has not previously been investigated in detail. In this study, color changes of C. lytica colonies were observed at various angles of direct illumination or observation. Its iridescent green appearance was dominant on various growth media. Red and violet colors were also discerned on colony edges. Remarkable C. lytica bacterial iridescence was revealed and characterized using high-resolution optical spectrometry. In addition to this, by culturing other bacterial strains to which various forms of faintly iridescent traits have previously been attributed, we identify four principal appearance characteristics of structural color in prokaryotes. A new general classification of bacterial iridescence is therefore proposed in this study. Furthermore, a specific separate class is described for iridescent C. lytica strains because they exhibit what is so far a unique intense glitter-like iridescence in reflection. C. lytica is the first prokaryote discovered to produce the same sort of intense iridescence under direct illumination as that associated with higher eukaryotes, like some insects and birds. Due to the nature of bacterial biology, cultivation, and ubiquity, this discovery may be of significant interest for both ecological and nanoscience endeavors. PMID:22267664

  12. Regulation of iron transport related genes by boron in the marine bacterium Marinobacter algicola DG893.

    PubMed

    Romano, Ariel; Trimble, Lyndsay; Hobusch, Ashtian R; Schroeder, Kristine J; Amin, Shady A; Hartnett, Andrej D; Barker, Ryan A; Crumbliss, Alvin L; Carrano, Carl J

    2013-08-01

    While there has been extensive interest in the use of boron isotope ratios as a surrogate of pH in paleoclimate studies in the context of climate change-related questions, the high (0.4 mM) concentration and the depth-independent (conservative or non-nutrient-like) concentration profile of this element have led to boron being neglected as a potentially biologically relevant element in the modern ocean. Here we report that boron affects the expression of a number of protein and genes in the "algal-associated" Gram-negative marine bacterium Marinobacter algicola DG893. Most intriguingly, a number of these proteins and genes are related to iron uptake. In a recent separate publication we have shown that boron regulates one such iron transport related protein, i.e. the periplasmic iron binding protein FbpA via a direct interaction of the metalloid with this protein. Here we show that a number of other iron uptake related genes are also affected by boron but in the opposite way i.e. they are up-regulated. We propose that the differential effect of boron on FbpA expression relative to other iron transport related genes is a result of an interaction between boron and the global iron regulatory protein Fur.

  13. Effects of Inorganic Particles on Metabolism by a Periphytic Marine Bacterium

    PubMed Central

    Gordon, Andrew S.; Gerchakov, Sol M.; Millero, Frank J.

    1983-01-01

    Measurements were made of adsorption of a periphytic marine bacterium, glucose, and glutamic acid to inorganic particles in seawater and defined bacterial growth medium. Measurements of the metabolism of bacteria were made in the presence and absence of particles by microcalorimetry and radiorespirometry. It was found that hydroxyapatite adsorbs glutamic acid, but not glucose, from the experimental medium. It was also found that hydroxyapatite adsorbs essentially all of the bacteria from the medium when the bacterial concentration is approximately 6 × 105 bacteria per ml. If the bacterial concentration is approximately 6 × 107, then only a small fraction of cells become attached. It was therefore possible to select bacterial concentrations and organic nutrients so that bacterial attachment, organic nutrient adsorption, or both would occur in different experiments. In this experimental system the metabolism by attached and nonattached bacteria of adsorbing and nonadsorbing organic nutrients was measured. The results show that bacterial activity in this model system was not enhanced by the particles, regardless of whether the bacteria, the organic nutrient, or both were associated with the surface. In fact, the respiratory activity of the attached bacteria was diminished in comparison with that of free bacteria. PMID:16346191

  14. Anti-methicillin-resistant Staphylococcus aureus (MRSA) substance from the marine bacterium Pseudomonas sp. UJ-6.

    PubMed

    Lee, Dae-Sung; Eom, Sung-Hwan; Jeong, Seong-Yun; Shin, Hee Jae; Je, Jae-Young; Lee, Eun-Woo; Chung, Yong-Hyun; Kim, Young-Mog; Kang, Chang-Keun; Lee, Myung-Suk

    2013-03-01

    A multivalent approach to discover a novel antibiotic substance against methicillin-resistant Staphylococcus aureus (MRSA), a marine bacterium, UJ-6, exhibiting an antibacterial activity against MRSA was isolated from seawater. The isolated strain was identified to be Pseudomonas sp. by the morphology, biochemical, and genetical analyses. The ethyl acetate extract of Pseudomonas sp. UJ-6 culture showed significant ant-MRSA activity. Bioassay-guided isolation of the extract using a growth inhibitory assay led to the isolation and identification of an active compound exhibiting anti-MRSA activity. Based on the analyses of the physicochemical and spectroscopic data including nuclear magnetic resonance and mass, the compound was identified to be 1-acetyl-beta-carboline. The minimum inhibitory concentration (MIC) of the compound was determined to be in a range of 32-128 μg/ml against MRSA strains. The MIC values against MRSA were superior or equal to those of other natural compounds such as catechins, suggesting that 1-acetyl-beta-carboline would be a good candidate in applications of the treatment of MRSA infection.

  15. Affinity purification of metalloprotease from marine bacterium using immobilized metal affinity chromatography.

    PubMed

    Li, Shangyong; Wang, Linna; Yang, Juan; Bao, Jing; Liu, Junzhong; Lin, Shengxiang; Hao, Jianhua; Sun, Mi

    2016-06-01

    In this study, an efficient affinity purification protocol for an alkaline metalloprotease from marine bacterium was developed using immobilized metal affinity chromatography. After screening and optimization of the affinity ligands and spacer arm lengths, Cu-iminmodiacetic acid was chosen as the optimal affinity ligand, which was coupled to Sepharose 6B via a 14-atom spacer arm. The absorption analysis of this medium revealed a desorption constant Kd of 21.5 μg/mL and a theoretical maximum absorption Qmax of 24.9 mg/g. Thanks to this affinity medium, the enzyme could be purified by only one affinity purification step with a purity of approximately 95% pure when analyzed by high-performance liquid chromatography and reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis. The recovery of the protease activity reached 74.6%, which is much higher than the value obtained by traditional protocols (8.9%). These results contribute to the industrial purifications and contribute a significant reference for the purification of other metalloproteases. PMID:27058973

  16. Biomass Yield Efficiency of the Marine Anammox Bacterium, “Candidatus Scalindua sp.,” is Affected by Salinity

    PubMed Central

    Awata, Takanori; Kindaichi, Tomonori; Ozaki, Noriatsu; Ohashi, Akiyoshi

    2015-01-01

    The growth rate and biomass yield efficiency of anaerobic ammonium oxidation (anammox) bacteria are markedly lower than those of most other autotrophic bacteria. Among the anammox bacterial genera, the growth rate and biomass yield of the marine anammox bacterium “Candidatus Scalindua sp.” is still lower than those of other anammox bacteria enriched from freshwater environments. The activity and growth of marine anammox bacteria are generally considered to be affected by the presence of salinity and organic compounds. Therefore, in the present study, the effects of salinity and volatile fatty acids (VFAs) on the anammox activity, inorganic carbon uptake, and biomass yield efficiency of “Ca. Scalindua sp.” enriched from the marine sediments of Hiroshima Bay, Japan, were investigated in batch experiments. Differences in VFA concentrations (0–10 mM) were observed under varying salinities (0.5%–4%). Anammox activity was high at 0.5%–3.5% salinity, but was 30% lower at 4% salinity. In addition, carbon uptake was higher at 1.5%–3.5% salinity. The results of the present study clearly demonstrated that the biomass yield efficiency of the marine anammox bacterium “Ca. Scalindua sp.” was significantly affected by salinity. On the other hand, the presence of VFAs up to 10 mM did not affect anammox activity, carbon uptake, or biomass yield efficiency. PMID:25740428

  17. Synergistic effect of quorum sensing genes in biofilm development and PAHs degradation by a marine bacterium.

    PubMed

    Kumari, Supriya; Mangwani, Neelam; Das, Surajit

    2016-04-01

    Quorum sensing (QS) is a prevalently found intercellular signaling system in bacteria. QS system bestows behavioral coordination ability in bacteria at high population density. QS via acylated homoserine lactone (AHL) is extensively conserved in Gram-negative bacteria and plays crucial role in regulating many biological processes. The role of QS genes coding for AHL synthase enzyme (lasI and rhlI) was established in bioremediation of polycyclic aromatic hydrocarbons (PAHs) viz. phenanthrene and pyrene. AHL producing biofilm forming marine bacterium Pseudomonas aeruginosa N6P6 was isolated by selective enrichment on PAHs. AHL production was confirmed using AHL bioreporters and GC-MS analysis. Biofilm development and its architecture was significantly (P < 0.05) affected by alterations in lasI/rhlI expression. The lasI/rhlI gene expression pattern significantly influences biofilm formation and subsequent degradation of PAHs. The integrated density of Pseudomonas aeruginosa N6P6 biofilm was highest for 48 h old biofilm and the PAHs (phenanthrene and pyrene) degradation was also found maximum (85.6 % and 47.56 %) with this biofilm. A significant positive correlation (P < 0.05) was observed between lasI expression and PAHs degradation. The role of QS genes in biofilm formation and degradation of PAHs was validated by blocking the transcription of lasI/rhlI by a QS inhibitor (QSI) tannic acid. Further, application of such QS positive isolates in PAHs contaminated sites could be a promising strategy to improve the PAHs bioremediation.

  18. Biochemical and Structural Characterization of the Complex Agarolytic Enzyme System from the Marine Bacterium Zobellia galactanivorans*

    PubMed Central

    Hehemann, Jan-Hendrik; Correc, Gaëlle; Thomas, François; Bernard, Thomas; Barbeyron, Tristan; Jam, Murielle; Helbert, William; Michel, Gurvan; Czjzek, Mirjam

    2012-01-01

    Zobellia galactanivorans is an emerging model bacterium for the bioconversion of algal biomass. Notably, this marine Bacteroidetes possesses a complex agarolytic system comprising four β-agarases and five β-porphyranases, all belonging to the glycoside hydrolase family 16. Although β-agarases are specific for the neutral agarobiose moieties, the recently discovered β-porphyranases degrade the sulfated polymers found in various quantities in natural agars. Here, we report the biochemical and structural comparison of five β-porphyranases and β-agarases from Z. galactanivorans. The respective degradation patterns of two β-porphyranases and three β-agarases are analyzed by their action on defined hybrid oligosaccharides. In light of the high resolution crystal structures, the biochemical results allowed a detailed mapping of substrate specificities along the active site groove of the enzymes. Although PorA displays a strict requirement for C6-sulfate in the −2- and +1-binding subsites, PorB tolerates the presence of 3–6-anhydro-l-galactose in subsite −2. Both enzymes do not accept methylation of the galactose unit in the −1 subsite. The β-agarase AgaD requires at least four consecutive agarose units (DP8) and is highly intolerant to modifications, whereas for AgaB oligosaccharides containing C6-sulfate groups at the −4, +1, and +3 positions are still degraded. Together with a transcriptional analysis of the expression of these enzymes, the structural and biochemical results allow proposition of a model scheme for the agarolytic system of Z. galactanivorans. PMID:22778272

  19. Defluviimonas indica sp. nov., a marine bacterium isolated from a deep-sea hydrothermal vent environment.

    PubMed

    Jiang, Lijing; Xu, Hongxiu; Shao, Zongze; Long, Minnan

    2014-06-01

    A Gram-stain-negative, strictly aerobic, chemoheterotrophic marine bacterium, designated 20V17(T), was isolated from a deep-sea hydrothermal vent chimney collected from the South-west Indian Ridge. Cells of strain 20V17(T) were motile, short rods, 1.2-1.8 µm in length and 0.5-0.7 µm in width. Growth was observed at between 20 and 37 °C (optimum 25 °C-28 °C), pH 5.0 and 8.0 (optimum pH 7.0) and 0.5 and 8% (w/v) NaCl (optimum 1.5-2.0% NaCl). The major fatty acids were C(18 : 1)ω7c (74.4%), C(19 : 0) cyclo ω8c (11%), C(18 : 0) (5.1%) and C(18 : 0) 3-OH (2.8%), and the polar lipid profile comprised diphosphatidylglycerol, phosphatidylethanolamine, an unidentified glycolipid and four unidentified phospholipids. Ubiquinone 10 was the major quinone. The G+C content of genomic DNA was 66.3 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain 20V17(T) belonged to the genus Defluviimonas and shared 96.5 and 96.1% sequence similarity with Defluviimonas denitrificans D9-3(T) and Defluviimonas aestuarii BS14(T), respectively. On the basis of the taxonomic data obtained in this study, strain 20V17(T) represents a novel species of the genus Defluviimonas, for which the name Defluviimonas indica sp. nov. is proposed. The type strain is 20V17(T) (CGMCC 1.10859(T) = JCM 17871(T) = MCCC 1A01802(T)).

  20. Recombinant production and characterization of a highly active alkaline phosphatase from marine bacterium Cobetia marina.

    PubMed

    Golotin, Vasily; Balabanova, Larissa; Likhatskaya, Galina; Rasskazov, Valery

    2015-04-01

    The psychrophilic marine bacterium, Cobetia marina, recovered from the mantle tissue of the marine mussel, Crenomytilus grayanus, which contained a gene encoding alkaline phosphatase (AP) with apparent biotechnology advantages. The enzyme was found to be more efficient than its counterparts and showed k cat value 10- to 100-fold higher than those of all known commercial APs. The enzyme did not require the presence of exogenous divalent cations and dimeric state of its molecule for activity. The recombinant enzyme (CmAP) production and purification were optimized with a final recovery of 2 mg of the homogenous protein from 1 L of the transgenic Escherichia coli Rosetta(DE3)/Pho40 cells culture. CmAP displayed a half-life of 16 min at 45 °C and 27 min at 40 °C in the presence of 2 mM EDTA, thus suggesting its relative thermostability in comparison with the known cold-adapted analogues. A high concentration of EDTA in the incubation mixture did not appreciably inhibit CmAP. The enzyme was stable in a wide range of pH (6.0-11.0). CmAP exhibited its highest activity at the reaction temperature of 40-50 °C and pH 9.5-10.3. The structural features of CmAP could be the reason for the increase in its stability and catalytic turnover. We have modeled the CmAP 3D structure on the base of the high-quality experimental structure of the close homologue Vibrio sp. AP (VAP) and mutated essential residues predicted to break Mg(2+) bonds in CmAP. It seems probable that the intrinsically tight binding of catalytic and structural metal ions together with the flexibility of intermolecular and intramolecular links in CmAP could be attributed to the adapted mutualistic lifestyle in oceanic waters. PMID:25260971

  1. A Comparative biochemical study on two marine endophytes, Bacterium SRCnm and Bacillus sp. JS, Isolated from red sea algae.

    PubMed

    Ahmed, Eman Fadl; Hassan, Hossam Mokhtar; Rateb, Mostafa Ezzat; Abdel-Wahab, Noha; Sameer, Somayah; Aly Taie, Hanan Anwar; Abdel-Hameed, Mohammed Sayed; Hammouda, Ola

    2016-01-01

    Two marine endophytic bacteria were isolated from the Red Sea algae; a red alga; Acanthophora dendroides and the brown alga Sargassum sabrepandum. The isolates were identified based on their 16SrRNA sequences as Bacterium SRCnm and Bacillus sp. JS. The objective of this study was to investigate the potential anti-microbial and antioxidant activities of the extracts of the isolated bacteria grown in different nutrient conditions. Compared to amoxicillin (25μg/disk) and erythromycin (15μg/disk), the extracts of Bacterium SRCn min media II, III, IV and V were potent inhibitors of the gram-positive bacterium Sarcina maxima even at low concentrations. Also, the multidrug resistant Staphylococcus aureus(MRSA) was more sensitive to the metabolites produced in medium (II) of the same endophyte than erythromycin (15μg/disk). A moderate activity of the Bacillus sp. JS extracts of media I and II was obtained against the same pathogen. The total compounds (500ug/ml) of both isolated endophytes showed moderate antioxidant activities (48.9% and 46.1%, respectively). LC/MS analysis of the bacterial extracts was carried out to investigate the likely natural products produced. Cyclo(D-cis-Hyp-L-Leu), dihydrosphingosine and 2-Amino-1,3-hexadecanediol were identified in the fermentation medium of Bacterium SRCnm, whereas cyclo (D-Pro-L-Tyr) and cyclo (L-Leu-L-Pro) were the suggested compounds of Bacillus sp. JS. PMID:26826831

  2. Trimethylamine and trimethylamine N-oxide are supplementary energy sources for a marine heterotrophic bacterium: implications for marine carbon and nitrogen cycling

    PubMed Central

    Lidbury, Ian DEA; Murrell, J Colin; Chen, Yin

    2015-01-01

    Bacteria of the marine Roseobacter clade are characterised by their ability to utilise a wide range of organic and inorganic compounds to support growth. Trimethylamine (TMA) and trimethylamine N-oxide (TMAO) are methylated amines (MA) and form part of the dissolved organic nitrogen pool, the second largest source of nitrogen after N2 gas, in the oceans. We investigated if the marine heterotrophic bacterium, Ruegeria pomeroyi DSS-3, could utilise TMA and TMAO as a supplementary energy source and whether this trait had any beneficial effect on growth. In R. pomeroyi, catabolism of TMA and TMAO resulted in the production of intracellular ATP which in turn helped to enhance growth rate and growth yield as well as enhancing cell survival during prolonged energy starvation. Furthermore, the simultaneous use of two different exogenous energy sources led to a greater enhancement of chemoorganoheterotrophic growth. The use of TMA and TMAO primarily as an energy source resulted in the remineralisation of nitrogen in the form of ammonium, which could cross feed into another bacterium. This study provides greater insight into the microbial metabolism of MAs in the marine environment and how it may affect both nutrient flow within marine surface waters and the flux of these climatically important compounds into the atmosphere. PMID:25148480

  3. Trimethylamine and trimethylamine N-oxide are supplementary energy sources for a marine heterotrophic bacterium: implications for marine carbon and nitrogen cycling.

    PubMed

    Lidbury, Ian D E A; Murrell, J Colin; Chen, Yin

    2015-03-01

    Bacteria of the marine Roseobacter clade are characterised by their ability to utilise a wide range of organic and inorganic compounds to support growth. Trimethylamine (TMA) and trimethylamine N-oxide (TMAO) are methylated amines (MA) and form part of the dissolved organic nitrogen pool, the second largest source of nitrogen after N2 gas, in the oceans. We investigated if the marine heterotrophic bacterium, Ruegeria pomeroyi DSS-3, could utilise TMA and TMAO as a supplementary energy source and whether this trait had any beneficial effect on growth. In R. pomeroyi, catabolism of TMA and TMAO resulted in the production of intracellular ATP which in turn helped to enhance growth rate and growth yield as well as enhancing cell survival during prolonged energy starvation. Furthermore, the simultaneous use of two different exogenous energy sources led to a greater enhancement of chemoorganoheterotrophic growth. The use of TMA and TMAO primarily as an energy source resulted in the remineralisation of nitrogen in the form of ammonium, which could cross feed into another bacterium. This study provides greater insight into the microbial metabolism of MAs in the marine environment and how it may affect both nutrient flow within marine surface waters and the flux of these climatically important compounds into the atmosphere.

  4. Adsorption of Pb(II) by a marine bacterium: the effect of cell concentration and pH

    NASA Astrophysics Data System (ADS)

    Lion, Leonard W.; Rochlin, Kevin L.

    1989-07-01

    Adsorption of Pb from synthetic seawater solution onto the marine bacterium Pseudomonas atlantica displayed many of the feature commonly encountered in studies of trace metal adsorption onto hydrous oxides. These included: (1) indication of multisite adsorption behaviour, and (2) 'particle effects' (indicated by decreased adsorption density with increasing surface concentration). For suspensions of P. atlantica this effect is attributed to the release of dissolved organic material which binds Pb in solution. Differences in Pb binding to P. atlantica relative to oxide surfaces includes: (1) relatively low fractional (%) adsorption over a wide range of solution pH, Pb, and cell concentrations, and (2) lack of a marked, pH-dependent, adsorption edge.

  5. Aliidiomarina iranensis sp. nov., a haloalkaliphilic bacterium from a coastal-marine wetland.

    PubMed

    Ali Amoozegar, Mohammad; Shahinpei, Azadeh; Abolhassan Shahzadeh Fazeli, Seyed; Schumann, Peter; Spröer, Cathrin; Ventosa, Antonio

    2016-05-01

    A novel Gram-stain-negative, straight rod-shaped, non-pigmented, slightly halophilic and alkaliphilic bacterium, designated strain GBPy7T, was isolated from a sample of the coastal-marine wetland Gomishan in Iran. Cells of strain GBPy7T were motile. Growth occurred on media with 1-15 % (w/v) NaCl (optimum 3 %), at pH 7-10 (optimum pH 8.5) and at 4-45 °C (optimum 37 °C). Phylogenetic analysis based on 16S rRNA gene sequence comparison indicated that strain GBPy7T belonged to the family Idiomarinaceae. Its closest relatives were Aliidiomarina shirensis AIST (98.1 % 16S rRNA gene sequence similarity) and other Aliidiomarina species (95.9-94.2 %), together with Idiomarina seosinensis CL-SP19T (94.3 %) and Idiomarina fontislapidosi F23T (94.3 %). The major cellular fatty acids of the isolate were iso-C15 : 0, iso-C17 : 0, iso-C17 : 1ω9c and C18 : 1ω7c and its polar lipid profile comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, one unknown phospholipid and one unknown aminophospholipid. Cells of strain GBPy7T contained ubiquinone Q-8. The G+C content of the genomic DNA of this strain was 51.6 mol%. The level of DNA-DNA relatedness between strain GBPy7T and A. shirensis IBRC-M 10414T was 21 %. The physiological, biochemical, genotypic and phylogenetic differences between strain GBPy7T and other previously described taxa indicate that the strain represents a novel species of the genus Aliidiomarina within the family Idiomarinaceae, for which the name Aliidiomarina iranensis sp. nov. is proposed. The type strain is GBPy7T ( = IBRC-M 10763T = CECT 8339T). PMID:26928783

  6. Aliidiomarina iranensis sp. nov., a haloalkaliphilic bacterium from a coastal-marine wetland.

    PubMed

    Ali Amoozegar, Mohammad; Shahinpei, Azadeh; Abolhassan Shahzadeh Fazeli, Seyed; Schumann, Peter; Spröer, Cathrin; Ventosa, Antonio

    2016-05-01

    A novel Gram-stain-negative, straight rod-shaped, non-pigmented, slightly halophilic and alkaliphilic bacterium, designated strain GBPy7T, was isolated from a sample of the coastal-marine wetland Gomishan in Iran. Cells of strain GBPy7T were motile. Growth occurred on media with 1-15 % (w/v) NaCl (optimum 3 %), at pH 7-10 (optimum pH 8.5) and at 4-45 °C (optimum 37 °C). Phylogenetic analysis based on 16S rRNA gene sequence comparison indicated that strain GBPy7T belonged to the family Idiomarinaceae. Its closest relatives were Aliidiomarina shirensis AIST (98.1 % 16S rRNA gene sequence similarity) and other Aliidiomarina species (95.9-94.2 %), together with Idiomarina seosinensis CL-SP19T (94.3 %) and Idiomarina fontislapidosi F23T (94.3 %). The major cellular fatty acids of the isolate were iso-C15 : 0, iso-C17 : 0, iso-C17 : 1ω9c and C18 : 1ω7c and its polar lipid profile comprised phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, one unknown phospholipid and one unknown aminophospholipid. Cells of strain GBPy7T contained ubiquinone Q-8. The G+C content of the genomic DNA of this strain was 51.6 mol%. The level of DNA-DNA relatedness between strain GBPy7T and A. shirensis IBRC-M 10414T was 21 %. The physiological, biochemical, genotypic and phylogenetic differences between strain GBPy7T and other previously described taxa indicate that the strain represents a novel species of the genus Aliidiomarina within the family Idiomarinaceae, for which the name Aliidiomarina iranensis sp. nov. is proposed. The type strain is GBPy7T ( = IBRC-M 10763T = CECT 8339T).

  7. Investigation of the mechanism of iron acquisition by the marine bacterium Alteromonas luteoviolaceus: Characterization of siderophore production

    SciTech Connect

    Reid, R.T.; Butler, A. )

    1991-12-01

    Iron availability in the ocean ranges from one to four orders of magnitude below typical growth requirements of bacteria. The discrepancy between Fe availability and requirements raises questions about the mechanisms that marine bacteria use to sequester Fe{sup 3+}. Surprisingly little is known about the siderophores produced by marine bacteria. Growth conditions of an open-ocean bacterial isolate, Alteromonas luteoviolaceus, were investigated to determine the conditions which enhance siderophore production. Methods to isolate and purify the siderophores were determined. The siderophores produced by A. luteoviolaceus were partially characterized by mass spectral analysis, amino acid analysis, qualitative analytical tests, chemical degradation, and nuclear magnetic resonance. A new set of outer membrane proteins was also produced when the bacterium was grown under Fe-limited conditions.

  8. Fermentation products of solvent tolerant marine bacterium Moraxella spp. MB1 and its biotechnological applications in salicylic acid bioconversion.

    PubMed

    Wahidullah, Solimabi; Naik, Deepak N; Devi, Prabha

    2013-01-01

    As part of a proactive approach to environmental protection, emerging issues with potential impact on the environment is the subject of ongoing investigation. One emerging area of environmental research concerns pharmaceuticals like salicylic acid, which is the main metabolite of various analgesics including aspirin. It is a common component of sewage effluent and also an intermediate in the degradation pathway of various aromatic compounds which are introduced in the marine environment as pollutants. In this study, biotransformation products of salicylic acid by seaweed, Bryopsis plumosa, associated marine bacterium, Moraxella spp. MB1, have been investigated. Phenol, conjugates of phenol and hydroxy cinnamic acid derivatives (coumaroyl, caffeoyl, feruloyl and trihydroxy cinnamyl) with salicylic acid (3-8) were identified as the bioconversion products by electrospray ionization mass spectrometry. These results show that the microorganism do not degrade phenolic acid but catalyses oxygen dependent transformations without ring cleavage. The degradation of salicylic acid is known to proceed either via gentisic acid pathway or catechol pathway but this is the first report of biotransformation of salicylic acid into cinnamates, without ring cleavage. Besides cinnamic acid derivatives (9-12), metabolites produced by the bacterium include antimicrobial indole (13) and β-carbolines, norharman (14), harman (15) and methyl derivative (16), which are beneficial to the host and the environment. PMID:24391802

  9. Fermentation products of solvent tolerant marine bacterium Moraxella spp. MB1 and its biotechnological applications in salicylic acid bioconversion.

    PubMed

    Wahidullah, Solimabi; Naik, Deepak N; Devi, Prabha

    2013-01-01

    As part of a proactive approach to environmental protection, emerging issues with potential impact on the environment is the subject of ongoing investigation. One emerging area of environmental research concerns pharmaceuticals like salicylic acid, which is the main metabolite of various analgesics including aspirin. It is a common component of sewage effluent and also an intermediate in the degradation pathway of various aromatic compounds which are introduced in the marine environment as pollutants. In this study, biotransformation products of salicylic acid by seaweed, Bryopsis plumosa, associated marine bacterium, Moraxella spp. MB1, have been investigated. Phenol, conjugates of phenol and hydroxy cinnamic acid derivatives (coumaroyl, caffeoyl, feruloyl and trihydroxy cinnamyl) with salicylic acid (3-8) were identified as the bioconversion products by electrospray ionization mass spectrometry. These results show that the microorganism do not degrade phenolic acid but catalyses oxygen dependent transformations without ring cleavage. The degradation of salicylic acid is known to proceed either via gentisic acid pathway or catechol pathway but this is the first report of biotransformation of salicylic acid into cinnamates, without ring cleavage. Besides cinnamic acid derivatives (9-12), metabolites produced by the bacterium include antimicrobial indole (13) and β-carbolines, norharman (14), harman (15) and methyl derivative (16), which are beneficial to the host and the environment.

  10. Fermentation Products of Solvent Tolerant Marine Bacterium Moraxella spp. MB1 and Its Biotechnological Applications in Salicylic Acid Bioconversion

    PubMed Central

    Wahidullah, Solimabi; Naik, Deepak N.; Devi, Prabha

    2013-01-01

    As part of a proactive approach to environmental protection, emerging issues with potential impact on the environment is the subject of ongoing investigation. One emerging area of environmental research concerns pharmaceuticals like salicylic acid, which is the main metabolite of various analgesics including aspirin. It is a common component of sewage effluent and also an intermediate in the degradation pathway of various aromatic compounds which are introduced in the marine environment as pollutants. In this study, biotransformation products of salicylic acid by seaweed, Bryopsis plumosa, associated marine bacterium, Moraxella spp. MB1, have been investigated. Phenol, conjugates of phenol and hydroxy cinnamic acid derivatives (coumaroyl, caffeoyl, feruloyl and trihydroxy cinnamyl) with salicylic acid (3–8) were identified as the bioconversion products by electrospray ionization mass spectrometry. These results show that the microorganism do not degrade phenolic acid but catalyses oxygen dependent transformations without ring cleavage. The degradation of salicylic acid is known to proceed either via gentisic acid pathway or catechol pathway but this is the first report of biotransformation of salicylic acid into cinnamates, without ring cleavage. Besides cinnamic acid derivatives (9–12), metabolites produced by the bacterium include antimicrobial indole (13) and β-carbolines, norharman (14), harman (15) and methyl derivative (16), which are beneficial to the host and the environment. PMID:24391802

  11. Antibacterial activity of antagonistic bacterium Bacillus subtilis DJM-51 against phytopathogenic Clavibacter michiganense subsp. michiganense ATCC 7429 in vitro.

    PubMed

    Jung, W J; Mabood, F; Souleimanov, A; Whyte, L G; Niederberger, T D; Smith, D L

    2014-12-01

    To investigate antibacterial activity against the tomato pathogen Clavibacter michiganense subsp. michiganense ATCC 7429 (Cmm ATCC 7429), Bacillus subtilis DJM-51 was isolated from rhizosphere soil. For isolation of bacteria, samples were taken from rhizosphere soil. The isolate, DJA-51, had strong antagonistic ability against Tomato pathogen Cmm ATCC 7429 on nutrient-broth yeast extract agar (NBYA) as indicated by inhibition zones around colonies. On the basis of the nucleotide sequence of a conserved segment of the 16S rRNA gene, the bacterium has been identified as B. subtilis DJM-51. The growth of Cmm ATCC 7429 on NBYA plates was inhibited by culture broth of B. subtilis DJM-51 including cells, by the supernatant of culture broth of B. subtilis DJM-51, and by the liquid material resulting from butanol extract of bacterial cultures. The OD value in co-culture mixture was lower than the control throughout the entire incubation period. Antibiotics obtained from B. subtilis DJM-51 inhibited the growth of Tomato pathogen Cmm ATCC 7429. These results provide potentially information about the protection of tomato from pathogen Cmm ATCC 7429 under greenhouse conditions in Quebec.

  12. Antibacterial activity of antagonistic bacterium Bacillus subtilis DJM-51 against phytopathogenic Clavibacter michiganense subsp. michiganense ATCC 7429 in vitro.

    PubMed

    Jung, W J; Mabood, F; Souleimanov, A; Whyte, L G; Niederberger, T D; Smith, D L

    2014-12-01

    To investigate antibacterial activity against the tomato pathogen Clavibacter michiganense subsp. michiganense ATCC 7429 (Cmm ATCC 7429), Bacillus subtilis DJM-51 was isolated from rhizosphere soil. For isolation of bacteria, samples were taken from rhizosphere soil. The isolate, DJA-51, had strong antagonistic ability against Tomato pathogen Cmm ATCC 7429 on nutrient-broth yeast extract agar (NBYA) as indicated by inhibition zones around colonies. On the basis of the nucleotide sequence of a conserved segment of the 16S rRNA gene, the bacterium has been identified as B. subtilis DJM-51. The growth of Cmm ATCC 7429 on NBYA plates was inhibited by culture broth of B. subtilis DJM-51 including cells, by the supernatant of culture broth of B. subtilis DJM-51, and by the liquid material resulting from butanol extract of bacterial cultures. The OD value in co-culture mixture was lower than the control throughout the entire incubation period. Antibiotics obtained from B. subtilis DJM-51 inhibited the growth of Tomato pathogen Cmm ATCC 7429. These results provide potentially information about the protection of tomato from pathogen Cmm ATCC 7429 under greenhouse conditions in Quebec. PMID:25457795

  13. Genome Sequence of Vibrio sp. Strain EJY3, an Agarolytic Marine Bacterium Metabolizing 3,6-Anhydro-l-Galactose as a Sole Carbon Source

    PubMed Central

    Roh, Hanseong; Yun, Eun Ju; Lee, Saeyoung; Ko, Hyeok-Jin; Kim, Sujin; Kim, Byung-Yong; Song, Heesang; Lim, Kwang-il

    2012-01-01

    The metabolic fate of 3,6-anhydro-l-galactose (l-AHG) is unknown in the global marine carbon cycle. Vibrio sp. strain EJY3 is an agarolytic marine bacterium that can utilize l-AHG as a sole carbon source. To elucidate the metabolic pathways of l-AHG, we have sequenced the complete genome of Vibrio sp. strain EJY3. PMID:22535948

  14. Cloning and characterization of a novel chondroitin sulfate/dermatan sulfate 4-O-endosulfatase from a marine bacterium.

    PubMed

    Wang, Wenshuang; Han, Wenjun; Cai, Xingya; Zheng, Xiaoyu; Sugahara, Kazuyuki; Li, Fuchuan

    2015-03-20

    Sulfatases are potentially useful tools for structure-function studies of glycosaminoglycans (GAGs). To date, various GAG exosulfatases have been identified in eukaryotes and prokaryotes. However, endosulfatases that act on GAGs have rarely been reported. Recently, a novel HA and CS lyase (HCLase) was identified for the first time from a marine bacterium (Han, W., Wang, W., Zhao, M., Sugahara, K., and Li, F. (2014) J. Biol. Chem. 289, 27886-27898). In this study, a putative sulfatase gene, closely linked to the hclase gene in the genome, was recombinantly expressed and characterized in detail. The recombinant protein showed a specific N-acetylgalactosamine-4-O-sulfatase activity that removes 4-O-sulfate from both disaccharides and polysaccharides of chondroitin sulfate (CS)/dermatan sulfate (DS), suggesting that this sulfatase represents a novel endosulfatase. The novel endosulfatase exhibited maximal reaction rate in a phosphate buffer (pH 8.0) at 30 °C and effectively removed 17-65% of 4-O-sulfates from various CS and DS and thus significantly inhibited the interactions of CS and DS with a positively supercharged fluorescent protein. Moreover, this endosulfatase significantly promoted the digestion of CS by HCLase, suggesting that it enhances the digestion of CS/DS by the bacterium. Therefore, this endosulfatase is a potential tool for use in CS/DS-related studies and applications.

  15. Azide anions inhibit GH-18 endochitinase and GH-20 Exo β-N-acetylglucosaminidase from the marine bacterium Vibrio harveyi.

    PubMed

    Sirimontree, Paknisa; Fukamizo, Tamo; Suginta, Wipa

    2016-02-01

    Vibrio harveyi is a bioluminescent marine bacterium that utilizes chitin as its sole source of energy. In the course of chitin degradation, the bacterium primarily secretes an endochitinase A (VhChiA) to hydrolyze chitin, generating chitooligosaccharide fragments that are readily transported into the cell and broken down to GlcNAc monomers by an exo β-N-acetylglucosaminidase (VhGlcNAcase). Here we report that sodium salts, especially sodium azide, inhibit two classes of these chitin-degrading enzymes (VhChiA and VhGlcNAcase) with distinct modes of action. Kinetic analysis of the enzymatic hydrolysis of pNP-glycoside substrates reveals that sodium azide inhibition of VhChiA has a mixed-type mode, but that it inhibits VhGlcNAcase competitively. We propose that azide anions inhibit chitinase activity by acting as strong nucleophiles that attack Cγ of the catalytic Glu or Cβ of the neighbouring Asp residues. Azide anions may bind not only to the catalytic centre, but also to the other subsites in the substrate-binding cleft of VhChiA. In contrast, azide anions may merely occupy the small-binding pocket of VhGlcNAcase, thereby blocking the accessibility of its active site by short-chain substrates. PMID:26330565

  16. Structure and anticancer activity of sulfated O-polysaccharide from marine bacterium Cobetia litoralis KMM 3880(T).

    PubMed

    Kokoulin, Maxim S; Kuzmich, Alexandra S; Kalinovsky, Anatoly I; Tomshich, Svetlana V; Romanenko, Lyudmila A; Mikhailov, Valery V; Komandrova, Nadezhda A

    2016-12-10

    We presented the structure of the polysaccharide moiety and anticancer activity in vitro of the sulfated lipopolysaccharide isolated from the marine bacterium Cobetia litoralis KMM 3880(T). The structure of O-polysaccharide was investigated by chemical methods along with (1)H and (13)C NMR spectroscopy. The O-polysaccharide was built up of branched trisaccharide repeating units consist of D-glucose (D-Glcр), D-mannose (D-Manр) and sulfated 3-deoxy-d-manno-oct-2-ulosonic acid (Kdo5S): →7-β-Kdoр4Ac5S-(2→4)-[β-d-Glcp-(1→2)-]-β-d-Manр6Ac-1→. We demonstrated that the lipopolysaccharide and О-deacetylated O-polysaccharide from Cobetia litoralis KMM 3880(T) inhibited a colony formation of human melanoma SK-MEL-28 and colorectal carcinoma HTC-116 cells. PMID:27577896

  17. Mechanistic Insight into Trimethylamine N-Oxide Recognition by the Marine Bacterium Ruegeria pomeroyi DSS-3

    PubMed Central

    Li, Chun-Yang; Chen, Xiu-Lan; Shao, Xuan; Wei, Tian-Di; Wang, Peng; Xie, Bin-Bin; Qin, Qi-Long; Zhang, Xi-Ying; Su, Hai-Nan; Song, Xiao-Yan; Shi, Mei; Zhou, Bai-Cheng

    2015-01-01

    ABSTRACT Trimethylamine N-oxide (TMAO) is an important nitrogen source for marine bacteria. TMAO can also be metabolized by marine bacteria into volatile methylated amines, the precursors of the greenhouse gas nitrous oxide. However, it was not known how TMAO is recognized and imported by bacteria. Ruegeria pomeroyi DSS-3, a marine Roseobacter, has an ATP-binding cassette transporter, TmoXWV, specific for TMAO. TmoX is the substrate-binding protein of the TmoXWV transporter. In this study, the substrate specificity of TmoX of R. pomeroyi DSS-3 was characterized. We further determined the structure of the TmoX/TMAO complex and studied the TMAO-binding mechanism of TmoX by biochemical, structural, and mutational analyses. A Ca2+ ion chelated by an extended loop in TmoX was shown to be important for maintaining the stability of TmoX. Molecular dynamics simulations indicate that TmoX can alternate between “open” and “closed” states for binding TMAO. In the substrate-binding pocket, four tryptophan residues interact with the quaternary amine of TMAO by cation-π interactions, and Glu131 forms a hydrogen bond with the polar oxygen atom of TMAO. The π-π stacking interactions between the side chains of Phe and Trp are also essential for TMAO binding. Sequence analysis suggests that the TMAO-binding mechanism of TmoX may have universal significance in marine bacteria, especially in the marine Roseobacter clade. This study sheds light on how marine microorganisms utilize TMAO. IMPORTANCE Trimethylamine N-oxide (TMAO) is an important nitrogen source for marine bacteria. The products of TMAO metabolized by bacteria are part of the precursors of the greenhouse gas nitrous oxide. It is unclear how TMAO is recognized and imported by bacteria. TmoX is the substrate-binding protein of a TMAO-specific transporter. Here, the substrate specificity of TmoX of Ruegeria pomeroyi DSS-3 was characterized. The TMAO-binding mechanism of TmoX was studied by biochemical, structural

  18. Complete genome of a coastal marine bacterium Muricauda lutaonensis KCTC 22339(T).

    PubMed

    Oh, Jeongsu; Choe, Hanna; Kim, Byung Kwon; Kim, Kyung Mo

    2015-10-01

    Muricauda lutaonensis KCTC 22339(T) is a yellow-pigmented, gram-negative, rod-shaped bacterium that was isolated from a coastal hot spring of a volcanic island in the Pacific Ocean, off the eastern coast of Taiwan. We here report the complete genome of M. lutaonensis KCTC 22339(T), which consists of 3,274,259bp with the G+C content of 44.97%. The completion of the M. lutaonensis genome sequence is expected to provide a valuable resource for understanding the secondary metabolic pathways related to bacterial pigmentation.

  19. Complete genome of a coastal marine bacterium Muricauda lutaonensis KCTC 22339(T).

    PubMed

    Oh, Jeongsu; Choe, Hanna; Kim, Byung Kwon; Kim, Kyung Mo

    2015-10-01

    Muricauda lutaonensis KCTC 22339(T) is a yellow-pigmented, gram-negative, rod-shaped bacterium that was isolated from a coastal hot spring of a volcanic island in the Pacific Ocean, off the eastern coast of Taiwan. We here report the complete genome of M. lutaonensis KCTC 22339(T), which consists of 3,274,259bp with the G+C content of 44.97%. The completion of the M. lutaonensis genome sequence is expected to provide a valuable resource for understanding the secondary metabolic pathways related to bacterial pigmentation. PMID:25986927

  20. Colonization of Morus alba L. by the plant-growth-promoting and antagonistic bacterium Burkholderia cepacia strain Lu10-1

    PubMed Central

    2010-01-01

    Background Anthracnose, caused by Colletotrichum dematium, is a serious threat to the production and quality of mulberry leaves in susceptible varieties. Control of the disease has been a major problem in mulberry cultivation. Some strains of Burkholderia cepacia were reported to be useful antagonists of plant pests and could increase the yields of several crop plants. Although B. cepacia Lu10-1 is an endophytic bacterium obtained from mulberry leaves, it has not been deployed to control C. dematium infection in mulberry nor its colonization patterns in mulberry have been studied using GFP reporter or other reporters. The present study sought to evaluate the antifungal and plant-growth-promoting properties of strain Lu10-1, to clarify its specific localization within a mulberry plant, and to better understand its potential as a biocontrol and growth-promoting agent. Results Lu10-1 inhibited conidial germination and mycelial growth of C. dematium in vitro; when applied on leaves or to the soil, Lu10-1 also inhibited the development of anthracnose in a greenhouse, but the effectiveness varied with the length of the interval between the strain treatment and inoculation with the pathogen. Strain Lu10-1 could survive in both sterile and non-sterile soils for more than 60 days. The strain produced auxins, contributed to P solubilization and nitrogenase activity, and significantly promoted the growth of mulberry seedlings. The bacteria infected mulberry seedlings through cracks formed at junctions of lateral roots with the main root and in the zone of differentiation and elongation, and the cells were able to multiply and spread, mainly to the intercellular spaces of different tissues. The growth in all the tissues was around 1-5 × 105 CFU per gram of fresh plant tissue. Conclusions Burkholderia cepacia strain Lu10-1 is an endophyte that can multiply and spread in mulberry seedlings rapidly and efficiently. The strain is antagonistic to C. dematium and acts as an

  1. Polaribacter butkevichii sp. nov., a novel marine mesophilic bacterium of the family Flavobacteriaceae.

    PubMed

    Nedashkovskaya, Olga I; Kim, Seung Bum; Lysenko, Anatoly M; Kalinovskaya, Nataliya I; Mikhailov, Valery V; Kim, In Seop; Bae, Kyung Sook

    2005-12-01

    A novel heterotrophic, yellow pigmented, aerobic, Gram-negative, nonmotile, oxidase- and catalase-positive bacterium KMM 3,938(T) was isolated from sea water collected in the Sea of Japan, Russia. The strain grew at mesophilic temperature range, and required the presence of NaCl for growth. 16S rRNA gene sequence analysis revealed that strain KMM 3,938(T) is a member of the family Flavobacteriaceae. The predominant fatty acids were C13:0 iso, C14:0 iso, C15:0 iso, C15:0, C15:1Delta6, 3OH-C15:0:3 iso, and 3OH-C15:0. The G + C content of the DNA of KMM 3938(T) was 32.4 mol%. On the basis of phenotypic, chemotaxonomic, genotypic, and phylogenetic characteristics, the novel bacterium was assigned to the genus Polaribacter as Polaribacter butkevichii sp. nov. The type strain is KMM 3938(T )(= KCTC 12100(T) = CCUG 48005(T)).

  2. Strategies developed by the marine bacterium Pseudomonas fluorescens BA3SM1 to resist metals: A proteome analysis.

    PubMed

    Poirier, Isabelle; Hammann, Philippe; Kuhn, Lauriane; Bertrand, Martine

    2013-03-15

    A global proteomic evaluation of the response of the marine bacterium Pseudomonas fluorescens BA3SM1 to Cd, Zn and Cu was performed by two dimensional gel electrophoresis followed by mass spectrometry. When stressed with Cd, the most toxic metal for P. fluorescens BA3SM1, cell growth is rapidly affected and the number of proteins up-regulated (sixteen for 0.4 mM Cd) remains low in comparison with results obtained for Zn and Cu (twenty eight for 1.5mM Zn and forty four for 1.5 mM Cu). The changes in protein expression indicate that the cell adapts to metals by inducing essentially seven defense mechanisms: cell aggregation/biofilm formation (Zn=Cu>Cd); modification of envelope properties to increase the extracellular metal biosorption and/or control the uptake of metal (Cu>Zn); metal export (Cd=Zn and probably Cu); responses to oxidative stress (Cu>Zn>Cd); intracellular metal sequestration (Zn=Cu and probably Cd); hydrolysis of abnormally folded proteins (Cd=Cu), and the over-synthesis of proteins inhibited by metal (Cd>Cu>Zn). To the best of our knowledge, this is the first report showing that a marine P. fluorescens is able to acquire a metal-resistant phenotype, making the strain BA3SM1 a promising agent for bioremediation processes.

  3. Gene Cloning, Expression and Characterization of a Novel Xylanase from the Marine Bacterium, Glaciecola mesophila KMM241

    PubMed Central

    Guo, Bing; Li, Ping-Yi; Yue, Yong-Sheng; Zhao, Hui-Lin; Dong, Sheng; Song, Xiao-Yan; Sun, Cai-Yun; Zhang, Wei-Xin; Chen, Xiu-Lan; Zhang, Xi-Ying; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2013-01-01

    Marine xylanases are rather less studied compared to terrestrial xylanases. In this study, a new xylanase gene, xynB, was cloned from the marine bacterium, Glaciecola mesophila KMM241, and expressed in Escherichia coli. xynB encodes a multi-domain xylanase XynB of glycoside hydrolase (GH) family 8. The recombinant XynB comprises an N-terminal domain (NTD) with unknown function and a catalytic domain, which is structurally novel among the characterized xylanases of GH family 8. XynB has the highest identity (38%) to rXyn8 among the characterized xylanases. The recombinant XynB showed maximal activity at pH 6–7 and 35 °C. It is thermolabile and salt-tolerant. XynB is an endo-xylanase that demands at least five sugar moieties for effective cleavage and to hydrolyze xylohexaose and xylopentaose into xylotetraose, xylotriose and xylobiose. NTD was expressed in Escherichia coli to analyze its function. The recombinant NTD exhibited a high binding ability to insoluble xylan and avicel and little binding ability to chitosan and chitin. Since the NTD shows no obvious homology to any known carbohydrate-binding module (CBM) sequence in public databases, XynB may contain a new type of CBM. PMID:23567318

  4. Respiration and respiratory enzyme activity in aerobic and anaerobic cultures of the marine denitrifying bacterium, Pseudomonas perfectomarinus

    NASA Astrophysics Data System (ADS)

    Packard, T. T.; Garfield, P. C.; Martinez, R.

    1983-03-01

    Oxygen consumption, nitrate reduction, respiratory electron transport activity, and nitrate reductase activity were measured in aerobic and anaerobic cultures of the marine bacterium, Pseudomonas perfectomarinus. The respiratory electron transport activity was closely correlated with oxygen consumption ( r = 0.98) in aerobic cultures and nearly as well correlated with nitrate reductase activity ( r = 0.91) and nitrate reduction ( r = 0.85) in anaerobic cultures. It was also well correlated with biomass in both aerobic ( r = 0.99) and anaerobic ( r = 0.94) cultures supporting the use of tetrazolium reduction as an index of living biomass. Time courses of nitrate and nitrate in the anaerobic cultures demonstrated that at nitrate concentrations above 1 mM, denitrification proceeds stepwise. Time courses of pH in anaerobic cultures revealed a rise from 7 to 8.5 during nitrite reduction indicating net proton utilization. This proton utilization is predicted by the stoichiometry of denitrification. Although the experiments were not under 'simulated in situ' conditions, the results are relevant to studies of denitrification, to bacterial ATP production, and to the respiratory activity of marine plankton in the ocean.

  5. Pyruvatibacter mobilis gen. nov., sp. nov., a marine bacterium from the culture broth of Picochlorum sp. 122.

    PubMed

    Wang, Guanghua; Tang, Mingxing; Wu, Hualian; Dai, Shikun; Li, Tao; Chen, Chenghao; He, Hui; Fan, Jiewei; Xiang, Wenzhou; Li, Xiang

    2016-01-01

    A Gram-stain-negative, aerobic bacterium, designated strain GYP-11T, was isolated from the culture broth of a marine microalga, Picochloruma sp. 122. Cells were dimorphic rods; free living cells were motile by means of a single polar flagellum, and star-shaped-aggregate-forming cells were attached with stalks and non-motile. Sodium pyruvate or Tween 20 was required for growth on marine agar 2216.16S rRNA gene sequence analysis revealed that this isolate shared 94.07 % similarity with its closest type strain, Parvibaculum hydrocarboniclasticum EPR92T. Phylogenetic analyses indicated that strain GYP-11T represents a distinct lineage in a robust clade consisting of strain GYP-11T, alphaproteobacterium GMD21A06 and Candidatus Phaeomarinobacter ectocarpi Ec32. This clade was close to the genera Parvibaculum and Tepidicaulis in the order Rhizobiales. Chemotaxonomic and physiological characteristics, including cellular fatty acids and carbon source profiles, also readily distinguished strain GYP-11T from all established genera and species. Thus, it is concluded that strain GYP-11T represents a novel species of a new genus in the order Rhizobiales, for which the name Pyruvatibacter mobilis gen. nov., sp. nov. is proposed. The type strain of Pyruvatibacter mobilis is GYP-11T ( = CGMCC 1.15125T = KCTC 42509T).

  6. Complete Genome Sequence of the Proteorhodopsin-Containing Marine Bacterium Sediminicola sp. YIK13

    PubMed Central

    Kwon, Yong Min

    2016-01-01

    Sediminicola sp. YIK13 is a marine flavobacterium, isolated from tidal flat sediment. Here, we present the first complete genome sequence of this genus, which consists of 3,569,807 bp with 39.4% GC content. This strain contains proteorhodopsin, as well as retinal biosynthesis genes, allowing it to utilize sunlight as an energy source. PMID:26823585

  7. Complete Genome Sequence of the Proteorhodopsin-Containing Marine Bacterium Sediminicola sp. YIK13.

    PubMed

    Kwon, Yong Min; Kim, Sang-Jin

    2016-01-01

    Sediminicola sp. YIK13 is a marine flavobacterium, isolated from tidal flat sediment. Here, we present the first complete genome sequence of this genus, which consists of 3,569,807 bp with 39.4% GC content. This strain contains proteorhodopsin, as well as retinal biosynthesis genes, allowing it to utilize sunlight as an energy source. PMID:26823585

  8. A halotolerant thermostable lipase from the marine bacterium Oceanobacillus sp. PUMB02 with an ability to disrupt bacterial biofilms

    PubMed Central

    Seghal Kiran, George; Nishanth Lipton, Anuj; Kennedy, Jonathan; Dobson, Alan DW; Selvin, Joseph

    2014-01-01

    A halotolerant thermostable lipase was purified and characterized from the marine bacterium Oceanobacillus sp. PUMB02. This lipase displayed a high degree of stability over a wide range of conditions including pH, salinity, and temperature. It was optimally active at 30 °C and pH 8.0 respectively and was stable at higher temperatures (50–70 °C) and alkaline pH. The molecular mass of the lipase was approximately 31 kDa based on SDS-PAGE and MALDI-ToF fingerprint analysis. Conditions for enhanced production of lipase by Oceanobacillus sp. PUMB02 were attained in response surface method-guided optimization with factors such as olive oil, sucrose, potassium chromate, and NaCl being evaluated, resulting in levels of 58.84 U/ml being achieved. The biofilm disruption potential of the PUMB02 lipase was evaluated and compared with a marine sponge metagenome derived halotolerant lipase Lpc53E1. Good biofilm disruption activity was observed with both lipases against potential food pathogens such as Bacillus cereus MTCC1272, Listeria sp. MTCC1143, Serratia sp. MTCC4822, Escherichia coli MTCC443, Pseudomonas fluorescens MTCC1748, and Vibrio parahemolyticus MTCC459. Phase contrast microscopy, scanning electron microscopy, and confocal laser scanning microscopy showed very effective disruption of pathogenic biofilms. This study reveals that marine derived hydrolytic enzymes such as lipases may have potential utility in inhibiting biofilm formation in a food processing environment and is the first report of the potential application of lipases from the genus Oceanobacillus in biofilm disruption strategies. PMID:25482232

  9. Antarctic marine bacterium Pseudoalteromonas sp. 22b as a source of cold-adapted beta-galactosidase.

    PubMed

    Turkiewicz, Marianna; Kur, Józef; Białkowska, Aneta; Cieśliński, Hubert; Kalinowska, Halina; Bielecki, Stanisław

    2003-07-01

    The marine, psychrotolerant, rod-shaped and Gram-negative bacterium 22b (the best of 41 beta-galactosidase producers out of 107 Antarctic strains subjected to screening), classified as Pseudoalteromonas sp. based on 16S rRNA gene sequence, isolated from the alimentary tract of Antarctic krill Thyssanoessa macrura, synthesizes an intracellular cold-adapted beta-galactosidase, which efficiently hydrolyzes lactose at 0-20 degrees C, as indicated by its specific activity of 21-67 U mg(-1) of protein (11-35% of maximum activity) in this temperature range, as well as k(cat) of 157 s(-1), and k(cat)/K(m) of 47.5 mM(-1) s(-1) at 20 degrees C. The maximum enzyme synthesis (lactose as a sufficient inducer) was observed at 6 degrees C, thus below the optimum growth temperature of the bacterium (15 degrees C). The enzyme extracted from cells was purified to homogeneity (25% recovery) by using the fast, three-step procedure, including affinity chromatography on PABTG-Sepharose. The enzyme is a tetramer composed of roughly 115 kDa subunits. It is maximally active at 40 degrees C (190 U mg(-1) of protein) and pH 6.0-8.0. PNPG is its preferred substrate (50% higher activity than against ONPG). The Pseudoalteromonas sp. 22b beta-galactosidase is activated by thiol compounds (70% rise in activity in the presence of 10 mM dithiotreitol), some metal ions (K(+), Na(+), Mn(2+)-40% increase, Mg(2+)-15% enhancement), and markedly inactivated by pCMB and heavy metal ions, particularly Cu(2+). Noteworthy, Ca(2+) ions do not affect the enzyme activity, and the homogeneous protein is stable at 4 degrees C for at least 30 days without any stabilizers.

  10. Genome Sequence of the Agar-Degrading Marine Bacterium Alteromonadaceae sp. Strain G7

    PubMed Central

    Kwak, Min-Jung; Song, Ju Yeon; Kim, Byung Kwon; Chi, Won-Jae; Kwon, Soon-Kyeong; Choi, Soobeom; Chang, Yong-Keun

    2012-01-01

    Here, we present the high-quality draft genome sequence of the agar-degrading marine gammaproteobacterium Alteromonadaceae sp. strain G7, which was isolated from coastal seawater to be utilized as a bioresource for production of agar-derived biofuels. The 3.91-Mb genome contains a number of genes encoding algal polysaccharide-degrading enzymes such as agarases and sulfatases. PMID:23209220

  11. Extracellular haem peroxidases mediate Mn(II) oxidation in a marine Roseobacter bacterium via superoxide production.

    PubMed

    Andeer, Peter F; Learman, Deric R; McIlvin, Matt; Dunn, James A; Hansel, Colleen M

    2015-10-01

    Manganese (Mn) oxides are among the strongest sorbents and oxidants in environmental systems. A number of biotic and abiotic pathways induce the oxidation of Mn(II) to Mn oxides. Here, we use a combination of proteomic analyses and activity assays, to identify the enzyme(s) responsible for extracellular superoxide-mediated Mn oxide formation by a bacterium within the ubiquitous Roseobacter clade. We show that animal haem peroxidases (AHPs) located on the outer membrane and within the secretome are responsible for Mn(II) oxidation. These novel peroxidases have previously been implicated in direct Mn(II) oxidation by phylogenetically diverse bacteria. Yet, we show that in this Roseobacter species, AHPs mediate Mn(II) oxidation not through a direct reaction but by producing superoxide and likely also by degrading hydrogen peroxide. These findings point to a eukaryotic-like oscillatory oxidative-peroxidative enzymatic cycle by these AHPs that leads to Mn oxide formation by this organism. AHP expression appears unaffected by Mn(II), yet the large energetic investment required to produce and secrete these enzymes points to an as yet unknown physiological function. These findings are further evidence that bacterial peroxidases and secreted enzymes, in general, are unappreciated controls on the cycling of metals and reactive oxygen species (ROS), and by extension carbon, in natural systems.

  12. Vibrio psychroerythrus sp. n.: Classification of the Psychrophilic Marine Bacterium, NRC 1004

    PubMed Central

    D'aoust, J. Y.; Kushner, D. J.

    1972-01-01

    A red-pigmented organism, formerly known as marine psychrophile NRC 1004, has been classified as Vibrio psychroerythrus sp. n. Classification was mainly based on morphology, the ability of the organism to oxidize and ferment glucose, its sensitivity to vibriostat 0/129, and its deoxyribonucleic acid base composition of 40.0 moles% guanine plus cytosine, determined by thermal denaturation. The organism gave positive reactions for catalase, oxidase, and starch hydrolysis and produced acid from maltose and dextrin but not from arabinose. It was indole- and citrate-negative and reduced nitrate to nitrite without producing gas. PMID:5053463

  13. Antiangiogenic activity of low-temperature lysozyme from a marine bacterium in vivo and in vitro

    NASA Astrophysics Data System (ADS)

    Wang, Zhenhua; Liu, Jincheng; Su, Ai; Sun, Mi; Wang, Chunbo

    2009-11-01

    We extracted marine low-temperature lysozyme (MLTL), a novel lysozyme, from a marine microorganism through fermentation. Our previous study suggested that a low molecular weight (16 kDa) may exert anti-tumor activity through antiangiogenesis. In this study, we extracted a high weight (39 kDa) and investigated its antiangiogenic activity in vivo and in vitro. Using zebrafish embryos as an in vivo study model, we found that treatment with MLTL significantly inhibited the growth of subintestinal vessels (SIVs) in a dose-dependent manner and that 400 µg/ml MLTL was sufficient to block the growth of SIVs. An in vitro study conducted using human umbilical vein endothelial cells (HUVECs) revealed that MLTL suppressed the proliferation, migration and tube formation of HUVECs in a dose-dependent manner. Interestingly, assays by flow cytometry and DNA electrophoresis indicated that MLTL was able to induce apoptosis of HUVECs. Moreover, further study demonstrated that the disruption of intracellular Ca2+ homeostasis may play an important role in MLTL induced apoptosis of HUVECs. Taken together, the results of this study demonstrate for the first time that MLTL inhibits angiogenesis through its pleiotropic effects on vascular endothelial cells and induces apoptosis through regulation of cellular Ca2+ levels. The results of this study also revealed a possible mechanism underlying the antiangiogenic effect of MLTL and suggested that MLTL may be a promising new antiangiogenic agent for use in cancer therapy.

  14. The Complete Genome Sequence of the Marine, Chemolithoautotrophic, Ammonia-Oxidizing Bacterium Nitrosococcus oceani ATCC19707

    SciTech Connect

    Klotz, M G; Arp, D J; Chain, P S; El-Sheikh, A F; Hauser, L J; Hommes, N G; Larimer, F W; Malfatti, S A; Norton, J M; Poret-Peterson, A T; Vergez, L M; Ward, B B

    2006-08-03

    The Gammaproteobacterium, Nitrosococcus oceani (ATCC 19707), is a Gram-negative obligate chemolithoautotroph capable of extracting energy and reducing power from the oxidation of ammonia to nitrite. Sequencing and annotation of the genome revealed a single circular chromosome (3,481,691 bp; 50.4% G+C) and a plasmid (40,420 bp) that contain 3052 and 41 candidate protein-encoding genes, respectively. The genes encoding proteins necessary for the function of known modes of lithotrophy and autotrophy were identified. In contrast to betaproteobacterial nitrifier genomes, the N. oceani genome contained two complete rrn operons. In contrast, only one copy of the genes needed to synthesize functional ammonia monooxygenase and hydroxylamine oxidoreductase, as well as the proteins that relay the extracted electrons to a terminal electron acceptor were identified. The N. oceani genome contained genes for 13 complete two-component systems. The genome also contained all the genes needed to reconstruct complete central pathways, the tricarboxylic acid cycle and the Embden-Meyerhof-Parnass and pentose phosphate pathways. The N. oceani genome contains the genes required to store and utilize energy from glycogen inclusion bodies and sucrose. Polyphosphate and pyrophosphate appear to be integrated in this bacterium's energy metabolism, stress tolerance and the ability to assimilate carbon via gluconeogenesis. One set of genes for type I RuBisCO was identified, while genes necessary for methanotrophy and for carboxysome formation were not identified. The N. oceani genome contains two copies each of the genes or operons necessary to assemble functional complexes I and IV as well as ATP synthase (one H{sup +}-dependent F{sub 0}F{sub 1}-type, one Na{sup +}-dependent V-type).

  15. Complete Genome Sequence of the Marine, Chemolithoautotrophic, Ammonia-Oxidizing Bacterium Nitrosococcus oceani ATCC 19707†

    PubMed Central

    Klotz, Martin G.; Arp, Daniel J.; Chain, Patrick S. G.; El-Sheikh, Amal F.; Hauser, Loren J.; Hommes, Norman G.; Larimer, Frank W.; Malfatti, Stephanie A.; Norton, Jeanette M.; Poret-Peterson, Amisha T.; Vergez, Lisa M.; Ward, Bess B.

    2006-01-01

    The gammaproteobacterium Nitrosococcus oceani (ATCC 19707) is a gram-negative obligate chemolithoautotroph capable of extracting energy and reducing power from the oxidation of ammonia to nitrite. Sequencing and annotation of the genome revealed a single circular chromosome (3,481,691 bp; G+C content of 50.4%) and a plasmid (40,420 bp) that contain 3,052 and 41 candidate protein-encoding genes, respectively. The genes encoding proteins necessary for the function of known modes of lithotrophy and autotrophy were identified. Contrary to betaproteobacterial nitrifier genomes, the N. oceani genome contained two complete rrn operons. In contrast, only one copy of the genes needed to synthesize functional ammonia monooxygenase and hydroxylamine oxidoreductase, as well as the proteins that relay the extracted electrons to a terminal electron acceptor, were identified. The N. oceani genome contained genes for 13 complete two-component systems. The genome also contained all the genes needed to reconstruct complete central pathways, the tricarboxylic acid cycle, and the Embden-Meyerhof-Parnass and pentose phosphate pathways. The N. oceani genome contains the genes required to store and utilize energy from glycogen inclusion bodies and sucrose. Polyphosphate and pyrophosphate appear to be integrated in this bacterium's energy metabolism, stress tolerance, and ability to assimilate carbon via gluconeogenesis. One set of genes for type I ribulose-1,5-bisphosphate carboxylase/oxygenase was identified, while genes necessary for methanotrophy and for carboxysome formation were not identified. The N. oceani genome contains two copies each of the genes or operons necessary to assemble functional complexes I and IV as well as ATP synthase (one H+-dependent F0F1 type, one Na+-dependent V type). PMID:16957257

  16. Complete Genome Sequence of the Marine, Chemolithoautotrophic, Ammonia-Oxidizing Bacterium Nitrosococcus oceani ATCC 19707

    SciTech Connect

    Klots, Martin G.; Arp, D J; Chain, Patrick S; El-Sheikh, Amal F.; Hauser, Loren John; Hommes, Norman G.; Larimer, Frank W; Malfatti, Stephanie; Norton, Jeanette M.; Poret-Peterson, Amisha T.; Vergez, Lisa; Ward, Bess B.

    2006-01-01

    The gammaproteobacterium Nitrosococcus oceani (ATCC 19707) is a gram-negative obligate chemolithoautotroph capable of extracting energy and reducing power from the oxidation of ammonia to nitrite. Sequencing and annotation of the genome revealed a single circular chromosome (3,481,691 bp; G+C content of 50.4%) and a plasmid (40,420 bp) that contain 3,052 and 41 candidate protein-encoding genes, respectively. The genes encoding proteins necessary for the function of known modes of lithotrophy and autotrophy were identified. Contrary to betaproteobacterial nitrifier genomes, the N. oceani genome contained two complete rrn operons. In contrast, only one copy of the genes needed to synthesize functional ammonia monooxygenase and hydroxylamine oxidoreductase, as well as the proteins that relay the extracted electrons to a terminal electron acceptor, were identified. The N. oceani genome contained genes for 13 complete two-component systems. The genome also contained all the genes needed to reconstruct complete central pathways, the tricarboxylic acid cycle, and the Embden-Meyerhof-Parnass and pentose phosphate pathways. The N. oceani genome contains the genes required to store and utilize energy from glycogen inclusion bodies and sucrose. Polyphosphate and pyrophosphate appear to be integrated in this bacterium's energy metabolism, stress tolerance, and ability to assimilate carbon via gluconeogenesis. One set of genes for type I ribulose-1,5-bisphosphate carboxylase/oxygenase was identified, while genes necessary for methanotrophy and for carboxysome formation were not identified. The N. oceani genome contains two copies each of the genes or operons necessary to assemble functional complexes I and IV as well as ATP synthase (one H+-dependent F0F1 type, one Na+-dependent V type).

  17. Altererythrobacter gangjinensis sp. nov., a marine bacterium isolated from a tidal flat.

    PubMed

    Jeong, Sang Hyeon; Jin, Hyun Mi; Lee, Hyo Jung; Jeon, Che Ok

    2013-03-01

    A Gram-stain-negative, ochre-pigmented, strictly aerobic bacterium, designated strain KJ7(T), was isolated from a tidal flat of the Gangjin bay in South Korea. Cells were halotolerant, non-motile, catalase- and oxidase-positive rods. Growth of strain KJ7(T) was observed at 5-35 °C (optimum, 25 °C), at pH 6.0-9.5 (optimum, pH 6.5-7.0) and in the presence of 0-9 % (w/v) NaCl (optimum, 2 %). The major cellular fatty acids were C18 : 1ω7c, C17 : 1ω6c, summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The polar lipid pattern indicated the presence of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, a sphingoglycolipid, an unidentified phospholipid and two unidentified lipids. The G+C content of the genomic DNA was 60.2±0.9 mol% and the predominant respiratory quinone was Q-10. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain KJ7(T) formed a phyletic lineage distinct from other members of the genus Altererythrobacter and was most closely related to Altererythrobacter luteolus SW-109(T) and Altererythrobacter namhicola KYW48(T) (95.6 and 95.0 % 16S rRNA gene sequence similarity, respectively). On the basis of phenotypic, chemotaxonomic and molecular features, strain KJ7(T) represents a novel species of the genus Altererythrobacter, for which the name Altererythrobacter gangjinensis sp. nov. is proposed. The type strain is KJ7(T) ( = KACC 16190(T) = JCM 17802(T)). PMID:22685101

  18. Virgibacillus zhanjiangensis sp. nov., a marine bacterium isolated from sea water.

    PubMed

    Peng, Qing-Zhong; Chen, Jun; Zhang, Yu-Qin; Chen, Qi-Hui; Peng, De-Jiao; Cui, Xiao-Long; Li, Wen-Jun; Chen, Yi-Guang

    2009-11-01

    A Gram-positive, endospore-forming, catalase- and oxidase-positive, motile, rod-shaped, aerobic bacterium, designated strain JSM 079157(T), was isolated from surface seawater off the coastline of Naozhou Island in South China Sea. The organism was able to grow with 1-15% (w/v) total salts (optimum, 4-7%), and at pH 6.0-10.0 (optimum, pH 7.5) and 10-45 degrees C (optimum, 30 degrees C). meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The predominant menaquinone was MK-7, and the polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The major cellular fatty acids were anteiso-C(15:0) (45.1%) and anteiso-C(17:0) (16.2%), and the DNA G + C content was 39.5 mol%. A phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain JSM 079157(T) should be assigned to the genus Virgibacillus, being related most closely to the type strains of Virgibacillus litoralis (97.4% sequence similarity), Virgibacillus necropolis (97.3%) and Virgibacillus carmonensis (97.1%). These four strains formed a distinct subcluster in the phylogenetic tree. The levels of DNA-DNA relatedness between the new isolate and the type strains of V. litoralis, V. necropolis and V. carmonensis were 30.4, 19.3 and 12.6%, respectively. The results of the phylogenetic analysis, combined with DNA-DNA relatedness data, phenotypic characteristics and chemotaxonomic information, support the suggestion that strain JSM 079157(T) represents a new species of the genus Virgibacillus, for which the name Virgibacillus zhanjiangensis sp. nov. is proposed. The type strain is JSM 079157(T) (=DSM 21084(T) = KCTC 13227(T)). PMID:19774482

  19. Shewanella algicola sp. nov., a marine bacterium isolated from brown algae.

    PubMed

    Kim, Ji-Young; Yoo, Han-Su; Lee, Dong-Heon; Park, So-Hyun; Kim, Young-Ju; Oh, Duck-Chul

    2016-06-01

    A Gram-stain-negative, aerobic, rod-shaped bacterium motile by means of a single polar flagella, strain ST-6T, was isolated from a brown alga (Sargassum thunbergii) collected in Jeju, Republic of Korea. Strain ST-6T was psychrotolerant, growing at 4-30 °C (optimum 20 °C). Phylogenetic analysis based on 16S rRNA and gyrB gene sequences revealed that strain ST-6T belonged to a distinct lineage in the genus Shewanella. Strain ST-6T was related most closely to Shewanella basaltis J83T, S. gaetbuli TF-27T, S. arctica IT12T, S. vesiculosa M7T and S. aestuarii SC18T, showing 96-97 % and 85-70 % 16S rRNA and gyrB gene sequences similarities, respectively. DNA-DNA relatedness values between strain ST-6T and the type strains of two species of the genus Shewanella were <22.6 %. The major cellular fatty acids (>5 %) were summed feature 3 (comprising C16:1ω7c and/ or iso-C15:0 2-OH), C16:0, iso-C13:0 and C17:1ω8c. The DNA G+C content of strain ST-6Twas 42.4 mol%, and the predominant isoprenoid quinones were menaquinone MK-7 and ubiquinones Q-7 and Q-8. On the basis of its phenotypic properties and phylogenetic distinctiveness, strain ST-6T is considered to represent a novel species of the genus Shewanella, for which the name Shewanella algicola sp. nov. is proposed. The type strain is ST-6T (= KCTC 23253T = JCM 31091T). PMID:26962005

  20. Virgibacillus zhanjiangensis sp. nov., a marine bacterium isolated from sea water.

    PubMed

    Peng, Qing-Zhong; Chen, Jun; Zhang, Yu-Qin; Chen, Qi-Hui; Peng, De-Jiao; Cui, Xiao-Long; Li, Wen-Jun; Chen, Yi-Guang

    2009-11-01

    A Gram-positive, endospore-forming, catalase- and oxidase-positive, motile, rod-shaped, aerobic bacterium, designated strain JSM 079157(T), was isolated from surface seawater off the coastline of Naozhou Island in South China Sea. The organism was able to grow with 1-15% (w/v) total salts (optimum, 4-7%), and at pH 6.0-10.0 (optimum, pH 7.5) and 10-45 degrees C (optimum, 30 degrees C). meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The predominant menaquinone was MK-7, and the polar lipids were diphosphatidylglycerol and phosphatidylglycerol. The major cellular fatty acids were anteiso-C(15:0) (45.1%) and anteiso-C(17:0) (16.2%), and the DNA G + C content was 39.5 mol%. A phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain JSM 079157(T) should be assigned to the genus Virgibacillus, being related most closely to the type strains of Virgibacillus litoralis (97.4% sequence similarity), Virgibacillus necropolis (97.3%) and Virgibacillus carmonensis (97.1%). These four strains formed a distinct subcluster in the phylogenetic tree. The levels of DNA-DNA relatedness between the new isolate and the type strains of V. litoralis, V. necropolis and V. carmonensis were 30.4, 19.3 and 12.6%, respectively. The results of the phylogenetic analysis, combined with DNA-DNA relatedness data, phenotypic characteristics and chemotaxonomic information, support the suggestion that strain JSM 079157(T) represents a new species of the genus Virgibacillus, for which the name Virgibacillus zhanjiangensis sp. nov. is proposed. The type strain is JSM 079157(T) (=DSM 21084(T) = KCTC 13227(T)).

  1. Bacillus neizhouensis sp. nov., a halophilic marine bacterium isolated from a sea anemone.

    PubMed

    Chen, Yi-Guang; Zhang, Yu-Qin; Wang, Yong-Xia; Liu, Zhi-Xiong; Klenk, Hans-Peter; Xiao, Huai-Dong; Tang, Shu-Kun; Cui, Xiao-Long; Li, Wen-Jun

    2009-12-01

    A novel Gram-stain-positive, slightly halophilic, facultatively alkaliphilic, non-motile, catalase- and oxidase-positive, endospore-forming, rod-shaped, aerobic bacterium, strain JSM 071004(T), was isolated from a sea anemone collected from Neizhou Bay in the South China Sea. Growth occurred with 0.5-10 % (w/v) total salts (optimum 2-4 %) and at pH 6.5-10.0 (optimum pH 8.5) and 4-30 degrees C (optimum 25 degrees C). meso-Diaminopimelic acid was present in the cell-wall peptidoglycan. The predominant respiratory quinone was menaquinone 7 (MK-7) and the polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major cellular fatty acids were anteiso-C(15 : 0) and iso-C(15 : 0). The genomic DNA G+C content was 39.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JSM 071004(T) belongs to the genus Bacillus, being related most closely to the type strain of Bacillus agaradhaerens (sequence similarity 97.3 %), followed by the type strains of Bacillus cellulosilyticus (96.2 %), Bacillus clarkii (96.1 %) and Bacillus polygoni (96.0 %). The combination of phylogenetic analysis, DNA-DNA hybridization, phenotypic characteristics and chemotaxonomic data support the proposal that strain JSM 071004(T) represents a novel species of the genus Bacillus, for which the name Bacillus neizhouensis sp. nov. is proposed, with JSM 071004(T) (=CCTCC AB 207161(T) =DSM 19794(T) =KCTC 13187(T)) as the type strain.

  2. Zooshikella marina sp. nov. a cycloprodigiosin- and prodigiosin-producing marine bacterium isolated from beach sand.

    PubMed

    Ramaprasad, E V V; Bharti, Dave; Sasikala, Ch; Ramana, Ch V

    2015-12-01

    A red-pigmented bacterium producing a metallic green sheen, designated strain JC333T, was isolated from a sand sample collected from Shivrajpur-Kachigad beach, Gujarat, India. Phylogenetic analyses based on the 16S rRNA gene sequence of strain JC333T showed highest sequence similarity to Zooshikella ganghwensis JC2044T (99.24 %) and less than 91.94 % similarity with other members of the class Gammaproteobacteria. DNA-DNA hybridizations between JC333T and Z. ganghwensis JC2044T showed low relatedness values of 19 ± 1.3 % (reciprocal 21 ± 2.2 %). The major respiratory quinone was ubiquinone-9 (Q9) and the polar lipid profile was composed of the major components diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, an unidentified aminophospholipid and an unidentified lipid. The presence of C16 : 1ω7c/C16 : 1ω6c, C16 : 0, C18 : 1ω7c and C12 : 0 as major fatty acids supported the affiliation of strain JC333T to the genus Zooshikella. Prodigiosin, cycloprodigiosin and eight other prodigiosin analogues were the pigments of JC333T. Characterization based on 16S rRNA gene sequence analysis, physiological parameters, pigment analysis, ubiquinone, and polar lipid and fatty acid compositions revealed that JC333T represents a novel species of the genus Zooshikella, for which the name Zooshikella marina sp. nov. is proposed. The type strain is JC333T ( = KCTC 42659T = LMG 28823T).

  3. Genome Sequence of Polycyclovorans algicola Strain TG408, an Obligate Polycyclic Aromatic Hydrocarbon-Degrading Bacterium Associated with Marine Eukaryotic Phytoplankton

    PubMed Central

    Thompson, Haydn F.; Angelova, Angelina; Whitman, William B.; Huntemann, Marcel; Copeland, Alex; Chen, Amy; Kyrpides, Nikos; Markowitz, Victor; Palaniappan, Krishnaveni; Ivanova, Natalia; Mikhailova, Natalia; Ovchinnikova, Galina; Andersen, Evan; Pati, Amrita; Stamatis, Dimitrios; Reddy, T. B. K.; Ngan, Chew Yee; Chovatia, Mansi; Daum, Chris; Shapiro, Nicole; Cantor, Michael N.; Woyke, Tanja

    2015-01-01

    Polycyclovorans algicola strain TG408 is a recently discovered bacterium associated with marine eukaryotic phytoplankton and exhibits the ability to utilize polycyclic aromatic hydrocarbons (PAHs) almost exclusively as sole sources of carbon and energy. Here, we present the genome sequence of this strain, which is 3,653,213 bp, with 3,477 genes and an average G+C content of 63.8%. PMID:25814607

  4. Characterization of a novel thiosulfate dehydrogenase from a marine acidophilic sulfur-oxidizing bacterium, Acidithiobacillus thiooxidans strain SH.

    PubMed

    Sharmin, Sultana; Yoshino, Eriko; Kanao, Tadayoshi; Kamimura, Kazuo

    2016-01-01

    A marine acidophilic sulfur-oxidizing bacterium, Acidithiobacillus thiooxidans strain SH, was isolated to develop a bioleaching process for NaCl-containing sulfide minerals. Because the sulfur moiety of sulfide minerals is metabolized to sulfate via thiosulfate as an intermediate, we purified and characterized the thiosulfate dehydrogenase (TSD) from strain SH. The enzyme had an apparent molecular mass of 44 kDa and was purified 71-fold from the solubilized membrane fraction. Tetrathionate was the product of the TSD-oxidized thiosulfate and ferricyanide or ubiquinone was the electron acceptor. Maximum enzyme activity was observed at pH 4.0, 40 °C, and 200 mM NaCl. To our knowledge, this is the first report of NaCl-stimulated TSD activity. TSD was structurally different from the previously reported thiosulfate-oxidizing enzymes. In addition, TSD activity was strongly inhibited by 2-heptyl-4-hydroxy-quinoline N-oxide, suggesting that the TSD is a novel thiosulfate:quinone reductase.

  5. Isolation and identification of a bacterium from marine shrimp digestive tract: A new degrader of starch and protein

    NASA Astrophysics Data System (ADS)

    Li, Jiqiu; Tan, Beiping; Mai, Kangsen

    2011-09-01

    It is a practical approach to select candidate probiotic bacterial stains on the basis of their special traits. Production of digestive enzyme was used as a trait to select a candidate probiotic bacterial strain in this study. In order to select a bacterium with the ability to degrade both starch and protein, an ideal bacterial strain STE was isolated from marine shrimp ( Litopenaeus vannamei) intestines by using multiple selective media. The selected isolate STE was identified on the basis of its morphological, physiological, and biochemical characteristics as well as molecular analyses. Results of degradation experiments confirmed the ability of the selected isolate to degrade both starch and casein. The isolate STE was aerobic, Gram-negative, rod-shaped, motile and non-spore-forming, and had catalase and oxidase activities but no glucose fermentation activity. Among the tested carbon/nitrogen sources, only Tween40, alanyl-glycine, aspartyl-glycine, and glycyl-l-glutamic acid were utilized by the isolate STE. Results of homology comparison analyses of the 16S rDNA sequences showed that the isolate STE had a high similarity to several Pseudoalteromonas species and, in the phylogenetic tree, grouped with P. ruthenica with maximum bootstrap support (100%). In conclusion, the isolate STE was characterized as a novel strain belonging to the genus Pseudoalteromonas. This study provides a further example of a probiotic bacterial strain with specific characteristics isolated from the host gastrointestinal tract.

  6. Experimental Identification of Small Non-Coding RNAs in the Model Marine Bacterium Ruegeria pomeroyi DSS-3

    PubMed Central

    Rivers, Adam R.; Burns, Andrew S.; Chan, Leong-Keat; Moran, Mary Ann

    2016-01-01

    In oligotrophic ocean waters where bacteria are often subjected to chronic nutrient limitation, community transcriptome sequencing has pointed to the presence of highly abundant small RNAs (sRNAs). The role of sRNAs in regulating response to nutrient stress was investigated in a model heterotrophic marine bacterium Ruegeria pomeroyi grown in continuous culture under carbon (C) and nitrogen (N) limitation. RNAseq analysis identified 99 putative sRNAs. Sixty-nine were cis-encoded and located antisense to a presumed target gene. Thirty were trans-encoded and initial target prediction was performed computationally. The most prevalent functional roles of genes anti-sense to the cis-sRNAs were transport, cell-cell interactions, signal transduction, and transcriptional regulation. Most sRNAs were transcribed equally under both C and N limitation, and may be involved in a general stress response. However, 14 were regulated differentially between the C and N treatments and may respond to specific nutrient limitations. A network analysis of the predicted target genes of the R. pomeroyi cis-sRNAs indicated that they average fewer connections than typical protein-encoding genes, and appear to be more important in peripheral or niche-defining functions encoded in the pan genome. PMID:27065955

  7. Pseudoalteromonas bacteriolytica sp. nov., a marine bacterium that is the causative agent of red spot disease of Laminaria japonica.

    PubMed

    Sawabe, T; Makino, H; Tatsumi, M; Nakano, K; Tajima, K; Iqbal, M M; Yumoto, I; Ezura, Y; Christen, R

    1998-07-01

    An aerobic, polarly flagellated marine bacterium that produces a prodigiosin-like 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 degrees 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. PMID:9734030

  8. A Novel Bifunctional Hybrid with Marine Bacterium Alkaline Phosphatase and Far Eastern Holothurian Mannan-Binding Lectin Activities

    PubMed Central

    Balabanova, Larissa; Golotin, Vasily; Kovalchuk, Svetlana; Bulgakov, Alexander; Likhatskaya, Galina; Son, Oksana; Rasskazov, Valery

    2014-01-01

    A fusion between the genes encoding the marine bacterium Cobetia marina alkaline phosphatase (CmAP) and Far Eastern holothurian Apostichopus japonicus mannan-binding C-type lectin (MBL-AJ) was performed. Expression of the fusion gene in E. coli cells resulted in yield of soluble recombinant chimeric protein CmAP/MBL-AJ with the high alkaline phosphatase activity and specificity of the lectin MBL-AJ. The bifunctional hybrid CmAP/MBL-AJ was produced as a dimer with the molecular mass of 200 kDa. The CmAP/MBL-AJ dimer model showed the two-subunit lectin part that is associated with two molecules of alkaline phosphatase functioning independently from each other. The highly active CmAP label genetically linked to MBL-AJ has advantaged the lectin-binding assay in its sensitivity and time. The double substitution A156N/F159K in the lectin domain of CmAP/MBL-AJ has enhanced its lectin activity by 25±5%. The bifunctional hybrid holothurian's lectin could be promising tool for developing non-invasive methods for biological markers assessment, particularly for improving the MBL-AJ-based method for early detection of a malignant condition in cervical specimens. PMID:25397876

  9. Feifantangia zhejiangensis gen. nov., sp. nov., a marine bacterium isolated from seawater of the East China Sea.

    PubMed

    Zheng, Gang; Chen, Zuo-Guo; Jiang, Ri-Jin; Yang, Zhi-Jian

    2015-12-01

    A marine bacterium, NMD7(T), was isolated from seawater of the East China Sea. The cells were found to be aerobic, Gram-stain negative, non-motile rods. Growth of strain NMD7(T) could be observed in the medium without Na(+). Flexirubin-type pigments were observed to be produced. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain NMD7(T) is an authentic member of the Cytophaga-Flavobacterium-Bacteroides phylum, forming a monophyletic clade as retrieved in neighbor-joining, maximum-likelihood and maximum-parsimony phylogenetic trees, and is closely related to Formosa spongicola A2(T) (96.0 %). The predominant respiratory quinone was determined to be MK-6. Major cellular fatty acids were identified as iso-C15:0, iso-C15:1 G and iso-C17:0 3-OH. The main polar lipids were found to consist of phosphatidylethanolamine, one aminophospholipid, three aminolipids and five unidentified lipids. Based on phenotypic, chemotaxonomic and phylogenetic characteristics, it is proposed that strain NMD7(T) be classified as representing a new genus, Feifantangia gen. nov. and a new species, Feifantangia zhejiangensis sp. nov. The type strain is NMD7(T) (=KCTC 42445T =MCCC 1K00458T). PMID:26410371

  10. Marinobacterium mangrovicola sp. nov., a marine nitrogen-fixing bacterium isolated from mangrove roots of Rhizophora mangle.

    PubMed

    Alfaro-Espinoza, Gabriela; Ullrich, Matthias S

    2014-12-01

    A nitrogen-fixing marine bacterium, designated strain Gal22(T), was isolated from mangrove roots of Rhizophora mangle. Cells were Gram-stain-negative rods, motile with a single polar flagellum. Growth was observed at 4-42 °C, pH 5.5 to 10 and with 0-18 % (w/v) NaCl. Strain Gal22(T) was positive for catalase and oxidase. Q-8 was the predominant lipoquinone. The DNA G+C content was 57.0 mol%. Based on phylogenetic analysis of 16S rRNA gene, strain Gal22(T) belongs to the genus Marinobacterium. The closely related strains were shown to be Marinobacterium lutimaris DSM 22012(T) and Marinobacterium litorale IMCC1877(T) with 99 % and 96 % 16S rRNA gene sequence similarity, respectively. DNA-DNA relatedness analysis indicated that strain Gal22(T) was different from M. lutimaris DSM 22012(T). On the basis of genotypic, morphological and biochemical characteristics, a novel species, Marinobacterium mangrovicola sp. nov. (type strain, Gal22(T) = DSM 27697(T) = CIP 110653(T)), is proposed. PMID:25217624

  11. Enhancing production of a 24-membered ring macrolide compound by a marine bacterium using response surface methodology*

    PubMed Central

    Chen, Hua; Wu, Mian-bin; Chen, Zheng-jie; Wang, Ming-lu; Lin, Jian-ping; Yang, Li-rong

    2013-01-01

    A 24-membered ring macrolide compound, macrolactin A has potential applications in pharmaceuticals for its anti-infectious and antiviral activity. In this study, macrolactin A was produced by a marine bacterium, which was identified as Bacillus subtilis by 16S ribosomal RNA (rRNA) sequence analysis. Electrospray ionization mass spectrometry (ESI/MS) and nuclear magnetic resonance (NMR) spectroscopy analyses were used to characterize this compound. To improve the production, response surface methodology (RSM) involving Box-Behnken design (BBD) was employed. Faeces bombycis, the main by-product in sericulture, was used as a nitrogen source in fermentation. The interactions between three significant factors, F. bombycis, soluble starch, and (NH4)2SO4 were investigated. A quadratic model was constructed to fit the production and the factors. Optimum medium composition was obtained by analysis of the model. When cultivated in the optimum medium, the production of macrolactin A was increased to 851 mg/L, 2.7 times as compared to the original. This study is also useful to find another way in utilizing F. bombycis. PMID:23549852

  12. Characterization of a new marine nitrite oxidizing bacterium, Nitrospina watsonii sp. nov., a member of the newly proposed phylum "Nitrospinae".

    PubMed

    Spieck, Eva; Keuter, Sabine; Wenzel, Thilo; Bock, Eberhard; Ludwig, Wolfgang

    2014-05-01

    Nitrite oxidizing bacteria are an integral part of the nitrogen cycle in marine waters, but the knowledge about their diversity is limited. Recently, a high abundance of Nitrospina-like 16S rRNA gene sequences has been detected in oceanic habitats with low oxygen content by molecular methods. Here, we describe a new strain of Nitrospina, which was sampled in 100m depth from the Black Sea. It coexisted with a not-yet cultivated chemoorganotrophic gammaproteobacterium and could be purified by classical isolation methods including Percoll density gradient centrifugation. The new Nitrospina-like bacterium grew lithoautotrophically at 28°C in diluted seawater supplemented with inorganic salts and nitrite. Gram-negative rods were characterized morphologically, physiologically and partly biochemically. The 16S rRNA gene of the new strain of Nitrospina is 97.9% similar to the described species N. gracilis and DNA/DNA hybridization experiments revealed a relatedness of 30.0%. The data from both Nitrospina species and environmental clones were used for an extensive 16S rRNA based phylogenetic study applying high quality filtering. Treeing analyses confirm the newly defined phylum status for "Nitrospinae" [18]. The results of phylogenetic and genotypic analyses support the proposal of a novel species Nitrospina watsonii sp. nov. (type strain 347(T), LMG 27401(T), NCIMB 14887(T)). PMID:24581679

  13. Experimental Identification of Small Non-Coding RNAs in the Model Marine Bacterium Ruegeria pomeroyi DSS-3.

    PubMed

    Rivers, Adam R; Burns, Andrew S; Chan, Leong-Keat; Moran, Mary Ann

    2016-01-01

    In oligotrophic ocean waters where bacteria are often subjected to chronic nutrient limitation, community transcriptome sequencing has pointed to the presence of highly abundant small RNAs (sRNAs). The role of sRNAs in regulating response to nutrient stress was investigated in a model heterotrophic marine bacterium Ruegeria pomeroyi grown in continuous culture under carbon (C) and nitrogen (N) limitation. RNAseq analysis identified 99 putative sRNAs. Sixty-nine were cis-encoded and located antisense to a presumed target gene. Thirty were trans-encoded and initial target prediction was performed computationally. The most prevalent functional roles of genes anti-sense to the cis-sRNAs were transport, cell-cell interactions, signal transduction, and transcriptional regulation. Most sRNAs were transcribed equally under both C and N limitation, and may be involved in a general stress response. However, 14 were regulated differentially between the C and N treatments and may respond to specific nutrient limitations. A network analysis of the predicted target genes of the R. pomeroyi cis-sRNAs indicated that they average fewer connections than typical protein-encoding genes, and appear to be more important in peripheral or niche-defining functions encoded in the pan genome. PMID:27065955

  14. Shotgun Redox Proteomics: Identification and Quantitation of Carbonylated Proteins in the UVB-Resistant Marine Bacterium, Photobacterium angustum S14

    PubMed Central

    Matallana-Surget, Sabine; Cavicchioli, Ricardo; Fauconnier, Charles; Wattiez, Ruddy; Leroy, Baptiste; Joux, Fabien; Raftery, Mark J.; Lebaron, Philippe

    2013-01-01

    UVB oxidizes proteins through the generation of reactive oxygen species. One consequence of UVB irradiation is carbonylation, the irreversible formation of a carbonyl group on proline, lysine, arginine or threonine residues. In this study, redox proteomics was performed to identify carbonylated proteins in the UVB resistant marine bacterium Photobacterium angustum. Mass-spectrometry was performed with either biotin-labeled or dinitrophenylhydrazide (DNPH) derivatized proteins. The DNPH redox proteomics method enabled the identification of 62 carbonylated proteins (5% of 1221 identified proteins) in cells exposed to UVB or darkness. Eleven carbonylated proteins were quantified and the UVB/dark abundance ratio was determined at both the protein and peptide levels. As a result we determined which functional classes of proteins were carbonylated, which residues were preferentially modified, and what the implications of the carbonylation were for protein function. As the first large scale, shotgun redox proteomics analysis examining carbonylation to be performed on bacteria, our study provides a new level of understanding about the effects of UVB on cellular proteins, and provides a methodology for advancing studies in other biological systems. PMID:23874515

  15. Production of cold-adapted amylase by marine bacterium Wangia sp. C52: optimization, modeling, and partial characterization.

    PubMed

    Liu, Jianguo; Zhang, Zhiqiang; Liu, Zhiqiang; Zhu, Hu; Dang, Hongyue; Lu, Jianren; Cui, Zhanfeng

    2011-10-01

    The aim of this work was to optimize the fermentation parameters in the shake-flask culture of marine bacterium Wangia sp. C52 to increase cold-adapted amylase production using two statistical experimental methods including Plackett-Burman design, which was applied to find the key ingredients for the best medium composition, and response surface methodology, which was used to determine the optimal concentrations of these components. The results showed starch, tryptone, and initial pH had significant effects on the cold-adapted amylase production. A central composite design was then employed to further optimize these three factors. The experimental results indicated that the optimized composition of medium was 6.38 g  L(-1) starch, 33.84 g  L(-1) tryptone, 3.00 g  L(-1) yeast extract, 30 g  L(-1) NaCl, 0.60 g  L(-1) MgSO(4) and 0.56 g  L(-1) CaCl(2). The optimized cultivation conditions for amylase production were pH 7.18, a temperature of 20°C, and a shaking speed of 180 rpm. Under the proposed optimized conditions, the amylase experimental yield (676.63 U  mL(-1)) closely matched the yield (685.60 U  mL(-1)) predicted by the statistical model. The optimization of the medium contributed to tenfold higher amylase production than that of the control in shake-flask experiments.

  16. The abundant marine bacterium Pelagibacter simultaneously catabolizes dimethylsulfoniopropionate to the gases dimethyl sulfide and methanethiol.

    PubMed

    Sun, Jing; Todd, Jonathan D; Thrash, J Cameron; Qian, Yanping; Qian, Michael C; Temperton, Ben; Guo, Jiazhen; Fowler, Emily K; Aldrich, Joshua T; Nicora, Carrie D; Lipton, Mary S; Smith, Richard D; De Leenheer, Patrick; Payne, Samuel H; Johnston, Andrew W B; Davie-Martin, Cleo L; Halsey, Kimberly H; Giovannoni, Stephen J

    2016-01-01

    Marine phytoplankton produce ∼10(9) tonnes of dimethylsulfoniopropionate (DMSP) per year(1,2), an estimated 10% of which is catabolized by bacteria through the DMSP cleavage pathway to the climatically active gas dimethyl sulfide(3,4). SAR11 Alphaproteobacteria (order Pelagibacterales), the most abundant chemo-organotrophic bacteria in the oceans, have been shown to assimilate DMSP into biomass, thereby supplying this cell's unusual requirement for reduced sulfur(5,6). Here, we report that Pelagibacter HTCC1062 produces the gas methanethiol, and that a second DMSP catabolic pathway, mediated by a cupin-like DMSP lyase, DddK, simultaneously shunts as much as 59% of DMSP uptake to dimethyl sulfide production. We propose a model in which the allocation of DMSP between these pathways is kinetically controlled to release increasing amounts of dimethyl sulfide as the supply of DMSP exceeds cellular sulfur demands for biosynthesis. PMID:27573103

  17. Toxic Effect of a Marine Bacterium on Aquatic Organisms and Its Algicidal Substances against Phaeocystis globosa

    PubMed Central

    Yang, Qiuchan; Chen, Lina; Hu, Xiaoli; Zhao, Ling; Yin, Pinghe; Li, Qiang

    2015-01-01

    Harmful algal blooms have caused enormous damage to the marine ecosystem and the coastal economy in China. In this paper, a bacterial strain B1, which had strong algicidal activity against Phaeocystis globosa, was isolated from the coastal waters of Zhuhai in China. The strain B1 was identified as Bacillus sp. on the basis of 16S rDNA gene sequence and morphological characteristics. To evaluate the ecological safety of the algicidal substances produced by strain B1, their toxic effects on marine organisms were tested. Results showed that there were no adverse effects observed in the growth of Chlorella vulgaris, Chaetoceros muelleri, and Isochrystis galbana after exposure to the algicidal substances at a concentration of 1.0% (v/v) for 96 h. The 48h LC50 values for Brachionus plicatilis, Moina mongolica Daday and Paralichthys olivaceus were 5.7, 9.0 and 12.1% (v/v), respectively. Subsequently, the algicidal substances from strain B1 culture were isolated and purified by silica gel column, Sephadex G-15 column and high-performance liquid chromatography. Based on quadrupole time-of-flight mass spectrometry and PeakView Software, the purified substances were identified as prolyl-methionine and hypoxanthine. Algicidal mechanism indicated that prolyl-methionine and hypoxanthine inhibited the growth of P. globosa by disrupting the antioxidant systems. In the acute toxicity assessment using M. mongolica, 24h LC50 values of prolyl-methionine and hypoxanthine were 7.0 and 13.8 g/L, respectively. The active substances produced by strain B1 can be considered as ecologically and environmentally biological agents for controlling harmful algal blooms. PMID:25646807

  18. Toxic effect of a marine bacterium on aquatic organisms and its algicidal substances against Phaeocystis globosa.

    PubMed

    Yang, Qiuchan; Chen, Lina; Hu, Xiaoli; Zhao, Ling; Yin, Pinghe; Li, Qiang

    2015-01-01

    Harmful algal blooms have caused enormous damage to the marine ecosystem and the coastal economy in China. In this paper, a bacterial strain B1, which had strong algicidal activity against Phaeocystis globosa, was isolated from the coastal waters of Zhuhai in China. The strain B1 was identified as Bacillus sp. on the basis of 16S rDNA gene sequence and morphological characteristics. To evaluate the ecological safety of the algicidal substances produced by strain B1, their toxic effects on marine organisms were tested. Results showed that there were no adverse effects observed in the growth of Chlorella vulgaris, Chaetoceros muelleri, and Isochrystis galbana after exposure to the algicidal substances at a concentration of 1.0% (v/v) for 96 h. The 48h LC50 values for Brachionus plicatilis, Moina mongolica Daday and Paralichthys olivaceus were 5.7, 9.0 and 12.1% (v/v), respectively. Subsequently, the algicidal substances from strain B1 culture were isolated and purified by silica gel column, Sephadex G-15 column and high-performance liquid chromatography. Based on quadrupole time-of-flight mass spectrometry and PeakView Software, the purified substances were identified as prolyl-methionine and hypoxanthine. Algicidal mechanism indicated that prolyl-methionine and hypoxanthine inhibited the growth of P. globosa by disrupting the antioxidant systems. In the acute toxicity assessment using M. mongolica, 24h LC50 values of prolyl-methionine and hypoxanthine were 7.0 and 13.8 g/L, respectively. The active substances produced by strain B1 can be considered as ecologically and environmentally biological agents for controlling harmful algal blooms.

  19. Antibiofilm Activity of the Marine Bacterium Pseudoalteromonas sp. Strain 3J6▿

    PubMed Central

    Dheilly, Alexandra; Soum-Soutéra, Emmanuelle; Klein, Géraldine L.; Bazire, Alexis; Compère, Chantal; Haras, Dominique; Dufour, Alain

    2010-01-01

    Biofilm formation results in medical threats or economic losses and is therefore a major concern in a variety of domains. In two-species biofilms of marine bacteria grown under dynamic conditions, Pseudoalteromonas sp. strain 3J6 formed mixed biofilms with Bacillus sp. strain 4J6 but was largely predominant over Paracoccus sp. strain 4M6 and Vibrio sp. strain D01. The supernatant of Pseudoalteromonas sp. 3J6 liquid culture (SN3J6) was devoid of antibacterial activity against free-living Paracoccus sp. 4M6 and Vibrio sp. D01 cells, but it impaired their ability to grow as single-species biofilms and led to higher percentages of nonviable cells in 48-h biofilms. Antibiofilm molecules of SN3J6 were able to coat the glass surfaces used to grow biofilms and reduced bacterial attachment about 2-fold, which might partly explain the biofilm formation defect but not the loss of cell viability. SN3J6 had a wide spectrum of activity since it affected all Gram-negative marine strains tested except other Pseudoalteromonas strains. Biofilm biovolumes of the sensitive strains were reduced 3- to 530-fold, and the percentages of nonviable cells were increased 3- to 225-fold. Interestingly, SN3J6 also impaired biofilm formation by three strains belonging to the human-pathogenic species Pseudomonas aeruginosa, Salmonella enterica, and Escherichia coli. Such an antibiofilm activity is original and opens up a variety of applications for Pseudoalteromonas sp. 3J6 and/or its active exoproducts in biofilm prevention strategies. PMID:20363799

  20. Toxic effect of a marine bacterium on aquatic organisms and its algicidal substances against Phaeocystis globosa.

    PubMed

    Yang, Qiuchan; Chen, Lina; Hu, Xiaoli; Zhao, Ling; Yin, Pinghe; Li, Qiang

    2015-01-01

    Harmful algal blooms have caused enormous damage to the marine ecosystem and the coastal economy in China. In this paper, a bacterial strain B1, which had strong algicidal activity against Phaeocystis globosa, was isolated from the coastal waters of Zhuhai in China. The strain B1 was identified as Bacillus sp. on the basis of 16S rDNA gene sequence and morphological characteristics. To evaluate the ecological safety of the algicidal substances produced by strain B1, their toxic effects on marine organisms were tested. Results showed that there were no adverse effects observed in the growth of Chlorella vulgaris, Chaetoceros muelleri, and Isochrystis galbana after exposure to the algicidal substances at a concentration of 1.0% (v/v) for 96 h. The 48h LC50 values for Brachionus plicatilis, Moina mongolica Daday and Paralichthys olivaceus were 5.7, 9.0 and 12.1% (v/v), respectively. Subsequently, the algicidal substances from strain B1 culture were isolated and purified by silica gel column, Sephadex G-15 column and high-performance liquid chromatography. Based on quadrupole time-of-flight mass spectrometry and PeakView Software, the purified substances were identified as prolyl-methionine and hypoxanthine. Algicidal mechanism indicated that prolyl-methionine and hypoxanthine inhibited the growth of P. globosa by disrupting the antioxidant systems. In the acute toxicity assessment using M. mongolica, 24h LC50 values of prolyl-methionine and hypoxanthine were 7.0 and 13.8 g/L, respectively. The active substances produced by strain B1 can be considered as ecologically and environmentally biological agents for controlling harmful algal blooms. PMID:25646807

  1. Molecular Uptake of Chitooligosaccharides through Chitoporin from the Marine Bacterium Vibrio harveyi

    PubMed Central

    Suginta, Wipa; Chumjan, Watcharin; Mahendran, Kozhinjampara R.; Janning, Petra; Schulte, Albert; Winterhalter, Mathias

    2013-01-01

    Background Chitin is the most abundant biopolymer in marine ecosystems. However, there is no accumulation of chitin in the ocean-floor sediments, since marine bacteria Vibrios are mainly responsible for a rapid turnover of chitin biomaterials. The catabolic pathway of chitin by Vibrios is a multi-step process that involves chitin attachment and degradation, followed by chitooligosaccharide uptake across the bacterial membranes, and catabolism of the transport products to fructose-6-phosphate, acetate and NH3. Principal Findings This study reports the isolation of the gene corresponding to an outer membrane chitoporin from the genome of Vibrio harveyi. This porin, expressed in E. coli, (so called VhChiP) was found to be a SDS-resistant, heat-sensitive trimer. Immunoblotting using anti-ChiP polyclonal antibody confirmed the expression of the recombinant ChiP, as well as endogenous expression of the native protein in the V. harveyi cells. The specific function of VhChiP was investigated using planar lipid membrane reconstitution technique. VhChiP nicely inserted into artificial membranes and formed stable, trimeric channels with average single conductance of 1.8±0.13 nS. Single channel recordings at microsecond-time resolution resolved translocation of chitooligosaccharides, with the greatest rate being observed for chitohexaose. Liposome swelling assays showed no permeation of other oligosaccharides, including maltose, sucrose, maltopentaose, maltohexaose and raffinose, indicating that VhChiP is a highly-specific channel for chitooligosaccharides. Conclusion/Significance We provide the first evidence that chitoporin from V. harveyi is a chitooligosaccharide specific channel. The results obtained from this study help to establish the fundamental role of VhChiP in the chitin catabolic cascade as the molecular gateway that Vibrios employ for chitooligosaccharide uptake for energy production. PMID:23383078

  2. Rheinheimera aestuari sp. nov., a marine bacterium isolated from coastal sediment.

    PubMed

    Baek, Kyunghwa; Jeon, Che Ok

    2015-08-01

    A Gram-stain-negative, strictly aerobic, non-pigmented, motile bacterium with a single polar flagellum, designated H29T, was isolated from coastal sediment of Jeju Island, South Korea. Cells were non-spore-forming rods showing catalase- and oxidase-positive reactions. Growth of strain H29T was observed at 10-40 °C (optimum, 20-25 °C) and pH 6.0-9.0 (optimum, pH 7.0-8.0), and in the presence of 1-4% (w/v) NaCl (optimum, 2-3%). Strain H29T contained C16 : 0, iso-C15 : 0 3-OH and summed feature 3 (comprising C16 : 1ω7c/C16 : 1ω6c) as the major fatty acids and ubiquinone-8 (Q-8) as the sole isoprenoid quinone. Phosphatidylethanolamine and phosphatidylglycerol were identified as the major polar lipids. The G+C content of the genomic DNA was 46.5 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain H29T formed a phyletic lineage with Rheinheimera hassiensis E48T within the genus Rheinheimera of the family Chromatiaceae. Strain H29T was most closely related to Rheinheimera pacifica KMM 1406T, Rheinheimera muenzenbergensis E49T, Rheinheimera hassiensis E48T and Rheinheimera baltica OSBAC1T with 97.8%, 97.6%, 97.4% and 97.2% 16S rRNA gene sequence similarities, respectively. However, DNA-DNA hybridization values of strain H29T with type strains of these species were lower than 70%. On the basis of the phenotypic, chemotaxonomic and molecular properties, strain H29T represents a novel species of the genus Rheinheimera, for which the name Rheinheimeraaestuarii sp. nov. is proposed. The type strain is H29T ( = KACC 18251T = JCM 30404T). PMID:25957052

  3. Shewanella aestuarii sp. nov., a marine bacterium isolated from a tidal flat.

    PubMed

    Park, Hye Yoon; Jeon, Che Ok

    2013-12-01

    A Gram-stain-negative, non-spore-forming, facultatively anaerobic bacterium, designated strain SC18(T), was isolated from a tidal flat of Suncheon bay in South Korea. Cells were rod-shaped and motile by means of a polar flagellum. Cells were catalase-, oxidase- and β-haemolysis-positive. Growth was observed at 4-37 °C (optimum, 25-30 °C), at pH 5.0-9.0 (optimum, pH 7.0) and in the presence of 0-5.0 % (w/v) NaCl (optimum, 0-2 %). The major cellular fatty acids were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 and C16 : 0. The polar lipid pattern indicated the presence of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylmethylethanolamine, an unidentified aminolipid and three unidentified lipids. Strain SC18(T) contained Q-7, Q-8, MK-7 and MMK-7 as the dominant respiratory quinones and the G+C content of the genomic DNA was 41.3 mol%. Phylogenetic analysis based on 16S rRNA and gyrase B (gyrB) gene sequences showed that strain SC18(T) formed a tight phyletic lineage with members of the genus Shewanella. Strain SC18(T) was related most closely to Shewanella denitrificans OS217(T) (97.3 % 16S rRNA gene sequence similarity) and Shewanella gaetbuli TF-27(T) (97.1 %), but the DNA-DNA relatedness levels between strain SC18(T) and the type strains of S. denitrificans and S. gaetbuli were 18.3±2.8 and 22.5±1.6 % (mean±sd), respectively. On the basis of phenotypic, chemotaxonomic and molecular features, strain SC18(T) represents a novel species of the genus Shewanella, for which the name Shewanella aestuarii sp. nov. is proposed. The type strain is SC18(T) ( = KACC 16187(T) = JCM 17801(T)).

  4. Rheinheimera gaetbuli sp. nov., a Marine Bacterium Isolated from a Tidal Flat.

    PubMed

    Baek, Kyunghwa; Jeon, Che Ok

    2016-03-01

    A gram-staining-negative, strictly aerobic, rod-shaped, and motile bacterium with a single polar flagellum, designated H26(T), was isolated from tidal flat sediment in Jeju Island, South Korea. Growth of strain H26(T) was observed at 4-35 °C (optimum, 20-25 °C), pH 6.0-9.0 (optimum, pH 7.0-8.0), and 1-4 % NaCl (optimum, 2-3 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain H26(T) formed a phyletic lineage within the genus Rheinheimera, family Chromatiaceae. Strain H26(T) was most closely related to Rheinheimera baltica OSBAC1(T), Rheinheimera aestuarii H29(T), Rheinheimera muenzenbergensis E49(T), and Rheinheimera aquimaris SW-353(T) with 98.5, 98.1, 97.8, and 97.5 % of 16S rRNA gene sequence similarities, respectively. The DNA-DNA relatedness levels between strain H26(T) and the type strains of R. baltica, R. aestuarii, R. muenzenbergensis, and R. aquimaris were 35.5 ± 3.2, 33.4 ± 1.5, 31.2 ± 2.2, and 28.7 ± 0.9 %, respectively. The major fatty acids of strain H26(T) were iso-C15:0 3-OH, summed feature 3 (comprising C16:1 ω7c/C16:1 ω6c), C16:0, summed feature 8 (comprising C18:1 ω7c/C18:1 ω6c), iso-C17:0 3-OH, and C12:0 3-OH and the strain contained ubiquinone (Q-8) as the sole isoprenoid quinone. Phosphatidylethanolamine, phosphatidylglycerol, and an aminolipid were identified as the major polar lipids and the G + C content of the genomic DNA was 52.0 mol%. Based on the phenotypic, chemotaxonomic, and molecular properties, strain H26(T) represents a novel species of the genus Rheinheimera, for which the name Rheinheimera gaetbuli sp. nov. is proposed. The type strain was H26(T) (=KACC 18254(T) = JCM 30403(T)). PMID:26660082

  5. Polycyclovorans algicola gen. nov., sp. nov., an aromatic-hydrocarbon-degrading marine bacterium found associated with laboratory cultures of marine phytoplankton.

    PubMed

    Gutierrez, Tony; Green, David H; Nichols, Peter D; Whitman, William B; Semple, Kirk T; Aitken, Michael D

    2013-01-01

    A strictly aerobic, halotolerant, rod-shaped bacterium, designated strain TG408, was isolated from a laboratory culture of the marine diatom Skeletonema costatum (CCAP1077/1C) by enrichment with polycyclic aromatic hydrocarbons (PAHs) as the sole carbon source. 16S rRNA gene sequence analysis placed this organism within the order Xanthomonadales of the class Gammaproteobacteria. Its closest relatives included representatives of the Hydrocarboniphaga-Nevskia-Sinobacter clade (<92% sequence similarity) in the family Sinobacteraceae. The strain exhibited a narrow nutritional spectrum, preferring to utilize aliphatic and aromatic hydrocarbon compounds and small organic acids. Notably, it displayed versatility in degrading two- and three-ring PAHs. Moreover, catechol 2,3-dioxygenase activity was detected in lysates, indicating that this strain utilizes the meta-cleavage pathway for aromatic compound degradation. Cells produced surface blebs and contained a single polar flagellum. The predominant isoprenoid quinone of strain TG408 was Q-8, and the dominant fatty acids were C(16:0), C(16:1) ω7c, and C(18:1) ω7c. The G+C content of the isolate's DNA was 64.3 mol% ± 0.34 mol%. On the basis of distinct phenotypic and genotypic characteristics, strain TG408 represents a novel genus and species in the class Gammaproteobacteria for which the name Polycyclovorans algicola gen. nov., sp. nov., is proposed. Quantitative PCR primers targeting the 16S rRNA gene of this strain were developed and used to show that this organism is found associated with other species of marine phytoplankton. Phytoplankton may be a natural biotope in the ocean where new species of hydrocarbon-degrading bacteria await discovery and which contribute significantly to natural remediation processes. PMID:23087039

  6. Anti-biofilm activity of the Antarctic marine bacterium Pseudoalteromonas haloplanktis TAC125.

    PubMed

    Papa, Rosanna; Parrilli, Ermenegilda; Sannino, Filomena; Barbato, Gaetano; Tutino, Maria Luisa; Artini, Marco; Selan, Laura

    2013-06-01

    Considering the increasing impact of bacterial biofilms on human health, industrial and food-processing activities, the interest in the development of new approaches for the prevention and treatment of adhesion and biofilm formation capabilities has increased. A viable approach should target adhesive properties without affecting bacterial vitality in order to avoid the rapid appearance of escape mutants. It is known that marine bacteria belonging to the genus Pseudoalteromonas produce compounds of biotechnological interest, including anti-biofilm molecules. Pseudoalteromonas haloplanktis TAC125 is the first Antarctic Gram-negative strain whose genome was sequenced. In this work the anti-biofilm activity of P. haloplanktis supernatant was examined on different staphylococci. Results obtained demonstrated that supernatant of P. haloplanktis, grown in static condition, inhibits biofilm of Staphylococcus epidermidis. In order to define the chemical nature of the biofilm-inhibiting compound, the supernatant was subject to various treatments. Data reported demonstrated that the biologically active component is sensible to treatment with sodium periodate suggesting its saccharidic nature. PMID:23411371

  7. Phage infection of an environmentally relevant marine bacterium alters host metabolism and lysate composition

    PubMed Central

    Ankrah, Nana Yaw D; May, Amanda L; Middleton, Jesse L; Jones, Daniel R; Hadden, Mary K; Gooding, Jessica R; LeCleir, Gary R; Wilhelm, Steven W; Campagna, Shawn R; Buchan, Alison

    2014-01-01

    Viruses contribute to the mortality of marine microbes, consequentially altering biological species composition and system biogeochemistry. Although it is well established that host cells provide metabolic resources for virus replication, the extent to which infection reshapes host metabolism at a global level and the effect of this alteration on the cellular material released following viral lysis is less understood. To address this knowledge gap, the growth dynamics, metabolism and extracellular lysate of roseophage-infected Sulfitobacter sp. 2047 was studied using a variety of techniques, including liquid chromatography–tandem mass spectrometry (LC-MS/MS)-based metabolomics. Quantitative estimates of the total amount of carbon and nitrogen sequestered into particulate biomass indicate that phage infection redirects ∼75% of nutrients into virions. Intracellular concentrations for 82 metabolites were measured at seven time points over the infection cycle. By the end of this period, 71% of the detected metabolites were significantly elevated in infected populations, and stable isotope-based flux measurements showed that these cells had elevated metabolic activity. In contrast to simple hypothetical models that assume that extracellular compounds increase because of lysis, a profile of metabolites from infected cultures showed that >70% of the 56 quantified compounds had decreased concentrations in the lysate relative to uninfected controls, suggesting that these small, labile nutrients were being utilized by surviving cells. These results indicate that virus-infected cells are physiologically distinct from their uninfected counterparts, which has implications for microbial community ecology and biogeochemistry. PMID:24304672

  8. Structural properties of the tubular appendage spinae from marine bacterium Roseobacter sp. strain YSCB

    PubMed Central

    Bernadac, A.; Wu, L.-F.; Santini, C.-L.; Vidaud, C.; Sturgis, J. N.; Menguy, N.; Bergam, P.; Nicoletti, C.; Xiao, T.

    2012-01-01

    Spinae are tubular surface appendages broadly found in Gram-negative bacteria. Little is known about their architecture, function or origin. Here, we report structural characterization of the spinae from marine bacteria Roseobacter sp. YSCB. Electron cryo-tomography revealed that a single filament winds into a hollow flared base with progressive change to a cylinder. Proteinase K unwound the spinae into proteolysis-resistant filaments. Thermal treatment ripped the spinae into ribbons that were melted with prolonged heating. Circular dichroism spectroscopy revealed a dominant beta-structure of the spinae. Differential scanning calorimetry analyses showed three endothermic transformations at 50–85°C, 98°C and 123°C, respectively. The heating almost completely disintegrated the spinae, abolished the 98°C transition and destroyed the beta-structure. Infrared spectroscopy identified the amide I spectrum maximum at a position similar to that of amyloid fibrils. Therefore, the spinae distinguish from other bacterial appendages, e.g. flagella and stalks, in both the structure and mechanism of assembly. PMID:23230515

  9. Spongiispira norvegica gen. nov., sp. nov., a marine bacterium isolated from the boreal sponge Isops phlegraei.

    PubMed

    Kaesler, Ines; Graeber, Ingeborg; Borchert, Martin S; Pape, Thomas; Dieckmann, Ralf; von Döhren, Hans; Nielsen, Preben; Lurz, Rudi; Michaelis, Walter; Szewzyk, Ulrich

    2008-08-01

    The bacterial strain Gp_4_7.1T, isolated from the marine sponge Isops phlegraei collected at the Sula Ridge off the Norwegian coast, was characterized. The isolate was a motile spirillum that was monopolarly and monotrichously flagellated. It was aerobic, Gram-negative, oxidase-positive and catalase-negative. Optimal growth occurred between 20 and 30 degrees C, at pH 7-8 and with a salt concentration of 2-3 % (w/v). The isolate showed a relatively restricted nutritional profile. Substrate utilization tests were only positive for arabinose. Enzyme tests were positive for esterase lipase C8, lipase C14, leucine arylamidase and naphthol-AS-BI-phosphohydrolase. The strain was not able to reduce nitrate. The major cellular fatty acids were C16:1 omega7 and C16:0. The DNA G+C content was 62.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequence comparison classified the strain as a member of the order Oceanospirillales in the class Gammaproteobacteria. Strain Gp_4_7.1T formed a distinct phyletic line with less than 94 % 16S rRNA gene sequence similarity to its closest relatives with validly published names. Based on the determined data, it is proposed that the strain represents a novel species in a new genus, Spongiispira norvegica gen. nov., sp. nov.; the type strain of Spongiispira norvegica is Gp_4_7.1T (=DSM 17749T =NCIMB 14401T).

  10. Proteomic Analysis of Stationary Phase in the Marine Bacterium 'Candidatus Pelagibacter ubique'

    SciTech Connect

    Sowell, Sarah M.; Norbeck, Angela D.; Lipton, Mary S.; Nicora, Carrie D.; Callister, Stephen J.; Smith, Richard D.; Barofsky, Douglas F.; Giovannoni, Stephen J.

    2008-05-01

    Candidatus Pelagibacter ubique, an abundant marine alphaproteobacterium, subsists in nature at low ambient nutrient concentrations and may often be exposed to nutrient limitation, but its genome revealed no evidence of global regulatory adaptations to stationary phase. We used high-resolution capillary liquid chromatography (LC) coupled online to an LTQ mass spectrometer to build an Accurate Mass and Time (AMT) tag library, and employed the AMT tag approach to quantitatively examine proteome differences between exponentially growing and stationary phase Cand. P. ubique cells cultivated in a seawater medium. The AMT tag library represented 72% of the predicted protein coding genes. Stationary phase protein abundance increased for OsmC, which mitigates oxidative damage, and for molecular chaperones, enzymes involved in methionine and cysteine biosynthesis, proteins involved in rho-dependent transcription termination, and the signal transduction enzymes CheY-FisH and ChvG. Our findings indicate that Cand. P. ubique responds adaptively to stationary phase by increasing the abundance of a suite of proteins that contribute to homeostasis, but does not undergo major proteome remodeling. We speculate that this limited response may enable Cand. P. ubique to cope with ambient conditions in which nutrients are often insufficient for short periods, and the ability to resume growth overrides the capacity for long term survival afforded by more comprehensive global stationary phase responses.

  11. Biogeochemical controls and isotopic signatures of nitrous oxide production by a marine ammonia-oxidizing bacterium

    NASA Astrophysics Data System (ADS)

    Frame, C. H.; Casciotti, K. L.

    2010-09-01

    Nitrous oxide (N2O) is a trace gas that contributes to the greenhouse effect and stratospheric ozone depletion. The N2O yield from nitrification (moles N2O-N produced per mole ammonium-N consumed) has been used to estimate marine N2O production rates from measured nitrification rates and global estimates of oceanic export production. However, the N2O yield from nitrification is not constant. Previous culture-based measurements indicate that N2O yield increases as oxygen (O2) concentration decreases and as nitrite (NO2-) concentration increases. Here, we have measured yields of N2O from cultures of the marine β-proteobacterium Nitrosomonas marina C-113a as they grew on low-ammonium (50 μM) media. These yields, which were typically between 4 × 10-4 and 7 × 10-4 for cultures with cell densities between 2 × 102 and 2.1 × 104 cells ml-1, were lower than previous reports for ammonia-oxidizing bacteria. The observed impact of O2 concentration on yield was also smaller than previously reported under all conditions except at high starting cell densities (1.5 × 106 cells ml-1), where 160-fold higher yields were observed at 0.5% O2 (5.1 μM dissolved O2) compared with 20% O2 (203 μM dissolved O2). At lower cell densities (2 × 102 and 2.1 × 104 cells ml-1), cultures grown under 0.5% O2 had yields that were only 1.25- to 1.73-fold higher than cultures grown under 20% O2. Thus, previously reported many-fold increases in N2O yield with dropping O2 could be reproduced only at cell densities that far exceeded those of ammonia oxidizers in the ocean. The presence of excess NO2- (up to 1 mM) in the growth medium also increased N2O yields by an average of 70% to 87% depending on O2 concentration. We made stable isotopic measurements on N2O from these cultures to identify the biochemical mechanisms behind variations in N2O yield. Based on measurements of δ15Nbulk, site preference (SP = δ15Nα-δ15Nβ), and δ18O of N2O (δ18O-N2O), we estimate that nitrifier

  12. Biogeochemical controls and isotopic signatures of nitrous oxide production by a marine ammonia-oxidizing bacterium

    NASA Astrophysics Data System (ADS)

    Frame, C. H.; Casciotti, K. L.

    2010-04-01

    Nitrous oxide (N2O) is a trace gas that contributes to greenhouse warming of the atmosphere and stratospheric ozone depletion. The N2O yield from nitrification (moles N2O-N produced/mole ammonium-N consumed) has been used to estimate marine N2O production rates from measured nitrification rates and global estimates of oceanic export production. However, the N2O yield from nitrification is not constant. Previous culture-based measurements indicate that N2O yield increases as oxygen (O2) concentration decreases and as nitrite (NO2-) concentration increases. These results were obtained in substrate-rich conditions and may not reflect N2O production in the ocean. Here, we have measured yields of N2O from cultures of the marine β-proteobacterium Nitrosomonas marina C-113a as they grew on low-ammonium (50 μM) media. These yields were lower than previous reports, between 4×10-4 and 7×10-4 (moles N/mole N). The observed impact of O2 concentration on yield was also smaller than previously reported under all conditions except at high starting cell densities (1.5×10

  13. Shewanella arctica sp. nov., an iron-reducing bacterium isolated from Arctic marine sediment.

    PubMed

    Kim, So-Jeong; Park, Soo-Je; Oh, Yong-Sik; Lee, Sang-Ah; Shin, Kee-Sun; Roh, Dong-Hyun; Rhee, Sung-Keun

    2012-05-01

    Two strains of dissimilatory iron-reducing bacteria, which could couple lactate oxidation to iron reduction for energy conservation, were isolated from Arctic marine sediment. The strains, IR12(T) and IR26, were both Gram-staining-negative, catalase- and oxidase-positive and facultative anaerobes. Their cells were rod-shaped and motile by means of a polar flagellum. Both strains grew in the presence of 0.5-3.5 % (w/v) NaCl, with an absolute requirement for Na(+). Both were psychrotolerant since they could grow at 4-28 °C but had an optimum growth temperature of 20 °C. Both grew at pH 4.5-9.0 (optimum, pH 7.5). The major fatty acids of strains IR12(T) and IR26 were summed feature 3 (C(16 : 1)ω6c and/or C(16 : 1)ω7c) and C(16 : 0). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strains IR12(T) and IR26 belonged to the class Gammaproteobacteria and were most closely related to Shewanella vesiculosa M7(T), Shewanella livingstonensis NF22(T) and Shewanella frigidimarina ACAM 591(T) (with 98.5 and 98.8 %, 98.5 and 98.8 %, and 98.5 and 98.8 % sequence similarities, respectively). The genomic DNA G+C contents of strains IR12(T) and IR26 were 40.0 and 40.3 mol%, respectively. DNA-DNA relatedness data indicated that the two novel strains represented a single species that was distinct from S. vesiculosa M7(T), S. livingstonensis NF22(T) and S. frigidimarina ACAM 591(T). Based on the phylogenetic, phenotypic and DNA-DNA relatedness data, the two new strains represent a single novel species of the genus Shewanella, for which the name Shewanella arctica sp. nov. is proposed. The type strain is IR12(T) ( = KCTC 23109(T) = JCM 16723(T)).

  14. Molecular characterization of a homolog of the ferric-uptake regulator, Fur, from the marine bacterium Marinobacter algicola DG893.

    PubMed

    Barker, Ryan A; Tisnado, Jerrell; Lambert, Lisa A; Gärdes, Astrid; Carrano, Mary W; Carrano, Paul N; Gillian, Christopher; Carrano, Carl J

    2015-02-01

    Full length recombinant iron regulatory protein, Fur, has been isolated and characterized from the algal-associated marine bacterium Marinobacter algicola DG893. Under nondenaturing conditions the Fur protein behaves on size exclusion chromatography as a dimer while it is monomeric under SDS PAGE conditions. ICP-MS and fluorescence quenching experiments show that Mb-Fur binds a single metal ion (Zn, Mn, or Co) per monomer. Electrophoretic mobility shift assays were used to probe the interaction of Mb-Fur with the purported Fur box in the promoter region upstream of the vibrioferrin biosynthetic operon. Interaction of Mb-Fur with a 100 bp DNA fragment containing the Fur box in the presence of 10 µM Mn, Co or Zn(II) resulted in decreased migration of DNA on a 7.5% polyacrylamide gel. In the absence of the Fur protein or the metal, no interaction is seen. The presence of EDTA in the binding, loading or running buffers also abolished all activity demonstrating the importance of the metal in formation of the promoter-repressor complex. Based on a high degree of similarity between Mb-Fur and its homolog from Pseudomonas aeruginosa (PA) whose X-ray structure is known we developed a structural model for the former which suggested that only one of the several metal binding sites found in other Fur's would be functional. This is consistent with the single metal binding stoichiometry we observed. Since the purported metal binding site was one that has been described as "structural" rather than "functional" in PA and yet the monometallic Mb-Fur retains DNA Fur box binding ability it reopens the question of which site is which, or if different species have adapted the sites for different purposes.

  15. Photobacterium panuliri sp. nov., an alkalitolerant marine bacterium isolated from eggs of spiny lobster, Panulirus penicillatus from Andaman Sea.

    PubMed

    Deep, Kamal; Poddar, Abhijit; Das, Subrata K

    2014-11-01

    A facultative anaerobe, alkalitolerant, gram-negative marine bacterium strain LBS5(T), was isolated from eggs carried on the pleopods of female spiny lobster (Panulirus penicillatus) in Andaman Sea from a depth of 3.5 m. Heterotrophic growth was observed at 15-38 °C and pH 5.5-11. Optimum growth occurred at 28 °C and pH 7.5. It can grow in the presence of 0.5-7 % NaCl (w/v), and the optimal NaCl required for growth was 2-4 %. 16S rRNA gene sequence analysis revealed the strain LBS5(T) belongs to the genus Photobacterium and showed 99.6 % similarity with P. aquae AE6(T), 98.2 % with P. aphoticum M46(T), 97 % with P. rosenbergii CC1(T), 96.9 % with P. lutimaris DF-42(T), and 96.6 % with P. halotolerans MACL01(T). The DNA-DNA similarities between strains LBS5(T) with other closely related strains were well below 70 %. The DNA G + C content was 50.52 (±0.9) mol%. The major fatty acids were C16:1w7c/w6c, C18:1w6c/w7c, C16:0, C15:0 iso, C16:0 10-methyl/17:1 iso w9c, C17:0 iso. Polar lipids included a phosphatidylglycerol, a diphosphatidylglycerol, a phosphatidylethanolamine, and one unidentified lipid. Based on the polyphasic evidences, strain LBS5(T) represents a novel species of the genus Photobacterium for which Photobacterium panuliri sp. nov. is proposed. The type strain is LBS5(T) (=DSM 27646(T) = LMG 27617(T) = JCM 19199(T)).

  16. Vibrio oceanisediminis sp. nov., a nitrogen-fixing bacterium isolated from an artificial oil-spill marine sediment.

    PubMed

    Kang, Sang Rim; Srinivasan, Sathiyaraj; Lee, Sang-Seob

    2015-10-01

    A Gram-staining-negative, halophilic, facultatively anaerobic, motile, rod-shaped and nitrogen-fixing bacterium, designated strain S37T, was isolated from an artificial oil-spill sediment sample from the coast of Taean, South Korea. Cells grew at 10-37 °C and pH 5.0-9.0, with optimal growth at 28 °C and pH 6.0-8.0. Growth was observed with 1-9 % (w/v) NaCl in marine broth, with optimal growth with 3-5 % NaCl, but no growth was observed in the absence of NaCl. According to the results of 16S rRNA gene sequence analysis, strain S37T represents a member of the genus Vibrio of the class Gammaproteobacteria and forms a clade with Vibrio plantisponsor MSSRF60T (97.38 %), Vibrio diazotrophicus ATCC 33466T (97.31 %), Vibrio aestuarianus ATCC 35048T (97.07 %) Vibrio areninigrae J74T (96.76 %) and Vibrio hispanicus LMG 13240T (96.76 %). The major fatty acids were C16 : 0, C16 : 1ω7c/C16 : 1ω6c and C18 : 1ω7c/C18 : 1ω6c. The DNA G+C content was 41.9 %. The DNA-DNA hybridization analysis results showed a 30.2 % association value with the closely related type strain V. plantisponsor DSM 21026T. On the basis of phenotypic and chemotaxonomic characteristics, strain S37T represents a novel species of the genus Vibrio, for which the name Vibrio oceanisediminis sp. nov., is proposed with the type strain S37T ( = KEMB 2255-005T = JCM 30409T).

  17. Analysis of N-acetylglucosamine metabolism in the marine bacterium Pirellula sp. strain 1 by a proteomic approach.

    PubMed

    Rabus, Ralf; Gade, Dörte; Helbig, Roger; Bauer, Margarete; Glöckner, Frank Oliver; Kube, Michael; Schlesner, Heinz; Reinhardt, Richard; Amann, Rudolf

    2002-06-01

    Pirellula sp. strain 1 is a marine bacterium that can grow with the chitin monomer N-acetylglucosamine as sole source of carbon and nitrogen under aerobic conditions, and that is a member of the bacterial phylum Planctomycetes. As a basis for the proteomic studies we quantified growth of strain 1 with N-acetylglucosamine and glucose, revealing doubling times of 14 and 10 h, respectively. Studies with dense cell suspensions indicated that the capacity to degrade N-acetylglucosamine and glucose may not be tightly regulated. Proteins from soluble extracts prepared from exponential cultures grown either with N-acetylglucosamine or glucose were separated by two-dimensional gel electrophoresis and visualized by fluorescence staining (Sypro Ruby). Analysis of the protein patterns revealed the presence of several protein spots only detectable in soluble extracts of N-acetylglucosamine grown cells. Determination of amino acid sequences and peptide mass fingerprints from tryptic fragments of the most abundant one of these spots allowed the identification of the coding gene on the genomic sequence of Pirellula sp. strain 1. This gene showed similarities to a dehydrogenase from Bacillus subtilis, and is closely located to a gene similar to glucosamine-6-phosphate isomerase from B. subtilis. Genes of two other proteins expressed during growth on N-acetylglucosamine as well as on glucose were also identified and found to be similar to a glyceraldehyde-3-phosphate-dehydrogenase and a NADH-dehydrogenase, respectively. Thus the coding genes of three proteins expressed during growth of Pirellula sp. strain 1 on carbohydrates were identified and related by sequence similarity to carbohydrate metabolism.

  18. Photobacterium panuliri sp. nov., an alkalitolerant marine bacterium isolated from eggs of spiny lobster, Panulirus penicillatus from Andaman Sea.

    PubMed

    Deep, Kamal; Poddar, Abhijit; Das, Subrata K

    2014-11-01

    A facultative anaerobe, alkalitolerant, gram-negative marine bacterium strain LBS5(T), was isolated from eggs carried on the pleopods of female spiny lobster (Panulirus penicillatus) in Andaman Sea from a depth of 3.5 m. Heterotrophic growth was observed at 15-38 °C and pH 5.5-11. Optimum growth occurred at 28 °C and pH 7.5. It can grow in the presence of 0.5-7 % NaCl (w/v), and the optimal NaCl required for growth was 2-4 %. 16S rRNA gene sequence analysis revealed the strain LBS5(T) belongs to the genus Photobacterium and showed 99.6 % similarity with P. aquae AE6(T), 98.2 % with P. aphoticum M46(T), 97 % with P. rosenbergii CC1(T), 96.9 % with P. lutimaris DF-42(T), and 96.6 % with P. halotolerans MACL01(T). The DNA-DNA similarities between strains LBS5(T) with other closely related strains were well below 70 %. The DNA G + C content was 50.52 (±0.9) mol%. The major fatty acids were C16:1w7c/w6c, C18:1w6c/w7c, C16:0, C15:0 iso, C16:0 10-methyl/17:1 iso w9c, C17:0 iso. Polar lipids included a phosphatidylglycerol, a diphosphatidylglycerol, a phosphatidylethanolamine, and one unidentified lipid. Based on the polyphasic evidences, strain LBS5(T) represents a novel species of the genus Photobacterium for which Photobacterium panuliri sp. nov. is proposed. The type strain is LBS5(T) (=DSM 27646(T) = LMG 27617(T) = JCM 19199(T)). PMID:24962598

  19. Lutibacter litoralis gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from tidal flat sediment.

    PubMed

    Choi, Dong H; Cho, Byung C

    2006-04-01

    A rod-shaped marine bacterium, designated strain CL-TF09T, isolated from a tidal flat in Ganghwa, Korea, was characterized based on its physiological and biochemical features, fatty acid profile and phylogenetic position. 16S rRNA gene sequence analysis revealed a clear affiliation with the family Flavobacteriaceae. Strain CL-TF09T showed the closest phylogenetic relationship with the genera Tenacibaculum and Polaribacter; sequence similarities between CL-TF09T and the type strains of Tenacibaculum and Polaribacter species ranged from 90.7 to 91.8 %. Cells of strain CL-TF09T were non-motile and grew on solid media as yellow colonies. The strain grew in the presence of 1-5 % sea salts, within a temperature range of 5-30 degrees C and at pH 7-8. The strain had iso-C(15 : 0) 3-OH (17.4 %), iso-C(15 : 0) (16.7 %), anteiso-C(15 : 0) (15.1 %) and iso-C(16 : 0) 3-OH (13.4 %) as predominant fatty acids. The DNA G+C content was 33.9 mol%. Based on the physiological, fatty acid composition and phylogenetic data presented, strain CL-TF09T is considered to represent a novel genus and species of the family Flavobacteriaceae, for which the name Lutibacter litoralis gen. nov., sp. nov. is proposed. The type strain is CL-TF09T (=KCCM 42118T = JCM 13034T).

  20. Genome sequence of the pink–pigmented marine bacterium Loktanella hongkongensis type strain (UST950701–009PT), a representative of the Roseobacter group

    DOE PAGESBeta

    Lau, Stanley CK; Riedel, Thomas; Fiebig, Anne; Han, James; Huntemann, Marcel; Petersen, Jörn; Ivanova, Natalia N.; Markowitz, Victor; Woyke, Tanja; Göker, Markus; et al

    2015-08-11

    Loktanella hongkongensis UST950701-009PT is a Gram-negative, non-motile and rod-shaped bacterium isolated from a marine biofilm in the subtropical seawater of Hong Kong. When growing as a monospecies biofilm on polystyrene surfaces, this bacterium is able to induce larval settlement and metamorphosis of a ubiquitous polychaete tubeworm Hydroides elegans. The inductive cues are low-molecular weight compounds bound to the exopolymeric matrix of the bacterial cells. In the present study we describe the features of L. hongkongensis strain DSM 17492T together with its genome sequence and annotation and novel aspects of its phenotype. The 3,198,444 bp long genome sequence encodes 3104 protein-codingmore » genes and 57 RNA genes. Lastly, the two unambiguously identified extrachromosomal replicons contain replication modules of the RepB and the Rhodobacteraceae-specific DnaA-like type, respectively.« less

  1. Genome sequence of the pink–pigmented marine bacterium Loktanella hongkongensis type strain (UST950701–009PT), a representative of the Roseobacter group

    SciTech Connect

    Lau, Stanley CK; Riedel, Thomas; Fiebig, Anne; Han, James; Huntemann, Marcel; Petersen, Jörn; Ivanova, Natalia N.; Markowitz, Victor; Woyke, Tanja; Göker, Markus; Kyrpides, Nikos C.; Klenk, Hans-Peter; Qian, Pei-Yuan

    2015-08-11

    Loktanella hongkongensis UST950701-009PT is a Gram-negative, non-motile and rod-shaped bacterium isolated from a marine biofilm in the subtropical seawater of Hong Kong. When growing as a monospecies biofilm on polystyrene surfaces, this bacterium is able to induce larval settlement and metamorphosis of a ubiquitous polychaete tubeworm Hydroides elegans. The inductive cues are low-molecular weight compounds bound to the exopolymeric matrix of the bacterial cells. In the present study we describe the features of L. hongkongensis strain DSM 17492T together with its genome sequence and annotation and novel aspects of its phenotype. The 3,198,444 bp long genome sequence encodes 3104 protein-coding genes and 57 RNA genes. Lastly, the two unambiguously identified extrachromosomal replicons contain replication modules of the RepB and the Rhodobacteraceae-specific DnaA-like type, respectively.

  2. A novel algicide: evidence of the effect of a fatty acid compound from the marine bacterium, Vibrio sp. BS02 on the harmful dinoflagellate, Alexandrium tamarense.

    PubMed

    Li, Dong; Zhang, Huajun; Fu, Lijun; An, Xinli; Zhang, Bangzhou; Li, Yi; Chen, Zhangran; Zheng, Wei; Yi, Lin; Zheng, Tianling

    2014-01-01

    Alexandrium tamarense is a notorious bloom-forming dinoflagellate, which adversely impacts water quality and human health. In this study we present a new algicide against A. tamarense, which was isolated from the marine bacterium Vibrio sp. BS02. MALDI-TOF-MS, NMR and algicidal activity analysis reveal that this compound corresponds to palmitoleic acid, which shows algicidal activity against A. tamarense with an EC50 of 40 μg/mL. The effects of palmitoleic acid on the growth of other algal species were also studied. The results indicate that palmitoleic acid has potential for selective control of the Harmful algal blooms (HABs). Over extended periods of contact, transmission electron microscopy shows severe ultrastructural damage to the algae at 40 μg/mL concentrations of palmitoleic acid. All of these results indicate potential for controlling HABs by using the special algicidal bacterium and its active agent. PMID:24626054

  3. A novel algicide: evidence of the effect of a fatty acid compound from the marine bacterium, Vibrio sp. BS02 on the harmful dinoflagellate, Alexandrium tamarense.

    PubMed

    Li, Dong; Zhang, Huajun; Fu, Lijun; An, Xinli; Zhang, Bangzhou; Li, Yi; Chen, Zhangran; Zheng, Wei; Yi, Lin; Zheng, Tianling

    2014-01-01

    Alexandrium tamarense is a notorious bloom-forming dinoflagellate, which adversely impacts water quality and human health. In this study we present a new algicide against A. tamarense, which was isolated from the marine bacterium Vibrio sp. BS02. MALDI-TOF-MS, NMR and algicidal activity analysis reveal that this compound corresponds to palmitoleic acid, which shows algicidal activity against A. tamarense with an EC50 of 40 μg/mL. The effects of palmitoleic acid on the growth of other algal species were also studied. The results indicate that palmitoleic acid has potential for selective control of the Harmful algal blooms (HABs). Over extended periods of contact, transmission electron microscopy shows severe ultrastructural damage to the algae at 40 μg/mL concentrations of palmitoleic acid. All of these results indicate potential for controlling HABs by using the special algicidal bacterium and its active agent.

  4. A Novel Algicide: Evidence of the Effect of a Fatty Acid Compound from the Marine Bacterium, Vibrio sp. BS02 on the Harmful Dinoflagellate, Alexandrium tamarense

    PubMed Central

    Fu, Lijun; An, Xinli; Zhang, Bangzhou; Li, Yi; Chen, Zhangran; Zheng, Wei; Yi, Lin; Zheng, Tianling

    2014-01-01

    Alexandrium tamarense is a notorious bloom-forming dinoflagellate, which adversely impacts water quality and human health. In this study we present a new algicide against A. tamarense, which was isolated from the marine bacterium Vibrio sp. BS02. MALDI-TOF-MS, NMR and algicidal activity analysis reveal that this compound corresponds to palmitoleic acid, which shows algicidal activity against A. tamarense with an EC50 of 40 μg/mL. The effects of palmitoleic acid on the growth of other algal species were also studied. The results indicate that palmitoleic acid has potential for selective control of the Harmful algal blooms (HABs). Over extended periods of contact, transmission electron microscopy shows severe ultrastructural damage to the algae at 40 μg/mL concentrations of palmitoleic acid. All of these results indicate potential for controlling HABs by using the special algicidal bacterium and its active agent. PMID:24626054

  5. Discovery That Theonellasterol a Marine Sponge Sterol Is a Highly Selective FXR Antagonist That Protects against Liver Injury in Cholestasis

    PubMed Central

    Renga, Barbara; Mencarelli, Andrea; D'Amore, Claudio; Cipriani, Sabrina; D'Auria, Maria Valeria; Sepe, Valentina; Chini, Maria Giovanna; Monti, Maria Chiara; Bifulco, Giuseppe; Zampella, Angela; Fiorucci, Stefano

    2012-01-01

    Background The farnesoid-x-receptor (FXR) is a bile acid sensor expressed in the liver and gastrointestinal tract. Despite FXR ligands are under investigation for treatment of cholestasis, a biochemical condition occurring in a number of liver diseases for which available therapies are poorly effective, mice harboring a disrupted FXR are protected against liver injury caused by bile acid overload in rodent models of cholestasis. Theonellasterol is a 4-methylene-24-ethylsteroid isolated from the marine sponge Theonella swinhoei. Here, we have characterized the activity of this theonellasterol on FXR-regulated genes and biological functions. Principal Findings Interrogation of HepG2 cells, a human hepatocyte cell line, by microarray analysis and transactivation assay shows that theonellasterol is a selective FXR antagonist, devoid of any agonistic or antagonistic activity on a number of human nuclear receptors including the vitamin D receptor, PPARs, PXR, LXRs, progesterone, estrogen, glucorticoid and thyroid receptors, among others. Exposure of HepG2 cells to theonellasterol antagonizes the effect of natural and synthetic FXR agonists on FXR-regulated genes, including SHP, OSTα, BSEP and MRP4. A proof-of-concept study carried out to investigate whether FXR antagonism rescues mice from liver injury caused by the ligation of the common bile duct, a model of obstructive cholestasis, demonstrated that theonellasterol attenuates injury caused by bile duct ligation as measured by assessing serum alanine aminostrasferase levels and extent of liver necrosis at histopathology. Analysis of genes involved in bile acid uptake and excretion by hepatocytes revealed that theonellasterol increases the liver expression of MRP4, a basolateral transporter that is negatively regulated by FXR. Administering bile duct ligated mice with an FXR agonist failed to rescue from liver injury and downregulated the expression of MRP4. Conclusions FXR antagonism in vivo results in a positive

  6. A Novel Type II NAD+-Specific Isocitrate Dehydrogenase from the Marine Bacterium Congregibacter litoralis KT71

    PubMed Central

    Wu, Ming-Cai; Tian, Chang-Qing; Cheng, Hong-Mei; Xu, Lei; Wang, Peng; Zhu, Guo-Ping

    2015-01-01

    In most living organisms, isocitrate dehydrogenases (IDHs) convert isocitrate into ɑ-ketoglutarate (ɑ-KG). Phylogenetic analyses divide the IDH protein family into two subgroups: types I and II. Based on cofactor usage, IDHs are either NAD+-specific (NAD-IDH) or NADP+-specific (NADP-IDH); NADP-IDH evolved from NAD-IDH. Type I IDHs include NAD-IDHs and NADP-IDHs; however, no type II NAD-IDHs have been reported to date. This study reports a novel type II NAD-IDH from the marine bacterium Congregibacter litoralis KT71 (ClIDH, GenBank accession no. EAQ96042). His-tagged recombinant ClIDH was produced in Escherichia coli and purified; the recombinant enzyme was NAD+-specific and showed no detectable activity with NADP+. The Km values of the enzyme for NAD+ were 262.6±7.4 μM or 309.1±11.2 μM with Mg2+ or Mn2+ as the divalent cation, respectively. The coenzyme specificity of a ClIDH Asp487Arg/Leu488His mutant was altered, and the preference of the mutant for NADP+ was approximately 24-fold higher than that for NAD+, suggesting that ClIDH is an NAD+-specific ancestral enzyme in the type II IDH subgroup. Gel filtration and analytical ultracentrifugation analyses revealed the homohexameric structure of ClIDH, which is the first IDH hexamer discovered thus far. A 163-amino acid segment of CIIDH is essential to maintain its polymerization structure and activity, as a truncated version lacking this region forms a non-functional monomer. ClIDH was dependent on divalent cations, the most effective being Mn2+. The maximal activity of purified recombinant ClIDH was achieved at 35°C and pH 7.5, and a heat inactivation experiment showed that a 20-min incubation at 33°C caused a 50% loss of ClIDH activity. The discovery of a NAD+-specific, type II IDH fills a gap in the current classification of IDHs, and sheds light on the evolution of type II IDHs. PMID:25942017

  7. Preparative isolation and purification of macrolactin antibiotics from marine bacterium Bacillus amyloliquefaciens using high-speed counter-current chromatography in stepwise elution mode.

    PubMed

    He, Shan; Wang, Hongqiang; Yan, Xiaojun; Zhu, Peng; Chen, Juanjuan; Yang, Rui

    2013-01-11

    Preparative high-speed counter-current chromatography (HSCCC) was successfully applied to the isolation and purification of two macrolactin antibiotics from marine bacterium Bacillus amyloliquefaciens for the first time using stepwise elution with a pair of two-phase solvent systems composed of n-hexane-ethyl acetate-methanol-water at (1:4:1:4, v/v) and (3:4:3:4, v/v). The preparative HSCCC separation was performed on 300 mg of crude sample yielding macrolactin B (22.7 mg) and macrolactin A (40.4 mg) in a one-step separation, with purities over 95% as determined by HPLC. The structures of these compounds were identified by MS, (1)H NMR and (13)C NMR. Our results demonstrated that HSCCC was an efficient technique to separate marine antibiotics, which provide an approach to solve the problem of their sample availability for drug development.

  8. Inhibitory activity of an extract from a marine bacterium Halomonas sp. HSB07 against the red-tide microalga Gymnodinium sp. (Pyrrophyta)

    NASA Astrophysics Data System (ADS)

    Liu, Juan; Li, Fuchao; Liu, Ling; Jiang, Peng; Liu, Zhaopu

    2013-11-01

    In recent years, red tides occurred frequently in coastal areas worldwide. Various methods based on the use of clay, copper sulfate, and bacteria have been successful in controlling red tides to some extent. As a new defensive agent, marine microorganisms are important sources of compounds with potent inhibitory bioactivities against red-tide microalgae, such as Gymnodinium sp. (Pyrrophyta). In this study, we isolated a marine bacterium, HSB07, from seawater collected from Hongsha Bay, Sanya, South China Sea. Based on its 16S rRNA gene sequence and biochemical characteristics, the isolated strain HSB07 was identified as a member of the genus Halomonas. A crude ethyl acetate extract of strain HSB07 showed moderate inhibition activity against Gymnodinium sp. in a bioactive prescreening experiment. The extract was further separated into fractions A, B, and C by silica gel column chromatography. Fractions B and C showed strong inhibition activities against Gymnodinium. This is the first report of inhibitory activity of secondary metabolites of a Halomonas bacterium against a red-tide-causing microalga.

  9. Whole-Genome Sequence of Marine Bacterium Phaeodactylibacter xiamenensis Strain KD52, Isolated from the Phycosphere of Microalga Phacodactylum tricornutum

    PubMed Central

    Chen, Zhangran; Lei, Xueqian; Li, Yi; Zhang, Jingyan; Zhang, Huajun; Yang, Luxi; Zheng, Wei

    2014-01-01

    Phaeodactylibacter xiamenensis KD52 is a novel bacterium isolated from a culture of the alga Phaeodactylum tricornutum in Xiamen, Fujian Province, China. Here, we present the first draft genome sequence of this strain, which will provide an opportunity to further understand the functional genes related to signing for nutrition from the host algae and the molecular mechanisms underlying its beneficial properties. PMID:25502677

  10. Influence of nitrogen substrates and substrate C:N ratios on the nitrogen isotopic composition of amino acids from the marine bacterium Vibrio harveyi

    NASA Astrophysics Data System (ADS)

    Maki, K.; Ohkouchi, N.; Chikaraishi, Y.; Fukuda, H.; Miyajima, T.; Nagata, T.

    2014-09-01

    Nitrogen (N) isotopic compositions of individual hydrolysable amino acids (δ15NAAs) in N pools have been increasingly used for trophic position assessment and evaluation of sources and transformation processes of organic matter in marine environments. However, there are limited data about variability in δ15NAAs patterns and how this variability influences marine bacteria, an important mediator of trophic transfer and organic matter transformation. We explored whether marine bacterial δ15NAAs profiles change depending on the type and C:N ratio of the substrate. The δ15NAAs profile of a marine bacterium, Vibrio harveyi, was examined using medium containing either glutamate, alanine or ammonium as the N source [substrate C:N ratios (range, 3 to 20) were adjusted with glucose]. The data were interpreted as a reflection of isotope fractionations associated with de novo synthesis of amino acids by bacteria. Principal component analysis (PCA) using the δ15N offset values normalized to glutamate + glutamine δ15N revealed that δ15NAAs profiles differed depending on the N source and C:N ratio of the substrate. High variability in the δ15N offset of alanine and valine largely explained this bacterial δ15NAAs profile variability. PCA was also conducted using bacterial and phytoplankton (cyanobacteria and eukaryotic algae) δ15NAAs profile data reported previously. The results revealed that bacterial δ15NAAs patterns were distinct from those of phytoplankton. Therefore, the δ15NAAs profile is a useful indicator of biochemical responses of bacteria to changes in substrate conditions, serving as a potentially useful method for identifying organic matter sources in marine environments.

  11. Isolation of a phenol-utilizing marine bacterium from Durban Harbour (South Africa) and its preliminary characterization as Marinobacter sp. KM2.

    PubMed

    Moxley, Karis; Schmidt, Stefan

    2012-01-01

    Many aromatic hydrocarbons assigned to the so-called high production volume chemicals (HPVCs) are frequently encountered constituents of wastewaters that end up in the sea. Although the pollutant-degrading capabilities of freshwater bacteria are well known, the catabolism of pollutants by marine bacteria has received limited attention. A marine bacterium with the ability to aerobically utilize phenol - an HPVC and common aromatic pollutant - as its sole source of carbon and energy, was isolated from water samples from Durban Harbour, South Africa. The isolate, designated strain KM2, was assigned to the genus Marinobacter based on a variety of phenotypic properties and by analysis of the 16S rRNA gene sequence. The isolate displays an absolute growth requirement for NaCl which cannot be offset by replacement of NaCl with other salts. In addition to 4-methylphenol and 3,4-dimethylphenol, it utilizes a range of aliphatic hydrocarbons such as butan-1-ol and hexadecane under aerobic conditions. The transient formation of an intermediate exhibiting the UV-Vis spectral characteristics for 2-hydroxymuconic semialdehyde in cultures growing on phenol suggests that the isolate catabolizes this compound via the meta cleavage pathway. These results indicate that members of the genus Marinobacter might participate in the elimination of aromatic pollutants in South African marine environments. PMID:22339030

  12. A putative siderophore-interacting protein from the marine bacterium Shewanella frigidimarina NCIMB 400: cloning, expression, purification, crystallization and X-ray diffraction analysis.

    PubMed

    Trindade, Inês B; Fonseca, Bruno M; Matias, Pedro M; Louro, Ricardo O; Moe, Elin

    2016-09-01

    Siderophore-binding proteins (SIPs) perform a key role in iron acquisition in multiple organisms. In the genome of the marine bacterium Shewanella frigidimarina NCIMB 400, the gene tagged as SFRI_RS12295 encodes a protein from this family. Here, the cloning, expression, purification and crystallization of this protein are reported, together with its preliminary X-ray crystallographic analysis to 1.35 Å resolution. The SIP crystals belonged to the monoclinic space group P21, with unit-cell parameters a = 48.04, b = 78.31, c = 67.71 Å, α = 90, β = 99.94, γ = 90°, and are predicted to contain two molecules per asymmetric unit. Structure determination by molecular replacement and the use of previously determined ∼2 Å resolution SIP structures with ∼30% sequence identity as templates are ongoing. PMID:27599855

  13. A putative siderophore-interacting protein from the marine bacterium Shewanella frigidimarina NCIMB 400: cloning, expression, purification, crystallization and X-ray diffraction analysis

    PubMed Central

    Trindade, Inês B.; Fonseca, Bruno M.; Matias, Pedro M.; Louro, Ricardo O.; Moe, Elin

    2016-01-01

    Siderophore-binding proteins (SIPs) perform a key role in iron acquisition in multiple organisms. In the genome of the marine bacterium Shewanella frigidimarina NCIMB 400, the gene tagged as SFRI_RS12295 encodes a protein from this family. Here, the cloning, expression, purification and crystallization of this protein are reported, together with its preliminary X-ray crystallographic analysis to 1.35 Å resolution. The SIP crystals belonged to the monoclinic space group P21, with unit-cell parameters a = 48.04, b = 78.31, c = 67.71 Å, α = 90, β = 99.94, γ = 90°, and are predicted to contain two molecules per asymmetric unit. Structure determination by molecular replacement and the use of previously determined ∼2 Å resolution SIP structures with ∼30% sequence identity as templates are ongoing. PMID:27599855

  14. Antibiofilm Activity of the Marine Bacterium Pseudoalteromonas sp. 3J6 Against Vibrio tapetis, the Causative Agent of Brown Ring Disease.

    PubMed

    Rodrigues, Sophie; Paillard, Christine; Dufour, Alain; Bazire, Alexis

    2015-03-01

    Vibrio tapetis CECT4600 is a pathogenic Gram-negative bacterium causing the brown ring disease in the Manila clam Ruditapes philippinarum. This vibriosis is induced by bacterial attachment on the periostracal lamina, yielding a decalcification of the bivalve shell. As in many bacterial species, pathogenesis is likely related to biofilm formation. The proteinaceous exoproducts of the marine bacterium Pseudoalteromonas sp. 3J6 inhibit the formation of biofilm by most of the tested marine bacteria without affecting their planktonic growth. In the present work, we examined the sensitivity of V. tapetis to Pseudoalteromonas sp. 3J6 and its exoproducts. In V. tapetis CECT4600-GFP-Pseudoalteromonas sp. 3J6 co-cultures, the latter outcompeted V. tapetis whatever the growth mode (planktonic or biofilm), which could result from a slower growth of V. tapetis. Biofilms containing only V. tapetis were grown in vitro on a glass substratum under dynamic conditions. When the glass was coated with a culture supernatant of Pseudoalteromonas sp. 3J6 (SN(3J6)) prior to inoculating V. tapetis CECT4600-GFP, the bacterial attachment was about fivefold lower than in control experiment without SN3J6 and the biofilm formation was delayed by about 24 h: A full biofilm was obtained at 48 versus 24 h for the control. Moreover, a preformed V. tapetis biofilm (grown on SN(3J6)-free glass substratum) could be disrupted by incubating it with SN3J6. This data suggest that Pseudoalteromonas sp. 3J6 is a good candidate to set up an anti-V. tapetis strategy usable in aquaculture to grow V. tapetis-free Manila clam spats.

  15. A new 24-membered lactone and a new polyene delta-lactone from the marine bacterium Bacillus marinus.

    PubMed

    Xue, Chunmei; Tian, Li; Xu, Minjuan; Deng, Zhiwei; Lin, Wenhan

    2008-11-01

    A new 24-membered macrolide macrolactin T (1), and a new polyene delta-lactone macrolactin U (2), along with macrolactins A, B, D, O, and S, were isolated from the cultured broth of the bacterium Bacillus marinus, which was isolated from Suaeda salsa collected in the coastline of Bohai Sea of China. The structures of 1 and 2 were elucidated on the basis of extensive spectroscopic data analyses. The inhibitory activity of macrolactins T, B and D against fungi Pyricularia oryzae and Alternaria solani, and bacteria Staphylococcus aureus is reported. PMID:19168981

  16. Quorum sensing in marine snow and its possible influence on production of extracellular hydrolytic enzymes in marine snow bacterium Pantoea ananatis B9.

    PubMed

    Jatt, Abdul Nabi; Tang, Kaihao; Liu, Jiwen; Zhang, Zenghu; Zhang, Xiao-Hua

    2015-02-01

    Marine snow is a continuous shower of organic and inorganic detritus, and plays a crucial role in transporting materials from the sea surface to the deep ocean. The aims of the current study were to identify N-acyl homoserine lactone (AHL)-based quorum sensing (QS) signaling molecules directly from marine snow particles and to investigate the possible regulatory link between QS signals and extracellular hydrolytic enzymes produced by marine snow bacteria. The marine snow samples were collected from the surface water of China marginal seas. Two AHLs, i.e. 3OC6-HSL and C8-HSL, were identified directly from marine snow particles, while six different AHL signals, i.e. C4-HSL, 3OC6-HSL, C6-HSL, C10-HSL, C12-HSL and C14-HSL were produced by Pantoea ananatis B9 inhabiting natural marine snow particles. Of the extracellular hydrolytic enzymes produced by P. ananatis B9, alkaline phosphatase activity was highly enhanced in growth medium supplemented with exogenous AHL (C10-HSL), while quorum quenching enzyme (AiiA) drastically reduced the enzyme activity. To our knowledge, this is the first report revealing six different AHL signals produced by P. ananatis B9 and AHL-based QS system enhanced the extracellular hydrolytic enzyme in P. ananatis B9. Furthermore, this study first time revealing 3OC6-HSL production by Paracoccus carotinifaciens affiliated with Alphaproteobacteria. PMID:25764555

  17. Quorum sensing in marine snow and its possible influence on production of extracellular hydrolytic enzymes in marine snow bacterium Pantoea ananatis B9.

    PubMed

    Jatt, Abdul Nabi; Tang, Kaihao; Liu, Jiwen; Zhang, Zenghu; Zhang, Xiao-Hua

    2015-02-01

    Marine snow is a continuous shower of organic and inorganic detritus, and plays a crucial role in transporting materials from the sea surface to the deep ocean. The aims of the current study were to identify N-acyl homoserine lactone (AHL)-based quorum sensing (QS) signaling molecules directly from marine snow particles and to investigate the possible regulatory link between QS signals and extracellular hydrolytic enzymes produced by marine snow bacteria. The marine snow samples were collected from the surface water of China marginal seas. Two AHLs, i.e. 3OC6-HSL and C8-HSL, were identified directly from marine snow particles, while six different AHL signals, i.e. C4-HSL, 3OC6-HSL, C6-HSL, C10-HSL, C12-HSL and C14-HSL were produced by Pantoea ananatis B9 inhabiting natural marine snow particles. Of the extracellular hydrolytic enzymes produced by P. ananatis B9, alkaline phosphatase activity was highly enhanced in growth medium supplemented with exogenous AHL (C10-HSL), while quorum quenching enzyme (AiiA) drastically reduced the enzyme activity. To our knowledge, this is the first report revealing six different AHL signals produced by P. ananatis B9 and AHL-based QS system enhanced the extracellular hydrolytic enzyme in P. ananatis B9. Furthermore, this study first time revealing 3OC6-HSL production by Paracoccus carotinifaciens affiliated with Alphaproteobacteria.

  18. Photoinhibition of Phaeocystis globosa resulting from oxidative stress induced by a marine algicidal bacterium Bacillus sp. LP-10.

    PubMed

    Guan, Chengwei; Guo, Xiaoyun; Li, Yi; Zhang, Huajun; Lei, Xueqian; Cai, Guanjing; Guo, Jiajia; Yu, Zhiming; Zheng, Tianling

    2015-01-01

    Harmful algal blooms caused by Phaeocystis globosa have resulted in staggering losses to coastal countries because of their world-wide distribution. Bacteria have been studied for years to control the blooms of harmful alga, however, the action mechanism of them against harmful algal cells is still not well defined. Here, a previously isolated algicidal bacterium Bacillus sp. LP-10 was used to elucidate the potential mechanism involved in the dysfunction of P. globosa algal cells at physiological and molecular levels. Our results showed Bacillus sp. LP-10 induced an obvious rise of reactive oxygen species (ROS), which was supposed to be major reason for algal cell death. Meanwhile, the results revealed a significant decrease of photosynthetic physiological indexes and apparent down-regulated of photosynthesis-related genes (psbA and rbcS) and protein (PSII reaction center protein D1), after treated by Bacillus sp. LP-10 filtrates, suggesting photoinhibition occurred in the algal cells. Furthermore, our results indicated that light played important roles in the algal cell death. Our work demonstrated that the major lethal reason of P. globosa cells treated by the algicidal bacterium was the photoinhibition resulted from oxidative stress induced by Bacillus sp. LP-10. PMID:26601700

  19. Photoinhibition of Phaeocystis globosa resulting from oxidative stress induced by a marine algicidal bacterium Bacillus sp. LP-10.

    PubMed

    Guan, Chengwei; Guo, Xiaoyun; Li, Yi; Zhang, Huajun; Lei, Xueqian; Cai, Guanjing; Guo, Jiajia; Yu, Zhiming; Zheng, Tianling

    2015-11-25

    Harmful algal blooms caused by Phaeocystis globosa have resulted in staggering losses to coastal countries because of their world-wide distribution. Bacteria have been studied for years to control the blooms of harmful alga, however, the action mechanism of them against harmful algal cells is still not well defined. Here, a previously isolated algicidal bacterium Bacillus sp. LP-10 was used to elucidate the potential mechanism involved in the dysfunction of P. globosa algal cells at physiological and molecular levels. Our results showed Bacillus sp. LP-10 induced an obvious rise of reactive oxygen species (ROS), which was supposed to be major reason for algal cell death. Meanwhile, the results revealed a significant decrease of photosynthetic physiological indexes and apparent down-regulated of photosynthesis-related genes (psbA and rbcS) and protein (PSII reaction center protein D1), after treated by Bacillus sp. LP-10 filtrates, suggesting photoinhibition occurred in the algal cells. Furthermore, our results indicated that light played important roles in the algal cell death. Our work demonstrated that the major lethal reason of P. globosa cells treated by the algicidal bacterium was the photoinhibition resulted from oxidative stress induced by Bacillus sp. LP-10.

  20. Photoinhibition of Phaeocystis globosa resulting from oxidative stress induced by a marine algicidal bacterium Bacillus sp. LP-10

    PubMed Central

    Guan, Chengwei; Guo, Xiaoyun; Li, Yi; Zhang, Huajun; Lei, Xueqian; Cai, Guanjing; Guo, Jiajia; Yu, Zhiming; Zheng, Tianling

    2015-01-01

    Harmful algal blooms caused by Phaeocystis globosa have resulted in staggering losses to coastal countries because of their world-wide distribution. Bacteria have been studied for years to control the blooms of harmful alga, however, the action mechanism of them against harmful algal cells is still not well defined. Here, a previously isolated algicidal bacterium Bacillus sp. LP-10 was used to elucidate the potential mechanism involved in the dysfunction of P. globosa algal cells at physiological and molecular levels. Our results showed Bacillus sp. LP-10 induced an obvious rise of reactive oxygen species (ROS), which was supposed to be major reason for algal cell death. Meanwhile, the results revealed a significant decrease of photosynthetic physiological indexes and apparent down-regulated of photosynthesis-related genes (psbA and rbcS) and protein (PSII reaction center protein D1), after treated by Bacillus sp. LP-10 filtrates, suggesting photoinhibition occurred in the algal cells. Furthermore, our results indicated that light played important roles in the algal cell death. Our work demonstrated that the major lethal reason of P. globosa cells treated by the algicidal bacterium was the photoinhibition resulted from oxidative stress induced by Bacillus sp. LP-10. PMID:26601700

  1. Draft Genome Sequence of a Novel Marine Bacterium, Paraglaciecola sp. Strain S66, with Hydrolytic Activity against Seaweed Polysaccharides.

    PubMed

    Schultz-Johansen, Mikkel; Glaring, Mikkel A; Bech, Pernille K; Stougaard, Peter

    2016-01-01

    A novel agarolytic gammaproteobacterium, ITALIC! Paraglaciecolasp. S66, was isolated from marine samples of eelgrass ( ITALIC! Zosterasp.) and sequenced. The draft genome contains a large number of enzyme-encoding genes with predicted function against several complex polysaccharides found in the cell walls of algae. PMID:27103729

  2. Draft Genome Sequence of Arenibacter sp. Strain C-21, an Iodine-Accumulating Bacterium Isolated from Surface Marine Sediment

    PubMed Central

    Ito, Kohei; Nakajima, Nobuyoshi; Yamamura, Shigeki; Tomita, Masaru

    2016-01-01

    Arenibacter sp. strain C-21, isolated from surface marine sediment of Japan, accumulates iodine in the presence of glucose and iodide (I-). We report here the draft genome sequence of this strain to provide insight into the molecular mechanism underlying its iodine-accumulating ability. PMID:27738047

  3. Draft Genome Sequence of a Novel Marine Bacterium, Paraglaciecola sp. Strain S66, with Hydrolytic Activity against Seaweed Polysaccharides

    PubMed Central

    Schultz-Johansen, Mikkel; Glaring, Mikkel A.; Bech, Pernille K.

    2016-01-01

    A novel agarolytic gammaproteobacterium, Paraglaciecola sp. S66, was isolated from marine samples of eelgrass (Zostera sp.) and sequenced. The draft genome contains a large number of enzyme-encoding genes with predicted function against several complex polysaccharides found in the cell walls of algae. PMID:27103729

  4. Draft Genome Sequence of a Novel Marine Bacterium, Paraglaciecola sp. Strain S66, with Hydrolytic Activity against Seaweed Polysaccharides.

    PubMed

    Schultz-Johansen, Mikkel; Glaring, Mikkel A; Bech, Pernille K; Stougaard, Peter

    2016-01-01

    A novel agarolytic gammaproteobacterium, ITALIC! Paraglaciecolasp. S66, was isolated from marine samples of eelgrass ( ITALIC! Zosterasp.) and sequenced. The draft genome contains a large number of enzyme-encoding genes with predicted function against several complex polysaccharides found in the cell walls of algae.

  5. Involvement of quorum sensing genes in biofilm development and degradation of polycyclic aromatic hydrocarbons by a marine bacterium Pseudomonas aeruginosa N6P6.

    PubMed

    Mangwani, Neelam; Kumari, Supriya; Das, Surajit

    2015-12-01

    Biofilm-forming and acyl homoserine lactone (AHL) synthase-positive Pseudomonas aeruginosa N6P6 was isolated from seawater after selective enrichment with two polycyclic aromatic hydrocarbons (PAHs), viz. phenanthrene and pyrene. AHL synthesis was detected qualitatively using bioreporter strains. This marine bacterium putatively synthesized N-(3-oxododecanoyl)-L-homoserine lactone and N-butyryl-L-homoserine lactone, which were identified by TLC, GC-MS, and HPLC. Two quorum sensing (QS) genes coding for AHL synthase, i.e., lasI and rhlI, were identified in the bacterium. lasI and rhlI gene expression was studied during biofilm mode of growth at different phases using quantitative real-time PCR (qRT-PCR). The expression of lasI increased with increase in biofilm growth. In contrast, the expression of rhlI decreased during log phase of biofilm growth. The changes in lasI/rhlI expression level had significant effects (P<0.05) on biofilm architecture and subsequent PAH degradation rate. Degradation of phenanthrene and pyrene by P. aeruginosa N6P6 was affected by biofilm growth and lasI expression. The respective phenanthrene degradation for 15, 24, 48, and 72 h old biofilm after 7 days was 21.5, 54.2, 85.6, and 85.7%. However, the corresponding pyrene degradation was 15, 18.28, 47.56, and 46.48%, respectively, after 7 days. A significant positive correlation (P<0.05) was observed between lasI expression and PAHs degradation. However, in the presence of tannic acid, a QS inhibitor (QSI), PAHs degradation, biofilm formation, and pyocyanin production reduced significantly which confirmed the pivotal role of QS in biodegradation of PAHs. The findings suggest that AHLs play a pivotal role during biofilm development and subsequent bioremediation of PAHs.

  6. Red to red - the marine bacterium Hahella chejuensis and its product prodigiosin for mitigation of harmful algal blooms.

    PubMed

    Kim, Dockyu; Kim, Jihyun F; Yim, Joung Han; Kwon, Soon-Kyeong; Lee, Choong Hwan; Lee, Hong Kum

    2008-10-01

    Harmful algal blooms (HABs), commonly called red tides, are caused by some toxic phytoplanktons, and have made massive economic losses as well as marine environmental disturbances. As an effective and environment-friendly strategy to control HAB outbreaks, biological methods using marine bacteria capable of killing the harmful algae or algicidal extracellular compounds from them have been given attention. A new member of the gamma-Proteobacteria, Hahella chejuensis KCTC 2396, was originally isolated from the Korean seashore for its ability to secrete industrially useful polysaccharides, and was characterized to produce a red pigment. This pigment later was identified as an alkaloid compound, prodigiosin. During the past several decades, prodigiosin has been extensively studied for its medical potential as immunosuppressants and antitumor agents, owing to its antibiotic and cytotoxic activities. The lytic activity of this marvelous molecule against Cochlodinium polykrikoides cells at very low concentrations (1 ppb) was serendipitously detected, making H. chejuensis a strong candidate among the biological agents for HAB control. This review provides a brief overview of algicidal marine bacteria and their products, and describes in detail the algicidal characteristics, biosynthetic process, and genetic regulation of prodigiosin as a model among the compounds active against red-tide organisms from the biochemical and genetic viewpoints. PMID:18955809

  7. Red to red - the marine bacterium Hahella chejuensis and its product prodigiosin for mitigation of harmful algal blooms.

    PubMed

    Kim, Dockyu; Kim, Jihyun F; Yim, Joung Han; Kwon, Soon-Kyeong; Lee, Choong Hwan; Lee, Hong Kum

    2008-10-01

    Harmful algal blooms (HABs), commonly called red tides, are caused by some toxic phytoplanktons, and have made massive economic losses as well as marine environmental disturbances. As an effective and environment-friendly strategy to control HAB outbreaks, biological methods using marine bacteria capable of killing the harmful algae or algicidal extracellular compounds from them have been given attention. A new member of the gamma-Proteobacteria, Hahella chejuensis KCTC 2396, was originally isolated from the Korean seashore for its ability to secrete industrially useful polysaccharides, and was characterized to produce a red pigment. This pigment later was identified as an alkaloid compound, prodigiosin. During the past several decades, prodigiosin has been extensively studied for its medical potential as immunosuppressants and antitumor agents, owing to its antibiotic and cytotoxic activities. The lytic activity of this marvelous molecule against Cochlodinium polykrikoides cells at very low concentrations (1 ppb) was serendipitously detected, making H. chejuensis a strong candidate among the biological agents for HAB control. This review provides a brief overview of algicidal marine bacteria and their products, and describes in detail the algicidal characteristics, biosynthetic process, and genetic regulation of prodigiosin as a model among the compounds active against red-tide organisms from the biochemical and genetic viewpoints.

  8. Flavobacterium ahnfeltiae sp. nov., a new marine polysaccharide-degrading bacterium isolated from a Pacific red alga.

    PubMed

    Nedashkovskaya, Olga I; Balabanova, Larissa A; Zhukova, Natalia V; Kim, So-Jeong; Bakunina, Irina Y; Rhee, Sung-Keun

    2014-10-01

    A Gram-negative, aerobic, rod-shaped, motile by gliding and yellow-pigmented bacterium, designated strain 10Alg 130(T), that displayed the ability to destroy polysaccharides of red and brown algae, was isolated from the red alga Ahnfeltia tobuchiensis. The phylogenetic analysis based on 16S rRNA gene sequence placed the novel strain within the genus Flavobacterium, the type genus of the family Flavobacteriaceae, the phylum Bacteroidetes, with sequence similarities of 96.2 and 95.7 % to Flavobacterium jumunjiense KCTC 23618(T) and Flavobacterium ponti CCUG 58402(T), and 95.3-92.5 % to other recognized Flavobacterium species. The prevalent fatty acids of strain 10Alg 130(T) were iso-C15:0, iso-C15:0 3-OH, iso-C17:0 3-OH, C15:0 and iso-C17:1ω9c. The polar lipid profile consisted of phosphatidylethanolamine, two unknown aminolipids and three unknown lipids. The DNA G+C content of the type strain was 34.3 mol%. The new isolate and the type strains of recognized species of the genus Flavobacterium could strongly be distinguished by a number of phenotypic characteristics. A combination of the genotypic and phenotypic data showed that the algal isolate represents a novel species of the genus Flavobacterium, for which the name Flavobacterium ahnfeltiae sp. nov. is proposed. The type strain is 10Alg 130(T) (=KCTC 32467(T) = KMM 6686(T)).

  9. Characterisation of a Marine Bacterium Vibrio Brasiliensis T33 Producing N-acyl Homoserine Lactone Quorum Sensing Molecules

    PubMed Central

    Tan, Wen-Si; Yunos, Nina Yusrina Muhamad; Tan, Pui-Wan; Mohamad, Nur Izzati; Adrian, Tan-Guan-Sheng; Yin, Wai-Fong; Chan, Kok-Gan

    2014-01-01

    N-acylhomoserine lactones (AHL) plays roles as signal molecules in quorum sensing (QS) in most Gram-negative bacteria. QS regulates various physiological activities in relation with population density and concentration of signal molecules. With the aim of isolating marine water-borne bacteria that possess QS properties, we report here the preliminary screening of marine bacteria for AHL production using Chromobacterium violaceum CV026 as the AHL biosensor. Strain T33 was isolated based on preliminary AHL screening and further identified by using 16S rDNA sequence analysis as a member of the genus Vibrio closely related to Vibrio brasiliensis. The isolated Vibrio sp. strain T33 was confirmed to produce N-hexanoyl-l-homoserine lactone (C6-HSL) and N-(3-oxodecanoyl)-l-homoserine lactone (3-oxo-C10 HSL) through high resolution tandem mass spectrometry analysis. We demonstrated that this isolate formed biofilms which could be inhibited by catechin. To the best of our knowledge, this is the first report that documents the production of these AHLs by Vibrio brasiliensis strain T33. PMID:25006994

  10. A unique capsular polysaccharide structure from the psychrophilic marine bacterium Colwellia psychrerythraea 34H that mimics antifreeze (glyco)proteins.

    PubMed

    Carillo, Sara; Casillo, Angela; Pieretti, Giuseppina; Parrilli, Ermenegilda; Sannino, Filomena; Bayer-Giraldi, Maddalena; Cosconati, Sandro; Novellino, Ettore; Ewert, Marcela; Deming, Jody W; Lanzetta, Rosa; Marino, Gennaro; Parrilli, Michelangelo; Randazzo, Antonio; Tutino, Maria L; Corsaro, M Michela

    2015-01-14

    The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a γ-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea 34H cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments.

  11. A thermophilic, hydrogenogenic and carboxydotrophic bacterium, Calderihabitans maritimus gen. nov., sp. nov., from a marine sediment core of an undersea caldera.

    PubMed

    Yoneda, Yasuko; Yoshida, Takashi; Yasuda, Hisato; Imada, Chiaki; Sako, Yoshihiko

    2013-10-01

    A hydrogenogenic, carboxydotrophic marine bacterium, strain KKC1(T), was isolated from a sediment core sample taken from a submerged marine caldera. Cells were non-motile, Gram-stain-negative, 1.0-3.0 µm straight rods, often observed with round endospores. Strain KKC1(T) grew at 55-68 °C, pH 5.2-9.2 and 0.8-14 % (w/v) salinity. Optimum growth occurred at 65 °C, pH 7.0-7.5 and 2.46 % salinity with a doubling time of 3.7 h. The isolate grew chemolithotrophically, producing H2 from carbon monoxide (CO) oxidation with reduction of various electron acceptors, e.g. sulfite, thiosulfate, fumarate, ferric iron and AQDS (9,10-anthraquinone 2,6-disulfonate). KKC1(T) grew heterotrophically on pyruvate, lactate, fumarate, glucose, fructose and mannose with thiosulfate as an electron acceptor. When grown mixotrophically on CO and pyruvate, C16 : 0 constituted almost half of the total cellular fatty acids. The DNA G+C content was 50.6 mol%. The 16S rRNA gene sequence of KKC1(T) was most closely related to those of members of the genus Moorella with similarity ranging from 91 to 89 %. Based on physiological and phylogenetic novelty, we propose the isolate as a representative of a new genus and novel species with the name Calderihabitans maritimus gen. nov., sp. nov.; the type strain of the type species is KKC1(T) ( = DSM 26464(T) = NBRC 109353(T)).

  12. Oleiphilaceae fam. nov., to include Oleiphilus messinensis gen. nov., sp. nov., a novel marine bacterium that obligately utilizes hydrocarbons.

    PubMed

    Golyshin, Peter N; Chernikova, Tatiana N; Abraham, Wolf-Rainer; Lünsdorf, Heinrich; Timmis, Kenneth N; Yakimov, Michail M

    2002-05-01

    A bacterial isolate, ME102T, was obtained from an n-hexadecane enrichment culture of seawater/sediment samples collected in the harbour of Messina (Italy). This gram-negative, aerobic, motile, rod-shaped bacterium used a narrow spectrum of organic compounds, including aliphatic hydrocarbons, alkanoates and alkanoles, as carbon and energy sources. None of the sugars, organic acids or amino acids tested was used. During cultivation on n-alkanes as the sole source of carbon and energy, the cells formed a biofilm on the surface of the alkane droplets. Large-scale (sometimes >50% of the cell mass) intracellular accumulation of alkanoates occurred in cells adsorbed on the alkane surface and under nitrogen-limiting conditions. 16S rRNA gene sequence analysis showed that this isolate represents a distinct lineage in the gamma-Proteobacteria and has about 91% sequence identity to members of Marinobacter and Alcanivorax, the closest genera. Four different types of polar lipid could be detected, phosphatidyl glycerol, phosphatidyl ethylamine, phosphatidyl dimethylethylamine and lipids belonging to an unknown type of phospholipid (m/z between 861 and 879). The principal fatty acids in the polar lipid fatty acid profile were 16:0 and 16:1. The putative gene encoding the key enzyme of alkane catabolism, alkane hydroxylase (AlkB), has been cloned. The protein sequence of the putative AlkB of the isolate ME102T was related to the AlkB of Pseudomonas oleovorans and Alcanivorax borkumensis, showing about 60% sequence identity. On the basis of physiological studies and taking into account the distant phylogenetic position of isolate ME102T relative to previously described organisms, a novel genus and species is proposed, Oleiphilus messinensis gen. nov., sp. nov., within a new family, Oleiphilaceae fam. nov. Strain ME102T (= DSM 13489T = LMG 20357T) is the type and only strain of O. messinensis. PMID:12054256

  13. Optimization of culture conditions and medium composition for the marine algicidal bacterium Alteromonas sp. DH46 by uniform design

    NASA Astrophysics Data System (ADS)

    Lin, Jing; Zheng, Wei; Tian, Yun; Wang, Guizhong; Zheng, Tianling

    2013-09-01

    Harmful algal blooms (HABs) have led to extensive ecological and environmental issues and huge economic losses. Various HAB control techniques have been developed, and biological methods have been paid more attention. Algicidal bacteria is a general designation for bacteria which inhibit algal growth in a direct or indirect manner, and kill or damage the algal cells. A metabolite which is strongly toxic to the dinoflagellate Alexandrium tamarense was produced by strain DH46 of the alga-lysing bacterium Alteromonas sp. The culture conditions were optimized using a single-factor test method. Factors including carbon source, nitrogen source, temperature, initial pH value, rotational speed and salinity were studied. The results showed that the cultivation of the bacteria at 28°C and 180 r min-1 with initial pH 7 and 30 salt contcentration favored both the cell growth and the lysing effect of strain DH46. The optimal medium composition for strain DH46 was determined by means of uniform design experimentation, and the most important components influencing the cell density were tryptone, yeast extract, soluble starch, NaNO3 and MgSO4. When the following culture medium was used (tryptone 14.0g, yeast extract 1.63g, soluble starch 5.0 g, NaNO3 1.6 g, MgSO4 2.3 g in 1L), the largest bacterial dry weight (7.36 g L-1) was obtained, which was an enhancement of 107% compared to the initial medium; and the algal lysis rate was as high as 98.4% which increased nearly 10% after optimization.

  14. Idiomarina atlantica sp. nov., a marine bacterium isolated from the deep sea sediment of the North Atlantic Ocean.

    PubMed

    Du, Juan; Lai, Qiliang; Liu, Yang; Du, Yaping; Liu, Xiupian; Sun, Fengqin; Shao, Zongze

    2015-02-01

    An aerobic Gram-negative, slightly curved rod-shaped and non-motile bacterium, designated G5_TVMV8_7(T), was isolated from the deep sea sediment sample of the North Atlantic Ocean. Strain G5_TVMV8_7(T) displayed growth at 4-45 °C (optimum, 25-35 °C), at pH 6.0-11.0 (optimum, 7.0-8.0) and in 1.0-15.0 % (w/v) NaCl (optimum, 3.0-5.0 %). Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain G5_TVMV8_7(T) belongs to the genus Idiomarina, sharing the highest similarity with Idiomarina salinarum ISL-52(T) (97.4 %) and I. homiensis PO-M2(T) (97.1 %) followed by other validly described species of the genus Idiomarina (96.9-93.5 %). The G + C content of the genomic DNA was found to be 50.2 mol %. The digital DNA-DNA hybridization value between strain G5_TVMV8_7(T) and I. salinarum ISL-52(T) was 17.70 ± 2.24 %. The average nucleotide identity values between strain G5_TVMV8_7T and I. salinarum ISL-52(T) was found to be 70.03 %. The major fatty acids were C16:0 (12.7 %), iso-C15:0 (11.5 %) and Sum In Feature 8 (C18:1 ω7c/ω6c) (13.5 %). The predominant respiratory quinone was identified as Q-8, and the polar lipids as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol including several unidentified polar lipids. Based on the genotypic and phenotypic results, a new species Idiomarina atlantica is proposed. The type strain is G5_TVMV8_7(T) (= MCCC 1A10513(T) = KCTC 42141(T)).

  15. Multiple N-acyl-L-homoserine lactone autoinducers of luminescence in the marine symbiotic bacterium Vibrio fischeri.

    PubMed

    Kuo, A; Blough, N V; Dunlap, P V

    1994-12-01

    In Vibrio fischeri, the synthesis of N-3-oxohexanoyl-L-homoserine lactone, the autoinducer for population density-responsive induction of the luminescence operon (the lux operon, luxICDABEG), is dependent on the autoinducer synthase gene luxI. Gene replacement mutants of V. fischeri defective in luxI, which had been expected to produce no autoinducer, nonetheless exhibited lux operon transcriptional activation. Mutants released into the medium a compound that, like N-3-oxohexanoyl-L-homoserine lactone, activated expression of the lux system in a dose-dependent manner and was both extractable with ethyl acetate and labile to base. The luxI-independent compound, also like N-3-oxohexanoyl-L-homoserine lactone, was produced by V. fischeri cells in a regulated, population density-responsive manner and required the transcriptional activator LuxR for activity in the lux system. The luxI-independent compound was identified as N-octanoyl-L-homoserine lactone by coelution with the synthetic compound in reversed-phase high-pressure liquid chromatography, by derivatization treatment with 2,4-dinitrophenylhydrazine, by mass spectrometry, and by nuclear magnetic resonance spectroscopy. A locus, ain, necessary and sufficient for Escherichia coli to synthesize N-octanoyl-L-homoserine lactone was cloned from the V. fischeri genome and found to be distinct from luxI by restriction mapping and Southern hybridization. N-Octanoyl-L-homoserine lactone and ain constitute a second, novel autoinduction system for population density-responsive signalling and regulation of lux gene expression, and possibly other genes, in V. fischeri. A third V. fischeri autoinducer, N-hexanoyl-L-homoserine lactone, dependent on luxI for its synthesis, was also identified. The presence of multiple chemically and genetically distinct but cross-acting autoinduction systems in V. fischeri indicates unexpected complexity for autoinduction as a regulatory mechanism in this bacterium.

  16. Physiological and Genetic Description of Dissimilatory Perchlorate Reduction by the Novel Marine Bacterium Arcobacter sp. Strain CAB

    PubMed Central

    Carlström, Charlotte I.; Wang, Ouwei; Melnyk, Ryan A.; Bauer, Stefan; Lee, Joyce; Engelbrektson, Anna; Coates, John D.

    2013-01-01

    ABSTRACT A novel dissimilatory perchlorate-reducing bacterium (DPRB), Arcobacter sp. strain CAB, was isolated from a marina in Berkeley, CA. Phylogenetically, this halophile was most closely related to Arcobacter defluvii strain SW30-2 and Arcobacter ellisii. With acetate as the electron donor, strain CAB completely reduced perchlorate (ClO4−) or chlorate (ClO3−) [collectively designated (per)chlorate] to innocuous chloride (Cl−), likely using the perchlorate reductase (Pcr) and chlorite dismutase (Cld) enzymes. When grown with perchlorate, optimum growth was observed at 25 to 30°C, pH 7, and 3% NaCl. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) preparations were dominated by free-swimming straight rods with 1 to 2 polar flagella per cell. Strain CAB utilized a variety of organic acids, fructose, and hydrogen as electron donors coupled to (per)chlorate reduction. Further, under anoxic growth conditions strain CAB utilized the biogenic oxygen produced as a result of chlorite dismutation to oxidize catechol via the meta-cleavage pathway of aerobic catechol degradation and the catechol 2,3-dioxygenase enzyme. In addition to (per)chlorate, oxygen and nitrate were alternatively used as electron acceptors. The 3.48-Mb draft genome encoded a distinct perchlorate reduction island (PRI) containing several transposases. The genome lacks the pcrC gene, which was previously thought to be essential for (per)chlorate reduction, and appears to use an unrelated Arcobacter c-type cytochrome to perform the same function. PMID:23695836

  17. Marinobacter zhanjiangensis sp. nov., a marine bacterium isolated from sea water of a tidal flat of the South China Sea.

    PubMed

    Zhuang, Da-Chun; Chen, Yi-Guang; Zhang, Yu-Qin; Tang, Shu-Kun; Wu, Xiao-Lei; Tan, Zhou-Cai; Li, Wen-Jun; Cui, Xiao-Long

    2009-10-01

    A novel Gram-negative, catalase- and oxidase-positive, non-sporulating, rod-shaped, aerobic bacterium, designated strain JSM 078120(T), was isolated from sea water collected from a tidal flat of Naozhou Island, South China Sea. Growth occurred with 1-15% (w/v) total salts (optimum, 2-4%), at pH 6.0-10.0 (optimum, pH 7.5) and at 4-35 degrees C (optimum, 25-30 degrees C). The major cellular fatty acids were C(18:1) omega9c, C(16:0), C(12:0) 3-OH and C(16:1) omega7c. The predominant respiratory quinone was ubiquinone Q-9, and the genomic DNA G + C content was 60.6 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain JSM 078120(T) should be assigned to the genus Marinobacter, being related most closely to the type strains of Marinobacter segnicrescens (sequence similarity 98.2%), Marinobacter bryozoorum (97.9%) and Marinobacter gudaonensis (97.6%). The sequence similarities between the novel isolate and the type strains of other recognized Marinobacter species ranged from 96.7 (with Marinobacter salsuginis) to 93.3% (with Marinobacter litoralis). The levels of DNA-DNA relatedness between strain JSM 078120(T) and the type strains of M. segnicrescens, M. bryozoorum and M. gudaonensis were 25.3, 20.6 and 18.8%, respectively. The combination of phylogenetic analysis, DNA-DNA relatedness, phenotypic characteristics and chemotaxonomic data supported the view that strain JSM 078120(T) represents a novel species of the genus Marinobacter, for which the name Marinobacter zhanjiangensis sp. nov. is proposed. The type strain is JSM 078120(T) (= CCTCC AB 208029(T) = DSM 21077(T) = KCTC 22280(T)).

  18. Biochemical characterization and structural analysis of a new cold-active and salt-tolerant esterase from the marine bacterium Thalassospira sp.

    PubMed

    De Santi, Concetta; Leiros, Hanna-Kirsti S; Di Scala, Alessia; de Pascale, Donatella; Altermark, Bjørn; Willassen, Nils-Peder

    2016-05-01

    A gene encoding an esterase, ThaEst2349, was identified in the marine psychrophilic bacterium Thalassospira sp. GB04J01. The gene was cloned and overexpressed in E. coli as a His-tagged fusion protein. The recombinant enzyme showed optimal activity at 45 °C and the thermal stability displayed a retention of 75 % relative activity at 40 °C after 2 h. The optimal pH was 8.5 but the enzyme kept more than 75 % of its maximal activity between pH 8.0 and 9.5. ThaEst2349 also showed remarkable tolerance towards high concentrations of salt and it was active against short-chain p-nitrophenyl esters, displaying optimal activity with the acetate. The enzyme was tested for tolerance of organic solvents and the results are suggesting that it could function as an interesting candidate for biotechnological applications. The crystal structure of ThaEst2349 was determined to 1.69 Å revealing an asymmetric unit containing two chains, which also is the biological unit. The structure has a characteristic cap domain and a catalytic triad comprising Ser158, His285 and Asp255. To explain the cold-active nature of the enzyme, we compared it against thermophilic counterparts. Our hypothesis is that a high methionine content, less hydrogen bonds and less ion pairs render the enzyme more flexible at low temperatures. PMID:27016194

  19. Indirect Oxidation of Co(II) in the Presence of the Marine Mn(II)-Oxidizing Bacterium Bacillus Sp. Strain SG-1

    SciTech Connect

    Murray, K.J.; Webb, S.M.; Bargar, J.R.; Tebo, B.M.; /Scripps Inst. Oceanography /SLAC, SSRL /Oregon Health Sci. U.

    2009-04-29

    Cobalt(II) oxidation in aquatic environments has been shown to be linked to Mn(II) oxidation, a process primarily mediated by bacteria. This work examines the oxidation of Co(II) by the spore-forming marine Mn(II)-oxidizing bacterium Bacillus sp. strain SG-1, which enzymatically catalyzes the formation of reactive nanoparticulate Mn(IV) oxides. Preparations of these spores were incubated with radiotracers and various amounts of Co(II) and Mn(II), and the rates of Mn(II) and Co(II) oxidation were measured. Inhibition of Mn(II) oxidation by Co(II) and inhibition of Co(II) oxidation by Mn(II) were both found to be competitive. However, from both radiotracer experiments and X-ray spectroscopic measurements, no Co(II) oxidation occurred in the complete absence of Mn(II), suggesting that the Co(II) oxidation observed in these cultures is indirect and that a previous report of enzymatic Co(II) oxidation may have been due to very low levels of contaminating Mn. Our results indicate that the mechanism by which SG-1 oxidizes Co(II) is through the production of the reactive nanoparticulate Mn oxide.

  20. Biochemical and Structural Characterization of a Five-domain GH115 α-Glucuronidase from the Marine Bacterium Saccharophagus degradans 2-40T.

    PubMed

    Wang, Weijun; Yan, Ruoyu; Nocek, Boguslaw P; Vuong, Thu V; Di Leo, Rosa; Xu, Xiaohui; Cui, Hong; Gatenholm, Paul; Toriz, Guillermo; Tenkanen, Maija; Savchenko, Alexei; Master, Emma R

    2016-07-01

    Glucuronic acid (GlcAp) and/or methylglucuronic acid (MeGlcAp) decorate the major forms of xylan in hardwood and coniferous softwoods as well as many cereal grains. Accordingly, the complete utilization of glucuronoxylans or conversion to sugar precursors requires the action of main chain xylanases as well as α-glucuronidases that release the α- (1→2)-linked (Me)GlcAp side groups. Herein, a family GH115 enzymefrom the marine bacterium Saccharophagus degradans 2-40(T), SdeAgu115A, demonstrated activity toward glucuronoxylan and oligomers thereof with preference toward MeGlcAp linked to internal xylopyranosyl residues. Unique biochemical characteristics of NaCl activation were also observed. The crystal structure of SdeAgu115A revealed a five-domain architecture, with an additional insertion C(+) domain that had significant impact on the domain arrangement of SdeAgu115A monomer and its dimerization. The participation of domain C(+) in substrate binding was supported by reduced substrate inhibition upon introducing W773A, W689A, and F696A substitutions within this domain. In addition to Asp-335, the catalytic essentiality of Glu-216 was revealed by site-specific mutagenesis. A primary sequence analysis suggested that the SdeAgu115A architecture is shared by more than half of GH115 members, thus defining a distinct archetype for GH115 enzymes. PMID:27129264

  1. Aliikangiella marina gen. nov., sp. nov., a marine bacterium from the culture broth of Picochlorum sp. 122, and proposal of Kangiellaceae fam. nov. in the order Oceanospirillales.

    PubMed

    Wang, Guanghua; Tang, Mingxing; Wu, Huanlian; Dai, Shikun; Li, Tao; Chen, Chenghao; He, Hui; Fan, Jiewei; Xiang, Wenzhou; Li, Xiang

    2015-12-01

    A Gram-stain-negative, non-motile, non-spore-forming, long rod-shaped bacterium, designated strain GYP-15T, was isolated from the culture broth of a marine microalga, Picochloruma sp. 122. Phylogenetic analyses revealed that strain GYP-15T shared 90.6 % 16S rRNA gene sequence similarity with its closest relative, Kangiella aquimarina KCTC 12183T, and represents a distinct phylogenetic lineage in a robust clade consisting of GYP-15T and members of the genera Kangiella and Pleionea in the order Oceanospirillales. Chemotaxonomic and physiological characteristics, including major cellular fatty acids, NaCl tolerance and pattern of carbon source utilization, could also readily distinguish strain GYP-15T from all established genera and species. Thus, it is concluded that strain GYP-15T represents a novel species of a new genus, for which the name Aliikangiella marina gen. nov., sp. nov. is proposed. The type strain of Aliikangiella marina is GYP-15T ( = MCCC 1K01163T = KCTC 42667T). Based on phylogenetic results, 16S rRNA gene signature nucleotide pattern and some physiological characteristics, the three genera Kangiella, Pleionea and Aliikangiella are proposed to make up a novel family, Kangiellaceae fam. nov., in the order Oceanospirillales.

  2. Wenzhouxiangella marina gen. nov, sp. nov, a marine bacterium from the culture broth of Picochlorum sp. 122, and proposal of Wenzhouxiangellaceae fam. nov. in the order Chromatiales.

    PubMed

    Wang, Guanghua; Tang, Mingxing; Li, Tao; Dai, Shikun; Wu, Huanlian; Chen, Chenghao; He, Hui; Fan, Jiewei; Xiang, Wenzhou; Li, Xiang

    2015-06-01

    A Gram-stain negative, non-motile, non-phototrophic, non-alkaliphilic, obligately aerobic, chemoheterotrophic, and rod-shaped bacterium, designated strain Ma-11(T), was isolated from the culture broth of a marine microalga, Picochloruma sp. 122. Phylogenetic analyses showed that strain Ma-11(T) has less than 91 % similarity to its closest relative, Thioalkalivibrio sulfidiphilus HL-EbGR7(T), represents a distinct phylogenetic lineage in the order Chromatiales, and could not be assigned to any defined families in this order. Chemotaxonomic, genetic and physiological characteristics, including major fatty acids, genomic G+C content, lack of motility, aerophilicity and chemoheterotrophicity, could readily distinguish strain Ma-11(T) from any established members of the order Chromatiales. Based on the 16S rRNA gene sequence analysis and its signature nucleotide pattern, a new family Wenzhouxiangellaceae fam. nov. comprising the genus Wenzhouxiangella gen. nov. and species Wenzhouxiangella marina sp. nov. is proposed. The type strain is Ma-11(T) (=CGMCC 1.14936(T) = KCTC 42284(T) = MCCC 1K00261(T)).

  3. In vitro quenching of fish pathogen Edwardsiella tarda AHL production using marine bacterium Tenacibaculum sp. strain 20J cell extracts.

    PubMed

    Romero, Manuel; Muras, Andrea; Mayer, Celia; Buján, Noemí; Magariños, Beatriz; Otero, Ana

    2014-04-01

    Quorum quenching (QQ) has become an interesting alternative for solving the problem of bacterial antibiotic resistance, especially in the aquaculture industry, since many species of fish-pathogenic bacteria control their virulence factors through quorum sensing (QS) systems mediated by N-acylhomoserine lactones (AHLs). In a screening for bacterial strains with QQ activity in different marine environments, Tenacibaculum sp. strain 20J was identified and selected for its high degradation activity against a wide range of AHLs. In this study, the QQ activity of live cells and crude cell extracts (CCEs) of strain 20J was characterized and the possibilities of the use of CCEs of this strain to quench the production of AHLs in cultures of the fish pathogen Edwardsiella tarda ACC35.1 was explored. E. tarda ACC35.1 produces N-hexanoyl-L-homoserine lactone (C6-HSL) and N-oxohexanoyl-L-homoserine lactone (OC6-HSL). This differs from profiles registered for other E. tarda strains and indicates an important intra-specific variability in AHL production in this species. The CCEs of strain 20J presented a wide-spectrum QQ activity and, unlike Bacillus thuringiensis serovar Berliner ATCC10792 CCEs, were effective in eliminating the AHLs produced in E. tarda ACC35.1 cultures. The fast and wide-spectrum AHL-degradation activity shown by this member of the Cytophaga-Flexibacter-Bacteroidetes group consolidates this strain as a promising candidate for the control of AHL-based QS pathogens, especially in the marine fish farming industry.

  4. Spongiibacter marinus gen. nov., sp. nov., a halophilic marine bacterium isolated from the boreal sponge Haliclona sp. 1.

    PubMed

    Graeber, Ingeborg; Kaesler, Ines; Borchert, Martin S; Dieckmann, Ralf; Pape, Thomas; Lurz, Rudi; Nielsen, Preben; von Döhren, Hans; Michaelis, Walter; Szewzyk, Ulrich

    2008-03-01

    Strain HAL40b(T) was isolated from the marine sponge Haliclona sp. 1 collected at the Sula Ridge off the Norwegian coast and characterized by physiological, biochemical and phylogenetic analyses. The isolate was a small rod with a polar flagellum. It was aerobic, Gram-negative and oxidase- and catalase-positive. Optimal growth was observed at 20-30 degrees C, pH 7-9 and in 3 % NaCl. Substrate utilization tests were positive for arabinose, Tween 40 and Tween 80. Enzyme tests were positive for alkaline phosphatase, esterase lipase (C8), leucine arylamidase, acid phosphatase, naphthol-AS-BI-phosphohydrolase and N-acetyl-beta-glucosaminidase. The predominant cellular fatty acid was C(17 : 1) omega8, followed by C(17 : 0) and C(18 : 1) omega7. Analysis by matrix-assisted laser desorption/ionization time-of-flight MS was used to characterize the strain, producing a characteristic low-molecular-mass protein pattern that could be used as a fingerprint for identification of members of this species. The DNA G+C content was 69.1 mol%. Phylogenetic analysis supported by 16S rRNA gene sequence comparison classified the strain as a member of the class Gammaproteobacteria. Strain HAL40b(T) was only distantly related to other marine bacteria including Neptunomonas naphthovorans and Marinobacter daepoensis (type strain sequence similarity >90 %). Based on its phenotypic, physiological and phylogenetic characteristics, it is proposed that the strain should be placed into a new genus as a representative of a novel species, Spongiibacter marinus gen. nov., sp. nov.; the type strain of Spongiibacter marinus is HAL40b(T) (=DSM 17750(T) =CCUG 54896(T)).

  5. Taxonomic description and genome sequence of Salinicoccus sediminis sp. nov., a halotolerant bacterium isolated from marine sediment.

    PubMed

    Kumar, Rajendran Mathan; Kaur, Gurwinder; Kumar, Narender; Kumar, Anand; Singh, Nitin Kumar; Bala, Monu; Kaur, Navjot; Mayilraj, Shanmugam

    2015-11-01

    A Gram-staining-positive, coccoid, halotolerant bacterial strain, designated SV-16T, was isolated from marine sediment and subjected to a polyphasic taxonomic study. The strain exhibited phenotypic properties that included chemotaxonomic characteristics consistent with its classification in the genus Salinicoccus. Growth occurred at temperatures in the range 25-37 °C (optimum 30 °C), at pH 7.0-11.0 (optimum pH 8.0) and at NaCl concentrations of up to 25.0% (optimum 15.0%). The highest level of 16S rRNA gene sequence similarity was with Salinicoccus carnicancri CrmT (98.6%) followed by Salinicoccus halodurans W24T (96.6%). The predominant polar lipids were diphosphatidylglycerol, phosphatidylinositol and phosphatidylglycerol. The major cellular fatty acids were iso-C15:0, anteiso-C15:0, iso-C17:0 and anteiso-C17:0. The draft genome of strain SV-16T consisted of 2,591,284 bp with a DNA G+C content of 48.7 mol%. On the basis of the phenotypic characteristics and genotypic distinctiveness of strain SV-16T, it should be classified within a novel species of the genus Salinicoccus, for which the name Salinicoccus sediminis sp. nov. is proposed. The type strain is SV-16T ( = MTCC 11832T = DSM 28797T). PMID:26956594

  6. Isolation and physico-chemical characterisation of extracellular polymeric substances produced by the marine bacterium Vibrio parahaemolyticus.

    PubMed

    Kavita, Kumari; Mishra, Avinash; Jha, Bhavanath

    2011-03-01

    A marine bacterial strain identified as Vibrio parahaemolyticus by 16S rRNA gene (HM355955) sequencing and gas chromatography (GC) coupled with MIDI was selected from a natural biofilm by its capability to produce extracellular polymeric substances (EPS). The EPS had an average molecule size of 15.278 μm and exhibited characteristic diffraction peaks at 5.985°, 9.150° and 22.823°, with d-spacings of 14.76661, 9.29989 and 3.89650 Å, respectively. The Fourier-transform infrared spectroscopy (FTIR) spectrum revealed aliphatic methyl, primary amine, halide groups, uronic acid and saccharides. Gas chromatography mass spectrometry (GCMS) confirmed the presence of arabinose, galactose, glucose and mannose. (1)HNMR (nuclear magnetic resonance) revealed functional groups characteristic of polysaccharides. The EPS were amorphous in nature (CI(xrd) 0.092), with a 67.37% emulsifying activity, thermostable up to 250°C and displayed pseudoplastic rheology. MALDI-TOF-TOF analysis revealed a series of masses, exhibiting low-mass peaks (m/z) corresponding to oligosaccharides and higher-mass peaks for polysaccharides consisting of different ratios of pentose and hexose moieties. This is the first report of a detailed characterisation of the EPS produced by V. parahaemolyticus, which could be further explored for biotechnological and industrial use. PMID:21409653

  7. Transcriptional and translational regulatory responses to iron limitation in the globally distributed marine bacterium Candidatus Pelagibacter ubique

    SciTech Connect

    Smith, Daniel P.; Kitner, J. B.; Norbeck, Angela D.; Clauss, Therese RW; Lipton, Mary S.; Schwalbach, M. S.; Steindler, L.; Nicora, Carrie D.; Smith, Richard D.; Giovannoni, Stephen J.

    2010-05-05

    Abstract Background: Iron is recognized as an important micronutrient that limits microbial plankton productivity over vast regions of the oceans. We investigated the gene expression responses of Candidatus Pelagibacter ubique cultures to iron limitation in natural seawater media supplemented with a siderophore to chelate iron. Methodology/Principal Findings: Microarray data indicated transcription of the periplasmic iron binding protein sfuC increased by 16-fold, and iron transporter subunits, iron-sulfur center assembly genes, and the putative ferroxidase rubrerythrin transcripts increased to a lesser extent. Quantitative peptide mass spectrometry revealed that sfuC protein abundance increased 27-fold, despite an average decrease of 59% across the global proteome. Two RNA-binding proteins, CspE and CspL, correlated well with iron availability, suggesting that they may contribute to the observed differences between the transcriptome and proteome. Conclusions/Significance: We propose sfuC as a marker gene for indicating iron limitation in marine metatranscriptomic and metaproteomic ecological surveys. The marked proteome reduction was not directly correlated to changes in the transcriptome, implicating post-transcriptional regulatory mechanisms as modulators of protein expression. We propose a model in which the RNA-binding activity of cspE and cspL selectively enables protein synthesis of the iron acquisition protein sfuC during transient growth-limiting episodes of iron scarcity.

  8. Psychrobium conchae gen. nov., sp. nov., a psychrophilic marine bacterium isolated from the Iheya North hydrothermal field.

    PubMed

    Nogi, Yuichi; Abe, Mariko; Kawagucci, Shinsuke; Hirayama, Hisako

    2014-11-01

    A novel psychrophilic, marine, bacterial strain designated BJ-1(T) was isolated from the Iheya North hydrothermal field in the Okinawa Trough off Japan. Cells were Gram-negative, rod-shaped, non-spore-forming, aerobic chemo-organotrophs and motile by means of a single polar flagellum. Growth occurred at temperatures below 16 °C, with the optimum between 9 and 12 °C. Phylogenetic analysis based on the 16S rRNA gene sequence indicated that the closest relatives of strain BJ-1(T) were Shewanella denitrificans OS-217(T) (93.5% similarity), Shewanella profunda DSM 15900(T) (92.9%), Shewanella gaetbuli TF-27(T) (92.9%), Paraferrimonas sedimenticola Mok-106(T) (92.1%) and Ferrimonas kyonanensis Asr22-7(T) (91.7%). The major respiratory quinone was Q-8. The predominant fatty acids were C(16:1)ω7c and C(16:0). The G+C content of the novel strain was 40.5 mol%. Based on phylogenetic, phenotypic and chemotaxonomic evidence, it is proposed that strain BJ-1(T) represents a novel species in a new genus, for which the name Psychrobium conchae gen. nov., sp. nov. is proposed. The type strain of Psychrobium conchae is BJ-1(T) ( =JCM 30103(T) =DSM 28701(T)).

  9. Bacillus toyonensis strain AEMREG6, a bacterium isolated from South African marine environment sediment samples produces a glycoprotein bioflocculant.

    PubMed

    Okaiyeto, Kunle; Nwodo, Uchechukwu U; Mabinya, Leonard V; Okoh, Anthony I

    2015-01-01

    A bioflocculant-producing bacteria, isolated from sediment samples of a marine environment in the Eastern Cape Province of South Africa demonstrated a flocculating activity above 60% for kaolin clay suspension. Analysis of the 16S ribosomal deoxyribonucleic acid (rDNA) nucleotide sequence of the isolate in the GenBank database showed 99% similarity to Bacillus toyonensis strain BCT-7112 and it was deposited in the GenBank as Bacillus toyonensis strain AEMREG6 with accession number KP406731. The bacteria produced a bioflocculant (REG-6) optimally in the presence of glucose and NH4NO3 as the sole carbon and nitrogen source, respectively, initial medium pH of 5 and Ca2+ as the cation of choice. Chemical analysis showed that purified REG-6 was a glycoprotein mainly composed of polysaccharide (77.8%) and protein (11.5%). It was thermally stable and had strong flocculating activity against kaolin suspension over a wide range of pH values (3-11) with a relatively low dosage requirement of 0.1 mg/mL in the presence of Mn2+. Fourier transform infrared spectroscopy (FTIR) revealed the presence of hydroxyl, carboxyl and amide groups preferred for flocculation. Scanning electron microscopy (SEM) revealed that bridging was the main flocculation mechanism of REG-6. The outstanding flocculating performance of REG-6 holds great potential to replace the hazardous chemical flocculants currently used in water treatment. PMID:25806549

  10. Pseudacidovorax intermedius NH-1, a novel marine nitrogen-fixing bacterium isolated from the South China Sea.

    PubMed

    Zhang, Li-hong; Chen, San-feng

    2012-09-01

    We have taxonomically and phylogenetically characterized a novel nitrogen-fixing bacterial strain, NH-1, which was recently isolated from surface sediments of the South China Sea. The presence of the nifH gene was determined by PCR amplification. The strain NH-1 was found to belong to the genus Pseudacidovorax based on phenotypic characterization, 16S rDNA sequencing, G+C content and DNA-DNA hybridization. Isolate NH-1 was identified as Pseudacidovorax intermedius. In addition, we investigated the links between environmental factors and the nitrogenase activity of NH-1. We found that the nitrogen fixation capacity of NH-1 varied strongly when cells were grown with different ammonium ion and oxygen concentrations, amino acids and carbohydrates. This is the first report of the isolation of Pseudacidovorax from the ocean and the first study to explore the effects of different culture conditions on the nitrogenase activities of the isolate. This study provides evidence that marine nitrogen-fixing microorganisms are far more diverse than currently recognized.

  11. Biosorption and Biomineralization of U(VI) by the Marine Bacterium Idiomarina loihiensis MAH1: Effect of Background Electrolyte and pH

    PubMed Central

    Morcillo, Fernando; González-Muñoz, María T.; Reitz, Thomas; Romero-González, María E.; Arias, José M.; Merroun, Mohamed L.

    2014-01-01

    The main goal of this study is to compare the effects of pH, uranium concentration, and background electrolyte (seawater and NaClO4 solution) on the speciation of uranium(VI) associated with the marine bacterium Idiomarina loihiensis MAH1. This was done at the molecular level using a multidisciplinary approach combining X-ray Absorption Spectroscopy (XAS), Time-Resolved Laser-Induced Fluorescence Spectroscopy (TRLFS), and High Resolution Transmission Electron Microscopy (HRTEM). We showed that the U(VI)/bacterium interaction mechanism is highly dependent upon pH but also the nature of the used background electrolyte played a role. At neutral conditions and a U concentration ranging from 5·10−4 to 10−5 M (environmentally relevant concentrations), XAS analysis revealed that uranyl phosphate mineral phases, structurally resembling meta-autunite [Ca(UO2)2(PO4)2 2–6H2O] are precipitated at the cell surfaces of the strain MAH1. The formation of this mineral phase is independent of the background solution but U(VI) luminescence lifetime analyses demonstrated that the U(VI) speciation in seawater samples is more intricate, i.e., different complexes were formed under natural conditions. At acidic conditions, pH 2, 3 and 4.3 ([U] = 5·10−4 M, background electrolyte  = 0.1 M NaClO4), the removal of U from solution was due to biosorption to Extracellular Polysaccharides (EPS) and cell wall components as evident from TEM analysis. The LIII-edge XAS and TRLFS studies showed that the biosorption process observed is dependent of pH. The bacterial cell forms a complex with U through organic phosphate groups at pH 2 and via phosphate and carboxyl groups at pH 3 and 4.3, respectively. The differences in the complexes formed between uranium and bacteria on seawater compared to NaClO4 solution demonstrates that the actinide/microbe interactions are influenced by the three studied factors, i.e., the pH, the uranium concentration and the chemical composition of the

  12. [Desulfovibrio hontreensis sp. nov., a Sulfate-Reducing Bacterium Isolated from Marine Biofoulings at the South Vietnam Coastal Area].

    PubMed

    Tarasov, A L; Osipov, G A; Borzenkov, I A

    2015-01-01

    A Desulfovibrio strain physiologically similar to and phylogeneticall related to "D. caledoniensis" SEBR 7250, D. portus MSL79, and D. dechloracetivorans ATCC 700912 (96.9, 95.9, and 95.8% similarity of the 16S rRNA gen sequences, respectively) was isolated from marine biofouling in the coastal zone of the South China Sae (Nha Trang, South Vietnam). The cells of strain ME were gram-negative motile vibrios (0.4-0.6 x 1.3-2 μm) with a single flagellum. The strain grew at 20 to 39 degrees C (growth optimum at 34-37 degrees C), pH 5.8 to 8.5 (pH optimum at 6.8-7.5), and salinity from 0.08 to 1.1 M Na+ (optimum at 0.2-0.3 M Na+). In the presence of sulfate, the strain grew autotrophically with hydrogen or on lactate, formate, pyruvate, fumarate, and malate. Weak growth occurred on succinate, glycerol, and fructose. In the absence of sulfate, the strain was able to ferment pyruvate, malate (weakly), but not lactate. Sulfate, sulfite, thiosulfate, elemental sulfur, and dimethyl sulfoxide were used as electron acceptors. Vitamins and yeast extract were not required for growth. The G+C content was 52.4 mol %. Predominant fatty acids were C18:0 (13.9%), C16:0 (9.6%), iso-C16:0 (9.5%), C18: 1w7 (8.8%), anteiso-C15:0 (8.1%), and iso-C 17:1 (7.2%). The fatty acid composition was close to that of D. dechloracetivorans BO and has some similarity to that of D. portus. Based on its genotypic and phenotypic characteristics, strain ME maybe considered as a new species, for which the name Desulfovibrio hontrensis sp. nov. is proposed. PMID:27169246

  13. Structural flexibility of the heme cavity in the cold-adapted truncated hemoglobin from the Antarctic marine bacterium Pseudoalteromonas haloplanktis TAC125.

    PubMed

    Giordano, Daniela; Pesce, Alessandra; Boechi, Leonardo; Bustamante, Juan Pablo; Caldelli, Elena; Howes, Barry D; Riccio, Alessia; di Prisco, Guido; Nardini, Marco; Estrin, Dario; Smulevich, Giulietta; Bolognesi, Martino; Verde, Cinzia

    2015-08-01

    Truncated hemoglobins build one of the three branches of the globin protein superfamily. They display a characteristic two-on-two α-helical sandwich fold and are clustered into three groups (I, II and III) based on distinct structural features. Truncated hemoglobins are present in eubacteria, cyanobacteria, protozoa and plants. Here we present a structural, spectroscopic and molecular dynamics characterization of a group-II truncated hemoglobin, encoded by the PSHAa0030 gene from Pseudoalteromonas haloplanktis TAC125 (Ph-2/2HbO), a cold-adapted Antarctic marine bacterium hosting one flavohemoglobin and three distinct truncated hemoglobins. The Ph-2/2HbO aquo-met crystal structure (at 2.21 Å resolution) shows typical features of group-II truncated hemoglobins, namely the two-on-two α-helical sandwich fold, a helix Φ preceding the proximal helix F, and a heme distal-site hydrogen-bonded network that includes water molecules and several distal-site residues, including His(58)CD1. Analysis of Ph-2/2HbO by electron paramagnetic resonance, resonance Raman and electronic absorption spectra, under varied solution conditions, shows that Ph-2/2HbO can access diverse heme ligation states. Among these, detection of a low-spin heme hexa-coordinated species suggests that residue Tyr(42)B10 can undergo large conformational changes in order to act as the sixth heme-Fe ligand. Altogether, the results show that Ph-2/2HbO maintains the general structural features of group-II truncated hemoglobins but displays enhanced conformational flexibility in the proximity of the heme cavity, a property probably related to the functional challenges, such as low temperature, high O2 concentration and low kinetic energy of molecules, experienced by organisms living in the Antarctic environment.

  14. Vibrio panuliri sp. nov., a marine bacterium isolated from spiny lobster, Panulirus penicillatus and transfer of Vibrio ponticus from Scophthalmi clade to the newly proposed Ponticus clade.

    PubMed

    Kumari, Prabla; Poddar, Abhijit; Schumann, Peter; Das, Subrata K

    2014-12-01

    A novel marine bacterium, strain LBS2(T) was isolated from eggs carried on pleopods of the spiny lobster collected from Andaman Sea. Heterotrophic growth occurred at 1-7% NaCl. 16S rRNA gene sequence similarity revealed the strain LBS2(T) belonged to the genus Vibrio and showed above 97% similarity with eight type strains of the genus Vibrio. Multilocus analysis based on ftsZ, gapA, gyrB, mreB, pyrH recA, rpoA, and topA revealed LBS2(T) formed a separate cluster with Vibrio ponticus DSM 16217(T) with 89.8% multilocus gene sequence similarity. However, strain LBS2(T) is distantly related with other members of the Scophthalmi clade in terms of 16S rRNA signatures, phenotypic variations and multilocus gene sequence similarity, for which we propose LBS2(T) belongs to a new clade i.e. Ponticus clade with V. ponticus DSM 16217(T) as the representative type strain of the clade. DNA-DNA homologies between strain LBS2(T) and closely related strains were well below 70%. DNA G + C content was 45.3 mol%. On the basis of our polyphasic study, strain LBS2(T) represents a novel species of the genus Vibrio, for which the name Vibrio panuliri sp. nov. is proposed. The type strain is LBS2(T) (= JCM 19500(T) = DSM 27724(T) = LMG 27902(T)).

  15. Bacillus mesophilus sp. nov., an alginate-degrading bacterium isolated from a soil sample collected from an abandoned marine solar saltern.

    PubMed

    Zhou, Yan-Xia; Liu, Guo-Hong; Liu, Bo; Chen, Guan-Jun; Du, Zong-Jun

    2016-07-01

    A novel Gram-stain positive, endospore-forming bacterium, designated SA4(T), was isolated from a soil sample collected from an abandoned marine solar saltern at Wendeng, Shandong Province, PR China. Cells were observed to be rod shaped, alginase positive, catalase positive and motile. The strain was found to grow at temperatures ranging from 15 to 40 °C (optimum 35 °C), and pH 5.0-11.0 (optimum pH 8.0) with 0-7.0 % (w/v) NaCl concentration (optimum NaCl 3.0 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SA4(T) belongs to the genus Bacillus and exhibits 16S rRNA gene sequence similarities of 96.6, 96.5, 96.3 and 96.2 % with Bacillus horikoshii DSM 8719(T), Bacillus acidicola 105-2(T), Bacillus shackletonii LMG 18435(T) and Bacillus pocheonensis Gsoil 420(T), respectively. The menaquinone was identified as MK-7 and the major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids detected were anteiso-C15:0 (22.3 %), iso-C15:0 (22.6 %), iso-C16:0 (14.8 %) and iso-C14:0 (14.7 %). The DNA G+C content was determined to be 42.4 mol %. Phenotypic, chemotaxonomic and genotypic properties clearly indicated that isolate SA4(T) represents a novel species within the genus Bacillus, for which the name Bacillus mesophius sp. nov. is proposed. The type strain is SA4(T) (=DSM 101000(T)=CCTCC AB 2015209(T)).

  16. Structure and activity of the cold-active and anion-activated carboxyl esterase OLEI01171 from the oil-degrading marine bacterium Oleispira antarctica

    PubMed Central

    Lemak, Sofia; Tchigvintsev, Anatoli; Petit, Pierre; Flick, Robert; Singer, Alexander U.; Brown, Greg; Evdokimova, Elena; Egorova, Olga; Gonzalez, Claudio F.; Chernikova, Tatyana N.; Yakimov, Michail M.; Kube, Michael; Reinhardt, Richard; Golyshin, Peter N.; Savchenko, Alexei; Yakunin, Alexander F.

    2014-01-01

    The uncharacterized α/β-hydrolase protein OLEI01171 from the psychrophilic marine bacterium Oleispira antarctica belongs to the PF00756 family of putative esterases, which also includes human esterase D. In the present paper we show that purified recombinant OLEI01171 exhibits high esterase activity against the model esterase substrate α-naphthyl acetate at 5 – 30°C with maximal activity at 15–20°C. The esterase activity of OLEI01171 was stimulated 3–8-fold by the addition of chloride or several other anions (0.1–1.0 M). Compared with mesophilic PF00756 esterases, OLEI01171 exhibited a lower overall protein thermostability. Two crystal structures ofOLEI01171 were solved at 1.75 and 2.1 Å resolution and revealed a classical serine hydrolase catalytic triad and the presence of a chloride or bromide ion bound in the active site close to the catalytic Ser148.Both anions were found to co-ordinate a potential catalytic water molecule located in the vicinity of the catalytic triad His257. The results of the present study suggest that the bound anion perhaps contributes to the polarization of the catalytic water molecule and increases the rate of the hydrolysis of an acyl-enzyme intermediate. Alanine replacement mutagenesis of OLEI01171 identified ten amino acid residues important for esterase activity. The replacement of Asn225 by lysine had no significant effect on the activity or thermostability of OLEI01171, but resulted in a detectable increase of activity at 35–45°C. The present study has provided insight into the molecular mechanisms of activity of a cold-active and anion-activated carboxyl esterase. PMID:22519667

  17. Anti-methicillin-resistant Staphylococcus aureus (MRSA) activity of MC21-B, an antibacterial compound produced by the marine bacterium Pseudoalteromonas phenolica O-BC30T.

    PubMed

    Isnansetyo, Alim; Kamei, Yuto

    2009-08-01

    The aim of this study was to purify, characterise and evaluate the in vitro activity of MC21-B, an antibiotic produced by the marine bacterium Pseudoalteromonas phenolica O-BC30(T). MC21-B was purified by sequential silica and Cosmosil chromatography followed by high-performance liquid chromatography (HPLC). The chemical structure of MC21-B was determined by ultraviolet, infrared, electron impact mass and nuclear magnetic resonance spectrometric analyses. To evaluate its antibacterial activity, minimum inhibitory concentrations (MICs) against 10 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) as well as kill times were determined. Antifungal activity was determined by the paper disk diffusion method. Cytotoxicity against human cells was determined with MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide]. Based on spectrophotometric analyses, MC21-B was predicted to be a novel substance, 2,2',3-tribromobiphenyl-4,4'-dicarboxylic acid. MC21-B exhibited anti-MRSA activity against all 10 clinical isolates of MRSA, with MICs between 1 microg/mL and 4 microg/mL. MC21-B was highly active against Bacillus subtilis and Enterococcus serolicida but was inactive against Gram-negative bacteria and fungi. Furthermore, MC21-B exhibited cytotoxic activity against human normal dermal fibroblasts and human leukaemic (MOLT) cells at 3-12-fold higher concentrations than required for its antibacterial activity. These results demonstrated that MC21-B has high in vitro activity against MRSA and might be useful as a lead compound in developing new anti-MRSA substances.

  18. Vibrio panuliri sp. nov., a marine bacterium isolated from spiny lobster, Panulirus penicillatus and transfer of Vibrio ponticus from Scophthalmi clade to the newly proposed Ponticus clade.

    PubMed

    Kumari, Prabla; Poddar, Abhijit; Schumann, Peter; Das, Subrata K

    2014-12-01

    A novel marine bacterium, strain LBS2(T) was isolated from eggs carried on pleopods of the spiny lobster collected from Andaman Sea. Heterotrophic growth occurred at 1-7% NaCl. 16S rRNA gene sequence similarity revealed the strain LBS2(T) belonged to the genus Vibrio and showed above 97% similarity with eight type strains of the genus Vibrio. Multilocus analysis based on ftsZ, gapA, gyrB, mreB, pyrH recA, rpoA, and topA revealed LBS2(T) formed a separate cluster with Vibrio ponticus DSM 16217(T) with 89.8% multilocus gene sequence similarity. However, strain LBS2(T) is distantly related with other members of the Scophthalmi clade in terms of 16S rRNA signatures, phenotypic variations and multilocus gene sequence similarity, for which we propose LBS2(T) belongs to a new clade i.e. Ponticus clade with V. ponticus DSM 16217(T) as the representative type strain of the clade. DNA-DNA homologies between strain LBS2(T) and closely related strains were well below 70%. DNA G + C content was 45.3 mol%. On the basis of our polyphasic study, strain LBS2(T) represents a novel species of the genus Vibrio, for which the name Vibrio panuliri sp. nov. is proposed. The type strain is LBS2(T) (= JCM 19500(T) = DSM 27724(T) = LMG 27902(T)). PMID:25445014

  19. A novel cold-active and salt-tolerant α-amylase from marine bacterium Zunongwangia profunda: molecular cloning, heterologous expression and biochemical characterization.

    PubMed

    Qin, Yongjun; Huang, Zongqing; Liu, Ziduo

    2014-03-01

    A novel gene (amyZ) encoding a cold-active and salt-tolerant α-amylase (AmyZ) was cloned from marine bacterium Zunongwangia profunda (MCCC 1A01486) and the protein was expressed in Escherichia coli. The gene has a length of 1785 bp and encodes an α-amylase of 594 amino acids with an estimated molecular mass of 66 kDa by SDS-PAGE. The enzyme belongs to glycoside hydrolase family 13 and shows the highest identity (25%) to the characterized α-amylase TVA II from thermoactinomyces vulgaris R-47. The recombinant α-amylase showed the maximum activity at 35 °C and pH 7.0, and retained about 39% activity at 0 °C. AmyZ displayed extreme salt tolerance, with the highest activity at 1.5 M NaCl and 93% activity even at 4 M NaCl. The catalytic efficiency (k cat/K m) of AmyZ increased from 115.51 (with 0 M NaCl) to 143.30 ml mg(-1) s(-1) (with 1.5 M NaCl) at 35 °C and pH 7.0, using soluble starch as substrate. Besides, the thermostability of the enzyme was significantly improved in the presence of 1.5 M NaCl or 1 mM CaCl2. AmyZ is one of the very few α-amylases that tolerate both high salinity and low temperatures, making it a potential candidate for research in basic and applied biology.

  20. Kisspeptin antagonists.

    PubMed

    Roseweir, Antonia Kathryn; Millar, Robert P

    2013-01-01

    Kisspeptin is now known to be an important regulator of the hypothalamic--pituitary-gonadal axis and is the target of a range of regulators, such as steroid hormone feedback, nutritional and metabolic regulation. Kisspeptin binds to its cognate receptor, KISS1R (also called GPR54), on GnRH neurons and stimulates their activity, which in turn provides an obligatory signal for GnRH secretion-thus gating down-stream events supporting reproduction. The development of peripherally active kisspeptin antagonists could offer a unique therapeutic agent for treating hormone-dependent disorders of reproduction, including precocious puberty, endometriosis, and metastatic prostate cancer. The following chapter discusses the advances made in the search for both peptide and small molecule kisspeptin antagonists and their use in delineating the role of kisspeptin within the reproductive system. To date, four peptide antagonists and one small molecule antagonist have been designed.

  1. Endothelin antagonists.

    PubMed

    Benigni, A; Remuzzi, G

    1999-01-01

    The very potent endogenous vasoconstrictor endothelin was discovered in 1988. We know now that there are three isoforms (1, 2, and 3) and two receptor subtypes (A and B). A whole range of peptide and non-peptide antagonists has been developed, some selective for A or B receptors and others with non-selective A/B antagonistic activity. So far the main application of these agents has been experimental--ie, endothelin blockers are used to throw light on disease mechanisms, most notably cardiovascular and renal. However, the non-selective antagonist bosentan and a few other agents have been studied clinically. Evidence so far from preclinical studies and healthy volunteers and from the limited number of investigations in patients permits a listing of the potential areas of clinical interest. These are mainly cardiovascular (eg, hypertension, cerebrovascular damage, and possibly heart failure) and renal. Clouds on the horizon are the need to show that these new agents are better than existing drugs; the possibility of conflicting actions if mixed A/B antagonists are used; and animal evidence hinting that endothelin blockade during development could be dangerous.

  2. Anticancer potential of pyrrole (1, 2, a) pyrazine 1, 4, dione, hexahydro 3-(2-methyl propyl) (PPDHMP) extracted from a new marine bacterium, Staphylococcus sp. strain MB30.

    PubMed

    Lalitha, P; Veena, V; Vidhyapriya, P; Lakshmi, Pragna; Krishna, R; Sakthivel, N

    2016-05-01

    Marine bacterium, strain MB30 isolated from the deep sea sediment of Bay of Bengal, India, exhibited antimicrobial activity against human pathogenic bacteria. Based on the 16S rRNA sequence homology and subsequent phylogenetic tree analysis, the strain MB30 was identified as Staphylococcus sp. The bioactive metabolite produced by the strain MB30 was purified through silica gel column chromatography and preparative HPLC. Purified metabolite was further characterized by FT-IR, LC-MS and NMR analyses. On the basis of spectroscopic data, the metabolite was identified as pyrrole (1, 2, a) pyrazine 1, 4, dione, hexahydro 3-(2-methyl propyl) (PPDHMP). The PPDHMP exhibited in vitro anticancer potential against lung (A549) and cervical (HeLa) cancer cells in a dose-dependent manner with the IC50 concentration of 19.94 ± 1.23 and 16.73 ± 1.78 μg ml(-1) respectively. The acridine orange (AO)/ethidium bromide (EB) and 4,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining of the IC50 concentration of PPDHMP-treated cancer cells exhibited an array of morphological changes such as nuclear condensation, cell shrinkage and formation of apoptotic bodies. The PPDHMP-treated cancer cells induced the progressive accumulation of fragmented DNA in a time-dependent manner. Based on the flow cytometric analysis, it has become evident that the compound was also effective in arresting the cell cycle at G1 phase. Further, the Western blotting analysis confirmed the down-regulation of cyclin-D1, cyclin dependent kinase (CDK-2), anti-apoptotic Bcl-2 family proteins (Bcl-2 and Bcl-xL), activation of caspase-9 and 3 with the cleavage of PARP. The PPDHMP-treated cancer cells also showed the inhibition of migration and invasive capacity of cancer cells. In the present investigation, for the first time, we have reported the extraction, purification and characterization of an anticancer metabolite, PPDHMP from a new marine bacterium, Staphylococcus sp. strain MB30. PMID:26852140

  3. Fed-batch cultivation of the marine bacterium Sulfitobacter pontiacus using immobilized substrate and purification of sulfite oxidase by application of membrane adsorber technology.

    PubMed

    Muffler, Kai; Ulber, Roland

    2008-03-01

    Sulfitobacter pontiacus, a gram-negative heterotrophic bacterium isolated from the Black Sea is well known to produce a soluble AMP-independent sulfite oxidase (sulfite: acceptor oxidoreductase) of high activity. Such an enzyme can be of great help in establishing biosensor systems for detection of sulfite in food and beverages considering the high sensitivity of biosensors and the increasing demand for such biosensor devices. For obtaining efficient amounts of the enzyme, an induction of its biosynthesis by supplementing sufficient concentrations of sodium sulfite to the fermentation broth is required. Owing to the fact that a high initial concentration of sodium sulfite decreases dramatically the enzyme expression, different fed-batch strategies can be applied to circumvent such inhibition or repression of the enzyme respectively. By the use of sulfite species immobilized in polyvinyl alcohol gels, an approach to the controlled and continuous feeding of sulfite to the cultivation media could be established to diminish inhibitory concentrations. Furthermore, the purification of the enzyme is described by using membrane adsorber technology.

  4. Genome sequence of Phaeobacter daeponensis type strain (DSM 23529T), a facultatively anaerobic bacterium isolated from marine sediment, and emendation of Phaeobacter daeponensis

    PubMed Central

    Dogs, Marco; Teshima, Hazuki; Petersen, Jörn; Fiebig, Anne; Chertkov, Olga; Dalingault, Hajnalka; Chen, Amy; Pati, Amrita; Goodwin, Lynne A.; Chain, Patrick; Detter, John C.; Ivanova, Natalia; Lapidus, Alla; Rohde, Manfred; Gronow, Sabine; Kyrpides, Nikos C.; Woyke, Tanja; Simon, Meinhard; Göker, Markus; Klenk, Hans-Peter; Brinkhoff, Thorsten

    2013-01-01

    TF-218T is the type strain of the species Phaeobacter daeponensis Yoon et al. 2007, a facultatively anaerobic Phaeobacter species isolated from tidal flats. Here we describe the draft genome sequence and annotation of this bacterium together with previously unreported aspects of its phenotype. We analyzed the genome for genes involved in secondary metabolite production and its anaerobic lifestyle, which have also been described for its closest relative Phaeobacter caeruleus. The 4,642,596 bp long genome of strain TF-218T contains 4,310 protein-coding genes and 78 RNA genes including four rRNA operons and consists of five replicons: one chromosome and four extrachromosomal elements with sizes of 276 kb, 174 kb, 117 kb and 90 kb. Genome analysis showed that TF-218T possesses all of the genes for indigoidine biosynthesis, and on specific media the strain showed a blue pigmentation. We also found genes for dissimilatory nitrate reduction, gene-transfer agents, NRPS/ PKS genes and signaling systems homologous to the LuxR/I system. PMID:24501652

  5. Analysis of defence systems and a conjugative IncP-1 plasmid in the marine polyaromatic hydrocarbons-degrading bacterium Cycloclasticus sp. 78-ME.

    PubMed

    Yakimov, Michail M; Crisafi, Francesca; Messina, Enzo; Smedile, Francesco; Lopatina, Anna; Denaro, Renata; Pieper, Dietmar H; Golyshin, Peter N; Giuliano, Laura

    2016-08-01

    Marine prokaryotes have evolved a broad repertoire of defence systems to protect their genomes from lateral gene transfer including innate or acquired immune systems and infection-induced programmed cell suicide and dormancy. Here we report on the analysis of multiple defence systems present in the genome of the strain Cycloclasticus sp. 78-ME isolated from petroleum deposits of the tanker 'Amoco Milford Haven'. Cycloclasticus are ubiquitous bacteria globally important in polyaromatic hydrocarbons degradation in marine environments. Two 'defence islands' were identified in 78-ME genome: the first harbouring CRISPR-Cas with toxin-antitoxin system, while the second was composed by an array of genes for toxin-antitoxin and restriction-modification proteins. Among all identified spacers of CRISPR-Cas system only seven spacers match sequences of phages and plasmids. Furthermore, a conjugative plasmid p7ME01, which belongs to a new IncP-1θ ancestral archetype without any accessory mobile elements was found in 78-ME. Our results provide the context to the co-occurrence of diverse defence mechanisms in the genome of Cycloclasticus sp. 78-ME, which protect the genome of this highly specialized PAH-degrader. This study contributes to the further understanding of complex networks established in petroleum-based microbial communities. PMID:27345842

  6. Isolation and characterization of a thermophilic, obligately anaerobic and heterotrophic marine Chloroflexi bacterium from a Chloroflexi-dominated microbial community associated with a Japanese shallow hydrothermal system, and proposal for Thermomarinilinea lacunofontalis gen. nov., sp. nov.

    PubMed

    Nunoura, Takuro; Hirai, Miho; Miyazaki, Masayuki; Kazama, Hiromi; Makita, Hiroko; Hirayama, Hisako; Furushima, Yasuo; Yamamoto, Hiroyuki; Imachi, Hiroyuki; Takai, Ken

    2013-01-01

    A novel marine thermophilic and heterotrophic Anaerolineae bacterium in the phylum Chloroflexi, strain SW7(T), was isolated from an in situ colonization system deployed in the main hydrothermal vent of the Taketomi submarine hot spring field located on the southern part of Yaeyama Archipelago, Japan. The microbial community associated with the hydrothermal vent was predominated by thermophilic heterotrophs such as Thermococcaceae and Anaerolineae, and the next dominant population was thermophilic sulfur oxidizers. Both aerobic and anaerobic hydrogenotrophs including methanogens were detected as minor populations. During the culture-dependent viable count analysis in this study, an Anaerolineae strain SW7(T) was isolated from an enrichment culture at a high dilution rate. Strain SW7(T) was an obligately anaerobic heterotroph that grew with fermentation and had non-motile thin rods 3.5-16.5 μm in length and 0.2 μm in width constituting multicellular filaments. Growth was observed between 37-65°C (optimum 60°C), pH 5.5-7.3 (optimum pH 6.0), and 0.5-3.5% (w/v) NaCl concentration (optimum 1.0%). Based on the physiological and phylogenetic features of a new isolate, we propose a new species representing a novel genus Thermomarinilinea: the type strain of Thermomarinilinea lacunofontalis sp. nov., is SW7(T) (=JCM15506(T)=KCTC5908(T)). PMID:23666537

  7. Complete genome, catabolic sub-proteomes and key-metabolites of Desulfobacula toluolica Tol2, a marine, aromatic compound-degrading, sulfate-reducing bacterium.

    PubMed

    Wöhlbrand, Lars; Jacob, Jacob H; Kube, Michael; Mussmann, Marc; Jarling, René; Beck, Alfred; Amann, Rudolf; Wilkes, Heinz; Reinhardt, Richard; Rabus, Ralf

    2013-05-01

    Among the dominant deltaproteobacterial sulfate-reducing bacteria (SRB), members of the genus Desulfobacula are not only present in (hydrocarbon-rich) marine sediments, but occur also frequently in the anoxic water bodies encountered in marine upwelling areas. Here, we present the 5.2 Mbp genome of Desulfobacula toluolica Tol2, which is the first of an aromatic compound-degrading, marine SRB. The genome has apparently been shaped by viral attacks (e.g. CRISPRs) and its high plasticity is reflected by 163 detected genes related to transposases and integrases, a total of 494 paralogous genes and 24 group II introns. Prediction of the catabolic network of strain Tol2 was refined by differential proteome and metabolite analysis of substrate-adapted cells. Toluene and p-cresol are degraded by separate suites of specific enzymes for initial arylsuccinate formation via addition to fumarate (p-cresol-specific enzyme HbsA represents a new phylogenetic branch) as well as for subsequent modified β-oxidation of arylsuccinates to the central intermediate benzoyl-CoA. Proteogenomic evidence suggests specific electron transfer (EtfAB) and membrane proteins to channel electrons from dehydrogenation of both arylsuccinates directly to the membrane redox pool. In contrast to the known anaerobic degradation pathways in other bacteria, strain Tol2 deaminates phenylalanine non-oxidatively to cinnamate by phenylalanine ammonia-lyase and subsequently forms phenylacetate (both metabolites identified in (13) C-labelling experiments). Benzoate degradation involves CoA activation, reductive dearomatization by a class II benzoyl-CoA reductase and hydrolytic ring cleavage as found in the obligate anaerobe Geobacter metallireducens GS-15. The catabolic sub-proteomes displayed high substrate specificity, reflecting the genomically predicted complex and fine-tuned regulatory network of strain Tol2. Despite the genetic equipment for a TCA cycle, proteomic evidence supports complete oxidation of

  8. A marine inducible prophage vB_CibM-P1 isolated from the aerobic anoxygenic phototrophic bacterium Citromicrobium bathyomarinum JL354

    NASA Astrophysics Data System (ADS)

    Zheng, Qiang; Zhang, Rui; Xu, Yongle; , Richard Allen White, III; Wang, Yu; Luo, Tingwei; Jiao, Nianzhi

    2014-11-01

    A prophage vB_CibM-P1 was induced by mitomycin C from the epipelagic strain Citromicrobium bathyomarinum JL354, a member of the alpha-IV subcluster of marine aerobic anoxygenic phototrophic bacteria (AAPB). The induced bacteriophage vB_CibM-P1 had Myoviridae-like morphology and polyhedral heads (approximately capsid 60-100 nm) with tail fibers. The vB_CibM-P1 genome is ~38 kb in size, with 66.0% GC content. The genome contains 58 proposed open reading frames that are involved in integration, DNA packaging, morphogenesis and bacterial lysis. VB_CibM-P1 is a temperate phage that can be directly induced in hosts. In response to mitomycin C induction, virus-like particles can increase to 7 × 109 per ml, while host cells decrease an order of magnitude. The vB_CibM-P1 bacteriophage is the first inducible prophage from AAPB.

  9. Leuconostoc gasicomitatum is the dominating lactic acid bacterium in retail modified-atmosphere-packaged marinated broiler meat strips on sell-by-day.

    PubMed

    Susiluoto, Tuija; Korkeala, Hannu; Björkroth, K Johanna

    2003-01-15

    Lactic acid bacteria (LAB) in retail, modified-atmosphere-packaged (MAP), marinated broiler meat strips on sell-by-day were mainly identified as Leuconostoc gasicomitatum. A total of 32 packages, three to five packages of seven differently marinated broiler meat products, were studied at the end of the producer-defined shelf life (at 6 degrees C, 7-9 days depending on the manufacturer). Prior to the microbiological analyses, appearance and smell of the product was checked and pH measured. Bacteria were cultured on MRS and Tomato Juice Agar (TJA), Rogosa SL agar (SLA), Plate Count Agar (PCA) and Streptomycin Thallium Acetate Agar (STAA) for the enumeration of LAB, lactobacilli, total bacterial count and Brochothrix thermosphacta, respectively. The average CFU/g of the 32 packages was 2.3 x 10(8) on PCA. The highest bacterial average, 3.1 x 10(8), was recovered on TJA, the corresponding CFU/g averages on MRS and SLA being 2.3 x 10(8) and 1.3 x 10(8), respectively. Despite the high LAB numbers detected, radical spoilage changes such as unpleasant odor, slime production and formation of gas were not seen. B. thermosphacta did not form a significant part of the bacterial population since none of the levels exceeded the spoilage threshold level of 10(5) CFU/g reported in previous studies for this organism. In order to characterize the dominating LAB population, as many as 85, 85 and 88 colonies from MRS, TJA and SLA, respectively, were randomly picked and cultured pure. LAB were identified to species level using a 16 and 23S rDNA HindIiI RFLP (ribotyping) database. Fifty-six of the 170 isolates picked from the non-selective LAB media (MRS and TJA) were identified as L. gasicomitatum, followed by Carnobacterium divergens (41 isolates), Lactobacillus sakei and Lactobacillus curvatus subsp. melibiosus (31 isolates) and L. curvatus subsp. curvatus (20 isolates) species. SLA proved not to be completely selective for lactobacilli because the growth of Leuconostoc spp. was not

  10. Gageopeptins A and B, new inhibitors of zoospore motility of the phytopathogen Phytophthora capsici from a marine-derived bacterium Bacillus sp. 109GGC020.

    PubMed

    Tareq, Fakir Shahidullah; Hasan, Choudhury M; Lee, Hyi-Seung; Lee, Yeon-Ju; Lee, Jong Seok; Surovy, Musrat Zahan; Islam, Md Tofazzal; Shin, Hee Jae

    2015-08-15

    The motility of zoospores is critical in the disease cycles of the peronosporomycetes that cause devastating diseases in plants, fishes, vertebrates, and microbes. In the course of screening for secondary metabolites regulating the motility of zoospores of Phytophthora capsici, we discovered two new inhibitors from the ethyl acetate extract of the fermentation broth of a marine-derived strain Bacillus sp. 109GGC020. The structures of these novel metabolites were elucidated as new cyclic lipopeptides and named gageopeptins A (1) and B (2) by spectroscopic analyses including high resolution MS and extensive 1D and 2D NMR. The stereoconfigurations of 1 and 2 were assigned based on the chemical derivatization studies and reviews of the literature data. Although compounds 1 and 2 impaired the motility of zoospores of P. capsici in dose- and time-dependent manners, compound 1 (IC50 = 1 μg/ml) was an approximately 400-fold stronger motility inhibitor than 2 (IC50 = 400 μg/ml). Interestingly, the zoospores halted by compound 1 were subsequently lysed at higher concentrations (IC50 = 50 μg/ml). Compounds 1 and 2 were also tested against some bacteria and fungi by broth dilution assay, and exhibited moderate antibacterial and good antifungal activities.

  11. Halotolerant, acid-alkali stable, chelator resistant and raw starch digesting α-amylase from a marine bacterium Bacillus subtilis S8-18.

    PubMed

    Kalpana, Balu Jancy; Pandian, Shunmugiah Karutha

    2014-08-01

    A halotolerant α-amylase having the ability of digesting the insoluble raw starches was characterized from Bacillus subtilis S8-18, a marine sediment isolate from Palk Bay region. The electrophoresis techniques unveiled that the α-amylase was indeed a monomer with a molecular weight of 57 kDa. The optimum temperature and pH for the enzyme activity were 60 °C and 6.0 respectively. The enzyme was highly stable for 24 h over a wide range of pH from 4.0 to 12.0 by showing 84-94% activity. Interestingly, by retaining 72% activity even after 24 h, the enzyme also showed tolerance towards 28% NaCl. The α-amylase retained a minimum of 93% residual activity in 1 mM concentration for the selected divalent metal ions. The enzyme was found to be chelator resistant as it remained unaffected by 1 mM of EDTA and exhibited 96% activity even at 5 mM concentration. Furthermore, though 1% SDS caused remarkable reduction (68%) in amylase activity, the enzyme showed tolerance towards other detergents (1% of Triton-X and Tween 80) with 85% activity. Additionally, the α-amylase enzyme is capable of hydrolyzing the insoluble raw starch substrates which was evident from the scanning electron microscopic (SEM) and spectrophotometric analyses.

  12. Cyclobacterium lianum sp. nov., a marine bacterium isolated from sediment of an oilfield in the South China Sea, and emended description of the genus Cyclobacterium.

    PubMed

    Ying, Jiao-Yan; Wang, Bao-Jun; Yang, Su-Sheng; Liu, Shuang-Jiang

    2006-12-01

    The marine bacterial strain HY9(T) was isolated from sediment from the South China Sea. Strain HY9(T) is aerobic, heterotrophic and rose-pigmented. The cells are non-motile and curved, i.e. ring-like or horseshoe-shaped. The 16S rRNA gene sequence of strain HY9(T) was determined and blast searches revealed that it possessed significant sequence similarities with respect to Cyclobacterium species (92.8-93.6 %). Phylogenetic analysis confirmed that strain HY9(T) was tightly clustered with members of the genus Cyclobacterium. The cellular morphology and chemotaxonomic and phenotypic properties of strain HY9(T) showed that it should be classified as a member of the genus Cyclobacterium. Significant evolutionary distances and a range of phenotypic features distinguished strain HY9(T) from previously described Cyclobacterium species. Hence, strain HY9(T) represents a novel species in the genus Cyclobacterium, for which the name Cyclobacterium lianum sp. nov. is proposed. The type strain is HY9(T) (=CGMCC 1.6102(T)=JCM 14011(T)). On the basis of this study and previously described properties of Cyclobacterium species, an emended description of the genus Cyclobacterium is proposed.

  13. Exceptional production of both prodigiosin and cycloprodigiosin as major metabolic constituents by a novel marine bacterium, Zooshikella rubidus S1-1.

    PubMed

    Lee, Jong Suk; Kim, Yong-Sook; Park, Sooyeon; Kim, Jihoon; Kang, So-Jung; Lee, Mi-Hwa; Ryu, Sangryeol; Choi, Jong Myoung; Oh, Tae-Kwang; Yoon, Jung-Hoon

    2011-07-01

    A Gram-negative, red-pigment-producing marine bacterial strain, designated S1-1, was isolated from the tidal flat sediment of the Yellow Sea, Korea. On the basis of phenotypic, phylogenetic, and genetic data, strain S1-1 (KCTC 11448BP) represented a new species of the genus Zooshikella. Thus, we propose the name Zooshikella rubidus sp. nov. Liquid chromatography and mass spectrometry of the red pigments produced by strain S1-1 revealed that the major metabolic compounds were prodigiosin and cycloprodigiosin. In addition, this organism produced six minor prodigiosin analogues, including two new structures that were previously unknown. To our knowledge, this is the first description of a microorganism that simultaneously produces prodigiosin and cycloprodigiosin as two major metabolites. Both prodigiosin and cycloprodigiosin showed antimicrobial activity against several microbial species. These bacteria were approximately 1.5-fold more sensitive to cycloprodigiosin than to prodigiosin. The metabolites also showed anticancer activity against human melanoma cells, which showed significantly more sensitivity to prodigiosin than to cycloprodigiosin. The secondary metabolite profiles of strain S1-1 and two reference bacterial strains were compared by liquid chromatography-mass spectrometry. Multivariate statistical analyses based on secondary metabolite profiles by liquid chromatography-mass spectrometry indicated that the metabolite profile of strain S1-1 could clearly be distinguished from those of two phylogenetically related, prodigiosin-producing bacterial strains.

  14. Ochrovirga pacifica gen. nov., sp. nov., a novel agar-lytic marine bacterium of the family Flavobacteriaceae isolated from a seaweed.

    PubMed

    Kwon, Young-Kyung; Kim, Ji Hyung; Kim, Jennifer Jooyoun; Yang, Sung-Hyun; Ye, Bo-Ram; Heo, Soo-Jin; Hyun, Jung-Ho; Qian, Zhong-Ji; Park, Heung-Sik; Kang, Do-Hyung; Oh, Chulhong

    2014-10-01

    A strain designated as S85(T) was isolated from a seaweed collected from coastal area of Chuuk State in Micronesia. The strain was gram-negative, rod-shaped, and non-motile and formed yellow colonies on the SWY agar (0.2 % yeast extract and 1.5 % agar in seawater) and Marine agar 2216. The strain grew at pH 5-9 (optimum, pH 8), at 15-40 °C (optimum, 25-28 °C), and with 1-9 % (w/v) NaCl (optimum, 3 %). The phylogenetic analysis based on 16S rRNA gene sequence showed that strain S85(T) was related to Lutibacter litoralis CL-TF09(T) and Maritimimonas rapanae A31(T) with 91.4 % and with 90.5 % similarity, respectively. The dominant fatty acids were iso-C15:0, iso-C15:0 3-OH and iso-C17:0 3-OH, C16:0 3-OH and summed feature 3 (C16:1 ω7c and/or iso-C15:0 2-OH). The major isoprenoid quinone was MK-6. The DNA G+C content of the type strain was 34.6 mol %. The major polar lipids were phosphatidylethanolamine, an unknown glycolipid and two unknown polar lipids. Based on this polyphasic taxonomic data, strain S85(T) stands for a novel species of a new genus, and we propose the name Ochrovirga pacifica gen. nov., sp. nov. The type strain of O. pacifica is S85(T) (=KCCM 90106 =JCM 18327(T)).

  15. Substrate Recognition and Hydrolysis by a Family 50 exo-β-Agarase, Aga50D, from the Marine Bacterium Saccharophagus degradans*

    PubMed Central

    Pluvinage, Benjamin; Hehemann, Jan-Hendrik; Boraston, Alisdair B.

    2013-01-01

    The bacteria that metabolize agarose use multiple enzymes of complementary specificities to hydrolyze the glycosidic linkages in agarose, a linear polymer comprising the repeating disaccharide subunit of neoagarobiose (3,6-anhydro-l-galactose-α-(1,3)-d-galactose) that are β-(1,4)-linked. Here we present the crystal structure of a glycoside hydrolase family 50 exo-β-agarase, Aga50D, from the marine microbe Saccharophagus degradans. This enzyme catalyzes a critical step in the metabolism of agarose by S. degradans through cleaving agarose oligomers into neoagarobiose products that can be further processed into monomers. The crystal structure of Aga50D to 1.9 Å resolution reveals a (β/α)8-barrel fold that is elaborated with a β-sandwich domain and extensive loops. The structures of catalytically inactivated Aga50D in complex with non-hydrolyzed neoagarotetraose (2.05 Å resolution) and neoagarooctaose (2.30 Å resolution) provide views of Michaelis complexes for a β-agarase. In these structures, the d-galactose residue in the −1 subsite is distorted into a 1S3 skew boat conformation. The relative positioning of the putative catalytic residues are most consistent with a retaining catalytic mechanism. Additionally, the neoagarooctaose complex showed that this extended substrate made substantial interactions with the β-sandwich domain, which resembles a carbohydrate-binding module, thus creating additional plus (+) subsites and funneling the polymeric substrate through the tunnel-shaped active site. A synthesis of these results in combination with an additional neoagarobiose product complex suggests a potential exo-processive mode of action of Aga50D on the agarose double helix. PMID:23921382

  16. Discovery and Characterization of a Distinctive Exo-1,3/1,4-β-Glucanase from the Marine Bacterium Pseudoalteromonas sp. Strain BB1▿ †

    PubMed Central

    Nakatani, Yoshio; Lamont, Iain L.; Cutfield, John F.

    2010-01-01

    Marine bacteria residing on local red, green, and brown seaweeds were screened for exo-1,3-β-glucanase (ExoP) activity. Of the 90 bacterial species isolated from 32 seaweeds, only one, a Pseudoalteromonas sp., was found to display such activity. It was isolated from a Durvillaea sp., a brown kelp known to contain significant amounts of the storage polysaccharide laminarin (1,3-β-d-glucan with some 1,6-β branching). Four chromatographic steps were utilized to purify the enzyme (ExoP). Chymotryptic digestion provided peptide sequences for primer design and subsequent gene cloning. The exoP gene coded for 840 amino acids and was located just 50 bp downstream from a putative lichenase (endo-1,3-1,4-β-glucanase) gene, suggesting possible cotranscription of these genes. Sequence comparisons revealed ExoP to be clustered within a group of bacterial glycosidases with high similarity to a group of glycoside hydrolase (GH3) plant enzymes, of which the barley exo-1,3/1,4-β-glucanase (ExoI) is the best characterized. The major difference between the bacterial and plant proteins is an extra 200- to 220-amino-acid extension at the C terminus of the former. This additional sequence does not correlate with any known functional domain, but ExoP was not active against laminarin when this region was removed. Production of recombinant ExoP allowed substrate specificity studies to be performed. The enzyme was found to possess similar levels of exoglucanase activity against both 1,4-β linkages and 1,3-β linkages, and so ExoP is designated an exo-1,3/1,4-β-exoglucanase, the first such bacterial enzyme to be characterized. This broader specificity could allow the enzyme to assist in digesting both cell wall cellulose and cytoplasmic laminarin. PMID:20729316

  17. Dethiosulfatibacter aminovorans gen. nov., sp. nov., a novel thiosulfate-reducing bacterium isolated from coastal marine sediment via sulfate-reducing enrichment with Casamino acids.

    PubMed

    Takii, Susumu; Hanada, Satoshi; Tamaki, Hideyuki; Ueno, Yutaka; Sekiguchi, Yuji; Ibe, Akihiro; Matsuura, Katsumi

    2007-10-01

    A sulfate-reducing enrichment culture originating from coastal marine sediment of the eutrophic Tokyo Bay, Japan, was successfully established with Casamino acids as a substrate. A thiosulfate reducer, strain C/G2(T), was isolated from the enrichment culture after further enrichment with glutamate. Cells of strain C/G2(T) were non-motile rods (0.6-0.8 microm x 2.2-4.8 microm) and were found singly or in pairs and sometimes in short chains. Spores were not formed. Cells of strain C/G2(T) stained Gram-negatively, despite possessing Gram-positive cell walls. The optimum temperature for growth was 28-30 degrees C, the optimum pH was around 7.8 and the optimum salt concentration was 20-30 g l(-1). Lactate, pyruvate, serine, cysteine, threonine, glutamate, histidine, lysine, arginine, Casamino acids, peptone and yeast extract were fermented as single substrates and no sugar was used as a fermentative substrate. A Stickland reaction was observed with some pairs of amino acids. Fumarate, alanine, proline, phenylalanine, tryptophan, glutamine and aspartate were utilized only in the presence of thiosulfate. Strain C/G2(T) fermented glutamate to H2, CO2, acetate and propionate. Thiosulfate and elemental sulfur were reduced to sulfide. Sulfate, sulfite and nitrate were not utilized as electron acceptors. The growth of strain C/G2(T) on Casamino acids or glutamate was enhanced by co-culturing with Desulfovibrio sp. isolated from the original mixed culture enriched with Casamino acids. The DNA G+C content of strain C/G2(T) was 41.0 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain C/G2(T) formed a distinct cluster with species of the genus Sedimentibacter. The closest relative was Sedimentibacter hydroxybenzoicus (with a gene sequence similarity of 91 %). On the basis of its phylogenetic and phenotypic properties, strain C/G2(T) (=JCM 13356(T)=NBRC 101112(T)=DSM 17477(T)) is proposed as representing a new genus and novel species, Dethiosulfatibacter

  18. Aii20J, a wide-spectrum thermostable N-acylhomoserine lactonase from the marine bacterium Tenacibaculum sp. 20J, can quench AHL-mediated acid resistance in Escherichia coli.

    PubMed

    Mayer, C; Romero, M; Muras, A; Otero, A

    2015-11-01

    Acyl homoserine lactones (AHLs) are produced by many Gram-negative bacteria to coordinate gene expression in cellular density dependent mechanisms known as quorum sensing (QS). Since the disruption of the communication systems significantly reduces virulence, the inhibition of quorumsensing processes or quorum quenching (QQ) represents an interesting anti-pathogenic strategy to control bacterial infections. Escherichia coli does not produce AHLs but possesses an orphan AHL receptor, SdiA, which is thought to be able to sense the QS signals produced by other bacteria and controls important traits as the expression of glutamate-dependent acid resistance mechanism, therefore constituting a putative target for QQ. A novel AHL-lactonase, named Aii20J, has been identified, cloned and over expressed from the marine bacterium Tenacibaculum sp. strain 20 J presenting a wide-spectrum QQ activity. The enzyme, belonging to the metallo-β-lactamase family, shares less than 31 % identity with the lactonase AiiA from Bacillus spp. Aii20J presents a much higher specific activity than the Bacillus enzyme, maintains its activity after incubation at 100 ºC for 10 minutes, is resistant to protease K and α-chymotrypsin, and is unaffected by wide ranges of pH. The addition of Aii20J (20 μg/mL) to cultures of E. coli K-12 to which OC6-HSL was added resulted in a significant reduction in cell viability in comparison with the acidresistant cultures derived from the presence of the signal. Results confirm the interaction between AHLs and SdiA in E. coli for the expression of virulence-related genes and reveal the potential use of Aii20J as anti-virulence strategy against important bacterial pathogens and in other biotechnological applications.

  19. Aii20J, a wide-spectrum thermostable N-acylhomoserine lactonase from the marine bacterium Tenacibaculum sp. 20J, can quench AHL-mediated acid resistance in Escherichia coli.

    PubMed

    Mayer, C; Romero, M; Muras, A; Otero, A

    2015-11-01

    Acyl homoserine lactones (AHLs) are produced by many Gram-negative bacteria to coordinate gene expression in cellular density dependent mechanisms known as quorum sensing (QS). Since the disruption of the communication systems significantly reduces virulence, the inhibition of quorumsensing processes or quorum quenching (QQ) represents an interesting anti-pathogenic strategy to control bacterial infections. Escherichia coli does not produce AHLs but possesses an orphan AHL receptor, SdiA, which is thought to be able to sense the QS signals produced by other bacteria and controls important traits as the expression of glutamate-dependent acid resistance mechanism, therefore constituting a putative target for QQ. A novel AHL-lactonase, named Aii20J, has been identified, cloned and over expressed from the marine bacterium Tenacibaculum sp. strain 20 J presenting a wide-spectrum QQ activity. The enzyme, belonging to the metallo-β-lactamase family, shares less than 31 % identity with the lactonase AiiA from Bacillus spp. Aii20J presents a much higher specific activity than the Bacillus enzyme, maintains its activity after incubation at 100 ºC for 10 minutes, is resistant to protease K and α-chymotrypsin, and is unaffected by wide ranges of pH. The addition of Aii20J (20 μg/mL) to cultures of E. coli K-12 to which OC6-HSL was added resulted in a significant reduction in cell viability in comparison with the acidresistant cultures derived from the presence of the signal. Results confirm the interaction between AHLs and SdiA in E. coli for the expression of virulence-related genes and reveal the potential use of Aii20J as anti-virulence strategy against important bacterial pathogens and in other biotechnological applications. PMID:26092757

  20. ACTH Antagonists.

    PubMed

    Clark, Adrian John; Forfar, Rachel; Hussain, Mashal; Jerman, Jeff; McIver, Ed; Taylor, Debra; Chan, Li

    2016-01-01

    Adrenocorticotropin (ACTH) acts via a highly selective receptor that is a member of the melanocortin receptor subfamily of type 1 G protein-coupled receptors. The ACTH receptor, also known as the melanocortin 2 receptor (MC2R), is unusual in that it is absolutely dependent on a small accessory protein, melanocortin receptor accessory protein (MRAP) for cell surface expression and function. ACTH is the only known naturally occurring agonist for this receptor. This lack of redundancy and high degree of ligand specificity suggests that antagonism of this receptor could provide a useful therapeutic aid and a potential investigational tool. Clinical situations in which this could be useful include (1) Cushing's disease and ectopic ACTH syndrome - especially while preparing for definitive treatment of a causative tumor, or in refractory cases, or (2) congenital adrenal hyperplasia - as an adjunct to glucocorticoid replacement. A case for antagonism in other clinical situations in which there is ACTH excess can also be made. In this article, we will explore the scientific and clinical case for an ACTH antagonist, and will review the evidence for existing and recently described peptides and modified peptides in this role. PMID:27547198

  1. ACTH Antagonists

    PubMed Central

    Clark, Adrian John; Forfar, Rachel; Hussain, Mashal; Jerman, Jeff; McIver, Ed; Taylor, Debra; Chan, Li

    2016-01-01

    Adrenocorticotropin (ACTH) acts via a highly selective receptor that is a member of the melanocortin receptor subfamily of type 1 G protein-coupled receptors. The ACTH receptor, also known as the melanocortin 2 receptor (MC2R), is unusual in that it is absolutely dependent on a small accessory protein, melanocortin receptor accessory protein (MRAP) for cell surface expression and function. ACTH is the only known naturally occurring agonist for this receptor. This lack of redundancy and high degree of ligand specificity suggests that antagonism of this receptor could provide a useful therapeutic aid and a potential investigational tool. Clinical situations in which this could be useful include (1) Cushing’s disease and ectopic ACTH syndrome – especially while preparing for definitive treatment of a causative tumor, or in refractory cases, or (2) congenital adrenal hyperplasia – as an adjunct to glucocorticoid replacement. A case for antagonism in other clinical situations in which there is ACTH excess can also be made. In this article, we will explore the scientific and clinical case for an ACTH antagonist, and will review the evidence for existing and recently described peptides and modified peptides in this role. PMID:27547198

  2. Random antagonistic matrices

    NASA Astrophysics Data System (ADS)

    Cicuta, Giovanni M.; Molinari, Luca Guido

    2016-09-01

    The ensemble of antagonistic matrices is introduced and studied. In antagonistic matrices the entries {{ A }}i,j and {{ A }}j,i are real and have opposite signs, or are both zero, and the diagonal is zero. This generalization of antisymmetric matrices is suggested by the linearized dynamics of competitive species in ecology.

  3. Leukotriene receptor antagonist therapy

    PubMed Central

    Dempsey, O

    2000-01-01

    Leukotriene receptor antagonists (LTRA) are a new class of drugs for asthma treatment, available in tablet form. Their unique mechanism of action results in a combination of both bronchodilator and anti-inflammatory effects. While their optimal place in asthma management is still under review, LTRA represent an important advance in asthma pharmacotherapy.


Keywords: leukotriene receptor antagonist; asthma; montelukast; zafirlukast PMID:11085767

  4. Ago-Antagonistic Systems

    NASA Astrophysics Data System (ADS)

    Bernard-Weil, Élie

    Today, bio-medical sciences and human sciences in general are demanding some new epistemological paradigms, in the same manner that quantum physics began to proceed to a renewal of this kind eighteen years ago. Such paradigms seem to be connected with systems science, and especially a special branch of it, called agonistic-antagonistic systemics (AAS), combining co-operativity and conflict between two poles. AAS is under the necessity of considering, at the same time, both sides of whatever phenomenon—which may appear as contradictory, opposite or only different—and, finally, of taking into account the unity to which both sides belong. The dynamics study of the behavior of these couples, or of the so-called agonistic-antagonistic networks, allows to better understand the occurrence of amazing phenomena, as well as to consider special types of control, when agonistic antagonistic unbalances have occurred.

  5. Vasopressin receptor antagonists.

    PubMed

    Palmer, Biff F

    2015-01-01

    Arginine vasopressin (AVP) is the principal hormone involved in regulating the tonicity of body fluids. Less appreciated is the role that AVP plays in a variety of other physiologic functions including glucose metabolism, cardiovascular homeostasis, bone metabolism, and cognitive behavior. AVP receptor antagonists are now available and currently approved to treat hyponatremia. There is a great deal of interest in exploring the potential benefits that these drugs may play in blocking AVP-mediated effects in other organ systems. The purpose of this report is to provide an update on the expanding role of AVP receptor antagonists and what disease states these drugs may eventually be used for.

  6. Vasopressin receptor antagonists.

    PubMed

    Palmer, Biff F

    2015-01-01

    Arginine vasopressin (AVP) is the principal hormone involved in regulating the tonicity of body fluids. Less appreciated is the role that AVP plays in a variety of other physiologic functions including glucose metabolism, cardiovascular homeostasis, bone metabolism, and cognitive behavior. AVP receptor antagonists are now available and currently approved to treat hyponatremia. There is a great deal of interest in exploring the potential benefits that these drugs may play in blocking AVP-mediated effects in other organ systems. The purpose of this report is to provide an update on the expanding role of AVP receptor antagonists and what disease states these drugs may eventually be used for. PMID:25604388

  7. Opioid Antagonist Impedes Exposure.

    ERIC Educational Resources Information Center

    Merluzzi, Thomas V.; And Others

    1991-01-01

    Thirty spider-phobic adults underwent exposure to 17 phobic-related, graded performance tests. Fifteen subjects were assigned to naltrexone, an opioid antagonist, and 15 were assigned to placebo. Naltrexone had a significant effect on exposure, with naltrexone subjects taking significantly longer to complete first 10 steps of exposure and with…

  8. Novel Alginate Lyase (Aly5) from a Polysaccharide-Degrading Marine Bacterium, Flammeovirga sp. Strain MY04: Effects of Module Truncation on Biochemical Characteristics, Alginate Degradation Patterns, and Oligosaccharide-Yielding Properties

    PubMed Central

    Han, Wenjun; Gu, Jingyan; Cheng, Yuanyuan; Liu, Huihui; Li, Yuezhong

    2015-01-01

    Alginate lyases are important tools for oligosaccharide preparation, medical treatment, and energy bioconversion. Numerous alginate lyases have been elucidated. However, relatively little is known about their substrate degradation patterns and product-yielding properties, which is a limit to wider enzymatic applications and further enzyme improvements. Herein, we report the characterization and module truncation of Aly5, the first alginate lyase obtained from the polysaccharide-degrading bacterium Flammeovirga. Aly5 is a 566-amino-acid protein and belongs to a novel branch of the polysaccharide lyase 7 (PL7) superfamily. The protein rAly5 is an endolytic enzyme of alginate and associated oligosaccharides. It prefers guluronate (G) to mannuronate (M). Its smallest substrate is an unsaturated pentasaccharide, and its minimum product is an unsaturated disaccharide. The final alginate digests contain unsaturated oligosaccharides that generally range from disaccharides to heptasaccharides, with the tetrasaccharide fraction constituting the highest mass concentration. The disaccharide products are identified as ΔG units. While interestingly, the tri- and tetrasaccharide fractions each contain higher proportions of ΔG to ΔM ends, the larger final products contain only ΔM ends, which constitute a novel oligosaccharide-yielding property of guluronate lyases. The deletion of the noncatalytic region of Aly5 does not alter its M/G preference but significantly decreases the enzymatic activity and enzyme stability. Notably, the truncated protein accumulates large final oligosaccharide products but yields fewer small final products than Aly5, which are codetermined by its M/G preference to and size enlargement of degradable oligosaccharides. This study provides novel enzymatic properties and catalytic mechanisms of a guluronate lyase for potential uses and improvements. PMID:26519393

  9. The hydrocarbon-degrading marine bacterium Cobetia sp. strain MM1IDA2H-1 produces a biosurfactant that interferes with quorum sensing of fish pathogens by signal hijacking

    PubMed Central

    Ibacache-Quiroga, C; Ojeda, J; Espinoza-Vergara, G; Olivero, P; Cuellar, M; Dinamarca, M A

    2013-01-01

    Summary Biosurfactants are produced by hydrocarbon-degrading marine bacteria in response to the presence of water-insoluble hydrocarbons. This is believed to facilitate the uptake of hydrocarbons by bacteria. However, these diffusible amphiphilic surface-active molecules are involved in several other biological functions such as microbial competition and intra-or inter-species communication. We report the isolation and characterization of a marine bacterial strain identified as Cobetia sp. MM1IDA2H-1, which can grow using the sulfur-containing heterocyclic aromatic hydrocarbon dibenzothiophene (DBT). As with DBT, when the isolated strain is grown in the presence of a microbial competitor, it produces a biosurfactant. Because the obtained biosurfactant was formed by hydroxy fatty acids and extracellular lipidic structures were observed during bacterial growth, we investigated whether the biosurfactant at its critical micelle concentration can interfere with bacterial communication systems such as quorum sensing. We focused on Aeromonas salmonicida subsp. salmonicida, a fish pathogen whose virulence relies on quorum sensing signals. Using biosensors for quorum sensing based on Chromobacterium violaceum and Vibrio anguillarum, we showed that when the purified biosurfactant was mixed with N-acyl homoserine lactones produced by A. salmonicida, quorum sensing was inhibited, although bacterial growth was not affected. In addition, the transcriptional activities of A. salmonicida virulence genes that are controlled by quorum sensing were repressed by both the purified biosurfactant and the growth in the presence of Cobetia sp. MM1IDA2H-1. We propose that the biosurfactant, or the lipid structures interact with the N-acyl homoserine lactones, inhibiting their function. This could be used as a strategy to interfere with the quorum sensing systems of bacterial fish pathogens, which represents an attractive alternative to classical antimicrobial therapies in fish

  10. Acanthopleuribacter pedis gen. nov., sp. nov., a marine bacterium isolated from a chiton, and description of Acanthopleuribacteraceae fam. nov., Acanthopleuribacterales ord. nov., Holophagaceae fam. nov., Holophagales ord. nov. and Holophagae classis nov. in the phylum 'Acidobacteria'.

    PubMed

    Fukunaga, Yukiyo; Kurahashi, Midori; Yanagi, Kensuke; Yokota, Akira; Harayama, Shigeaki

    2008-11-01

    Strain FYK2218(T) was isolated from a specimen of the chiton Acanthopleura japonica, which had been collected from a beach on the Boso peninsula in Japan. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the strain belonged to the phylum 'Acidobacteria'. The most closely related type strains to strain FYK2218(T) were Holophaga foetida TMBS4(T) (83.6 % 16S rRNA gene sequence similarity) and Geothrix fermentans H-5(T) (83.6 %) in subdivision 8 of the 'Acidobacteria'. Cells of FYK2218(T) were motile, rod-shaped, Gram-negative, mesophilic and strictly aerobic. The G+C content of the strain was 56.7 mol%. The strain had isoprenoid quinones MK-6 and MK-7 as major components. Major fatty acids of the strain were iso-C(15 : 0), iso-C(17 : 0), C(16 : 0) and C(20 : 5)omega3c (cis-5,8,11,14,17-eicosapentaenoic acid). From the taxonomic data obtained in this study, it is proposed that the new marine isolate be placed into a novel genus and species named Acanthopleuribacter pedis gen. nov., sp. nov. within the new family, order and class Acanthopleuribacteraceae fam. nov., Acanthopleuribacterales ord. nov. and Holophagae classis nov. The family Holophagaceae fam. nov. is also described. The type strain of Acanthopleuribacter pedis is FYK2218(T) (=NBRC 101209(T) =KCTC 12899(T)).

  11. Acanthopleuribacter pedis gen. nov., sp. nov., a marine bacterium isolated from a chiton, and description of Acanthopleuribacteraceae fam. nov., Acanthopleuribacterales ord. nov., Holophagaceae fam. nov., Holophagales ord. nov. and Holophagae classis nov. in the phylum 'Acidobacteria'.

    PubMed

    Fukunaga, Yukiyo; Kurahashi, Midori; Yanagi, Kensuke; Yokota, Akira; Harayama, Shigeaki

    2008-11-01

    Strain FYK2218(T) was isolated from a specimen of the chiton Acanthopleura japonica, which had been collected from a beach on the Boso peninsula in Japan. Phylogenetic analyses based on 16S rRNA gene sequences revealed that the strain belonged to the phylum 'Acidobacteria'. The most closely related type strains to strain FYK2218(T) were Holophaga foetida TMBS4(T) (83.6 % 16S rRNA gene sequence similarity) and Geothrix fermentans H-5(T) (83.6 %) in subdivision 8 of the 'Acidobacteria'. Cells of FYK2218(T) were motile, rod-shaped, Gram-negative, mesophilic and strictly aerobic. The G+C content of the strain was 56.7 mol%. The strain had isoprenoid quinones MK-6 and MK-7 as major components. Major fatty acids of the strain were iso-C(15 : 0), iso-C(17 : 0), C(16 : 0) and C(20 : 5)omega3c (cis-5,8,11,14,17-eicosapentaenoic acid). From the taxonomic data obtained in this study, it is proposed that the new marine isolate be placed into a novel genus and species named Acanthopleuribacter pedis gen. nov., sp. nov. within the new family, order and class Acanthopleuribacteraceae fam. nov., Acanthopleuribacterales ord. nov. and Holophagae classis nov. The family Holophagaceae fam. nov. is also described. The type strain of Acanthopleuribacter pedis is FYK2218(T) (=NBRC 101209(T) =KCTC 12899(T)). PMID:18984699

  12. Albidovulum inexpectatum gen. nov., sp. nov., a nonphotosynthetic and slightly thermophilic bacterium from a marine hot spring that is very closely related to members of the photosynthetic genus Rhodovulum.

    PubMed

    Albuquerque, Luciana; Santos, João; Travassos, Pedro; Nobre, M Fernanda; Rainey, Fred A; Wait, Robin; Empadinhas, Nuno; Silva, Manuel T; da Costa, Milton S

    2002-09-01

    Several bacterial isolates, with an optimum growth temperature of about 50 degrees C, were recovered from the marine hot spring at Ferraria on the island of São Miguel in the Azores. The geothermal water emerged from a porous lava flow and rapidly cooled in contact with seawater except at low tide. The bacterial species represented by strains FRR-10(T) and FRR-11 was nonpigmented, strictly aerobic, and organotrophic. Several genes, bchZ, pufB, pufA, pufL, or pufM, encoding the photosynthetic reaction center proteins and the core light-harvesting complexes were not detected in these strains. The organism oxidized thiosulfate to sulfate with enhancement of growth. The organism did not require additional NaCl in the culture medium for growth, but NaCl at 1.0% enhanced growth. Phylogenetic analyses using the 16S rRNA gene sequence of strain FRR-10(T) indicated that the new organism represented a new species of the alpha-3 subclass of the Proteobacteria and that it branches within the species of the genus Rhodovulum. The contradiction of classifying an organism which branches within the radiation of the genus Rhodovulum but does not possess the hallmark characteristics of this genus is discussed. However, the absence of several of these characteristics, namely, the lack of photosynthesis and pigmentation, which could be related to colonization of dark environments, and growth at high temperatures, leads to our proposal that strains FRR-10(T) and FRR-11 should be classified as a new species of a novel genus, Albidovulum inexpectatum, representing, at present, the most thermophilic organism within the alpha-3 subclass of the Proteobacteria.

  13. Single Bacterium Detection Using Sers

    NASA Astrophysics Data System (ADS)

    Gonchukov, S. A.; Baikova, T. V.; Alushin, M. V.; Svistunova, T. S.; Minaeva, S. A.; Ionin, A. A.; Kudryashov, S. I.; Saraeva, I. N.; Zayarny, D. A.

    2016-02-01

    This work is devoted to the study of a single Staphylococcus aureus bacterium detection using surface-enhanced Raman spectroscopy (SERS) and resonant Raman spectroscopy (RS). It was shown that SERS allows increasing sensitivity of predominantly low frequency lines connected with the vibrations of Amide, Proteins and DNA. At the same time the lines of carotenoids inherent to this kind of bacterium are well-detected due to the resonance Raman scattering mechanism. The reproducibility and stability of Raman spectra strongly depend on the characteristics of nanostructured substrate, and molecular structure and size of the tested biological object.

  14. Draft Genome Sequence of Jeotgalibacillus soli DSM 23228, a Bacterium Isolated from Alkaline Sandy Soil

    PubMed Central

    Chan, Kok-Gan; Yaakop, Amira Suriaty; Chan, Chia Sing; Ee, Robson; Tan, Wen-Si; Gan, Han Ming

    2015-01-01

    Jeotgalibacillus soli, a bacterium capable of degrading N-acyl homoserine lactone, was isolated from a soil sample in Portugal. J. soli constitutes the only Jeotgalibacillus species isolated from a non-marine source. Here, the draft genome, several interesting glycosyl hydrolases, and its putative N-acyl homoserine lactonases are presented. PMID:25999554

  15. Properties of lactate dehydrogenase in a psychrophilic marine bacterium.

    PubMed Central

    Mitchell, P; Yen, H C; Mathemeier, P F

    1985-01-01

    Lactate dehydrogenase (EC 1.1.1.27) from Vibrio marinus MP-1 was purified 15-fold and ammonium activated. The optimum pH for pyruvate reduction was 7.4. Maximum lactate dehydrogenase activity occurred at 10 to 15 degrees C, and none occurred at 40 degrees C. The crude-extract enzyme was stable between 15 and 20 degrees C and lost 50% of its activity after 60 min at 45 degrees C. The partially purified enzyme was stable between 8 and 15 degrees C and lost 50% of its activity after 60 min at 30 degrees C. The thermal stability of lactate dehydrogenase was increased by mercaptoethanol, with 50% remaining activity at 42 degrees C. Images PMID:4004236

  16. Thalassolituus marinus sp. nov., a hydrocarbon-utilizing marine bacterium.

    PubMed

    Choi, Ahyoung; Cho, Jang-Cheon

    2013-06-01

    Gram-negative strains, motile by a single polar flagellum, non-pigmented and with a curved rod-shaped morphology, designated IMCC1826(T) and IMCC1883, were isolated from a surface seawater sample from the Yellow Sea. The two strains shared 99.9% 16S rRNA gene sequence similarity and showed 92% DNA-DNA relatedness, suggesting that they belonged to the same genomic species. Phylogenetic analysis based on 16S rRNA gene sequences showed that the two isolates were related most closely to the type strain of Thalassolituus oleivorans with a sequence similarity of 96.4% and formed a robust phyletic lineage with T. oleivorans. DNA-DNA relatedness between the two strains and T. oleivorans DSM 14913(T) was 8.7-11.6%. A putative alkane hydroxylase (alkB) gene was detected in strain IMCC1826(T) by PCR, but the amino acid sequence of the gene was distantly related to that of the AlkB homologue of T. oleivorans DSM 14913(T). As expected from the presence of the alkB gene, the new strains utilized n-tetradecane and n-hexadecane as a carbon source. The DNA G+C content was 54.6-56.0 mol% and the main isoprenoid quinone detected was Q-9. Polar lipids of strain IMCC1826(T) included diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine and amino-group-containing lipids. On the basis of taxonomic data obtained in this study, strains IMCC1826(T) and IMCC1883 represent a novel species of the genus Thalassolituus, for which the name Thalassolituus marinus sp. nov. is proposed, with IMCC1826(T) (=KCTC 23084(T)=NBRC 107590(T)) as the type strain. PMID:23148102

  17. Isolation and characterization of a fucoidan-degrading marine bacterium.

    PubMed

    Sakai, Takeshi; Ishizuka, Kumiko; Kato, Ikunoshin

    2003-01-01

    Fucoidan, a mixture of sulfated fucose-containing polysaccharides, was prepared from the algal bodies of Cladosiphon okamuranus (class Phaeophyceae, order Chordariales, family Chordariaceae) with a yield of 2.0% of the wet weight of the alga. To obtain enzymes that digest the fucoidan, we screened bacteria in the guy contents of the sea cucumber Stichopus japonicus for their ability to decrease the fucoidan in their culture media, and successfully isolated one bacterial strain that could decrease it. The bacterial strain was gram-negative and possessed menaquinone 7 as the predominant respiratory quinone, and the GC content of its genomic DNA was 52%. The results of the phylogenetic analysis of its 16S ribosomal DNA sequence indicated that the bacterial strain was a member of the division "Verrucomicrobia." However, as the bacterial strain is phylogenetically and phenotypically distinct from verrucomicrobial species described previously, the strain was assumed to be a new member of the division "Verrucomicrobia." When the bacterial strain was cultivated in an algal fucoidan-containing medium, the strain decreased fucoidan from C. okamuranus (44%), Nemacystus decipiens (19%), Laminaria japonica (31%), Kjellmaniella crassifolia (23%), sporophyl of Undaria pinnatifida (22%), Fucus vesiculosus (42%), and Ascophyllum nodosum (61%).

  18. Sodium ion-proton antiport in a marine bacterium.

    PubMed Central

    Niven, D F; MacLeod, R A

    1978-01-01

    Alteromonas haloplanktis ejected protons in response to a brief respiratory pulse; the rate of decay of the resulting pH change was accelerated when Na+ was present in the suspension medium. The addition of an anaerobic NaCl solution to an essentially Na+-free anaerobic bacterial suspension induced the acidification of the suspension medium. These results and others discussed provide substantial evidence for the existence of an Na+-H+ antiporter in this organism. PMID:26666

  19. Sexually antagonistic genes: experimental evidence.

    PubMed

    Rice, W R

    1992-06-01

    When selection differs between the sexes, a mutation beneficial to one sex may be harmful to the other (sexually antagonistic). Because the sexes share a common gene pool, selection in one sex can interfere with the other's adaptive evolution. Theory predicts that sexually antagonistic mutations should accumulate in tight linkage with a new sex-determining gene, even when the harm to benefit ratio is high. Genetic markers and artificial selection were used to make a pair of autosomal genes segregate like a new pair of sex-determining genes in a Drosophila melanogaster model system. A 29-generation study provides experimental evidence that sexually antagonistic genes may be common in nature and will accumulate in response to a new sex-determining gene. PMID:1604317

  20. Marine Careers.

    ERIC Educational Resources Information Center

    Gordon, Bernard L.

    The five papers in this publication on marine careers were selected so that science teachers, guidance councilors, and students could benefit from the experience and knowledge of individuals active in marine science. The areas considered are indicated by the titles: Professional Careers in Marine Science with the Federal Government, Marine Science…

  1. Draft Genome Sequence of Uncultured SAR324 Bacterium lautmerah10, Binned from a Red Sea Metagenome

    PubMed Central

    Thompson, Luke R.

    2016-01-01

    A draft genome of SAR324 bacterium lautmerah10 was assembled from a metagenome of a surface water sample from the Red Sea, Saudi Arabia. The genome is more complete and has a higher G+C content than that of previously sequenced SAR324 representatives. Its genomic information shows a versatile metabolism that confers an advantage to SAR324, which is reflected in its distribution throughout different depths of the marine water column. PMID:26868398

  2. Permanent draft genome of the malachite-green-tolerant bacterium Rhizobium sp. MGL06.

    PubMed

    Liu, Yang; Wang, Runping; Zeng, Runying

    2014-12-01

    Rhizobium sp. MGL06, the first Rhizobium isolate from a marine environment, is a malachite-green-tolerant bacterium with a broader salinity tolerance (range: 0.5% to 9%) than other rhizobia. This study sequences and annotates the draft genome sequence of this strain. Genome sequence information provides a basis for analyzing the malachite green tolerance, broad salinity adaptation, nitrogen fixation properties, and taxonomic classification of the isolate.

  3. Affinity purification of a siderophore that exhibits an antagonistic effect against soft rot bacterium.

    PubMed

    Helmy, Mohamed; Baddar, Doa; El'Masry, Mohamed Hisham

    2008-07-01

    Bacterial colonies were isolated from different Egyptian soil samples. From these isolates, one bacterial species was found to produce siderophore. Using classical and biochemical identification methods, the siderophore producing isolate was identified as Pseudomonas fluorescens. Based on the affinity of siderophores for metal ions, an affinity chromatography system was designed for the purification of the siderophore in one step. It was possible to isolate 25 mg siderophore per liter of culture media. The purified siderophore was found to exist in two forms of approximately 30 and 90 kD. They are believed to be polymers of several siderophore molecules. Both forms were found to be active against the pathogen Erwinia carotovora var. carotovora, the causal bacteria of soft rot disease on potato tubers. The advantage of this method over other purification methods is that it uses metal ion so it can be applied for the purification of the known types of siderophores. Moreover, the purification is based on affinity chromatography, so the siderophore purity state permits several biotechnological applications without further treatments. PMID:18707585

  4. Genome sequence of Xanthomonas sacchari R1, a biocontrol bacterium isolated from the rice seed.

    PubMed

    Fang, Yunxia; Lin, Haiyan; Wu, Liwen; Ren, Deyong; Ye, Weijun; Dong, Guojun; Zhu, Li; Guo, Longbiao

    2015-07-20

    Xanthomonas sacchari, was first identified as a pathogenic bacterium isolated from diseased sugarcane in Guadeloupe. In this study, R1 was first isolated from rice seed samples from Philippines in 2002. The antagonistic ability against several rice pathogens raises our attention. The genomic feature of this strain was described in this paper. The total genome size of X. sacchari R1 is 5,000,479 bp with 4315 coding sequences (CDS), 59 tRNAs, 2rRNAs and one plasmid. PMID:25931193

  5. Cadmium-nickel toxicity interactions towards a bacterium, filamentous fungi, and a cultured mammalian cell line

    SciTech Connect

    Babich, H.; Shopsis, C.; Borenfreund, E.

    1986-10-01

    The response of the biota to exposure to individual metals may differ from its response to multiple metals, as mixtures of metals may interact antagonistically or synergistically in their resultant toxicity. The present study evaluated the effects of a combination of Cd and Ni on the freshwater bacterium, Aeromonas hydrophila, the terrestrial fungi, Trichodema viride and Aspergillus niger, and the mammalian cell line, BALB/c mouse 3T3 fibroblasts. This particular spectrum of target cells was selected because studies in the literature show a wide variety of possible interactions between Cd and Ni in their combined toxicities towards bacteria cyanobacteria, slime molds, isolated rat hepatocytes, and rats.

  6. Synthesis of potential mescaline antagonists.

    PubMed

    DeSantis, F; Nieforth, K A

    1976-10-01

    1-[2-(3,4,5-Trimethoxyphenyl)ethyl]-3-pyrroline, 2-(3,4,5-trimethoxybenzyl)-1,2,3,6-tetrahydropyridine, N-n-propylmescaline, N-cyclopropylmethylmescaline, and N-allylmescaline were synthesized as potential mescaline antagonists. The ability of these compounds to antagonize mescaline-induced disruption of swim behavior is also given.

  7. N-Sulfonyl homoserine lactones as antagonists of bacterial quorum sensing.

    PubMed

    Castang, Sandra; Chantegrel, Bernard; Deshayes, Christian; Dolmazon, René; Gouet, Patrice; Haser, Richard; Reverchon, Sylvie; Nasser, William; Hugouvieux-Cotte-Pattat, Nicole; Doutheau, Alain

    2004-10-18

    A series of 11 new analogues of N-acylhomoserine lactones in which the carboxamide bond was replaced by a sulfonamide one, has been synthesised. These compounds were evaluated for their ability to competitively inhibit the action of 3-oxohexanoyl-L-homoserine lactone, the natural ligand of the quorum sensing transcriptional regulator LuxR, which in turn activates expression of bioluminescence in the model bacterium Vibrio fischeri. Several compounds were found to display antagonist activity. Molecular modeling suggests that the latter prevent a cascade of structural rearrangements necessary for the formation of the active LuxR dimer.

  8. Synthesis and biological evaluation of homoserine lactone derived ureas as antagonists of bacterial quorum sensing.

    PubMed

    Frezza, Marine; Castang, Sandra; Estephane, Jane; Soulère, Laurent; Deshayes, Christian; Chantegrel, Bernard; Nasser, William; Queneau, Yves; Reverchon, Sylvie; Doutheau, Alain

    2006-07-15

    A series of 15 racemic alkyl- and aryl-N-substituted ureas, derived from homoserine lactone, were synthesized and tested for their ability to competitively inhibit the action of 3-oxohexanoyl-l-homoserine lactone, the natural inducer of bioluminescence in the bacterium Vibrio fischeri. N-alkyl ureas with an alkyl chain of at least 4 carbon atoms, as well as certain ureas bearing a phenyl group at the extremity of the alkyl chain, were found to be significant antagonists. In the case of N-butyl urea, it has been shown that the antagonist activity was related to the inhibition of the dimerisation of the N-terminal domain of ExpR, a protein of the receptor LuxR family. Molecular modelling suggested that this would result from the formation of an additional hydrogen bond in the protein acylhomoserine lactone binding cavity.

  9. Mineralcorticoid antagonists in heart failure.

    PubMed

    D'Elia, Emilia; Krum, Henry

    2014-10-01

    Mineralocorticoid receptor antagonists (MRAs) have become mandated therapy in patients with reduced ejection fraction (systolic) heart failure (HF) across all symptom classes. These agents should also be prescribed in the early post-myocardial infarction setting in those with reduced ejection fraction and either HF symptoms or diabetes. This article explores the pathophysiological role of aldosterone, an endogenous ligand for the mineralcorticoid receptor (MR), and summarizes the clinical data supporting guideline recommendations for these agents in systolic HF. The use of MRAs in novel areas beyond systolic HF ejection is also explored. Finally, the current status of newer agents will be examined. PMID:25217431

  10. Marine biology

    SciTech Connect

    Thurman, H.V.; Webber, H.H.

    1984-01-01

    This book discusses both taxonomic and ecological topics on marine biology. Full coverage of marine organisms of all five kingdoms is provided, along with interesting and thorough discussion of all major marine habitats. Organization into six major parts allows flexibility. It also provides insight into important topics such as disposal of nuclear waste at sea, the idea that life began on the ocean floor, and how whales, krill, and people interact. A full-color photo chapter reviews questions, and exercises. The contents are: an overview marine biology: fundamental concepts/investigating life in the ocean; the physical ocean, the ocean floor, the nature of water, the nature and motion of ocean water; general ecology, conditions for life in the sea, biological productivity and energy transfer; marine organisms; monera, protista, mycota and metaphyta; the smaller marine animals, the large animals marine habitats, the intertidal zone/benthos of the continental shelf, the photic zone, the deep ocean, the ocean under stress, marine pollution, appendix a: the metric system and conversion factors/ appendix b: prefixes and suffixes/ appendix c: taxonomic classification of common marine organisms, and glossary, and index.

  11. Suppressing antagonistic bioengineering feedbacks doubles restoration success.

    PubMed

    Suykerbuyk, Wouter; Bouma, Tjeerd J; van der Heide, Tjisse; Faust, Cornelia; Govers, Laura L; Giesen, Wim B J T; de Jong, Dick J; van Katwijk, Marieke M

    2012-06-01

    In a seagrass restoration project, we explored the potential for enhancing the restoration process by excluding antagonistic engineering interactions (i.e., biomechanical warfare) between two ecosystem engineers: the bioturbating lugworm Arenicola marina and the sediment-stabilizing seagrass Zostera noltii Hornem. Applying a shell layer underneath half of our seagrass transplants successfully reduced adult lugworm density by over 80% and reduced lugworm-induced microtopography (a proxy for lugworm disturbance) at the wave-sheltered site. At the wave-exposed site adult lugworm densities and microtopography were already lower than at the sheltered site but were further reduced in the shell-treated units. Excluding lugworms and their bioengineering effects corresponded well with a strongly enhanced seagrass growth at the wave-sheltered site, which was absent at the exposed site. Enhanced seagrass growth in the present study was fully assigned to the removal of lugworms' negative engineering effects and not to any (indirect) evolving effects such as an altered biogeochemistry or sediment-stabilizing effects by the shell layer. The context-dependency implies that seagrass establishment at the exposed site is not constrained by negative ecosystem-engineering interactions only, but also by overriding physical stresses causing poor growth conditions. Present findings underline that, in addition to recent emphasis on considering positive (facilitating) interactions in ecological theory and practice, it is equally important to consider negative engineering interactions between ecosystem-engineering species. Removal of such negative interactions between ecosystem-engineering species can give a head start to the target species at the initial establishment phase, when positive engineering feedbacks by the target species on itself are still lacking. Though our study was carried out in a marine environment with variable levels of wave disturbance, similar principles may be

  12. Complete Genome Sequence of the Sugar Cane Endophyte Pseudomonas aurantiaca PB-St2, a Disease-Suppressive Bacterium with Antifungal Activity toward the Plant Pathogen Colletotrichum falcatum

    PubMed Central

    Bauer, Judith S.

    2014-01-01

    The endophytic bacterium Pseudomonas aurantiaca PB-St2 exhibits antifungal activity and represents a biocontrol agent to suppress red rot disease of sugar cane. Here, we report the completely sequenced 6.6-Mb genome of P. aurantiaca PB-St2. The sequence contains a repertoire of biosynthetic genes for secondary metabolites that putatively contribute to its antagonistic activity and its plant-microbe interactions. PMID:24459254

  13. Biological control of postharvest spoilage caused by Penicillium expansum and Botrytis cinerea in apple by using the bacterium Rahnella aquatilis.

    PubMed

    Calvo, Juan; Calvente, Viviana; de Orellano, María Edith; Benuzzi, Delia; Sanz de Tosetti, Maria Isabel

    2007-02-15

    The epiphytic bacterium Rahnella aquatilis, isolated from fruit and leaves of apples, was tested for antagonistic properties against Penicillium expansum and Botrytis cinerea on Red Delicious apple fruit. In "in vitro" assays, this bacterium inhibited completely the germination of P. expansum and B. cinerea spores, but it needed direct contact with the spores to do it. However the putative mechanism seemed be different for the two pathogens. The bacterium did not produce extracellular antibiotic substances and when the acute toxicity test was performed no mortality, toxicity symptoms or organ alterations of the test animals (Wistar rats) were observed. Assays of biological control of P. expansum and B. cinerea on apple fruit were carried out at different temperatures. At 15 degrees C and 90% RH, the incidence of disease caused by P. expansum on apples stored for 20 days, was reduced by nearly 100% by R. aquatilis (10(6) cells/ml), while in the case of B. cinerea, the reduction of decay severity was nearly 64% but there was no reduction in the incidence of disease. At 4 degrees C and 90% RH the treatment with the bacterium significantly inhibited the development of B. cinerea on apples stored for 40 days and the incidence of disease was reduced by nearly 100%, while the incidence of disease caused by P. expansum at 4 degrees C was 60%. The results obtained show that R. aquatilis would be an interesting microorganism to be used as a biocontrol agent.

  14. Marine Biomedicine

    ERIC Educational Resources Information Center

    Bang, Frederik B.

    1977-01-01

    Describes early scientific research involving marine invertebrate pathologic processes that may have led to new insights into human disease. Discussed are inquiries of Metchnikoff, Loeb, and Cantacuzene (immunolgic responses in sea stars, horseshoe crabs, and marine worms, respectively). Describes current research stemming from these early…

  15. Marine Biology

    ERIC Educational Resources Information Center

    Dewees, Christopher M.; Hooper, Jon K.

    1976-01-01

    A variety of informational material for a course in marine biology or oceanology at the secondary level is presented. Among the topics discussed are: food webs and pyramids, planktonic blooms, marine life, plankton nets, food chains, phytoplankton, zooplankton, larval plankton and filter feeders. (BT)

  16. Novel Waddlia Intracellular Bacterium in Artibeus intermedius Fruit Bats, Mexico

    PubMed Central

    Pierlé, Sebastián Aguilar; Morales, Cirani Obregón; Martínez, Leonardo Perea; Ceballos, Nidia Aréchiga; Rivero, Juan José Pérez; Díaz, Osvaldo López; Brayton, Kelly A.

    2015-01-01

    An intracellular bacterium was isolated from fruit bats (Artibeus intermedius) in Cocoyoc, Mexico. The bacterium caused severe lesions in the lungs and spleens of bats and intracytoplasmic vacuoles in cell cultures. Sequence analyses showed it is related to Waddlia spp. (order Chlamydiales). We propose to call this bacterium Waddlia cocoyoc. PMID:26583968

  17. Novel Waddlia Intracellular Bacterium in Artibeus intermedius Fruit Bats, Mexico.

    PubMed

    Pierlé, Sebastián Aguilar; Morales, Cirani Obregón; Martínez, Leonardo Perea; Ceballos, Nidia Aréchiga; Rivero, Juan José Pérez; Díaz, Osvaldo López; Brayton, Kelly A; Setién, Alvaro Aguilar

    2015-12-01

    An intracellular bacterium was isolated from fruit bats (Artibeus intermedius) in Cocoyoc, Mexico. The bacterium caused severe lesions in the lungs and spleens of bats and intracytoplasmic vacuoles in cell cultures. Sequence analyses showed it is related to Waddlia spp. (order Chlamydiales). We propose to call this bacterium Waddlia cocoyoc.

  18. Long-acting muscarinic antagonists.

    PubMed

    Melani, Andrea S

    2015-01-01

    Chronic obstructive pulmonary disease (COPD) is a major cause of death and disability worldwide. Inhaled bronchodilators are the mainstay of COPD pharmacological treatment. Long-acting muscarinic antagonists (LAMAs) are a major class of inhaled bronchodilators. Some LAMA/device systems with different characteristics and dosing schedules are currently approved for maintenance therapy of COPD and a range of other products are being developed. They improve lung function and patient-reported outcomes and reduce acute bronchial exacerbations with good safety. LAMAs are used either alone or associated with long-acting β₂-agonists, eventually in fixed dose combinations. Long-acting β₂-agonist/LAMA combinations assure additional benefits over the individual components alone. The reader will obtain a view of the safety and efficacy of the different LAMA/device systems in COPD patients. PMID:26109098

  19. A new alcohol antagonist: Phaclofen

    SciTech Connect

    Allan, A.M. ); Harris, R.A. )

    1989-01-01

    The ability of the GABA{sub B} receptor antagonist, phaclofen to alter behavioral effects of ethanol was evaluated by loss of righting reflex (sleep time), motor incoordination (bar holding), spontaneous locomotion (open field activity) and hypothermia. Pretreatment with phaclofen significantly decreased the effects of ethanol on motor incoordination, locomotor activity and hypothermia. However, phaclofen had no effect on either pentobarbital- or diazepam-induced motor incoordination. Phaclofen slightly increased the ED{sub 50} for loss of the righting reflex but did not alter either the duration of reflex loss produced by ethanol or blood ethanol levels at awakening. Our results suggest phaclofen is rapidly inactivated resulting in difficulty in observing antagonism of long duration ethanol effects. These findings suggest that the GABA{sub B} system may play a role in mediating several important actions of ethanol.

  20. [Differential therapy with calcium antagonists].

    PubMed

    Scholze, Jürgen E

    2003-12-01

    EFFICACY OF CALCIUM ANTAGONISTS: Calcium-channel blockers (CCBs) have long been recognized as potent agents for hypertensive therapy, with substantial blood pressure reduction in all age groups and races. CCBs improve endothelial function, may positively influence atherosclerosis in carotid arteries, reduce left ventricular hypertrophy, and hypertrophy of the resistance vessels, and improve arterial compliance. They do not adversely affect lipids and serum glucose. USE IN PRACTICE: CCBs are also a heterogenous class of drugs composed of the phenylalkylamine verapamil, the benzothiazepine diltiazem, and the large group of dihydropyridines (DHPs) with the prototype nifedipine, and an increasing number of newer agents (e. g. nitrendipine, nisoldipine, amlodipine, felodipine, lacidipine and lercanidipine). DHPs are primarily vasodilators, lowering blood pressure by decreasing peripheral vascular resistance at the level of the small arterioles which can be followed by an autonomic counterregulation especially in drugs with a rapid onset of action. This is markedly reduced or abolished in the treatment with the modern long acting DHPs and is also not the case in the treatment with non-DHPs. Prospective randomized controlled outcome studies demonstrated a significant reduction in stroke in elderly patients with isolated systolic hypertension compared with placebo (Syst-Eur [Syst-China]), and no significant differences in cardiovascular mortality and combined morbidity compared with diuretics, beta blockers or ACE-Inhibitors (STOP-2, INSIGHT, NORDIL, ALLHAT, INVEST). To normalize the blood pressure it is mostly necessary to combine antihypertensive drugs. Here are CCBs ideal partners for a therapy with ACE-inhibitors, AT1 antagonists or beta blockers (DHP) and diuretics (verapamil). With respect to the antihypertensive differential therapy the author recommends CCBs based on studies with the evidence grade 1-3; especially for elderly hypertensives (with isolated systolic

  1. Biocontrol of Aspergillus flavus on peanut kernels by use of a strain of marine Bacillus megaterium.

    PubMed

    Kong, Qing; Shan, Shihua; Liu, Qizheng; Wang, Xiudan; Yu, Fangtang

    2010-04-30

    A strain of marine Bacillus megaterium isolated from the Yellow Sea of East China was evaluated for its activity in reducing postharvest decay of peanut kernels caused by Aspergillus flavus in in vitro and in vivo tests. The results showed that the concentrations of antagonist had a significant effect on biocontrol effectiveness in vivo: when the concentration of the washed bacteria cell suspension was used at 1x10(9)CFU/ml, the percentage rate of rot of peanut kernels was 31.67%+/-2.89%, which was markedly lower than that treated with water (the control) after 7days of incubation at 28 degrees C. The results also showed that unwashed cell culture of B. megaterium was as effective as the washed cell suspension, and better biocontrol was obtained when longer incubation time of B. megaterium was applied. When the incubation time of B. megaterium was 60-h, the rate of decay declined to 41.67%+/-2.89%. Furthermore, relative to the expression of 18S rRNA, the mRNA abundances of aflR gene and aflS gene in the experiment group were 0.28+/-0.03 and 0.024+/-0.005 respectively, indicating that this strain of B. megaterium could significantly reduce the biosynthesis of aflatoxins and expression of aflR gene and aflS gene (p<0.01). To the best of our knowledge, this is a first report demonstrating that the marine bacterium B. megaterium could be used as a biocontrol agent against postharvest fungal disease caused by A. flavus. PMID:20156660

  2. Client Perceptions of Two Antagonist Programs.

    ERIC Educational Resources Information Center

    Capone, Thomas A.; And Others

    1980-01-01

    Reports results of a questionnaire administered to participants in an antagonist drug outpatient clinic and an antagonist drug work-release program to obtain awareness of acceptance of the program participants. Naltrexone patients recommended an alternative method of administering the drug and changing the money system to award deserving inmates…

  3. Antagonistic coevolution limits population persistence of a virus in a thermally deteriorating environment.

    PubMed

    Zhang, Quan-Guo; Buckling, Angus

    2011-03-01

    Understanding the conditions under which rapid evolutionary adaptation can prevent population extinction in deteriorating environments (i.e. evolutionary rescue) is a crucial aim in the face of global climate change. Despite a rapidly growing body of work in this area, little attention has been paid to the importance of interspecific coevolutionary interactions. Antagonistic coevolution commonly observed between hosts and parasites is likely to retard evolutionary rescue because it often reduces population sizes, and results in the evolution of costly host defence and parasite counter-defence. We used experimental populations of a bacterium Pseudomonas fluorescens SBW25 and a bacteriophage virus (SBW25Φ2), to study how host-parasite coevolution impacts viral population persistence in the face of gradually increasing temperature, an environmental stress for the virus but not the bacterium. The virus persisted much longer when it evolved in the presence of an evolutionarily constant host genotype (i.e. in the absence of coevolution) than when the bacterium and virus coevolved. Further experiments suggest that both a reduction in population size and costly infectivity strategies contributed to viral extinction as a result of coevolution. The results highlight the importance of interspecific evolutionary interactions for the evolutionary responses of populations to global climate change.

  4. Characterization of a novel extremely alkalophilic bacterium

    NASA Technical Reports Server (NTRS)

    Souza, K. A.; Deal, P. H.

    1977-01-01

    A new alkalophilic bacterium, isolated from a natural spring of high pH is characterized. It is a Gram-positive, non-sporulating, motile rod requiring aerobic and alkaline conditions for growth. The characteristics of this organism resemble those of the coryneform group of bacteria; however, there are no accepted genera within this group with which this organism can be closely matched. Therefore, a new genus may be warranted.

  5. Nanomechanical properties of the sea-water bacterium Paracoccus seriniphilus--a scanning force microscopy approach.

    PubMed

    Davoudi, Neda; Müller-Renno, Christine; Ziegler, Christiane; Raid, Indek; Seewig, Jörg; Schlegel, Christin; Muffler, Kai; Ulber, Roland

    2015-03-02

    The measurement of force-distance curves on a single bacterium provides a unique opportunity to detect properties such as the turgor pressure under various environmental conditions. Marine bacteria are very interesting candidates for the production of pharmaceuticals, but are only little studied so far. Therefore, the elastic behavior of Paracoccus seriniphilus, an enzyme producing marine organism, is presented in this study. After a careful evaluation of the optimal measurement conditions, the spring constant and the turgor pressure are determined as a function of ionic strength and pH. Whereas the ionic strength changes the turgor pressure passively, the results give a hint that the change to acidic pH increases the turgor pressure by an active mechanism. Furthermore, it could be shown, that P. seriniphilus has adhesive protrusions outside its cell wall.

  6. Antagonists of the kappa opioid receptor.

    PubMed

    Urbano, Mariangela; Guerrero, Miguel; Rosen, Hugh; Roberts, Edward

    2014-05-01

    The research community has increasingly focused on the development of OPRK antagonists as pharmacotherapies for the treatment of depression, anxiety, addictive disorders and other psychiatric conditions produced or exacerbated by stress. Short-acting OPRK antagonists have been recently developed as a potential improvement over long-acting prototypic ligands including nor-BNI and JDTic. Remarkably the short-acting LY2456302 is undergoing phase II clinical trials for the augmentation of the antidepressant therapy in treatment-resistant depression. This Letter reviews relevant chemical and pharmacological advances in the identification and development of OPRK antagonists.

  7. Genomic and functional analysis of Vibrio phage SIO-2 reveals novel insights into ecology and evolution of marine siphoviruses

    PubMed Central

    Baudoux, A-C.; Hendrix, R.W.; Lander, G.C.; Bailly, X.; Podell, S.; Paillard, C.; Johnson, J.E.; Potter, C.S.; Carragher, B.; Azam, F.

    2011-01-01

    We report on a genomic and functional analysis of a novel marine siphovirus, the Vibrio phage SIO-2. This phage is lytic for related Vibrio species of great ecological interest including the broadly antagonistic bacterium Vibrio sp. SWAT3 as well as notable members of the Harveyi clade (V. harveyi ATTC BAA-1116 and V. campbellii ATCC 25920). Vibrio phage SIO-2 has a circularly permuted genome of 80,598 bp, which displays unusual features. This genome is larger than that of most known siphoviruses and only 38 of the 116 predicted proteins had homologues in databases. Another divergence is manifest by the origin of core genes, most of which share robust similarities with unrelated viruses and bacteria spanning a wide range of phyla. These core genes are arranged in the same order as in most bacteriophages but they are unusually interspaced at two places with insertions of DNA comprising a high density of uncharacterized genes. The acquisition of these DNA inserts is associated with morphological variation of SIO-2 capsid, which assembles as a large (80 nm) shell with a novel T=12 symmetry. These atypical structural features confer on SIO-2 a remarkable stability to a variety of physical, chemical and environmental factors. Given this high level of functional and genomic novelty, SIO-2 emerges as a model of considerable interest in ecological and evolutionary studies. PMID:22225728

  8. Hypersensitive response and acyl-homoserine lactone production of the fire blight antagonists Erwinia tasmaniensis and Erwinia billingiae.

    PubMed

    Jakovljevic, Vladimir; Jock, Susanne; Du, Zhiqiang; Geider, Klaus

    2008-09-01

    Fire blight caused by the Gram-negative bacterium Erwinia amylovora can be controlled by antagonistic microorganisms. We characterized epiphytic bacteria isolated from healthy apple and pear trees in Australia, named Erwinia tasmaniensis, and the epiphytic bacterium Erwinia billingiae from England for physiological properties, interaction with plants and interference with growth of E. amylovora. They reduced symptom formation by the fire blight pathogen on immature pears and the colonization of apple flowers. In contrast to E. billingiae, E. tasmaniensis strains induced a hypersensitive response in tobacco leaves and synthesized levan in the presence of sucrose. With consensus primers deduced from lsc as well as hrpL, hrcC and hrcR of the hrp region of E. amylovora and of related bacteria, these genes were successfully amplified from E. tasmaniensis DNA and alignment of the encoded proteins to other Erwinia species supported a role for environmental fitness of the epiphytic bacterium. Unlike E. tasmaniensis, the epiphytic bacterium E. billingiae produced an acyl-homoserine lactone for bacterial cell-to-cell communication. Their competition with the growth of E. amylovora may be involved in controlling fire blight.

  9. Plant Evolution: Evolving Antagonistic Gene Regulatory Networks.

    PubMed

    Cooper, Endymion D

    2016-06-20

    Developing a structurally complex phenotype requires a complex regulatory network. A new study shows how gene duplication provides a potential source of antagonistic interactions, an important component of gene regulatory networks. PMID:27326708

  10. Plant Evolution: Evolving Antagonistic Gene Regulatory Networks.

    PubMed

    Cooper, Endymion D

    2016-06-20

    Developing a structurally complex phenotype requires a complex regulatory network. A new study shows how gene duplication provides a potential source of antagonistic interactions, an important component of gene regulatory networks.

  11. Marine energy.

    PubMed

    Kerr, David

    2007-04-15

    Marine energy is renewable and carbon free and has the potential to make a significant contribution to energy supplies in the future. In the UK, tidal power barrages and wave energy could make the largest contribution, and tidal stream energy could make a smaller but still a useful contribution. This paper provides an overview of the current status and prospects for electrical generation from marine energy. It concludes that a realistic potential contribution to UK electricity supplies is approximately 80 TWh per year but that many years of development and investment will be required if this potential is to be realized. PMID:17272244

  12. Identification and Evaluation of Strain B37 of Bacillus subtilis Antagonistic to Sapstain Fungi on Poplar Wood

    PubMed Central

    Zhang, XiaoHua; Zhao, GuiHua; Li, DeWei; Li, ShunPeng; Hong, Qing

    2014-01-01

    Devaluation of poplar products by sapstain accounts for huge and unpredictable losses each year in China. We had isolated four poplar sapstain fungi, Ceratocystis adiposa Hz91, Lasiodiplodia theobromae YM0737, L. theobromae Fx46, and Fusarium sp. YM05, from five poplar varieties and 13 antagonistic bacteria from nine diverse varieties. After being experimented with agar plates, wood chips, and enzyme activities, strain B37 was identified as the best poplar sapstain biocontrol bacterium. The strain B37 was identified as Bacillus subtilis using sequences of the 16S rRNA gene, physiological biochemical, and morphological characteristics. PMID:25401124

  13. Identification and evaluation of strain B37 of Bacillus subtilis antagonistic to sapstain fungi on poplar wood.

    PubMed

    Zhang, XiaoHua; Zhao, GuiHua; Li, DeWei; Li, ShunPeng; Hong, Qing

    2014-01-01

    Devaluation of poplar products by sapstain accounts for huge and unpredictable losses each year in China. We had isolated four poplar sapstain fungi, Ceratocystis adiposa Hz91, Lasiodiplodia theobromae YM0737, L. theobromae Fx46, and Fusarium sp. YM05, from five poplar varieties and 13 antagonistic bacteria from nine diverse varieties. After being experimented with agar plates, wood chips, and enzyme activities, strain B37 was identified as the best poplar sapstain biocontrol bacterium. The strain B37 was identified as Bacillus subtilis using sequences of the 16S rRNA gene, physiological biochemical, and morphological characteristics. PMID:25401124

  14. Detection of Salmonella bacterium in drinking water using microring resonator.

    PubMed

    Bahadoran, Mahdi; Noorden, Ahmad Fakhrurrazi Ahmad; Mohajer, Faeze Sadat; Abd Mubin, Mohamad Helmi; Chaudhary, Kashif; Jalil, Muhammad Arif; Ali, Jalil; Yupapin, Preecha

    2016-01-01

    A new microring resonator system is proposed for the detection of the Salmonella bacterium in drinking water, which is made up of SiO2-TiO2 waveguide embedded inside thin film layer of the flagellin. The change in refractive index due to the binding of the Salmonella bacterium with flagellin layer causes a shift in the output signal wavelength and the variation in through and drop port's intensities, which leads to the detection of Salmonella bacterium in drinking water. The sensitivity of proposed sensor for detecting of Salmonella bacterium in water solution is 149 nm/RIU and the limit of detection is 7 × 10(-4)RIU.

  15. Carbohydrase Systems of Saccharophagus degradans Degrading Marine Complex Polysaccharides

    PubMed Central

    Hutcheson, Steven W.; Zhang, Haitao; Suvorov, Maxim

    2011-01-01

    Saccharophagus degradans 2–40 is a γ-subgroup proteobacterium capable of using many of the complex polysaccharides found in the marine environment for growth. To utilize these complex polysaccharides, this bacterium produces a plethora of carbohydrases dedicated to the processing of a carbohydrate class. Aiding in the identification of the contributing genes and enzymes is the known genome sequence for this bacterium. This review catalogs the genes and enzymes of the S. degradans genome that are likely to function in the systems for the utilization of agar, alginate, α- and β-glucans, chitin, mannans, pectins, and xylans and discusses the cell biology and genetics of each system as it functions to transfer carbon back to the bacterium. PMID:21731555

  16. Marine Resources

    NASA Technical Reports Server (NTRS)

    Sherman, J. W., III

    1975-01-01

    The papers presented in the marine session may be broadly grouped into several classes: microwave region instruments compared to infrared and visible region sensors, satellite techniques compared to aircraft techniques, open ocean applications compared to coastal region applications, and basic research and understanding of ocean phenomena compared to research techniques that offer immediate applications.

  17. Marine Mammals.

    ERIC Educational Resources Information Center

    Meith, Nikki

    Marine mammals have not only fascinated and inspired human beings for thousands of years, but they also support a big business by providing flesh for sea-borne factories, sustaining Arctic lifestyles and traditions, and attracting tourists to ocean aquaria. While they are being harpooned, bludgeoned, shot, netted, and trained to jump through…

  18. Marine envenomations.

    PubMed

    Balhara, Kamna S; Stolbach, Andrew

    2014-02-01

    This article describes the epidemiology and presentation of human envenomation from marine organisms. Venom pathophysiology, envenomation presentation, and treatment options are discussed for sea snake, stingray, spiny fish, jellyfish, octopus, cone snail, sea urchin, and sponge envenomation. The authors describe the management of common exposures that cause morbidity as well as the keys to recognition and treatment of life-threatening exposures. PMID:24275176

  19. Marine Trades.

    ERIC Educational Resources Information Center

    Abbott, Alan

    This curriculum guide provides materials for a competency-based course in marine trades at the secondary level. The curriculum design uses the curriculum infused model for the teaching of basic skills as part of vocational education and demonstrates the relationship of vocationally related skills to communication, mathematics, and science…

  20. Genetic and functional diversity among the antagonistic potential fluorescent pseudomonads isolated from tea rhizosphere.

    PubMed

    Saikia, Ratul; Sarma, Rupak K; Yadav, Archana; Bora, Tarun C

    2011-02-01

    Twenty-five fluorescent pseudomonads from rhizospheric soil of six tea gardens in four district of Upper Assam, India were isolated and screened for antagonistic activity against fungal pathogens such as Fusarium oxysporum f. sp. raphani (For), Fusarium oxysporum f. sp. ciceri (Foc), Fusarium semitectum (Fs), and Rhizoctonia solani (Rs); and bacterial pathogens-Staphylococcus aureus (Sa), Escherichia coli (Ec), and Klebsiella pneumoniae (Kp). Most of the isolates exhibited strong antagonistic activity against the fungal pathogens and gram-positive bacterium i.e. Staphylococcus aureus. Productions of siderophore, salicylic acid (SA), hydrogen cyanide (HCN), and cell wall-degrading enzyme (chitinase) were studied to observe the possible mechanisms of antagonistic activity of the isolates. Correlation between the antagonistic potentiality of some isolates and their levels of production of siderophore, salicylic acid, and hydrogen cyanide was observed. Out of the 25 isolates, antibiotic-coding genes, 2,4-diacetylphloroglucinol (DAPG) and pyoluteorin (PLT) were detected in the isolates, Pf12 and Pf373, respectively. Genetic diversity of these fluorescent pseudomonads were analyzed with reference to four strains of Pseudomonas fluorescens NICM 2099(T), P. aeruginosa MTCC 2582(T), P. aureofaciens NICM 2026(T), and P. syringae MTCC 673(T). 16S rDNA-RFLP analysis of these isolates using three tetra cutter restriction enzymes (HaeIII, AluI and MspI) revealed two distinct clusters. Cluster A comprised only two isolates Pf141 and 24-PfM3, and cluster B comprised 23 isolates along with four reference strains. PMID:20689953

  1. Development of a microbial community of bacterial and yeast antagonists to control wound-invading postharvest pathogens of fruits.

    PubMed

    Janisiewicz, W J; Bors, B

    1995-09-01

    Two antagonists, the bacterium Pseudomonas syringae and the pink yeast Sporobolomyces roseus, against blue mold (caused by Penicillium expansum) on apple controlled this disease more effectively when combined at approximately equal biomass (50:50 of the same turbidity) than in individual applications. Addition of L-asparagine enhanced the biocontrol effectiveness of P. syringae but decreased that of S. roseus and had no significant effect when the antagonists were combined. Populations of both antagonists increased in apple wounds and were further stimulated by the addition of L-asparagine. The carrying capacity of wounds for P. syringae was not affected by S. roseus. Populations of P. syringae in wounds inoculated individually or in a 50:50 mixture with S. roseus reached the same level after 3 days at 22 degrees C. However, populations of S. roseus recovered after applications of the mixture were consistently lower than those recovered after individual applications. Similar effects were observed in in vitro tests in which populations of S. roseus grown in mixtures with P. syringae were consistently lower than those grown alone, while the populations of P. syringae were not affected by the presence of S. roseus. A total of 36 carbon and 35 nitrogen compounds were tested for utilization by both antagonists. Fourteen nitrogenous compounds were utilized by both P. syringae and S. roseus, and an additional nine compounds were utilized by P. syringae. S. roseus and P. syringae utilized 17 and 13 carbon sources, respectively; 9 sources were common to both antagonists. Populations of these antagonists in apple wounds appear to form a relatively stable community dominated by P. syringae.(ABSTRACT TRUNCATED AT 250 WORDS)

  2. High-affinity neuropeptide Y receptor antagonists.

    PubMed Central

    Daniels, A J; Matthews, J E; Slepetis, R J; Jansen, M; Viveros, O H; Tadepalli, A; Harrington, W; Heyer, D; Landavazo, A; Leban, J J

    1995-01-01

    Neuropeptide Y (NPY) is one of the most abundant peptide transmitters in the mammalian brain. In the periphery it is costored and coreleased with norepinephrine from sympathetic nerve terminals. However, the physiological functions of this peptide remain unclear because of the absence of specific high-affinity receptor antagonists. Three potent NPY receptor antagonists were synthesized and tested for their biological activity in in vitro, ex vivo, and in vivo functional assays. We describe here the effects of these antagonists inhibiting specific radiolabeled NPY binding at Y1 and Y2 receptors and antagonizing the effects of NPY in human erythroleukemia cell intracellular calcium mobilization perfusion pressure in the isolated rat kidney, and mean arterial blood pressure in anesthetized rats. PMID:7568074

  3. Antagonistic formation motion of cooperative agents

    NASA Astrophysics Data System (ADS)

    Lu, Wan-Ting; Dai, Ming-Xiang; Xue, Fang-Zheng

    2015-02-01

    This paper investigates a new formation motion problem of a class of first-order multi-agent systems with antagonistic interactions. A distributed formation control algorithm is proposed for each agent to realize the antagonistic formation motion. A sufficient condition is derived to ensure that all of the agents make an antagonistic formation motion in a distributed manner. It is shown that all of the agents can be spontaneously divided into several groups and that agents in the same group collaborate while agents in different groups compete. Finally, a numerical simulation is included to demonstrate our theoretical results. Project supported by the National Natural Science Foundation of China (Grant Nos. 61203080 and 61473051) and the Natural Science Foundation of Chongqing City (Grant No. CSTC 2011BB0081).

  4. Genome analysis of Pseudoalteromonas flavipulchra JG1 reveals various survival advantages in marine environment

    PubMed Central

    2013-01-01

    Background Competition between bacteria for habitat and resources is very common in the natural environment and is considered to be a selective force for survival. Many strains of the genus Pseudoalteromonas were confirmed to produce bioactive compounds that provide those advantages over their competitors. In our previous study, P. flavipulchra JG1 was found to synthesize a Pseudoalteromonas flavipulchra antibacterial Protein (PfaP) with L-amino acid oxidase activity and five small chemical compounds, which were the main competitive agents of the strain. In addition, the genome of this bacterium has been previously sequenced as Whole Genome Shotgun project (PMID: 22740664). In this study, more extensive genomic analysis was performed to identify specific genes or gene clusters which related to its competitive feature, and further experiments were carried out to confirm the physiological roles of these genes when competing with other microorganisms in marine environment. Results The antibacterial protein PfaP may also participate in the biosynthesis of 6-bromoindolyl-3-acetic acid, indicating a synergistic effect between the antibacterial macromolecule and small molecules. Chitinases and quorum quenching enzymes present in P. flavipulchra, which coincide with great chitinase and acyl homoserine lactones degrading activities of strain JG1, suggest other potential mechanisms contribute to antibacterial/antifungal activities. Moreover, movability and rapid response mechanisms to phosphorus starvation and other stresses, such as antibiotic, oxidative and heavy metal stress, enable JG1 to adapt to deleterious, fluctuating and oligotrophic marine environments. Conclusions The genome of P. flavipulchra JG1 exhibits significant genetic advantages against other microorganisms, encoding antimicrobial agents as well as abilities to adapt to various adverse environments. Genes involved in synthesis of various antimicrobial substances enriches the antagonistic mechanisms of P

  5. Marine Geology

    NASA Astrophysics Data System (ADS)

    van Andel, Tjeerd H.

    Marine geology was blessed early, about 30 years ago, with two great textbooks, one by P.H. Kuenen, the other by Francis P. Shepard, but in more recent years, no one has dared synthesize a field that has become so diverse and is growing so rapidly. There are many texts written for the beginning undergraduate student, mostly by marine geologists, but none can be handed conveniently to a serious advanced student or given to a colleague interested in what the field has wrought. The reason for this regrettable state is obvious; only an active, major scholar could hope to write such a book well, but the years would pass, his students dwindle, his grants vanish. He himself might be out of date before his book was. Kennett has earned a large measure of gratitude for his attempt to undertake this task. His personal price must have been high but so are our rewards.

  6. Marine Education: Progress and Promise.

    ERIC Educational Resources Information Center

    Fortner, Rosanne; Wildman, Terry M.

    1980-01-01

    Examined are the scope and status of precollege marine education, including history of marine education, present interdisciplinary marine education, informal approaches to marine education, marine awareness studies, and some implications of marine education. (Author/DS)

  7. Agrobacterium tumefaciens Is a Diazotrophic Bacterium

    PubMed Central

    Kanvinde, Lalita; Sastry, G. R. K.

    1990-01-01

    This is the first report that Agrobacterium tumefaciens can fix nitrogen in a free-living condition as shown by its abilities to grow on nitrogen-free medium, reduce acetylene to ethylene, and incorporate 15N supplied as 15N2. As with most other well-characterized diazotrophic bacteria, the presence of NH4+ in the medium and aerobic conditions repress nitrogen fixation by A. tumefaciens. The system requires molybdenum. No evidence for nodulation was found with pea, peanut, or soybean plants. Further understanding of the nitrogen-fixing ability of this bacterium, which has always been considered a pathogen, should cast new light on the evolution of a pathogenic versus symbiotic relationship. Images PMID:16348237

  8. Agrobacterium tumefaciens is a diazotrophic bacterium

    SciTech Connect

    Kanvinde, L.; Sastry, G.R.K. )

    1990-07-01

    This is the first report that Agrobacterium tumefaciens can fix nitrogen in a free-living condition as shown by its abilities to grown on nitrogen-free medium, reduce acetylene to ethylene, and incorporate {sup 15}N supplied as {sup 15}N{sub 2}. As with most other well-characterized diazotrophic bacteria, the presence of NH{sub 4}{sup +} in the medium and aerobic conditions repress nitrogen fixation by A. tumefaciens. The system requires molybdenum. No evidence for nodulation was found with pea, peanut, or soybean plants. Further understanding of the nitrogen-fixing ability of this bacterium, which has always been considered a pathogen, should cast new light on the evolution of a pathogenic versus symbiotic relationship.

  9. Immobilization of the Methanogenic bacterium methanosarcina barkeri

    SciTech Connect

    Scherer, P.; Kluge, M.; Klein, J.; Sahm, H.

    1981-05-01

    Whole cells of the methanogen Methanosarcina barkeri were immobilized in an alginate network which was crosslinked with Ca/sup 2+/ calcium ions. The rates of methanol conversion to methane of entrapped cells were found to be in the same range as the corresponding rates of free cells. Furthermore, immobilized cells were active for a longer period than free cells. The particle size of the spherical alginate beads and thus diffusion has no obvious influence on the turnover of methanol. The half-value period for methanol conversion activity determined in a buffer medium was approximately 4 days at 37/degree/C for entrapped cells. The high rates of methanol degradation indicated that the immobilization technique preserved the cellular functions of this methanogenic bacterium. 24 refs.

  10. [Control effect and bacteriostasis of mulberry endophytic bacterium Burkholderia cepacia Lu10-1 on silkworm septicemia].

    PubMed

    Dong, Fa-Bao; Mu, Zhi-Mei; Yu, Qi; Zhao, Kai; Liu, Zhao-Yang; Wang, Yan-Wen; Gao, Hui-Ju

    2012-11-01

    A laboratory test was conducted to study the control effect and bacteriostasis of antagonistic bacterium Burkholderia cepacia Lu10-1 isolated from mulberry on silkworm septicemia, aimed to develop a new microbial pesticide to control silkworm diseases. The supernatant of Lu10-1 zymotic fluid achieved 41.2% control efficiency and 24.0% prophylactic effect on silkworm septicemia. The antibacterial crude extract of Lu10-1 had stronger antagonistic activity against Bacillus bombyseptieus. The diameter of inhibition zone reached 18.20 mm, and the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the antibacterial crude extract were 1.56 and 3.13 mg x mL(-1), respectively. After treated with the antibacterial crude extract, B. bombyseptieus never appeared logarithmic growth phase, its cell membrane permeability changed, intracellular protein leaked out, intracellular macromolecular protein degraded, and at last, the thalli cracked, inner substances out-flowed, cavity formed, and cell ablated. It was considered that the antagonistic substances of Lu10-1 strain could be used for controlling silkworm septicemia, with preferable development foreground. PMID:23431798

  11. The chemical formula of a magnetotactic bacterium.

    PubMed

    Naresh, Mohit; Das, Sayoni; Mishra, Prashant; Mittal, Aditya

    2012-05-01

    Elucidation of the chemical logic of life is one of the grand challenges in biology, and essential to the progress of the upcoming field of synthetic biology. Treatment of microbial cells explicitly as a "chemical" species in controlled reaction (growth) environments has allowed fascinating discoveries of elemental formulae of a few species that have guided the modern views on compositions of a living cell. Application of mass and energy balances on living cells has proved to be useful in modeling of bioengineering systems, particularly in deriving optimized media compositions for growing microorganisms to maximize yields of desired bio-derived products by regulating intra-cellular metabolic networks. In this work, application of elemental mass balance during growth of Magnetospirillum gryphiswaldense in bioreactors has resulted in the discovery of the chemical formula of the magnetotactic bacterium. By developing a stoichiometric equation characterizing the formation of a magnetotactic bacterial cell, coupled with rigorous experimental measurements and robust calculations, we report the elemental formula of M. gryphiswaldense cell as CH(2.06)O(0.13)N(0.28)Fe(1.74×10(-3)). Remarkably, we find that iron metabolism during growth of this magnetotactic bacterium is much more correlated individually with carbon and nitrogen, compared to carbon and nitrogen with each other, indicating that iron serves more as a nutrient during bacterial growth rather than just a mineral. Magnetotactic bacteria have not only invoked some interest in the field of astrobiology for the last two decades, but are also prokaryotes having the unique ability of synthesizing membrane bound intracellular organelles. Our findings on these unique prokaryotes are a strong addition to the limited repertoire, of elemental compositions of living cells, aimed at exploring the chemical logic of life.

  12. Exopolysaccharides Play a Role in the Swarming of the Benthic Bacterium Pseudoalteromonas sp. SM9913

    PubMed Central

    Liu, Ang; Mi, Zi-Hao; Zheng, Xiao-Yu; Yu, Yang; Su, Hai-Nan; Chen, Xiu-Lan; Xie, Bin-Bin; Zhou, Bai-Cheng; Zhang, Yu-Zhong; Qin, Qi-Long

    2016-01-01

    Most marine bacteria secrete exopolysaccharide (EPS), which is important for bacterial survival in the marine environment. However, it is still unclear whether the self-secreted EPS is involved in marine bacterial motility. Here we studied the role of EPS in the lateral flagella-driven swarming motility of benthic bacterium Pseudoalteromonas sp. SM9913 (SM9913) by a comparison of wild SM9913 and ΔepsT, an EPS synthesis defective mutant. Reduction of EPS production in ΔepsT did not affect the growth rate or the swimming motility, but significantly decreased the swarming motility on a swarming plate, suggesting that the EPS may play a role in SM9913 swarming. However, the expression and assembly of lateral flagella in ΔepsT were not affected. Instead, ΔepsT had a different swarming behavior from wild SM9913. The swarming of ΔepsT did not have an obvious rapid swarming period, and its rate became much lower than that of wild SM9913 after 35 h incubation. An addition of surfactin or SM9913 EPS on the surface of the swarming plate could rescue the swarming level. These results indicate that the self-secreted EPS is required for the swarming of SM9913. This study widens our understanding of the function of the EPS of benthic bacteria. PMID:27092127

  13. Genomic characterization of a temperate phage of the psychrotolerant deep-sea bacterium Aurantimonas sp.

    PubMed

    Yoshida, Mitsuhiro; Yoshida-Takashima, Yukari; Nunoura, Takuro; Takai, Ken

    2015-01-01

    A temperate phage (termed AmM-1) was identified from the psychrotolerant Rhizobiales bacterium Aurantimonas sp. C5-1, which was isolated from bathypelagic water (water depth = 1,500 m) in the northwest Pacific. The AmM-1 genome is 47,800 bp in length and contains 67 coding sequences. Although phage AmM-1 morphologically belongs to the family Myoviridae, its genomic structure, particularly modular genome organization, is similar to that of lambda-type phages of Siphoviridae. Genetic and phylogenetic analyses of the structural core genes also revealed that AmM-1 has a mosaic genomic structure that includes a lambda-like head (Siphoviridae) and P2-like tail (Myoviridae). The sequences of the structural core genes of AmM-1 are distinct from those of previously characterized phage groups but similar to those of recently identified one prophage element and one phage of marine Rhizobiales bacteria: a potential prophage element in the marine psychrotolerant Aureimonas ureilytica DSM 18598 genome and the temperate phage RR-1A infecting Rhizobium radiobacter P007 isolated from deep subseafloor sediment. The mosaic genome structure of AmM-1 suggests the occurrence of genetic exchange between distinct temperate phages in marine Rhizobiales populations.

  14. Antagonist-elicited cannabis withdrawal in humans.

    PubMed

    Gorelick, David A; Goodwin, Robert S; Schwilke, Eugene; Schwope, David M; Darwin, William D; Kelly, Deanna L; McMahon, Robert P; Liu, Fang; Ortemann-Renon, Catherine; Bonnet, Denis; Huestis, Marilyn A

    2011-10-01

    Cannabinoid CB1 receptor antagonists have potential therapeutic benefits, but antagonist-elicited cannabis withdrawal has not been reported in humans. Ten male daily cannabis smokers received 8 days of increasingly frequent 20-mg oral Δ⁹-tetrahydrocannabinol (THC) dosages (40-120 mg/d) around-the-clock to standardize cannabis dependence while residing on a closed research unit. On the ninth day, double-blind placebo or 20- (suggested therapeutic dose) or 40-mg oral rimonabant, a CB1-cannabinoid receptor antagonist, was administered. Cannabis withdrawal signs and symptoms were assessed before and for 23.5 hours after rimonabant. Rimonabant, THC, and 11-hydroxy-THC plasma concentrations were quantified by mass spectrometry. The first 6 subjects received 20-mg rimonabant (1 placebo); the remaining 4 subjects received 40-mg rimonabant (1 placebo). Fourteen subjects enrolled; 10 completed before premature termination because of withdrawal of rimonabant from clinical development. Three of 5 subjects in the 20-mg group, 1 of 3 in the 40-mg group, and none of 2 in the placebo group met the prespecified withdrawal criterion of 150% increase or higher in at least 3 visual analog scales for cannabis withdrawal symptoms within 3 hours of rimonabant dosing. There were no significant associations between visual analog scale, heart rate, or blood pressure changes and peak rimonabant plasma concentration, area-under-the-rimonabant-concentration-by-time curve (0-8 hours), or peak rimonabant/THC or rimonabant/(THC + 11-hydroxy-THC) plasma concentration ratios. In summary, prespecified criteria for antagonist-elicited cannabis withdrawal were not observed at the 20- or 40-mg rimonabant doses. These data do not preclude antagonist-elicited withdrawal at higher rimonabant doses.

  15. Antagonist-elicited cannabis withdrawal in humans.

    PubMed

    Gorelick, David A; Goodwin, Robert S; Schwilke, Eugene; Schwope, David M; Darwin, William D; Kelly, Deanna L; McMahon, Robert P; Liu, Fang; Ortemann-Renon, Catherine; Bonnet, Denis; Huestis, Marilyn A

    2011-10-01

    Cannabinoid CB1 receptor antagonists have potential therapeutic benefits, but antagonist-elicited cannabis withdrawal has not been reported in humans. Ten male daily cannabis smokers received 8 days of increasingly frequent 20-mg oral Δ⁹-tetrahydrocannabinol (THC) dosages (40-120 mg/d) around-the-clock to standardize cannabis dependence while residing on a closed research unit. On the ninth day, double-blind placebo or 20- (suggested therapeutic dose) or 40-mg oral rimonabant, a CB1-cannabinoid receptor antagonist, was administered. Cannabis withdrawal signs and symptoms were assessed before and for 23.5 hours after rimonabant. Rimonabant, THC, and 11-hydroxy-THC plasma concentrations were quantified by mass spectrometry. The first 6 subjects received 20-mg rimonabant (1 placebo); the remaining 4 subjects received 40-mg rimonabant (1 placebo). Fourteen subjects enrolled; 10 completed before premature termination because of withdrawal of rimonabant from clinical development. Three of 5 subjects in the 20-mg group, 1 of 3 in the 40-mg group, and none of 2 in the placebo group met the prespecified withdrawal criterion of 150% increase or higher in at least 3 visual analog scales for cannabis withdrawal symptoms within 3 hours of rimonabant dosing. There were no significant associations between visual analog scale, heart rate, or blood pressure changes and peak rimonabant plasma concentration, area-under-the-rimonabant-concentration-by-time curve (0-8 hours), or peak rimonabant/THC or rimonabant/(THC + 11-hydroxy-THC) plasma concentration ratios. In summary, prespecified criteria for antagonist-elicited cannabis withdrawal were not observed at the 20- or 40-mg rimonabant doses. These data do not preclude antagonist-elicited withdrawal at higher rimonabant doses. PMID:21869692

  16. Engineering of a psychrophilic bacterium for the bioremediation of aromatic compounds.

    PubMed

    Parrilli, Ermengilda; Papa, Rosanna; Tutino, Maria Luisa; Sannia, Giovanni

    2010-01-01

    Microbial degradation of aromatic hydrocarbons has been studied with the aim of developing applications for the removal of toxic compounds. Efforts have been directed toward the genetic manipulation of mesophilic bacteria to improve their ability to degrade pollutants, even though many pollution problems occur in sea waters and in effluents of industrial processes which are characterized by low temperatures. From these considerations the idea of engineering a psychrophilic microorganism for the oxidation of aromatic compounds was developed.In a previous paper it was demonstrated that the recombinant Antarctic Pseudoalteromonas haloplanktis TAC125 (PhTAC/tou) expressing a toluene-o-xylene monooxygenase (ToMO) is able to convert several aromatic compounds into corresponding catechols. In our work we improved the metabolic capability of PhTAC/tou cells by combining action of recombinant ToMO enzyme with that of the endogenous P. haloplanktis TAC125 laccase-like protein. This strategy allowed conferring new and specific degradative capabilities to a bacterium isolated from an unpolluted environment; indeed engineered PhTAC/tou cells are able to grow on aromatic compounds as sole carbon and energy sources. Our approach demonstrates the possibility to use the engineered psychrophilic bacterium for the bioremediation of chemically contaminated marine environments and/or cold effluents.

  17. Marine Lubricants

    NASA Astrophysics Data System (ADS)

    Carter, B. H.; Green, D.

    Marine diesel engines are classified by speed, either large (medium speed) or very large (slow speed) with high efficiencies and burning low-quality fuel. Slow-speed engines, up to 200 rpm, are two-stroke with separate combustion chamber and sump connected by a crosshead, with trunk and system oil lubricants for each. Medium-speed diesels, 300-1500 rpm, are of conventional automotive design with one lubricant. Slow-speed engines use heavy fuel oil of much lower quality than conventional diesel with problems of deposit cleanliness, acidity production and oxidation. Lubricants are mainly SAE 30/40/50 monogrades using paraffinic basestocks. The main types of additives are detergents/dispersants, antioxidants, corrosion inhibitors, anti-wear/load-carrying/ep, pour-point depressants and anti-foam compounds. There are no simple systems for classifying marine lubricants, as for automotive, because of the wide range of engine design, ratings and service applications they serve. There are no standard tests; lubricant suppliers use their own tests or the Bolnes 3DNL, with final proof from field tests. Frequent lubricant analyses safeguard engines and require standard sampling procedures before determination of density, viscosity, flash point, insolubles, base number, water and wear metal content.

  18. High affinity retinoic acid receptor antagonists: analogs of AGN 193109.

    PubMed

    Johnson, A T; Wang, L; Gillett, S J; Chandraratna, R A

    1999-02-22

    A series of high affinity retinoic acid receptor (RAR) antagonists were prepared based upon the known antagonist AGN 193109 (2). Introduction of various phenyl groups revealed a preference for substitution at the para-position relative to the meta-site. Antagonists with the highest affinities for the RARs possessed hydrophobic groups, however, the presence of polar functionality was also well tolerated.

  19. Characterizations of intracellular arsenic in a bacterium

    NASA Astrophysics Data System (ADS)

    Wolfe-Simon, F.; Yannone, S. M.; Tainer, J. A.

    2011-12-01

    Life requires a key set of chemical elements to sustain growth. Yet, a growing body of literature suggests that microbes can alter their nutritional requirements based on the availability of these chemical elements. Under limiting conditions for one element microbes have been shown to utilize a variety of other elements to serve similar functions often (but not always) in similar molecular structures. Well-characterized elemental exchanges include manganese for iron, tungsten for molybdenum and sulfur for phosphorus or oxygen. These exchanges can be found in a wide variety of biomolecules ranging from protein to lipids and DNA. Recent evidence suggested that arsenic, as arsenate or As(V), was taken up and incorporated into the cellular material of the bacterium GFAJ-1. The evidence was interpreted to support As(V) acting in an analogous role to phosphate. We will therefore discuss our ongoing efforts to characterize intracellular arsenate and how it may partition among the cellular fractions of the microbial isolate GFAJ-1 when exposed to As(V) in the presence of various levels of phosphate. Under high As(V) conditions, cells express a dramatically different proteome than when grown given only phosphate. Ongoing studies on the diversity and potential role of proteins and metabolites produced in the presence of As(V) will be reported. These investigations promise to inform the role and additional metabolic potential for As in biology. Arsenic assimilation into biomolecules contributes to the expanding set of chemical elements utilized by microbes in unusual environmental niches.

  20. Lixivaptan: a novel vasopressin receptor antagonist.

    PubMed

    Ku, Elaine; Nobakht, Niloofar; Campese, Vito M

    2009-05-01

    Arginine vasopressin, also known as antidiuretic hormone, is a neuropeptide that functions in the maintenance of body water homeostasis. Inappropriate secretion of vasopressin has been implicated in the pathophysiology of multiple diseases, including polycystic kidney disease, syndrome of inappropriate antidiuretic hormone (SIADH) secretion, and the hyponatremia commonly associated with cirrhosis and congestive heart failure. Vasopressin receptor antagonists are novel agents that block the physiologic actions of vasopressin. Lixivaptan is a vasopressin receptor antagonist with high V2 receptor affinity and is now undergoing Phase III clinical trials. Studies so far have demonstrated that lixivaptan is efficacious in the correction of hyponatremia in SIADH, heart failure and liver cirrhosis with ascites, and few adverse effects have been noted. Thus, lixivaptan remains a promising therapeutic modality for the treatment of multiple diseases and prevention of the associated morbidity and mortality associated with hyponatremia.

  1. [Cutaneous adverse effects of TNFalpha antagonists].

    PubMed

    Failla, V; Sabatiello, M; Lebas, E; de Schaetzen, V; Dezfoulian, B; Nikkels, A F

    2012-01-01

    The TNFalpha antagonists, including adalimumab, etanercept and infliximab, represent a class of anti-inflammatory and immunosuppressive drugs. Although cutaneous adverse effects are uncommon, they are varied. There is no particular risk profile to develop cutaneous adverse effects. The principal acute side effects are injection site reactions and pruritus. The major long term cutaneous side effects are infectious and inflammatory conditions. Neoplastic skin diseases are exceptional. The association with other immunosuppressive agents can increase the risk of developing cutaneous adverse effects. Some adverse effects, such as lupus erythematosus, require immediate withdrawal of the biological treatment, while in other cases temporary withdrawal is sufficient. The majority of the other cutaneous adverse effects can be dealt without interrupting biologic treatment. Preclinical and clinical investigations revealed that the new biologics, aiming IL12/23, IL23 and IL17, present a similar profile of cutaneous adverse effects, although inflammatory skin reactions may be less often encountered compared to TNFalpha antagonists.

  2. Cytoplasmic and Periplasmic Proteomic Signatures of Exponentially Growing Cells of the Psychrophilic Bacterium Pseudoalteromonas haloplanktis TAC125 ▿ †

    PubMed Central

    Wilmes, Boris; Kock, Holger; Glagla, Susanne; Albrecht, Dirk; Voigt, Birgit; Markert, Stephanie; Gardebrecht, Antje; Bode, Rüdiger; Danchin, Antoine; Feller, Georges; Hecker, Michael; Schweder, Thomas

    2011-01-01

    The psychrophilic model bacterium Pseudoalteromonas haloplanktis is characterized by remarkably fast growth rates under low-temperature conditions in a range from 5°C to 20°C. In this study the proteome of cellular compartments, the cytoplasm and periplasm, of P. haloplanktis strain TAC125 was analyzed under exponential growth conditions at a permissive temperature of 16°C. By means of two-dimensional protein gel electrophoresis and mass spectrometry, a first inventory of the most abundant cytoplasmic and periplasmic proteins expressed in a peptone-supplemented minimal medium was established. By this approach major enzymes of the amino acid catabolism of this marine bacterium could be functionally deduced. The cytoplasmic proteome showed a predominance of amino acid degradation pathways and tricarboxylic acid (TCA) cycle enzymes but also the protein synthesis machinery. Furthermore, high levels of cold acclimation and oxidative stress proteins could be detected at this moderate growth temperature. The periplasmic proteome was characterized by a significant abundance of transporters, especially of highly expressed putative TonB-dependent receptors. This high capacity for protein synthesis, efficient amino acid utilization, and substrate transport may contribute to the fast growth rates of the copiotrophic bacterium P. haloplanktis in its natural environments. PMID:21183643

  3. Enhancement of Survival and Electricity Production in an Engineered Bacterium by Light-Driven Proton Pumping▿ †

    PubMed Central

    Johnson, Ethan T.; Baron, Daniel B.; Naranjo, Belén; Bond, Daniel R.; Schmidt-Dannert, Claudia; Gralnick, Jeffrey A.

    2010-01-01

    Microorganisms can use complex photosystems or light-dependent proton pumps to generate membrane potential and/or reduce electron carriers to support growth. The discovery that proteorhodopsin is a light-dependent proton pump that can be expressed readily in recombinant bacteria enables development of new strategies to probe microbial physiology and to engineer microbes with new light-driven properties. Here, we describe functional expression of proteorhodopsin and light-induced changes in membrane potential in the bacterium Shewanella oneidensis strain MR-1. We report that there were significant increases in electrical current generation during illumination of electrochemical chambers containing S. oneidensis expressing proteorhodopsin. We present evidence that an engineered strain is able to consume lactate at an increased rate when it is illuminated, which is consistent with the hypothesis that proteorhodopsin activity enhances lactate uptake by increasing the proton motive force. Our results demonstrate that there is coupling of a light-driven process to electricity generation in a nonphotosynthetic engineered bacterium. Expression of proteorhodopsin also preserved the viability of the bacterium under nutrient-limited conditions, providing evidence that fulfillment of basic energy needs of organisms may explain the widespread distribution of proteorhodopsin in marine environments. PMID:20453141

  4. TRPV1 antagonists as potential antitussive agents.

    PubMed

    McLeod, Robbie L; Correll, Craig C; Jia, Yanlin; Anthes, John C

    2008-01-01

    Cough is an important defensive pulmonary reflex that removes irritants, fluids, or foreign materials from the airways. However, when cough is exceptionally intense or when it is chronic and/or nonproductive it may require pharmacologic suppression. For many patients, antitussive therapies consist of OTC products with inconsequential efficacies. On the other hand, the prescription antitussive market is dominated by older opioid drugs such as codeine. Unfortunately, "codeine-like" drugs suppress cough at equivalent doses that also often produce significant ancillary liabilities such as GI constipation, sedation, and respiratory depression. Thus, the discovery of a novel and effective antitussive drug with an improved side effect profile relative to codeine would fulfill an unmet clinical need in the treatment of cough. Afferent pulmonary nerves are endowed with a multitude of potential receptor targets, including TRPV1, that could act to attenuate cough. The evidence linking TRPV1 to cough is convincing. TRPV1 receptors are found on sensory respiratory nerves that are important in the generation of the cough reflex. Isolated pulmonary vagal afferent nerves are responsive to TRPV1 stimulation. In vivo, TRPV1 agonists such as capsaicin elicit cough when aerosolized and delivered to the lungs. Pertinent to the debate on the potential use of TRPV1 antagonist as antitussive agents are the observations that airway afferent nerves become hypersensitive in diseased and inflamed lungs. For example, the sensitivity of capsaicin-induced cough responses following upper respiratory tract infection and in airway inflammatory diseases such as asthma and COPD is increased relative to that of control responses. Indeed, we have demonstrated that TRPV1 antagonism can attenuate antigen-induced cough in the allergic guinea pig. However, it remains to be determined if the emerging pharmacologic profile of TRPV1 antagonists will translate into a novel human antitussive drug. Current

  5. Taxonomic characterization of the cellulose-degrading bacterium NCIB 10462

    SciTech Connect

    Dees, C.; Ringleberg, D.; Scott, T.C.; Phelps, T.

    1994-06-01

    The gram negative cellulase-producing bacterium NCIB 10462 has been previously named Pseudomonas fluorescens subsp. or var. cellulosa. Since there is renewed interest in cellulose-degrading bacteria for use in bioconversion of cellulose to chemical feed stocks and fuels, we re-examined the characteristics of this microorganism to determine its proper taxonomic characterization and to further define it`s true metabolic potential. Metabolic and physical characterization of NCIB 10462 revealed that this was an alkalophilic, non-fermentative, gram negative, oxidase positive, motile, cellulose-degrading bacterium. The aerobic substrate utilization profile of this bacterium was found to have few characteristics consistent with a classification of P. fluorescens with a very low probability match with the genus Sphingomonas. Total lipid analysis did not reveal that any sphingolipid bases are produced by this bacterium. NCIB 10462 was found to grow best aerobically but also grows well in complex media under reducing conditions. NCIB 10462 grew slowly under full anaerobic conditions on complex media but growth on cellulosic media was found only under aerobic conditions. Total fatty acid analysis (MIDI) of NCIB 10462 failed to group this bacterium with a known pseudomonas species. However, fatty acid analysis of the bacteria when grown at temperatures below 37{degrees}C suggest that the organism is a pseudomonad. Since a predominant characteristic of this bacterium is it`s ability to degrade cellulose, we suggest it be called Pseudomonas cellulosa.

  6. Management of calcium channel antagonist overdose.

    PubMed

    Salhanick, Steven D; Shannon, Michael W

    2003-01-01

    Calcium channel antagonists are used primarily for the treatment of hypertension and tachyarrhythmias. Overdose of calcium channel antagonists can be lethal. Calcium channel antagonists act at the L-type calcium channels primarily in cardiac and vascular smooth muscle preventing calcium influx into cells with resultant decreases in vascular tone and cardiac inotropy and chronotropy. The L-type calcium channel is a complex structure and is thus affected by a large number of structurally diverse antagonists. In the setting of overdose, patients may experience vasodilatation and bradycardia leading to a shock state. Patients may also be hyperglycaemic and acidotic due to the blockade of L-type calcium channels in the pancreatic islet cells that affect insulin secretion. Aggressive therapy is warranted in the setting of toxicity. Gut decontamination with charcoal, or whole bowel irrigation or multiple-dose charcoal in the setting of extended-release products is indicated. Specific antidotes include calcium salts, glucagon and insulin. Calcium salts may be given in bolus doses or may be employed as a continuous infusion. Care should be exercised to avoid the administration of calcium in the setting of concomitant digoxin toxicity. Insulin administration has been used effectively to increase cardiac inotropy and survival. The likely mechanism involves a shift to carbohydrate metabolism in the setting of decreased availability of carbohydrates due to decreased insulin secretion secondary to blockade of calcium channels in pancreatic islet cells. Glucose should be administered as well to maintain euglycaemia. Supportive care including the use of phosphodiesterase inhibitors, adrenergic agents, cardiac pacing, balloon pump or extracorporeal bypass is frequently indicated if antidotal therapy is not effective. Careful evaluation of asymptomatic patients, including and electrocardiogram and a period of observation, is indicated. Patients ingesting a nonsustained

  7. [Inhibition of adherence of Corynebacterium diphtheriae to human buccal epithelium by glycoside hydrolases from marine hydrobiontes].

    PubMed

    Zaporozhets, T S; Makarenkova, I D; Bakunina, I Iu; Burtseva, Iu V; Kusaĭkin, M I; Balabanova, L A; Zviagintseva, T N; Besednova, N N; Rasskazov, V A

    2010-01-01

    A possibility of adhesion inhibition of Corynebacterium diphtheriae to human buccal epithelium by glycoside hydrolases of marine hydrobiontes was investigated using alpha-galactosidase from marine bacterium Pseudoalteromonas sp. KMM 701, total enzyme preparation and beta-1,3-glucanase from marine fungi Chaetomium, total enzyme preparation and beta-1,3-glucanase from marine mollusk Littorina kurila, and total enzyme preparation from crystalline style of marine mollusk Spisula sachalinensis were used. The enzymes were added to test-tubes containing buccal epithelial cells and/or the toxigenic bacterial strain C. diphtheriae No 1129, v. gravis. All the investigated enzymes were able to abort C. diphtheriae adherence, to human buccal epithelocytes. Inhibition of adhesion was more pronounced in the case of treatment of epithelocytes with highly purified enzymes of marine hydrobiontes in comparison with total enzyme preparations. The significant inhibition of C. diphtheriae adhesion was observed when the enzymes were added to the epithelocytes with the attached microorganisms. The results obtained show that glycoside hydrolases of marine hydrobiontes degrade any carbohydrates expressed on cell surface of bacterium or human buccal epithelocytes, impair unique lectin-carbohydrate interaction and prevent the adhesion. PMID:20695214

  8. Marine antivenoms.

    PubMed

    Currie, Bart J

    2003-01-01

    There is an enormous diversity and complexity of venoms and poisons in marine animals. Fatalities have occurred from envenoming by sea snakes, jellyfish, venomous fish such as stonefish, cone snails, and blue-ringed octopus. Deaths have also followed ingestion of toxins in shellfish, puffer fish (Fugu), and ciguatoxin-containing fish. However antivenoms are generally only available for envenoming by certain sea snakes, the major Australian box jellyfish (Chironex fleckeri) and stonefish. There have been difficulties in characterizing the toxins of C. fleckeri venom, and there are conflicting animals studies on the efficacy of C. fleckeri antivenom. The vast majority of C. fleckeri stings are not life-threatening, with painful skin welts the major finding. However fatalities that do occur usually do so within 5 to 20 minutes of the sting. This unprecedented rapid onset of cardiotoxicity in clinical envenoming suggests that antivenom may need to be given very early (within minutes) and possibly in large doses if a life is to be saved. Forty years of anecdotal experience supports the beneficial effect of stonefish antivenom in relieving the excruciating pain after stonefish spine penetration. It remains uncertain whether stonefish antivenom is efficacious in stings from spines of other venomous fish, and the recommendation of giving the antivenom intramuscularly needs reassessment. PMID:12807313

  9. Adhesion of marine fouling organisms on hydrophilic and amphiphilic polysaccharides.

    PubMed

    Bauer, Stella; Arpa-Sancet, Maria Pilar; Finlay, John A; Callow, Maureen E; Callow, James A; Rosenhahn, Axel

    2013-03-26

    Polysaccharides are a promising material for nonfouling surfaces because their chemical composition makes them highly hydrophilic and able to form water-storing hydrogels. Here we investigated the nonfouling properties of hyaluronic acid (HA) and chondroitin sulfate (CS) against marine fouling organisms. Additionally, the free carboxyl groups of HA and CS were postmodified with the hydrophobic trifluoroethylamine (TFEA) to block free carboxyl groups and render the surfaces amphiphilic. All coatings were tested with respect to their protein resistance and against settlement and adhesion of different marine fouling species. Both the settlement and adhesion strength of a marine bacterium (Cobetia marina), zoospores of the seaweed Ulva linza, and cells of a diatom (Navicula incerta) were reduced compared to glass control surfaces. In most cases, TFEA capping increased or maintained the performance of the HA coatings, whereas for the very well performing CS coatings the antifouling performance was reduced after capping. PMID:23425225

  10. Proteorhodopsin phototrophy promotes survival of marine bacteria during starvation.

    PubMed

    Gómez-Consarnau, Laura; Akram, Neelam; Lindell, Kristoffer; Pedersen, Anders; Neutze, Richard; Milton, Debra L; González, José M; Pinhassi, Jarone

    2010-01-01

    Proteorhodopsins are globally abundant photoproteins found in bacteria in the photic zone of the ocean. Although their function as proton pumps with energy-yielding potential has been demonstrated, the ecological role of proteorhodopsins remains largely unexplored. Here, we report the presence and function of proteorhodopsin in a member of the widespread genus Vibrio, uncovered through whole-genome analysis. Phylogenetic analysis suggests that the Vibrio strain AND4 obtained proteorhodopsin through lateral gene transfer, which could have modified the ecology of this marine bacterium. We demonstrate an increased long-term survival of AND4 when starved in seawater exposed to light rather than held in darkness. Furthermore, mutational analysis provides the first direct evidence, to our knowledge, linking the proteorhodopsin gene and its biological function in marine bacteria. Thus, proteorhodopsin phototrophy confers a fitness advantage to marine bacteria, representing a novel mechanism for bacterioplankton to endure frequent periods of resource deprivation at the ocean's surface.

  11. Complete genome sequence of the gliding freshwater bacterium Fluviicola taffensis type strain (RW262T)

    SciTech Connect

    Woyke, Tanja; Chertkov, Olga; Lapidus, Alla L.; Nolan, Matt; Lucas, Susan; Glavina Del Rio, Tijana; Tice, Hope; Cheng, Jan-Fang; Tapia, Roxanne; Han, Cliff; Goodwin, Lynne A.; Pitluck, Sam; Liolios, Konstantinos; Pagani, Ioanna; Ivanova, N; Huntemann, Marcel; Mavromatis, K; Mikhailova, Natalia; Pati, Amrita; Chen, Amy; Palaniappan, Krishna; Land, Miriam L; Hauser, Loren John; Brambilla, Evelyne-Marie; Rohde, Manfred; Mwirichia, Romano; Sikorski, Johannes; Tindall, Brian; Goker, Markus; Bristow, James; Eisen, Jonathan; Markowitz, Victor; Hugenholtz, Philip; Klenk, Hans-Peter; Kyrpides, Nikos C

    2011-01-01

    Fluviicola taffensis O'Sullivan et al. 2005 belongs to the monotypic genus Fluviicola within the family Cryomorphaceae. The species is of interest because of its isolated phylogenetic location in the genome-sequenced fraction of the tree of life. Strain RW262 T forms a monophyletic lineage with uncultivated bacteria represented in freshwater 16S rRNA gene libraries. A similar phylogenetic differentiation occurs between freshwater and marine bacteria in the family Flavobacteriaceae, a sister family to Cryomorphaceae. Most remarkable is the inability of this freshwater bacterium to grow in the presence of Na + ions. All other genera in the family Cryomorphaceae are from marine habitats and have an absolute requirement for Na + ions or natural sea water. F. taffensis is the first member of the family Cryomorphaceae with a completely sequenced and publicly available genome. The 4,633,577 bp long genome with its 4,082 protein-coding and 49 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  12. Antagonistic functional duality of cancer genes.

    PubMed

    Stepanenko, A A; Vassetzky, Y S; Kavsan, V M

    2013-10-25

    Cancer evolution is a stochastic process both at the genome and gene levels. Most of tumors contain multiple genetic subclones, evolving in either succession or in parallel, either in a linear or branching manner, with heterogeneous genome and gene alterations, extensively rewired signaling networks, and addicted to multiple oncogenes easily switching with each other during cancer progression and medical intervention. Hundreds of discovered cancer genes are classified according to whether they function in a dominant (oncogenes) or recessive (tumor suppressor genes) manner in a cancer cell. However, there are many cancer "gene-chameleons", which behave distinctly in opposite way in the different experimental settings showing antagonistic duality. In contrast to the widely accepted view that mutant NADP(+)-dependent isocitrate dehydrogenases 1/2 (IDH1/2) and associated metabolite 2-hydroxyglutarate (R)-enantiomer are intrinsically "the drivers" of tumourigenesis, mutant IDH1/2 inhibited, promoted or had no effect on cell proliferation, growth and tumorigenicity in diverse experiments. Similar behavior was evidenced for dozens of cancer genes. Gene function is dependent on genetic network, which is defined by the genome context. The overall changes in karyotype can result in alterations of the role and function of the same genes and pathways. The diverse cell lines and tumor samples have been used in experiments for proving gene tumor promoting/suppressive activity. They all display heterogeneous individual karyotypes and disturbed signaling networks. Consequently, the effect and function of gene under investigation can be opposite and versatile in cells with different genomes that may explain antagonistic duality of cancer genes and the cell type- or the cellular genetic/context-dependent response to the same protein. Antagonistic duality of cancer genes might contribute to failure of chemotherapy. Instructive examples of unexpected activity of cancer genes and

  13. The Lipid A from the haloalkaliphilic bacterium Salinivibrio sharmensis strain BAG(T).

    PubMed

    Carillo, Sara; Pieretti, Giuseppina; Lindner, Buko; Romano, Ida; Nicolaus, Barbara; Lanzetta, Rosa; Parrilli, Michelangelo; Corsaro, Maria Michela

    2013-01-21

    Lipid A is a major constituent of the lipopolysaccharides (or endotoxins), which are complex amphiphilic macromolecules anchored in the outer membrane of Gram-negative bacteria. The glycolipid lipid A is known to possess the minimal chemical structure for LPSs endotoxic activity, able to cause septic shock. Lipid A isolated from extremophiles is interesting, since very few cases of pathogenic bacteria have been found among these microorganisms. In some cases their lipid A has shown to have an antagonist activity, i.e., it is able to interact with the immune system of the host without triggering a proinflammatory response by blocking binding of substances that could elicit such a response. However, the relationship between the structure and the activity of these molecules is far from being completely clear. A deeper knowledge of the lipid A chemical structure can help the understanding of these mechanisms. In this manuscript, we present our work on the complete structural characterization of the lipid A obtained from the lipopolysaccharides (LPS) of the haloalkaliphilic bacterium Salinivibrio sharmensis. Lipid A was obtained from the purified LPS by mild acid hydrolysis. The lipid A, which contains different number of fatty acids residues, and its partially deacylated derivatives were completely characterized by means of electrospray ionization Fourier transform ion cyclotron (ESI FT-ICR) mass spectrometry and chemical analysis.

  14. The Lipid A from the Haloalkaliphilic Bacterium Salinivibrio sharmensis Strain BAGT

    PubMed Central

    Carillo, Sara; Pieretti, Giuseppina; Lindner, Buko; Romano, Ida; Nicolaus, Barbara; Lanzetta, Rosa; Parrilli, Michelangelo; Corsaro, Maria Michela

    2013-01-01

    Lipid A is a major constituent of the lipopolysaccharides (or endotoxins), which are complex amphiphilic macromolecules anchored in the outer membrane of Gram-negative bacteria. The glycolipid lipid A is known to possess the minimal chemical structure for LPSs endotoxic activity, able to cause septic shock. Lipid A isolated from extremophiles is interesting, since very few cases of pathogenic bacteria have been found among these microorganisms. In some cases their lipid A has shown to have an antagonist activity, i.e., it is able to interact with the immune system of the host without triggering a proinflammatory response by blocking binding of substances that could elicit such a response. However, the relationship between the structure and the activity of these molecules is far from being completely clear. A deeper knowledge of the lipid A chemical structure can help the understanding of these mechanisms. In this manuscript, we present our work on the complete structural characterization of the lipid A obtained from the lipopolysaccharides (LPS) of the haloalkaliphilic bacterium Salinivibrio sharmensis. Lipid A was obtained from the purified LPS by mild acid hydrolysis. The lipid A, which contains different number of fatty acids residues, and its partially deacylated derivatives were completely characterized by means of electrospray ionization Fourier transform ion cyclotron (ESI FT-ICR) mass spectrometry and chemical analysis. PMID:23337252

  15. Mineralocorticoid receptor antagonists and endothelial function

    PubMed Central

    Maron, Bradley A.; Leopold, Jane A.

    2010-01-01

    Hyperaldosteronism has been associated with endothelial dysfunction and impaired vascular reactivity in patients with hypertension or congestive heart failure. The mineralocorticoid receptor (MR) antagonists spironolactone and eplerenone have been shown to reduce morbidity and mortality, in part, by ameliorating the adverse effects of aldosterone on vascular function. Although spironolactone and eplerenone are increasingly utilized in patients with cardiovascular disease, widespread clinical use is limited by the development of gynecomastia with spironolactone and hyperkalemia with both agents. This suggests that the development of newer agents with favorable side effect profiles is warranted. PMID:18729003

  16. Estrogen receptor (ER) agonists and androgen receptor (AR) antagonists in effluents from Norwegian North Sea oil production platforms.

    PubMed

    Tollefsen, Knut-Erik; Harman, Christopher; Smith, Andy; Thomas, Kevin V

    2007-03-01

    The in vitro estrogen receptor (ER) agonist and androgen receptor (AR) antagonist potencies of offshore produced water effluents collected from the Norwegian Sector were determined using recombinant yeast estrogen and androgen screens. Solid phase extraction (SPE) concentrates of the effluents showed E2 agonist activities similar to those previously reported for the United Kingdom (UK) Continental Shelf (<0.1-4 ng E2 L(-1)). No activity was detected in the filtered oil droplets suggesting that produced water ER activity is primarily associated with the dissolved phase. Targeted analysis for methyl- to nonyl-substituted alkylphenol isomers show the occurrence of known ER agonists in the analysed samples. For the first time, AR antagonists were detected in both the dissolved and oil associated phase at concentrations of between 20 and 8000 microg of flutamide equivalents L(-1). The identity of the AR antagonists is unknown, however this represents a significant input into the marine environment of unknown compounds that exert a known biological effect. It is recommended that further analysis using techniques such as bioassay-directed analysis is performed to identify the compounds/groups of compounds that are responsible in order to improve the assessment of the risk posed by produced water discharges to the marine environment. PMID:17258235

  17. Rational discovery of novel nuclear hormone receptor antagonists

    NASA Astrophysics Data System (ADS)

    Schapira, Matthieu; Raaka, Bruce M.; Samuels, Herbert H.; Abagyan, Ruben

    2000-02-01

    Nuclear hormone receptors (NRs) are potential targets for therapeutic approaches to many clinical conditions, including cancer, diabetes, and neurological diseases. The crystal structure of the ligand binding domain of agonist-bound NRs enables the design of compounds with agonist activity. However, with the exception of the human estrogen receptor-, the lack of antagonist-bound "inactive" receptor structures hinders the rational design of receptor antagonists. In this study, we present a strategy for designing such antagonists. We constructed a model of the inactive conformation of human retinoic acid receptor- by using information derived from antagonist-bound estrogen receptor-α and applied a computer-based virtual screening algorithm to identify retinoic acid receptor antagonists. Thus, the currently available crystal structures of NRs may be used for the rational design of antagonists, which could lead to the development of novel drugs for a variety of diseases.

  18. Thalassolituus oleivorans gen. nov., sp. nov., a novel marine bacterium that obligately utilizes hydrocarbons.

    PubMed

    Yakimov, Michail M; Giuliano, Laura; Denaro, Renata; Crisafi, Ermanno; Chernikova, Tatiana N; Abraham, Wolf-Rainer; Luensdorf, Heinrich; Timmis, Kenneth N; Golyshin, Peter N

    2004-01-01

    An aerobic, heterotrophic, Gram-negative, curved bacterial strain, designated MIL-1T, was isolated by extinction dilution from an n-tetradecane enrichment culture that was established from sea water/sediment samples collected in the harbour of Milazzo, Italy. In the primary enrichment, the isolate formed creamy-white, medium-sized colonies on the surface of the agar. The isolate did not grow in the absence of NaCl; growth was optimal at 2.7% NaCl. Only a narrow spectrum of organic compounds, including aliphatic hydrocarbons (C7-C20), their oxidized derivatives and acetate, were used as growth substrates. The isolate was not able to grow under denitrifying conditions. The DNA G+C content and genome size of strain MIL-1T were estimated to be 53.2 mol% and 2.2 Mbp, respectively. The major cellular and phospholipid fatty acids were palmitoleic, palmitic and oleic acids (33.5, 29.5 and 11.0% and 18, 32 and 31%, respectively). 3-hydroxy lauric acid was the only hydroxy fatty acid detected. Thirteen different compounds that belonged to two types of phospholipid (phosphatidylethylamine and phosphatidylglycerol) were identified. 16S rRNA gene sequence analysis revealed that this isolate represents a distinct phyletic lineage within the gamma-Proteobacteria and has about 94.4% sequence similarity to Oceanobacter kriegii (the closest bacterial species with a validly published name). The deduced protein sequence of the putative alkane hydrolase, AlkB, of strain MIL-1T is related to the corresponding enzymes of Alcanivorax borkumensis and Pseudomonas oleovorans (81 and 80% similarity, respectively). On the basis of the analyses performed, Thalassolituus oleivorans gen. nov., sp. nov. is described. Strain MIL-1T (=DSM 14913T=LMG 21420T) is the type and only strain of T. oleivorans. PMID:14742471

  19. Complete genome sequence of the melanogenic marine bacterium Marinomonas mediterranea type strain (MMB-1T)

    SciTech Connect

    Lucas-Elio, Patricia; Goodwin, Lynne A.; Woyke, Tanja; Pitluck, Sam; Nolan, Matt; Kyrpides, Nikos C; Detter, J C; Copeland, A; Teshima, Hazuki; Bruce, David; Detter, J. Chris; Tapia, Roxanne; Han, Cliff; Land, Miriam L; Ivanova, N; Mikhailova, Natalia; Johnston, Andrew W. B.; Sanchez-Amat, Antonio

    2012-01-01

    Marinomonas mediterranea MMB-1 T Solano & Sanchez-Amat 1999 belongs to the family Oceanospirillaceae within the phylum Proteobacteria. This species is of interest because it is the only species described in the genus Marinomonas to date that can synthesize melanin pigments, which is mediated by the activity of a tyrosinase. M. mediterranea expresses other oxidases of biotechnological interest, such as a multicopper oxidase with laccase activity and a novel L-lysine-epsilon-oxidase. The 4,684,316 bp long genome harbors 4,228 proteincoding genes and 98 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.

  20. Draft Genome Sequence of Rhodovulum sp. Strain NI22, a Naphthalene-Degrading Marine Bacterium

    PubMed Central

    Brown, Lisa M.; Gunasekera, Thusitha S.; Bowen, Loryn L.

    2015-01-01

    Rhodovulum sp. strain NI22 is a hydrocarbon-degrading member of the genus Rhodovulum. The draft genome of Rhodovulum sp. NI22 is 3.8 Mb in size, with 3,756 coding sequences and 64.4% G+C content. The catechol and gentisate pathways for naphthalene degradation are predicted to be present in Rhodovulum sp. NI22. PMID:25614575

  1. Overexpression and characterization of lycopene cyclase (CrtY) from marine bacterium Paracoccus haeundaensis.

    PubMed

    Jeong, Tae Hyug; Ji, Keunho; Kim, Young Tae

    2013-02-01

    Lycopene cyclase converts lycopene to beta-carotene by catalyzing the formation of two beta-rings at each end of the linear carotene structure. This reaction takes place as a two-step reaction in which both sides of of the lycopene molecule are cyclized into beta-carotene rings via the monocyclic gamma-carotene as an intermediate. The crtY gene coding for lycopene cyclase from Paracoccus haeundaensis consists of 1,158 base pairs encoding 386 amino acids residues. An expression plasmid containing the crtY gene (pET44a-CrtY) was constructed and expressed in Escherichia coli, and produced a recombinant protein of approximately 43 kDa, corresponding to the molecular mass of lycopene cyclase. The expressed protein was purified to homogeneity by His-tag affinity chromatography and showed enzymatic activity corresponding to lycopene cyclase. We also determined the lycopene substrate specificity and NADPH cofactor requirements of the purified protein. The Km values for lycopene and NADPH were 3.5 microM and 2 mM, respectively. The results obtained from this study will provide a wider base of knowledge on the enzyme characterization of lycopene cyclase at the molecular level.

  2. Winogradskyella eckloniae sp. nov., a marine bacterium isolated from the brown alga Ecklonia cava.

    PubMed

    Kim, Ji-Young; Park, So-Hyun; Seo, Ga-Young; Kim, Young-Ju; Oh, Duck-Chul

    2015-09-01

    A novel bacterial strain, designated EC29(T), was isolated from the brown alga Ecklonia cava collected on Jeju Island, Republic of Korea. Cells of strain EC29(T) were Gram-stain-negative, aerobic, rod-shaped and motile by gliding. Growth was observed at 10-30 °C (optimum, 20-25 °C), at pH 6.0-9.5 (optimum, pH 7.5) and in the presence of 1-5% (w/v) NaCl. Phylogenetic analyses based on the 16S rRNA gene sequence revealed that the strain belonged to the genus Winogradskyella. Strain EC29(T) exhibited the highest 16S rRNA gene sequence similarities, of 96.5-97.8%, to the type strains of Winogradskyella pulchriflava EM106(T), Winogradskyella echinorum KMM 6211(T) and Winogradskyella ulvae KMM 6390(T). Strain EC29(T) exhibited < 27% DNA-DNA relatedness with Winogradskyella pulchriflava EM106(T) and Winogradskyella echinorum KMM 6211(T). The predominant fatty acids of strain EC29(T) were iso-C15 : 0, iso-C15 : 1 G, C15 : 0, iso-C17 : 0 3-OH, iso-C15 : 0 3-OH and anteiso-C15 : 0. The DNA G+C content was 31.1 mol% and the major respiratory quinone was menaquinone-6 (MK-6). Based on a polyphasic study, strain EC29(T) is considered to represent a novel species of the genus Winogradskyella, for which the name Winogradskyella eckloniae sp. nov. is proposed. The type strain is EC29(T) ( = KCTC 32172(T) = JCM 18703(T)). PMID:25979633

  3. Fabibacter misakiensis sp. nov., a marine bacterium isolated from coastal surface water.

    PubMed

    Wong, Shu-Kuan; Park, Sanghwa; Lee, Jung-Sook; Lee, Keun Chul; Chiura, Hiroshi Xavier; Kogure, Kazuhiro; Hamasaki, Koji

    2015-10-01

    A slightly curved-rod-shaped, pink-pigmented, Gram-stain-negative, aerobic bacterial strain with gliding motility, designated SK-8T, was isolated from coastal surface water of Misaki, Japan. Phylogenetic trees generated using 16S rRNA gene sequences revealed that strain SK-8T belonged to the genus Fabibacter and showed 96.0 % sequence similarity to the type strain of the most closely related species, Fabibacter pacificus DY53T. The novel isolate was phenotypically and physiologically different from previously described strains. The major cellular fatty acids were iso-C15 : 1 G, iso-C15 : 0 and iso-C17 : 0 3-OH. Major polar lipids were phosphatidylethanolamine, two aminophospholipids and an unidentified phospholipid. The DNA G+C content was 39.1 mol% and MK-7 was the only predominant isoprenoid quinone. On the basis of this taxonomic study employing a polyphasic approach, it was suggested that strain SK-8T represents a novel species of the genus Fabibacter, with the newly proposed name Fabibacter misakiensis sp. nov. The type strain is SK-8T ( = NBRC 110216T = KCTC 32969T). PMID:26296998

  4. RECA EXPRESSION IN RESPONSE TO SOLAR UVR IN THE MARINE BACTERIUM VIBRIO NATRIEGENS.

    EPA Science Inventory

    Medicinal plants may carry residuals of environmentally persistent pesticides or assimilate heavy metals in varying degrees. Several factors may influence contaminant accumulation, including species, level and duration of contaminant exposure, and topography. As part of a program...

  5. Luminescence control in the marine bacterium Vibrio fischeri: An analysis of the dynamics of lux regulation.

    PubMed

    James, S; Nilsson, P; James, G; Kjelleberg, S; Fagerström, T

    2000-03-01

    A mathematical model has been developed based on the fundamental properties of the control system formed by the lux genes and their products in Vibrio fischeri. The model clearly demonstrates how the components of this system work together to create two, stable metabolic states corresponding to the expression of the luminescent and non-luminescent phenotypes. It is demonstrated how the cell can "switch" between these steady states due to changes in parameters describing metabolic processes and the extracellular concentration of the signal molecule N-3-oxohexanoyl-l-homoserine lactone. In addition, it is shown how these parameters influence how sensitive the switch mechanism is to cellular LuxR and N-3-oxohexanoyl-l-homoserine lactone and complex concentration. While these properties could lead to the collective phenomenon known as quorum sensing, the model also predicts that under certain metabolic circumstances, basal expression of the lux genes could cause a cell to luminesce in the absence of extracellular signal molecule. Finally, the model developed in this study provides a basis for analysing the impact of other levels of control upon lux regulation.

  6. Simultaneous heterotrophic nitrification and aerobic denitrification by the marine origin bacterium Pseudomonas sp. ADN-42.

    PubMed

    Jin, Ruofei; Liu, Tianqi; Liu, Guangfei; Zhou, Jiti; Huang, Jianyu; Wang, Aijie

    2015-02-01

    Recent research has highlighted the existence of some bacteria that are capable of performing heterotrophic nitrification and have a phenomenal ability to denitrify their nitrification products under aerobic conditions. A high-salinity-tolerant strain ADN-42 was isolated from Hymeniacidon perleve and found to display high heterotrophic ammonium removal capability. This strain was identified as Pseudomonas sp. via 16S rRNA gene sequence analysis. Gene cloning and sequencing analysis indicated that the bacterial genome contains N2O reductase function (nosZ) gene. NH3-N removal rate of ADN-42 was very high. And the highest removal rate was 6.52 mg/L · h in the presence of 40 g/L NaCl. Under the condition of pure oxygen (DO >8 mg/L), NH3-N removal efficiency was 56.9 %. Moreover, 38.4 % of oxygen remained in the upper gas space during 72 h without greenhouse gas N2O production. Keeping continuous and low level of dissolved oxygen (DO <3 mg/L) was helpful for better denitrification performance. All these results indicated that the strain has heterotrophic nitrification and aerobic denitrification abilities, which guarantee future application in wastewater treatment.

  7. Jeotgalicoccus marinus sp. nov., a marine bacterium isolated from a sea urchin.

    PubMed

    Chen, Yi-Guang; Zhang, Yu-Qin; Shi, Jin-Xiao; Xiao, Huai-Dong; Tang, Shu-Kun; Liu, Zhu-Xiang; Huang, Ke; Cui, Xiao-Long; Li, Wen-Jun

    2009-07-01

    A novel non-sporulating, non-motile, catalase- and oxidase-positive, facultatively anaerobic, moderately halophilic, Gram-positive coccus, designated JSM 076033(T), was isolated from a sea urchin (Hemicentrotus pulcherrimus) collected from the South China Sea. Strain JSM 076033(T) was able to grow in the presence of 0.5-25.0 % (w/v) total salts and at pH 6.0-10.0 and 10-45 degrees C; optimum growth was observed with 5.0-10.0 % (w/v) total salts and at pH 7.0-8.0 and 25-30 degrees C. The major amino acid constituents of the cell wall were glycine, lysine and alanine. The major cellular fatty acids were anteiso-C(15 : 0), iso-C(15 : 0) and anteiso-C(17 : 0). The respiratory quinones were MK-7 (60.7 %) and MK-6 (39.3 %) and the polar lipids were diphosphatidylglycerol, phosphatidylglycerol and an unidentified phospholipid. The DNA G+C content was 40.3 mol%. A phylogenetic analysis based on 16S rRNA gene sequence comparisons revealed that strain JSM 076033(T) should be assigned to the genus Jeotgalicoccus. The sequence similarities between the novel isolate and the type strains of recognized Jeotgalicoccus species were in the range 95.2-97.2 %. The results of the phylogenetic analysis, combined with DNA-DNA relatedness data, phenotypic characteristics and chemotaxonomic information, support the view that strain JSM 076033(T) represents a novel species of the genus Jeotgalicoccus, for which the name Jeotgalicoccus marinus sp. nov. is proposed. The type strain is JSM 076033(T) (=CCTCC AA 207028(T) =DSM 19772(T) =KCTC 13189(T)).

  8. Marivirga lumbricoides sp. nov., a marine bacterium isolated from the South China Sea.

    PubMed

    Xu, Yongle; Zhang, Rui; Li, Qipei; Liu, Keshao; Jiao, Nianzhi

    2015-02-01

    A novel, aerobic, heterotrophic, orange-pigmented, Gram-staining-negative, rod-shaped, gliding bacterial strain, designated JLT2000(T), was isolated from surface water of the South China Sea. The strain was oxidase- and catalase-positive. The major cellular fatty acids of strain JLT2000 T: were C12 : 0, iso-C15 : 1 G, iso-C15 : 0, iso-C17 : 0 3-OH, summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 0. MK-7 was the major respiratory quinone and the major polar lipids were phosphatidylcholine and phosphatidylethanolamine. The genomic DNA G+C content of strain JLT2000(T) was 37.9 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain JLT2000(T) formed a branch within the genus Marivirga, but was clearly separated from the two established species of this genus, Marivirga tractuosa and Marivirga sericea. The 16S rRNA gene sequence similarity of strain JLT2000(T) with the type strains of these two species was 95.8 % and 96.1 %, respectively. Strain JLT2000(T) had a shorter cell length and wider growth range in different temperatures and salinities than those of Marivirga tractuosa NBRC 15989(T) and Marivirga sericea NBRC 15983(T). In addition, strain JLT2000(T) could utilize more carbon sources and hydrolyse more polymers than Marivirga tractuosa NBRC 15989(T) and Marivirga sericea NBRC 15983(T). Based on this polyphasic analysis, strain JLT2000(T) represents a novel species of the genus Marivirga, for which the name Marivirga lumbricoides sp. nov. is proposed. The type strain is JLT2000(T) ( = JCM 18012(T) = CGMCC 1.10832(T)).

  9. Simultaneous heterotrophic nitrification and aerobic denitrification by the marine origin bacterium Pseudomonas sp. ADN-42.

    PubMed

    Jin, Ruofei; Liu, Tianqi; Liu, Guangfei; Zhou, Jiti; Huang, Jianyu; Wang, Aijie

    2015-02-01

    Recent research has highlighted the existence of some bacteria that are capable of performing heterotrophic nitrification and have a phenomenal ability to denitrify their nitrification products under aerobic conditions. A high-salinity-tolerant strain ADN-42 was isolated from Hymeniacidon perleve and found to display high heterotrophic ammonium removal capability. This strain was identified as Pseudomonas sp. via 16S rRNA gene sequence analysis. Gene cloning and sequencing analysis indicated that the bacterial genome contains N2O reductase function (nosZ) gene. NH3-N removal rate of ADN-42 was very high. And the highest removal rate was 6.52 mg/L · h in the presence of 40 g/L NaCl. Under the condition of pure oxygen (DO >8 mg/L), NH3-N removal efficiency was 56.9 %. Moreover, 38.4 % of oxygen remained in the upper gas space during 72 h without greenhouse gas N2O production. Keeping continuous and low level of dissolved oxygen (DO <3 mg/L) was helpful for better denitrification performance. All these results indicated that the strain has heterotrophic nitrification and aerobic denitrification abilities, which guarantee future application in wastewater treatment. PMID:25432342

  10. Bartonella quintana lipopolysaccharide (LPS): structure and characteristics of a potent TLR4 antagonist for in-vitro and in-vivo applications

    PubMed Central

    Malgorzata-Miller, Gosia; Heinbockel, Lena; Brandenburg, Klaus; van der Meer, Jos W. M.; Netea, Mihai G.; Joosten, Leo A. B.

    2016-01-01

    The pattern recognition receptor TLR4 is well known as a crucial receptor during infection and inflammation. Several TLR4 antagonists have been reported to inhibit the function of TLR4. Both natural occurring antagonists, lipopolysaccharide (LPS) from Gram-negative bacteria as well as synthetic compounds based on the lipid A structure of LPS have been described as potent inhibitors of TLR4. Here, we have examined the characteristics of a natural TLR4 antagonist, isolated from Bartonella quintana bacterium by elucidating its chemical primary structure. We have found that this TLR4 antagonist is actually a lipooligosaccharide (LOS) instead of a LPS, and that it acts very effective, with a high inhibitory activity against triggering by the LPS-TLR4 system in the presence of a potent TLR4 agonist (E. coli LPS). Furthermore, we demonstrate that B. quintana LPS is not inactivated by polymyxin B, a classical cyclic cationic polypeptide antibiotic that bind the lipid A part of LPS, such as E. coli LPS. Using a murine LPS/D-galactosamine endotoxaemia model we showed that treatment with B. quintana LPS could improve the survival rate significantly. Since endogenous TLR4 ligands have been associated with several inflammatory- and immune-diseases, B. quintana LPS might be a novel therapeutic strategy for TLR4-driven pathologies. PMID:27670746

  11. Coiled to diffuse: Brownian motion of a helical bacterium.

    PubMed

    Butenko, Alexander V; Mogilko, Emma; Amitai, Lee; Pokroy, Boaz; Sloutskin, Eli

    2012-09-11

    We employ real-time three-dimensional confocal microscopy to follow the Brownian motion of a fixed helically shaped Leptospira interrogans (LI) bacterium. We extract from our measurements the translational and the rotational diffusion coefficients of this bacterium. A simple theoretical model is suggested, perfectly reproducing the experimental diffusion coefficients, with no tunable parameters. An older theoretical model, where edge effects are neglected, dramatically underestimates the observed rates of translation. Interestingly, the coiling of LI increases its rotational diffusion coefficient by a factor of 5, compared to a (hypothetical) rectified bacterium of the same contour length. Moreover, the translational diffusion coefficients would have decreased by a factor of ~1.5, if LI were rectified. This suggests that the spiral shape of the spirochaete bacteria, in addition to being employed for their active twisting motion, may also increase the ability of these bacteria to explore the surrounding fluid by passive Brownian diffusion.

  12. Hydrogen Production by the Thermophilic Bacterium Thermotoga neapolitana

    PubMed Central

    Pradhan, Nirakar; Dipasquale, Laura; d’Ippolito, Giuliana; Panico, Antonio; Lens, Piet N. L.; Esposito, Giovanni; Fontana, Angelo

    2015-01-01

    As the only fuel that is not chemically bound to carbon, hydrogen has gained interest as an energy carrier to face the current environmental issues of greenhouse gas emissions and to substitute the depleting non-renewable reserves. In the last years, there has been a significant increase in the number of publications about the bacterium Thermotoga neapolitana that is responsible for production yields of H2 that are among the highest achievements reported in the literature. Here we present an extensive overview of the most recent studies on this hyperthermophilic bacterium together with a critical discussion of the potential of fermentative production by this bacterium. The review article is organized into sections focused on biochemical, microbiological and technical issues, including the effect of substrate, reactor type, gas sparging, temperature, pH, hydraulic retention time and organic loading parameters on rate and yield of gas production. PMID:26053393

  13. Hydrogen Production by the Thermophilic Bacterium Thermotoga neapolitana.

    PubMed

    Pradhan, Nirakar; Dipasquale, Laura; d'Ippolito, Giuliana; Panico, Antonio; Lens, Piet N L; Esposito, Giovanni; Fontana, Angelo

    2015-06-04

    As the only fuel that is not chemically bound to carbon, hydrogen has gained interest as an energy carrier to face the current environmental issues of greenhouse gas emissions and to substitute the depleting non-renewable reserves. In the last years, there has been a significant increase in the number of publications about the bacterium Thermotoga neapolitana that is responsible for production yields of H2 that are among the highest achievements reported in the literature. Here we present an extensive overview of the most recent studies on this hyperthermophilic bacterium together with a critical discussion of the potential of fermentative production by this bacterium. The review article is organized into sections focused on biochemical, microbiological and technical issues, including the effect of substrate, reactor type, gas sparging, temperature, pH, hydraulic retention time and organic loading parameters on rate and yield of gas production.

  14. Understanding the detailed motion of a model bacterium

    NASA Astrophysics Data System (ADS)

    Thawani, Akanksha; Tirumkudulu, Mahesh

    2014-11-01

    Inspired by the motion of flagellated bacteria such as Escherichia coli and Bacillus subtilis, we have built a macroscopic model bacterium, in order to investigate the intricate aspects of their motion which cannot be visualized under a microscope. The flagellated rod shaped cells were approximated with a spherical head attached to a rigid metal helix, via a plastic hook. The motion of model bacterium was observed in a high viscosity silicone oil to replicate the low Reynolds number flow conditions. A significant wobble was observed even in the absence of an off-axis flagellum. We suspect that the flexibility in the hook connecting the head and flagellum is the cause for wobble, since wobble was observed to increase significantly with hook-flexibility. The motion of the model bacterium was predicted using the Slender Body theory of Lighthill, and was compared with the measured trajectories.

  15. Activins and activin antagonists in hepatocellular carcinoma

    PubMed Central

    Deli, Alev; Kreidl, Emanuel; Santifaller, Stefan; Trotter, Barbara; Seir, Katja; Berger, Walter; Schulte-Hermann, Rolf; Rodgarkia-Dara, Chantal; Grusch, Michael

    2008-01-01

    In many parts of the world hepatocellular carcinoma (HCC) is among the leading causes of cancer-related mortality but the underlying molecular pathology is still insufficiently understood. There is increasing evidence that activins, which are members of the transforming growth factor β (TGFβ) superfamily of growth and differentiation factors, could play important roles in liver carcinogenesis. Activins are disulphide-linked homo- or heterodimers formed from four different β subunits termed βA, βB, βC, and βE, respectively. Activin A, the dimer of two βA subunits, is critically involved in the regulation of cell growth, apoptosis, and tissue architecture in the liver, while the hepatic function of other activins is largely unexplored so far. Negative regulators of activin signals include antagonists in the extracellular space like the binding proteins follistatin and FLRG, and at the cell membrane antagonistic co-receptors like Cripto or BAMBI. Additionally, in the intracellular space inhibitory Smads can modulate and control activin activity. Accumulating data suggest that deregulation of activin signals contributes to pathologic conditions such as chronic inflammation, fibrosis and development of cancer. The current article reviews the alterations in components of the activin signaling pathway that have been observed in HCC and discusses their potential significance for liver tumorigenesis. PMID:18350601

  16. Smoking, calcium, calcium antagonists, and aging.

    PubMed

    Nicita-Mauro, V

    1990-01-01

    Aging is characterized, besides other changes, by a progressive increase in calcium content in the arterial wall, which is enhanced by diabetes mellitus, osteoporosis, arterial hypertension, and tabagism. As to tabagism, experiments in animals have shown that nicotine can increase calcium content of the arterial wall, and clinical studies have demonstrated that cigarette smoking induces peripheral vasoconstriction, with consequent increase in blood pressure levels. In order to study the role of calcium ions in the pathogenesis of the vasoconstrictive lesions caused by "acute" smoking, the author has studied the peripheral vascular effects of the calcium-channel antagonist nifedipine, a dihydropyridine derivative, and calcitonin, a hypocalcemizing hormone which possess vasoactive actions on 12 elderly regular smokers (mean age 65.8 years). The results demonstrated that both nifedipine (10 mg sublingually 20 min before smoking) and salmon calcitonin (100 MRC U/daily intramuscularly for three days) are able to prevent peripheral vasoconstriction evaluated by Doppler velocimetry, as well as the increase of blood pressure induced by smoking. On the basis of our results, the author proposes that cigarette smoking-induced vasoconstriction is a calcium-mediated process, which can be hindered by drugs with calcium antagonist action. PMID:2226675

  17. Antagonistic coevolution between quantitative and Mendelian traits.

    PubMed

    Yamamichi, Masato; Ellner, Stephen P

    2016-03-30

    Coevolution is relentlessly creating and maintaining biodiversity and therefore has been a central topic in evolutionary biology. Previous theoretical studies have mostly considered coevolution between genetically symmetric traits (i.e. coevolution between two continuous quantitative traits or two discrete Mendelian traits). However, recent empirical evidence indicates that coevolution can occur between genetically asymmetric traits (e.g. between quantitative and Mendelian traits). We examine consequences of antagonistic coevolution mediated by a quantitative predator trait and a Mendelian prey trait, such that predation is more intense with decreased phenotypic distance between their traits (phenotype matching). This antagonistic coevolution produces a complex pattern of bifurcations with bistability (initial state dependence) in a two-dimensional model for trait coevolution. Furthermore, with eco-evolutionary dynamics (so that the trait evolution affects predator-prey population dynamics), we find that coevolution can cause rich dynamics including anti-phase cycles, in-phase cycles, chaotic dynamics and deterministic predator extinction. Predator extinction is more likely to occur when the prey trait exhibits complete dominance rather than semidominance and when the predator trait evolves very rapidly. Our study illustrates how recognizing the genetic architectures of interacting ecological traits can be essential for understanding the population and evolutionary dynamics of coevolving species. PMID:27009218

  18. Extreme Ionizing-Radiation-Resistant Bacterium

    NASA Technical Reports Server (NTRS)

    Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.; Schwendner, Petra

    2012-01-01

    potential for transfer, and subsequent proliferation, on another solar body such as Mars and Europa. These organisms are more likely to escape planetary protection assays, which only take into account presence of spores. Hence, presences of extreme radiation-resistant Deinococcus in the cleanroom facility where spacecraft are assembled pose a serious risk for integrity of life-detection missions. The microorganism described herein was isolated from the surfaces of the cleanroom facility in which the Phoenix Lander was assembled. The isolated bacterial strain was subjected to a comprehensive polyphasic analysis to characterize its taxonomic position. This bacterium exhibits very low 16SrRNA similarity with any other environmental isolate reported to date. Both phenotypic and phylogenetic analyses clearly indicate that this isolate belongs to the genus Deinococcus and represents a novel species. The name Deinococcus phoenicis was proposed after the Phoenix spacecraft, which was undergoing assembly, testing, and launch operations in the spacecraft assembly facility at the time of isolation. D. phoenicis cells exhibited higher resistance to ionizing radiation (cobalt-60; 14 kGy) than the cells of the D. radiodurans (5 kGy). Thus, it is in the best interest of NASA to thoroughly characterize this organism, which will further assess in determining the potential for forward contamination. Upon the completion of genetic and physiological characteristics of D. phoenicis, it will be added to a planetary protection database to be able to further model and predict the probability of forward contamination.

  19. Extreme Ionizing-Radiation-Resistant Bacterium

    NASA Technical Reports Server (NTRS)

    Vaishampayan, Parag A.; Venkateswaran, Kasthuri J.; Schwendner, Petra

    2013-01-01

    potential for transfer, and subsequent proliferation, on another solar body such as Mars and Europa. These organisms are more likely to escape planetary protection assays, which only take into account presence of spores. Hence, presences of extreme radiation-resistant Deinococcus in the cleanroom facility where spacecraft are assembled pose a serious risk for integrity of life-detection missions. The microorganism described herein was isolated from the surfaces of the cleanroom facility in which the Phoenix Lander was assembled. The isolated bacterial strain was subjected to a comprehensive polyphasic analysis to characterize its taxonomic position. This bacterium exhibits very low 16SrRNA similarity with any other environmental isolate reported to date. Both phenotypic and phylogenetic analyses clearly indicate that this isolate belongs to the genus Deinococcus and represents a novel species. The name Deinococcus phoenicis was proposed after the Phoenix spacecraft, which was undergoing assembly, testing, and launch operations in the spacecraft assembly facility at the time of isolation. D. phoenicis cells exhibited higher resistance to ionizing radiation (cobalt-60; 14 kGy) than the cells of the D. radiodurans (5 kGy). Thus, it is in the best interest of NASA to thoroughly characterize this organism, which will further assess in determining the potential for forward contamination. Upon the completion of genetic and physiological characteristics of D. phoenicis, it will be added to a planetary protection database to be able to further model and predict the probability of forward contamination.

  20. History of the 'geste antagoniste' sign in cervical dystonia.

    PubMed

    Poisson, A; Krack, P; Thobois, S; Loiraud, C; Serra, G; Vial, C; Broussolle, E

    2012-08-01

    The geste antagoniste is a voluntary maneuver that temporarily reduces the severity of dystonic posture or movements. It is a classical feature of focal and particularly cervical dystonia. However, the precise historical aspects of geste antagoniste still remain obscure. The goals of this review were (1) to clarify the origin of the geste antagoniste sign; (2) to identify the factors that led to its diffusion in the international literature; (3) to follow the evolution of that term across the twentieth century. We used medical and neurological French, German and English literature of the late nineteenth and early twentieth centuries, and the PubMed database by entering the terms geste antagoniste, antagonistic gesture and sensory trick. The geste antagoniste sign is a legacy of the Paris Neurological School of the end of the nineteenth century. The term was introduced by Meige and Feindel in their 1902 book on tics, written in the vein of their master, Brissaud, who first described this sign in 1893. The almost immediate translations of this book by Giese into German and Kinnier Wilson into English contributed to the rapid spreading of the term geste antagoniste, which is still in use worldwide today. The term antagonistic gesture is the translation proposed by Kinnier Wilson, which also led to the use of the term geste antagonistique. The geste antagoniste sign has long been considered a solid argument for the psychogenic origins of dystonia until the 1980s when Marsden made strong arguments for its organic nature.

  1. H1 receptor antagonist treatment of chronic rhinitis.

    PubMed

    Simons, F E; Simons, K J

    1988-05-01

    In patients with chronic rhinitis, H1 receptor antagonists play an important role in relieving the symptoms of sneezing, itching, and rhinorrhea. New information about the pharmacokinetics and pharmacodynamics of first-generation H1 receptor antagonists such as chlorpheniramine has become available in the past few years. Comprehensive pharmacokinetic and pharmacodynamic studies of new relatively nonsedating H1 receptor antagonists such as terfenadine, astemizole, loratadine, and cetirizine are appearing. An understanding of the differences in pharmacokinetics and pharmacodynamics among H1 receptor antagonists is required for optimal use of these drugs.

  2. Isolation and characterization of a novel toluene-degrading, sulfate-reducing bacterium.

    PubMed Central

    Beller, H R; Spormann, A M; Sharma, P K; Cole, J R; Reinhard, M

    1996-01-01

    A novel sulfate-reducing bacterium isolated from fuel-contaminated subsurface soil, strain PRTOL1, mineralizes toluene as the sole electron donor and carbon source under strictly anaerobic conditions. The mineralization of 80% of toluene carbon to CO2 was demonstrated in experiments with [ring-U-14C]toluene; 15% of toluene carbon was converted to biomass and nonvolatile metabolic by-products, primarily the former. The observed stoichiometric ratio of moles of sulfate consumed per mole of toluene consumed was consistent with the theoretical ratio for mineralization of toluene coupled with the reduction of sulfate to hydrogen sulfide. Strain PRTOL1 also transforms o- and p-xylene to metabolic products when grown with toluene. However, xylene transformation by PRTOL1 is slow relative to toluene degradation and cannot be sustained over time. Stable isotope-labeled substrates were used in conjunction with gas chromatography-mass spectrometry to investigate the by-products of toluene and xylene metabolism. The predominant by-products from toluene, o-xylene, and p-xylene were benzylsuccinic acid, (2-methylbenzyl)succinic acid, and 4-methylbenzoic acid (or p-toluic acid), respectively. Metabolic by-products accounted for nearly all of the o-xylene consumed. Enzyme assays indicated that acetyl coenzyme A oxidation proceeded via the carbon monoxide dehydrogenase pathway. Compared with the only other reported toluene-degrading, sulfate-reducing bacterium, strain PRTOL1 is distinct in that it has a novel 16S rRNA gene sequence and was derived from a freshwater rather than marine environment. PMID:8919780

  3. Supermarket Marine Biology.

    ERIC Educational Resources Information Center

    Colby, Jennifer A.; And Others

    1995-01-01

    Describes a survey used to determine the availability of intact marine vertebrates and live invertebrates in supermarkets. Results shows that local supermarkets frequently provide a variety of intact marine organisms suitable for demonstrations, experiments, or dissections. (ZWH)

  4. Marine Education Knowledge Inventory.

    ERIC Educational Resources Information Center

    Hounshell, Paul B.; Hampton, Carolyn

    This 35-item, multiple-choice Marine Education Knowledge Inventory was developed for use in upper elementary/middle schools to measure a student's knowledge of marine science. Content of test items is drawn from oceanography, ecology, earth science, navigation, and the biological sciences (focusing on marine animals). Steps in the construction of…

  5. Marine Education Materials System.

    ERIC Educational Resources Information Center

    Gammisch, Sue; Gray, Kevin

    1980-01-01

    Described is a marine education materials clearinghouse, the Marine Education Materials System (MEMS). MEMS classifies marine education documents and reproduces them on microfiche for distribution. There are 25 distribution centers, each of which has a collection of documents and provides assistance on a request basis to teachers. (Author/DS)

  6. Marine Education for Inlanders.

    ERIC Educational Resources Information Center

    Broussard, Amy

    1981-01-01

    Under a U.S. Department of Commerce Sea Grant, Texas teachers have developed a three-book series designed to expose elementary and secondary students to the marine world. Book titles include "Marine Organisms in Science Teaching,""Children's Literature--Passage to the Sea," and "Investigating the Marine Environment and Its Resources." (LRA)

  7. Marine vehicle ride quality

    NASA Technical Reports Server (NTRS)

    Gornstein, R. J.; Shultz, W. M.; Stair, L. D.

    1972-01-01

    The effects of marine vehicle design on passenger exposure to vibration and discomfort are discussed. The ride quality of advanced marine vehicles is examined. as a basis for marine vehicle selection in modern water transport systems. The physiological effects of rough water on passengers are identified as requiring investigation in order to determine the acceptable limits.

  8. Mutually-antagonistic interactions in baseball networks

    NASA Astrophysics Data System (ADS)

    Saavedra, Serguei; Powers, Scott; McCotter, Trent; Porter, Mason A.; Mucha, Peter J.

    2010-03-01

    We formulate the head-to-head matchups between Major League Baseball pitchers and batters from 1954 to 2008 as a bipartite network of mutually-antagonistic interactions. We consider both the full network and single-season networks, which exhibit structural changes over time. We find interesting structure in the networks and examine their sensitivity to baseball’s rule changes. We then study a biased random walk on the matchup networks as a simple and transparent way to (1) compare the performance of players who competed under different conditions and (2) include information about which particular players a given player has faced. We find that a player’s position in the network does not correlate with his placement in the random walker ranking. However, network position does have a substantial effect on the robustness of ranking placement to changes in head-to-head matchups.

  9. Discovery of Octahydroindenes as PAR1 Antagonists

    PubMed Central

    2013-01-01

    Octahydroindene was identified as a novel scaffold for protease activated receptor 1 (PAR1) antagonists. Herein, the 2-position (C2) was explored for structure–activity relationship (SAR) studies. Compounds 14, 19, and 23b showed IC50 values of 1.3, 8.6, and 2.7 nM in a PAR1 radioligand binding assay, respectively, and their inhibitory activities on platelet activation were comparable to that of vorapaxar in a platelet rich plasma (PRP) aggregation assay. This series of compounds showed high potency and no significant cytotoxicity; however, the compounds were metabolically unstable in both human and rat liver microsomes. Current research efforts are focused on optimizing the compounds to improve metabolic stability and physicochemical properties as well as potency. PMID:24900604

  10. Gut bacterium of Dendrobaena veneta (Annelida: Oligochaeta) possesses antimycobacterial activity.

    PubMed

    Fiołka, Marta J; Zagaja, Mirosław P; Piersiak, Tomasz D; Wróbel, Marek; Pawelec, Jarosław

    2010-09-01

    The new bacterial strain with antimycobacterial activity has been isolated from the midgut of Dendrobaena veneta (Annelida). Biochemical and molecular characterization of isolates from 18 individuals identified all as Raoultella ornithinolytica genus with 99% similarity. The bacterium is a possible symbiont of the earthworm D. veneta. The isolated microorganism has shown the activity against four strains of fast-growing mycobacteria: Mycobacterium butiricum, Mycobacterium jucho, Mycobacterium smegmatis and Mycobacterium phlei. The multiplication of the gut bacterium on plates with Sauton medium containing mycobacteria has caused a lytic effect. After the incubation of the cell free extract prepared from the gut bacterium with four strains of mycobacteria in liquid Sauton medium, the cells of all tested strains were deformed and divided to small oval forms and sometimes created long filaments. The effect was observed by the use of light, transmission and scanning microscopy. Viability of all examined species of mycobacteria was significantly decreased. The antimycobacterial effect was probably the result of the antibiotic action produced by the gut bacterium of the earthworm. The application of ultrafiltration procedure allowed to demonstrate that antimicrobial substance with strong antimycobacterial activity from bacterial culture supernatant, is a protein with the molecular mass above 100 kDa.

  11. Complete Genome of the Cellulolytic Ruminal Bacterium Ruminococcus albus 7

    SciTech Connect

    Suen, Garret; Stevenson, David M; Bruce, David; Chertkov, Olga; Copeland, A; Cheng, Jan-Fang; Detter, J. Chris; Goodwin, Lynne A.; Han, Cliff; Hauser, Loren John; Ivanova, N; Kyrpides, Nikos C; Land, Miriam L; Lapidus, Alla L.; Lucas, Susan; Ovchinnikova, Galina; Pitluck, Sam; Tapia, Roxanne; Woyke, Tanja; Boyum, Julie; Mead, David; Weimer, Paul J

    2011-01-01

    Ruminococcus albus 7 is a highly cellulolytic ruminal bacterium that is a member of the phylum Firmicutes. Here, we describe the complete genome of this microbe. This genome will be useful for rumen microbiology and cellulosome biology and in biofuel production, as one of its major fermentation products is ethanol.

  12. Revised Genome Sequence of the Purple Photosynthetic Bacterium Blastochloris viridis

    PubMed Central

    Faulkner, Matthew; Liu, Xuan; Huang, Fang; Darby, Alistair C.; Hall, Neil

    2016-01-01

    Blastochloris viridis is a unique anaerobic, phototrophic purple bacterium that produces bacteriochlorophyll b. Here we report an improved genome sequence of Blastochloris viridis DSM133, which is instrumental to the studies of photosynthesis, metabolic versatility, and genetic engineering of this microorganism. PMID:26798090

  13. Antagonistic and Bargaining Games in Optimal Marketing Decisions

    ERIC Educational Resources Information Center

    Lipovetsky, S.

    2007-01-01

    Game theory approaches to find optimal marketing decisions are considered. Antagonistic games with and without complete information, and non-antagonistic games techniques are applied to paired comparison, ranking, or rating data for a firm and its competitors in the market. Mix strategy, equilibrium in bi-matrix games, bargaining models with…

  14. Early gonadotropin-releasing hormone antagonist start improves follicular synchronization and pregnancy outcome as compared to the conventional antagonist protocol

    PubMed Central

    Park, Chan Woo; Hwang, Yu Im; Koo, Hwa Seon; Kang, Inn Soo; Yang, Kwang Moon

    2014-01-01

    Objective To assess whether an early GnRH antagonist start leads to better follicular synchronization and an improved clinical pregnancy rate (CPR). Methods A retrospective cohort study. A total of 218 infertile women who underwent IVF between January 2011 and February 2013. The initial cohort (Cohort I) that underwent IVF between January 2011 and March 2012 included a total of 68 attempted IVF cycles. Thirty-four cycles were treated with the conventional GnRH antagonist protocol, and 34 cycles with an early GnRH antagonist start protocol. The second cohort (Cohort II) that underwent IVF between June 2012 and February 2013 included a total of 150 embryo-transfer (ET) cycles. Forty-three cycles were treated with the conventional GnRH antagonist protocol, 34 cycles with the modified early GnRH antagonist start protocol using highly purified human menopause gonadotropin and an addition of GnRH agonist to the luteal phase support, and 73 cycles with the GnRH agonist long protocol. Results The analysis of Cohort I showed that the number of mature oocytes retrieved was significantly higher in the early GnRH antagonist start cycles than in the conventional antagonist cycles (11.9 vs. 8.2, p=0.04). The analysis of Cohort II revealed higher but non-significant CPR/ET in the modified early GnRH antagonist start cycles (41.2%) than in the conventional antagonist cycles (30.2%), which was comparable to that of the GnRH agonist long protocol cycles (39.7%). Conclusion The modified early antagonist start protocol may improve the mature oocyte yield, possibly via enhanced follicular synchronization, while resulting in superior CPR as compared to the conventional antagonist protocol, which needs to be studied further in prospective randomized controlled trials. PMID:25599038

  15. Interaction between Antagonist of Cannabinoid Receptor and Antagonist of Adrenergic Receptor on Anxiety in Male Rat

    PubMed Central

    Komaki, Alireza; Abdollahzadeh, Fatemeh; Sarihi, Abdolrahman; Shahidi, Siamak; Salehi, Iraj

    2014-01-01

    Introduction Anxiety is among the most common and treatable mental disorders. Adrenergic and cannabinoid systems have an important role in the neurobiology of anxiety. The elevated plus-maze (EPM) has broadly been used to investigate anxiolytic and anxiogenic compounds. The present study investigated the effects of intraperitoneal (IP) injection of cannabinoid CB1 receptor antagonist (AM251) in the presence of alpha-1 adrenergic antagonist (Prazosin) on rat behavior in the EPM. Methods In this study, the data were obtained from male Wistar rat, which weighing 200- 250 g. Animal behavior in EPM were videotaped and saved in computer for 10 min after IP injection of saline, AM251 (0.3 mg/kg), Prazosin (0.3 mg/kg) and AM251 + Prazosin, subsequently scored for conventional indices of anxiety. During the test period, the number of open and closed arms entries, the percentage of entries into the open arms of the EPM, and the spent time in open and closed arms were recorded. Diazepam was considered as a positive control drug with anxiolytic effect (0.3, 0.6, 1.2 mg/kg). Results Diazepam increased the number of open arm entries and the percentage of spent time on the open arms. IP injection of AM251 before EPM trial decreased open arms exploration and open arm entry. Whereas, Prazosin increased open arms exploration and open arm entry. This study showed that both substances in simultaneous injection have conflicting effects on the responses of each of these two compounds in a single injection. Discussion Injection of CB1 receptor antagonist may have an anxiogenic profile in rat, whereas adrenergic antagonist has an anxiolytic effect. Further investigations are essential for better understanding of anxiolytic and anxiogenic properties and neurobiological mechanisms of action and probable interactions of the two systems. PMID:25337383

  16. Pharmacokinetic interactions with calcium channel antagonists (Part I).

    PubMed

    Schlanz, K D; Myre, S A; Bottorff, M B

    1991-11-01

    Calcium channel antagonists are a diverse class of drugs widely used in combination with other therapeutic agents. The potential exists for many clinically significant pharmacokinetic interactions between these and other concurrently administered drugs. The mechanisms of calcium channel antagonist-induced changes in drug metabolism include altered hepatic blood flow and impaired hepatic enzyme metabolising activity. Increases in serum concentrations and/or reductions in clearance have been reported for several drugs used with a number of calcium channel antagonists. A number of reports and studies of calcium channel antagonist interactions have yielded contradictory results and the clinical significance of pharmacokinetic changes seen with these agents is ill-defined. The first part of this article deals with interactions between calcium antagonists and marker compounds, theophylline, midazolam, lithium, doxorubicin, oral hypoglycaemics and cardiac drugs. PMID:1773549

  17. β1-adrenergic receptor antagonists signal via PDE4 translocation.

    PubMed

    Richter, Wito; Mika, Delphine; Blanchard, Elise; Day, Peter; Conti, Marco

    2013-03-01

    It is generally assumed that antagonists of Gs-coupled receptors do not activate cAMP signalling, because they do not stimulate cAMP production via Gs-protein/adenylyl cyclase activation. Here, we report a new signalling pathway whereby antagonists of β1-adrenergic receptors (β1ARs) increase cAMP levels locally without stimulating cAMP production directly. Binding of antagonists causes dissociation of a preformed complex between β1ARs and Type-4 cyclic nucleotide phosphodiesterases (PDE4s). This reduces the local concentration of cAMP-hydrolytic activity, thereby increasing submembrane cAMP and PKA activity. Our study identifies receptor/PDE4 complex dissociation as a novel mechanism of antagonist action that contributes to the pharmacological properties of β1AR antagonists and might be shared by other receptor subtypes.

  18. Protection of Marine Mammals.

    PubMed

    Knoll, Michaela; Ciaccia, Ettore; Dekeling, René; Kvadsheim, Petter; Liddell, Kate; Gunnarsson, Stig-Lennart; Ludwig, Stefan; Nissen, Ivor; Lorenzen, Dirk; Kreimeyer, Roman; Pavan, Gianni; Meneghetti, Nello; Nordlund, Nina; Benders, Frank; van der Zwan, Timo; van Zon, Tim; Fraser, Leanne; Johansson, Torbjörn; Garmelius, Martin

    2016-01-01

    Within the European Defense Agency (EDA), the Protection of Marine Mammals (PoMM) project, a comprehensive common marine mammal database essential for risk mitigation tools, was established. The database, built on an extensive dataset collection with the focus on areas of operational interest for European navies, consists of annual and seasonal distribution and density maps, random and systematic sightings, an encyclopedia providing knowledge on the characteristics of 126 marine mammal species, data on marine mammal protection areas, and audio information including numerous examples of various vocalizations. Special investigations on marine mammal acoustics were carried out to improve the detection and classification capabilities.

  19. Protection of Marine Mammals.

    PubMed

    Knoll, Michaela; Ciaccia, Ettore; Dekeling, René; Kvadsheim, Petter; Liddell, Kate; Gunnarsson, Stig-Lennart; Ludwig, Stefan; Nissen, Ivor; Lorenzen, Dirk; Kreimeyer, Roman; Pavan, Gianni; Meneghetti, Nello; Nordlund, Nina; Benders, Frank; van der Zwan, Timo; van Zon, Tim; Fraser, Leanne; Johansson, Torbjörn; Garmelius, Martin

    2016-01-01

    Within the European Defense Agency (EDA), the Protection of Marine Mammals (PoMM) project, a comprehensive common marine mammal database essential for risk mitigation tools, was established. The database, built on an extensive dataset collection with the focus on areas of operational interest for European navies, consists of annual and seasonal distribution and density maps, random and systematic sightings, an encyclopedia providing knowledge on the characteristics of 126 marine mammal species, data on marine mammal protection areas, and audio information including numerous examples of various vocalizations. Special investigations on marine mammal acoustics were carried out to improve the detection and classification capabilities. PMID:26611003

  20. Carotenoids in Marine Animals

    PubMed Central

    Maoka, Takashi

    2011-01-01

    Marine animals contain various carotenoids that show structural diversity. These marine animals accumulate carotenoids from foods such as algae and other animals and modify them through metabolic reactions. Many of the carotenoids present in marine animals are metabolites of β-carotene, fucoxanthin, peridinin, diatoxanthin, alloxanthin, and astaxanthin, etc. Carotenoids found in these animals provide the food chain as well as metabolic pathways. In the present review, I will describe marine animal carotenoids from natural product chemistry, metabolism, food chain, and chemosystematic viewpoints, and also describe new structural carotenoids isolated from marine animals over the last decade. PMID:21566799

  1. Novel pathway for assimilation of dimethylsulphoniopropionate widespread in marine bacteria.

    PubMed

    Reisch, Chris R; Stoudemayer, Melissa J; Varaljay, Vanessa A; Amster, I Jonathan; Moran, Mary Ann; Whitman, William B

    2011-05-12

    Dimethylsulphoniopropionate (DMSP) accounts for up to 10% of carbon fixed by marine phytoplankton in ocean surface waters, producing an estimated 11.7-103 Tmol S per year, most of which is processed by marine bacteria through the demethylation/demethiolation pathway. This pathway releases methanethiol (MeSH) instead of the climatically active gas dimethylsulphide (DMS) and enables marine microorganisms to assimilate the reduced sulphur. Despite recognition of this critical microbial transformation for over two decades, the biochemical pathway and enzymes responsible have remained unidentified. Here we show that three new enzymes related to fatty acid β-oxidation constitute the pathway that assimilates methylmercaptopropionate (MMPA), the first product of DMSP demethylation/demethiolation, and that two previously unknown coenzyme A (CoA) derivatives, 3-methylmercaptopropionyl-CoA (MMPA-CoA) and methylthioacryloyl-CoA (MTA-CoA), are formed as novel intermediates. A member of the marine roseobacters, Ruegeria pomeroyi DSS-3, requires the MMPA-CoA pathway for MMPA assimilation and MeSH production. This pathway and the ability to produce MeSH from MMPA are present in diverse bacteria, and the ubiquitous SAR11 clade bacterium Pelagibacter ubique possesses enzymes for at least the first two steps. Analysis of marine metagenomic data indicates that the pathway is widespread among bacterioplankton in the ocean surface waters, making it one of the most important known routes for acquisition of reduced carbon and sulphur by surface ocean heterotrophs.

  2. Optimization of the culture condition for an antitumor bacterium Serratia proteamacula 657 and identification of the active compounds.

    PubMed

    Miao, Li; Wang, Xueling; Jiang, Wei; Yang, Shengping; Zhou, Huiru; Zhai, Youpeng; Zhou, Xiaojian; Dong, Kunming

    2013-05-01

    Exploration of novel active anti-tumor compounds from marine microbes for pharmaceutical applications has been a continuously hot spot in natural product research. Bacterial growth and metabolites may greatly vary under different culture conditions. In this study, the effects of different culture conditions and medium components on the growth and bioactive metabolites of Serratia proteamacula 657, an anti-tumor bacterium found in our previous study, were investigated. The results showed that lower temperature, weak acidic condition and solid fermentation favored the bacterial growth and the production of active compounds. Four components in the culture medium, NaCl, peptone, yeast extract and MgSO4, were found important to the bacterial growth and active compounds production in medium optimization. Under the optimized condition of solid state fermentation at pH 6.0-7.0, 23-25 °C, with the MgSO4-free medium containing 10.0 g/L peptone, 1.0 g/L yeast extract and 19.45 g/L NaCl, the antitumor activity of S. proteamacula 657 and the yield of crude extracts increased about 15 times and 6 times than the sample obtained in the original liquid fermentation, respectively. The active components in the metabolites of S. proteamacula 657 were identified as a homolog of prodigiosin, a red bacterial pigment, based on the analysis of the NMR and GC-MS. The bacterium S. proteamacula 657, which is adapted to lower temperature, produced prodigiosin-like pigments with highly antitumor activity, suggesting the bacterium is a potential new source for prodigiosin production.

  3. Competition between antagonistic complement factors for a single protein on N. meningitidis rules disease susceptibility

    PubMed Central

    Caesar, Joseph JE; Lavender, Hayley; Ward, Philip N; Exley, Rachel M; Eaton, Jack; Chittock, Emily; Malik, Talat H; Goiecoechea De Jorge, Elena; Pickering, Matthew C; Tang, Christoph M; Lea, Susan M

    2014-01-01

    Genome-wide association studies have found variation within the complement factor H gene family links to host susceptibility to meningococcal disease caused by infection with Neisseria meningitidis (Davila et al., 2010). Mechanistic insights have been challenging since variation within this locus is complex and biological roles of the factor H-related proteins, unlike factor H, are incompletely understood. N. meningitidis subverts immune responses by hijacking a host-immune regulator, complement factor H (CFH), to the bacterial surface (Schneider et al., 2006; Madico et al., 2007; Schneider et al., 2009). We demonstrate that complement factor-H related 3 (CFHR3) promotes immune activation by acting as an antagonist of CFH. Conserved sequences between CFH and CFHR3 mean that the bacterium cannot sufficiently distinguish between these two serum proteins to allow it to hijack the regulator alone. The level of protection from complement attack achieved by circulating N. meningitidis therefore depends on the relative levels of CFH and CFHR3 in serum. These data may explain the association between genetic variation in both CFH and CFHR3 and susceptibility to meningococcal disease. DOI: http://dx.doi.org/10.7554/eLife.04008.001 PMID:25534642

  4. Antagonistic control of a dual-input mammalian gene switch by food additives.

    PubMed

    Xie, Mingqi; Ye, Haifeng; Hamri, Ghislaine Charpin-El; Fussenegger, Martin

    2014-08-01

    Synthetic biology has significantly advanced the design of mammalian trigger-inducible transgene-control devices that are able to programme complex cellular behaviour. Fruit-based benzoate derivatives licensed as food additives, such as flavours (e.g. vanillate) and preservatives (e.g. benzoate), are a particularly attractive class of trigger compounds for orthogonal mammalian transgene control devices because of their innocuousness, physiological compatibility and simple oral administration. Capitalizing on the genetic componentry of the soil bacterium Comamonas testosteroni, which has evolved to catabolize a variety of aromatic compounds, we have designed different mammalian gene expression systems that could be induced and repressed by the food additives benzoate and vanillate. When implanting designer cells engineered for gene switch-driven expression of the human placental secreted alkaline phosphatase (SEAP) into mice, blood SEAP levels of treated animals directly correlated with a benzoate-enriched drinking programme. Additionally, the benzoate-/vanillate-responsive device was compatible with other transgene control systems and could be assembled into higher-order control networks providing expression dynamics reminiscent of a lap-timing stopwatch. Designer gene switches using licensed food additives as trigger compounds to achieve antagonistic dual-input expression profiles and provide novel control topologies and regulation dynamics may advance future gene- and cell-based therapies.

  5. Comparative Genome Analyses of Serratia marcescens FS14 Reveals Its High Antagonistic Potential

    PubMed Central

    Li, Pengpeng; Kwok, Amy H. Y.; Jiang, Jingwei; Ran, Tingting; Xu, Dongqing; Wang, Weiwu; Leung, Frederick C.

    2015-01-01

    S. marcescens FS14 was isolated from an Atractylodes macrocephala Koidz plant that was infected by Fusarium oxysporum and showed symptoms of root rot. With the completion of the genome sequence of FS14, the first comprehensive comparative-genomic analysis of the Serratia genus was performed. Pan-genome and COG analyses showed that the majority of the conserved core genes are involved in basic cellular functions, while genomic factors such as prophages contribute considerably to genome diversity. Additionally, a Type I restriction-modification system, a Type III secretion system and tellurium resistance genes are found in only some Serratia species. Comparative analysis further identified that S. marcescens FS14 possesses multiple mechanisms for antagonism against other microorganisms, including the production of prodigiosin, bacteriocins, and multi-antibiotic resistant determinants as well as chitinases. The presence of two evolutionarily distinct Type VI secretion systems (T6SSs) in FS14 may provide further competitive advantages for FS14 against other microbes. To our knowledge, this is the first report of comparative analysis on T6SSs in the genus, which identifies four types of T6SSs in Serratia spp.. Competition bioassays of FS14 against the vital plant pathogenic bacterium Ralstonia solanacearum and fungi Fusarium oxysporum and Sclerotinia sclerotiorum were performed to support our genomic analyses, in which FS14 demonstrated high antagonistic activities against both bacterial and fungal phytopathogens. PMID:25856195

  6. Antagonistic coevolution with parasites increases the cost of host deleterious mutations

    PubMed Central

    Buckling, Angus; Wei, Yan; Massey, Ruth C; Brockhurst, Michael A; Hochberg, Michael E

    2005-01-01

    The fitness consequences of deleterious mutations are sometimes greater when individuals are parasitized, hence parasites may result in the more rapid purging of deleterious mutations from host populations. The significance of host deleterious mutations when hosts and parasites antagonistically coevolve (reciprocal evolution of host resistance and parasite infectivity) has not previously been experimentally investigated. We addressed this by coevolving the bacterium Pseudomonas fluorescens and a parasitic bacteriophage in laboratory microcosms, using bacteria with high and low mutation loads. Directional coevolution between bacterial resistance and phage infectivity occurred in all populations. Bacterial population fitness, as measured by competition experiments with ancestral genotypes in the absence of phage, declined with time spent coevolving. However, this decline was significantly more rapid in bacteria with high mutation loads, suggesting the cost of bacterial resistance to phage was greater in the presence of deleterious mutations (synergistic epistasis). As such, resistance to phage was more costly to evolve in the presence of a high mutation load. Consistent with these data, bacteria with high mutation loads underwent less rapid directional coevolution with their phage populations, and showed lower levels of resistance to their coevolving phage populations. These data suggest that coevolution with parasites increases the rate at which deleterious mutations are purged from host populations. PMID:16519233

  7. Antagonistic control of a dual-input mammalian gene switch by food additives

    PubMed Central

    Xie, Mingqi; Ye, Haifeng; Hamri, Ghislaine Charpin-El; Fussenegger, Martin

    2014-01-01

    Synthetic biology has significantly advanced the design of mammalian trigger-inducible transgene-control devices that are able to programme complex cellular behaviour. Fruit-based benzoate derivatives licensed as food additives, such as flavours (e.g. vanillate) and preservatives (e.g. benzoate), are a particularly attractive class of trigger compounds for orthogonal mammalian transgene control devices because of their innocuousness, physiological compatibility and simple oral administration. Capitalizing on the genetic componentry of the soil bacterium Comamonas testosteroni, which has evolved to catabolize a variety of aromatic compounds, we have designed different mammalian gene expression systems that could be induced and repressed by the food additives benzoate and vanillate. When implanting designer cells engineered for gene switch-driven expression of the human placental secreted alkaline phosphatase (SEAP) into mice, blood SEAP levels of treated animals directly correlated with a benzoate-enriched drinking programme. Additionally, the benzoate-/vanillate-responsive device was compatible with other transgene control systems and could be assembled into higher-order control networks providing expression dynamics reminiscent of a lap-timing stopwatch. Designer gene switches using licensed food additives as trigger compounds to achieve antagonistic dual-input expression profiles and provide novel control topologies and regulation dynamics may advance future gene- and cell-based therapies. PMID:25030908

  8. Comparative genome analyses of Serratia marcescens FS14 reveals its high antagonistic potential.

    PubMed

    Li, Pengpeng; Kwok, Amy H Y; Jiang, Jingwei; Ran, Tingting; Xu, Dongqing; Wang, Weiwu; Leung, Frederick C

    2015-01-01

    S. marcescens FS14 was isolated from an Atractylodes macrocephala Koidz plant that was infected by Fusarium oxysporum and showed symptoms of root rot. With the completion of the genome sequence of FS14, the first comprehensive comparative-genomic analysis of the Serratia genus was performed. Pan-genome and COG analyses showed that the majority of the conserved core genes are involved in basic cellular functions, while genomic factors such as prophages contribute considerably to genome diversity. Additionally, a Type I restriction-modification system, a Type III secretion system and tellurium resistance genes are found in only some Serratia species. Comparative analysis further identified that S. marcescens FS14 possesses multiple mechanisms for antagonism against other microorganisms, including the production of prodigiosin, bacteriocins, and multi-antibiotic resistant determinants as well as chitinases. The presence of two evolutionarily distinct Type VI secretion systems (T6SSs) in FS14 may provide further competitive advantages for FS14 against other microbes. To our knowledge, this is the first report of comparative analysis on T6SSs in the genus, which identifies four types of T6SSs in Serratia spp.. Competition bioassays of FS14 against the vital plant pathogenic bacterium Ralstonia solanacearum and fungi Fusarium oxysporum and Sclerotinia sclerotiorum were performed to support our genomic analyses, in which FS14 demonstrated high antagonistic activities against both bacterial and fungal phytopathogens.

  9. Actinoranone, A Cytotoxic Meroterpenoid of Unprecedented Structure from a Marine Adapted Streptomyces sp

    PubMed Central

    Nam, Sang-Jip; Kauffman, Christopher A.; Paul, Lauren A.; Jensen, Paul R.

    2014-01-01

    The isolation and structure elucidation of a new meroterpenoid, actinoranone (1), produced by a marine bacterium closely related to the genus Streptomyces is reported. Actinoranone is composed of an unprecedented dihydronaphthalenone polyketide linked to a bicyclic diterpenoid. The stereochemistry of 1 was defined by application of the advanced Mosher's method and by interpretation of spectroscopic data. Actinoranone (1) is significantly cytotoxic to HCT-116 human colon cancer cells with an LD50 = 2.0 μg/mL. PMID:24152065

  10. The death mechanism of the harmful algal bloom species Alexandrium tamarense induced by algicidal bacterium Deinococcus sp. Y35

    PubMed Central

    Li, Yi; Zhu, Hong; Lei, Xueqian; Zhang, Huajun; Cai, Guanjing; Chen, Zhangran; Fu, Lijun; Xu, Hong; Zheng, Tianling

    2015-01-01

    Harmful algal blooms (HABs) cause a variety of deleterious effects on aquatic ecosystems, especially the toxic dinoflagellate Alexandrium tamarense, which poses a serious threat to marine economic and human health based on releasing paralytic shellfish poison into the environment. The algicidal bacterium Deinococcus sp. Y35 which can induce growth inhibition on A. tamarense was used to investigate the functional mechanism. The growth status, reactive oxygen species (ROS) content, photosynthetic system and the nuclear system of algal cells were determined under algicidal activity. A culture of strain Y35 not only induced overproduction of ROS in algal cells within only 0.5 h of treatment, also decrease the total protein content as well as the response of the antioxidant enzyme. Meanwhile, lipid peroxidation was induced and cell membrane integrity was lost. Photosynthetic pigments including chlorophyll a and carotenoid decreased along with the photosynthetic efficiency being significantly inhibited. At the same time, photosynthesis-related gene expression showed down-regulation. More than, the destruction of cell nuclear structure and inhibition of proliferating cell nuclear antigen (PCNA) related gene expression were confirmed. The potential functional mechanism of the algicidal bacterium on A. tamarense was investigated and provided a novel viewpoint which could be used in HABs control. PMID:26441921

  11. Isolation of a Butyrate-Utilizing Bacterium in Coculture with Methanobacterium thermoautotrophicum from a Thermophilic Digester †

    PubMed Central

    Henson, J. Michael; Smith, P. H.

    1985-01-01

    Sludge from a thermophilic, 55°C digester produced methane without a lag period when enriched with butyrate. The sludge was found by most-probable-number enumeration to have ca. 5 × 106 butyrate-utilizing bacteria per ml. A thermophilic butyrate-utilizing bacterium was isolated in coculture with Methanobacterium thermoautotrophicum. This bacterium was a gram-negative, slightly curved rod, occurred singly, was nonmotile, and did not appear to produce spores. When this coculture was incubated with Methanospirillum hungatei at 37°C, the quantity of methane produced was less than 5% of the methane produced when the coculture was incubated at 55°C, the routine incubation temperature. The coculture required clarified digester fluid. The addition of yeast extract to medium containing 5% clarified digester fluid stimulated methane production when a Methanosarcina sp. was present. Hydrogen in the gas phase prevented butyrate utilization. However, when the hydrogen was removed, butyrate utilization began. Penicillin G and d-cycloserine caused the complete inhibition of butyrate utilization by the coculture. The ability of various ecosystems to convert butyrate to methane was studied. Marine sediments enriched with butyrate required a 2-week incubation period before methanogenesis began. Hypersaline sediments did not produce methane after 3 months when enriched with butyrate. Images PMID:16346813

  12. The death mechanism of the harmful algal bloom species Alexandrium tamarense induced by algicidal bacterium Deinococcus sp. Y35.

    PubMed

    Li, Yi; Zhu, Hong; Lei, Xueqian; Zhang, Huajun; Cai, Guanjing; Chen, Zhangran; Fu, Lijun; Xu, Hong; Zheng, Tianling

    2015-01-01

    Harmful algal blooms (HABs) cause a variety of deleterious effects on aquatic ecosystems, especially the toxic dinoflagellate Alexandrium tamarense, which poses a serious threat to marine economic and human health based on releasing paralytic shellfish poison into the environment. The algicidal bacterium Deinococcus sp. Y35 which can induce growth inhibition on A. tamarense was used to investigate the functional mechanism. The growth status, reactive oxygen species (ROS) content, photosynthetic system and the nuclear system of algal cells were determined under algicidal activity. A culture of strain Y35 not only induced overproduction of ROS in algal cells within only 0.5 h of treatment, also decrease the total protein content as well as the response of the antioxidant enzyme. Meanwhile, lipid peroxidation was induced and cell membrane integrity was lost. Photosynthetic pigments including chlorophyll a and carotenoid decreased along with the photosynthetic efficiency being significantly inhibited. At the same time, photosynthesis-related gene expression showed down-regulation. More than, the destruction of cell nuclear structure and inhibition of proliferating cell nuclear antigen (PCNA) related gene expression were confirmed. The potential functional mechanism of the algicidal bacterium on A. tamarense was investigated and provided a novel viewpoint which could be used in HABs control. PMID:26441921

  13. The death mechanism of the harmful algal bloom species Alexandrium tamarense induced by algicidal bacterium Deinococcus sp. Y35.

    PubMed

    Li, Yi; Zhu, Hong; Lei, Xueqian; Zhang, Huajun; Cai, Guanjing; Chen, Zhangran; Fu, Lijun; Xu, Hong; Zheng, Tianling

    2015-01-01

    Harmful algal blooms (HABs) cause a variety of deleterious effects on aquatic ecosystems, especially the toxic dinoflagellate Alexandrium tamarense, which poses a serious threat to marine economic and human health based on releasing paralytic shellfish poison into the environment. The algicidal bacterium Deinococcus sp. Y35 which can induce growth inhibition on A. tamarense was used to investigate the functional mechanism. The growth status, reactive oxygen species (ROS) content, photosynthetic system and the nuclear system of algal cells were determined under algicidal activity. A culture of strain Y35 not only induced overproduction of ROS in algal cells within only 0.5 h of treatment, also decrease the total protein content as well as the response of the antioxidant enzyme. Meanwhile, lipid peroxidation was induced and cell membrane integrity was lost. Photosynthetic pigments including chlorophyll a and carotenoid decreased along with the photosynthetic efficiency being significantly inhibited. At the same time, photosynthesis-related gene expression showed down-regulation. More than, the destruction of cell nuclear structure and inhibition of proliferating cell nuclear antigen (PCNA) related gene expression were confirmed. The potential functional mechanism of the algicidal bacterium on A. tamarense was investigated and provided a novel viewpoint which could be used in HABs control.

  14. Metal Reduction and Iron Biomineralization by a Psychrotolerant Fe(III)-Reducing Bacterium, Shewanella sp. Strain PV-4

    SciTech Connect

    Roh, Yul; Gao, Haichun; Vali, Hojatollah; Kennedy, David W.; Yang, Zamin; Gao, Weimin; Dohnalkova, Alice; Stapleton, Raymond D.; Moon, Ji-Won; Phelps, T. J.; Fredrickson, Jim K.; Zhou, Jizhong

    2006-05-01

    A marine psychrotolerant, dissimilatory Fe(III)-reducing bacterium, Shewanella sp. strain PV-4, from the microbial mat at a hydrothermal vent of Loihi Seamount in the Pacific Ocean has been further characterized, with emphases on metal reduction and iron biomineralization. The strain is able to reduce metals such as Fe(III), Co(III), Cr(VI), Mn(IV), and U(VI) as electron acceptors while using lactate, formate, pyruvate, or hydrogen as an electron donor. Growth during iron reduction occurred over the pH range of 7.0 to 8.9, a sodium chloride range of 0.05 to 5%, and a temperature range of 0 to 37°C, with an optimum growth temperature of 18°C. Unlike mesophilic dissimilatory Fe(III)-reducing bacteria, which produce mostly superparamagnetic magnetite (<35 nm), this psychrotolerant bacterium produces well-formed single-domain magnetite (>35 nm) at temperatures from 18 to 37°C. The genome size of this strain is about 4.5 Mb. Strain PV-4 is sensitive to a variety of commonly used antibiotics except ampicillin and can acquire exogenous DNA (plasmid pCM157) through conjugation.

  15. Value-added lipid production from brown seaweed biomass by two-stage fermentation using acetic acid bacterium and thraustochytrid.

    PubMed

    Arafiles, Kim Hazel V; Iwasaka, Hiroaki; Eramoto, Yuri; Okamura, Yoshiko; Tajima, Takahisa; Matsumura, Yukihiko; Nakashimada, Yutaka; Aki, Tsunehiro

    2014-11-01

    Thraustochytrid production of polyunsaturated fatty acids and xanthophylls have been generally sourced from crop-derived substrates, making the exploration of alternative feedstocks attractive since they promise increased sustainability and lower production costs. In this study, a distinct two-stage fermentation system was conceptualized for the first time, using the brown seaweed sugar mannitol as substrate for the intermediary biocatalyst Gluconobacter oxydans, an acetic acid bacterium, along with the marine thraustochytrid Aurantiochytrium sp. to produce the value-added lipids and xanthophylls. Jar fermenter culture resulted in seaweed mannitol conversion to fructose with an efficiency of 83 % by G. oxydans and, after bacteriostasis with sea salts, production of astaxanthin and docosahexaenoic acid by Aurantiochytrium sp. KH105. Astaxanthin productivity was high at 3.60 mg/L/day. This new system, therefore, widens possibilities of obtaining more varieties of industrially valuable products including foods, cosmetics, pharmaceuticals, and biofuel precursor lipids from seaweed fermentation upon the use of suitable thraustochytrid strains.

  16. Labrenzia sp. BM1: a quorum quenching bacterium that degrades N-acyl homoserine lactones via lactonase activity.

    PubMed

    Ghani, Norshazliza Ab; Norizan, Siti Nur Maisarah; Chan, Xin Yue; Yin, Wai-Fong; Chan, Kok-Gan

    2014-01-01

    We report the degradation of quorum sensing N-acylhomoserine lactone molecules by a bacterium isolated from a Malaysian marine water sample. MALDI-TOF and phylogenetic analysis indicated this isolate BM1 clustered closely to Labrenzia sp. The quorum quenching activity of this isolate was confirmed by using a series of bioassays and rapid resolution liquid chromatography analysis. Labrenzia sp. degraded a wide range of N-acylhomoserine lactones namely N-(3-hexanoyl)-L-homoserine lactone (C6-HSL), N-(3-oxohexanoyl)-L-homoserine lactone (3-oxo-C6-HSL) and N-(3-hydroxyhexanoyl)-L-homoserine lactone (3-hydroxy-C6-HSL). Re-lactonisation bioassays confirmed Labrenzia sp. BM1 degraded these signalling molecules efficiently via lactonase activity. To the best of our knowledge, this is the first documentation of a Labrenzia sp. capable of degrading N-acylhomoserine lactones and confirmation of its lactonase-based mechanism of action.

  17. Labrenzia sp. BM1: A Quorum Quenching Bacterium That Degrades N-acyl Homoserine Lactones via Lactonase Activity

    PubMed Central

    Ghani, Norshazliza Ab; Norizan, Siti Nur Maisarah; Chan, Xin Yue; Yin, Wai-Fong; Chan, Kok-Gan

    2014-01-01

    We report the degradation of quorum sensing N-acylhomoserine lactone molecules by a bacterium isolated from a Malaysian marine water sample. MALDI-TOF and phylogenetic analysis indicated this isolate BM1 clustered closely to Labrenzia sp. The quorum quenching activity of this isolate was confirmed by using a series of bioassays and rapid resolution liquid chromatography analysis. Labrenzia sp. degraded a wide range of N-acylhomoserine lactones namely N-(3-hexanoyl)-l-homoserine lactone (C6-HSL), N-(3-oxohexanoyl)-l-homoserine lactone (3-oxo-C6-HSL) and N-(3-hydroxyhexanoyl)-l-homoserine lactone (3-hydroxy-C6-HSL). Re-lactonisation bioassays confirmed Labrenzia sp. BM1 degraded these signalling molecules efficiently via lactonase activity. To the best of our knowledge, this is the first documentation of a Labrenzia sp. capable of degrading N-acylhomoserine lactones and confirmation of its lactonase-based mechanism of action. PMID:24995373

  18. Genome of the marine alphaproteobacterium Hoeflea phototrophica type strain (DFL-43T)

    PubMed Central

    Fiebig, Anne; Pradella, Silke; Petersen, Jörn; Michael, Victoria; Päuker, Orsola; Rohde, Manfred; Göker, Markus; Klenk, Hans-Peter; Wagner-Döbler, Irene

    2013-01-01

    Hoeflea phototrophica Biebl et al. 2006 is a member of the family Phyllobacteriaceae in the order Rhizobiales, which is thus far only partially characterized at the genome level. This marine bacterium contains the photosynthesis reaction-center genes pufL and pufM and is of interest because it lives in close association with toxic dinoflagellates such as Prorocentrum lima. The 4,467,792 bp genome (permanent draft sequence) with its 4,296 protein-coding and 69 RNA genes is a part of the Marine Microbial Initiative. PMID:24019991

  19. Superoxide Production by a Manganese-Oxidizing Bacterium Facilitates Iodide Oxidation

    PubMed Central

    Li, Hsiu-Ping; Daniel, Benjamin; Creeley, Danielle; Grandbois, Russell; Zhang, Saijin; Xu, Chen; Ho, Yi-Fang; Schwehr, Kathy A.; Kaplan, Daniel I.; Santschi, Peter H.; Hansel, Colleen M.

    2014-01-01

    The release of radioactive iodine (i.e., iodine-129 and iodine-131) from nuclear reprocessing facilities is a potential threat to human health. The fate and transport of iodine are determined primarily by its redox status, but processes that affect iodine oxidation states in the environment are poorly characterized. Given the difficulty in removing electrons from iodide (I−), naturally occurring iodide oxidation processes require strong oxidants, such as Mn oxides or microbial enzymes. In this study, we examine iodide oxidation by a marine bacterium, Roseobacter sp. AzwK-3b, which promotes Mn(II) oxidation by catalyzing the production of extracellular superoxide (O2−). In the absence of Mn2+, Roseobacter sp. AzwK-3b cultures oxidized ∼90% of the provided iodide (10 μM) within 6 days, whereas in the presence of Mn(II), iodide oxidation occurred only after Mn(IV) formation ceased. Iodide oxidation was not observed during incubations in spent medium or with whole cells under anaerobic conditions or following heat treatment (boiling). Furthermore, iodide oxidation was significantly inhibited in the presence of superoxide dismutase and diphenylene iodonium (a general inhibitor of NADH oxidoreductases). In contrast, the addition of exogenous NADH enhanced iodide oxidation. Taken together, the results indicate that iodide oxidation was mediated primarily by extracellular superoxide generated by Roseobacter sp. AzwK-3b and not by the Mn oxides formed by this organism. Considering that extracellular superoxide formation is a widespread phenomenon among marine and terrestrial bacteria, this could represent an important pathway for iodide oxidation in some environments. PMID:24561582

  20. Behavioural effects of histamine and its antagonists: a review.

    PubMed

    White, J M; Rumbold, G R

    1988-01-01

    This review focuses on the behavioural effects of histamine and drugs which affect histaminergic function, particularly the H1- and H2-receptors antagonists. Research in this area has assumed considerable importance with increasing interest in the role of brain histamine, the clinical use of both H1 and H2 antagonists and evidence of nonmedical use of H1 antagonists. Results from a number of studies show that H1 and H2 antagonists have clear, but distinct subjective effects and that H1 antagonists have discriminative effects in animals. While H1 antagonists are reinforcers in certain conditions, histamine itself is a punisher. Moderate doses of H1 antagonists affect psychomotor performance in some situations, but the results are variable. The exceptions are terfenadine and astemizole, which do not seem to penetrate the blood-brain barrier readily. In studies of schedule-controlled behaviour, marked changes in response rate have been observed following administration of H1 antagonists, with the magnitude and direction dependent on the dose and the baseline behaviour. Histamine reduces avoidance responding, an effect mediated via H1-receptors. Changes in drinking and aggressive behaviour have also been observed following histamine administration and distinct roles for H1- and H2-receptors have been delineated. Separate H1- and H2-receptor mechanisms have also been suggested to account for changes in activity level. While the H2 antagonists do not always have strong behavioural effects when administered peripherally, there is evidence that cimetidine has a depressant effect on sexual function. These and other findings reveal an important role for histaminergic systems in a wide range of behaviour. PMID:3133686

  1. Aldosterone receptor antagonists: current perspectives and therapies

    PubMed Central

    Guichard, Jason L; Clark, Donald; Calhoun, David A; Ahmed, Mustafa I

    2013-01-01

    Aldosterone is a downstream effector of angiotensin II in the renin–angiotensin–aldosterone system and binds to the mineralocorticoid receptor. The classical view of aldosterone primarily acting at the level of the kidneys to regulate plasma potassium and intravascular volume status is being supplemented by evidence of new “off-target” effects of aldosterone in other organ systems. The genomic effects of aldosterone are well known, but there is also evidence for non-genomic effects and these recently identified effects of aldosterone have required a revision in the traditional view of aldosterone’s role in human health and disease. The aim of this article is to review the biological action of aldosterone and the mineralocorticoid receptor leading to subsequent physiologic and pathophysiologic effects involving the vasculature, central nervous system, heart, and kidneys. Furthermore, we outline current evidence evaluating the use of mineralocorticoid receptor antagonists in the treatment of primary aldosteronism, primary hypertension, resistant hypertension, obstructive sleep apnea, heart failure, and chronic kidney disease. PMID:23836977

  2. The search for calcium receptor antagonists (calcilytics).

    PubMed

    Nemeth, E F

    2002-08-01

    The Ca(2+) receptor on the surface of parathyroid cells is the primary molecular entity regulating secretion of parathyroid hormone (PTH). Because of this, it is a particularly appealing target for new drugs intended to increase or decrease circulating levels of PTH. Calcilytic compounds are Ca(2+) receptor antagonists which increase the secretion of PTH. The first reported calcilytic compound was NPS 2143, an orally active molecule which elicits rapid, 3- to 4-fold increases in circulating levels of PTH. These rapid changes in plasma PTH levels are sufficient to increase bone turnover in ovariectomized, osteopenic rats. When administered together with an antiresorptive agent (estradiol), NPS 2143 causes an increase in trabecular bone volume and bone mineral density in osteopenic rats. The magnitude of these changes are far in excess of those caused by estradiol alone and are comparable with those achieved by daily administration of PTH or a peptide analog. These anabolic effects of NPS 2143 on bone are not associated with hyperplasia of the parathyroid glands. Calcilytic compounds can increase endogenous levels of circulating PTH to an extent that stimulates new bone formation. Such compounds could replace the use of exogenous PTH or its peptide fragments in treating osteoporosis. PMID:12200226

  3. Antagonistic neural networks underlying differentiated leadership roles

    PubMed Central

    Boyatzis, Richard E.; Rochford, Kylie; Jack, Anthony I.

    2014-01-01

    The emergence of two distinct leadership roles, the task leader and the socio-emotional leader, has been documented in the leadership literature since the 1950s. Recent research in neuroscience suggests that the division between task-oriented and socio-emotional-oriented roles derives from a fundamental feature of our neurobiology: an antagonistic relationship between two large-scale cortical networks – the task-positive network (TPN) and the default mode network (DMN). Neural activity in TPN tends to inhibit activity in the DMN, and vice versa. The TPN is important for problem solving, focusing of attention, making decisions, and control of action. The DMN plays a central role in emotional self-awareness, social cognition, and ethical decision making. It is also strongly linked to creativity and openness to new ideas. Because activation of the TPN tends to suppress activity in the DMN, an over-emphasis on task-oriented leadership may prove deleterious to social and emotional aspects of leadership. Similarly, an overemphasis on the DMN would result in difficulty focusing attention, making decisions, and solving known problems. In this paper, we will review major streams of theory and research on leadership roles in the context of recent findings from neuroscience and psychology. We conclude by suggesting that emerging research challenges the assumption that role differentiation is both natural and necessary, in particular when openness to new ideas, people, emotions, and ethical concerns are important to success. PMID:24624074

  4. Antagonists for acute oral cadmium chloride intoxication

    SciTech Connect

    Basinger, M.A.; Jones, M.M.; Holscher, M.A.; Vaughn, W.K.

    1988-01-01

    An examination has been carried out on the relative efficacy of a number of chelating agents when acting as antagonists for oral cadmium chloride intoxication in mice. The compounds were administered orally after the oral administration of cadmium chloride at 1 mmol/kg. Of the compounds examined, several were useful in terms of enhancing survival, but by far the most effective in both enhancing survival and leaving minimal residual levels of cadmium in the liver and the kidney, was meso-2,3-dimercaptosuccinic acid (DMSA). Several polyaminocarboxylic acids also enhanced survival. The most effective of these in reducing liver and kidney levels of cadmium were diethylenetriaminepentaacetic acid (DTPA), trans-1,2-diaminocyclohexane-N,N,N'N'-tetraacetic acid (CDTA), and triethylenetetraminehexaacetic acid (TTHA). D-Penicillamine (DPA) was found to promote survival but also led to kidney cadmium levels higher than those found in the controls. Sodium 2,3-dimercaptopropane-1-sulfonate (DMPS) was as effective in promoting survival as DMSA but left levels of cadmium in the kidney and liver that were approximately four times greater than those found with DMSA.

  5. Multilayers of fluorinated amphiphilic polyions for marine fouling prevention.

    PubMed

    Zhu, Xiaoying; Guo, Shifeng; Jańczewski, Dominik; Velandia, Fernando Jose Parra; Teo, Serena Lay-Ming; Vancso, G Julius

    2014-01-14

    Sequential layer-by-layer (LbL) deposition of polyelectrolytes followed by chemical cross-linking was investigated as a method to fabricate functional amphiphilic surfaces for marine biofouling prevention applications. A novel polyanion, grafted with amphiphilic perfluoroalkyl polyethylene glycol (fPEG) side chains, was synthesized and subsequently used to introduce amphiphilic character to the LbL film. The structure of the polyanion was confirmed by FTIR and NMR. Amphiphilicity of the film assembly was demonstrated by both water and hexadecane static contact angles. XPS studies of the cross-linked and annealed amphiphilic LbL films revealed the increased concentration of fPEG content at the film interface. In antifouling assays, the amphiphilic LbL films effectively prevented the adhesion of the marine bacterium Pseudomonas (NCIMB 2021).

  6. Bacterial bioluminescence as a lure for marine zooplankton and fish

    PubMed Central

    Zarubin, Margarita; Belkin, Shimshon; Ionescu, Michael; Genin, Amatzia

    2012-01-01

    The benefits of bioluminescence for nonsymbiotic marine bacteria have not been elucidated fully. One of the most commonly cited explanations, proposed more than 30 y ago, is that bioluminescence augments the propagation and dispersal of bacteria by attracting fish to consume the luminous material. This hypothesis, based mostly on the prevalence of luminous bacteria in fish guts, has not been tested experimentally. Here we show that zooplankton that contacts and feeds on the luminescent bacterium Photobacterium leiognathi starts to glow, and demonstrate by video recordings that glowing individuals are highly vulnerable to predation by nocturnal fish. Glowing bacteria thereby are transferred to the nutritious guts of fish and zooplankton, where they survive digestion and gain effective means for growth and dispersal. Using bioluminescence as bait appears to be highly beneficial for marine bacteria, especially in food-deprived environments of the deep sea. PMID:22203999

  7. Identification of a novel conformationally constrained glucagon receptor antagonist.

    PubMed

    Lee, Esther C Y; Tu, Meihua; Stevens, Benjamin D; Bian, Jianwei; Aspnes, Gary; Perreault, Christian; Sammons, Matthew F; Wright, Stephen W; Litchfield, John; Kalgutkar, Amit S; Sharma, Raman; Didiuk, Mary T; Ebner, David C; Filipski, Kevin J; Brown, Janice; Atkinson, Karen; Pfefferkorn, Jeffrey A; Guzman-Perez, Angel

    2014-02-01

    Identification of orally active, small molecule antagonists of the glucagon receptor represents a novel treatment paradigm for the management of type 2 diabetes mellitus. The present work discloses novel glucagon receptor antagonists, identified via conformational constraint of current existing literature antagonists. Optimization of lipophilic ligand efficiency (LLE or LipE) culminated in enantiomers (+)-trans-26 and (-)-trans-27 which exhibit good physicochemical and in vitro drug metabolism profiles. In vivo, significant pharmacokinetic differences were noted with the two enantiomers, which were primarily driven through differences in clearance rates. Enantioselective oxidation by cytochrome P450 was ruled out as a causative factor for pharmacokinetic differences.

  8. Multiple Targeting Approaches on Histamine H3 Receptor Antagonists

    PubMed Central

    Khanfar, Mohammad A.; Affini, Anna; Lutsenko, Kiril; Nikolic, Katarina; Butini, Stefania; Stark, Holger

    2016-01-01

    With the very recent market approval of pitolisant (Wakix®), the interest in clinical applications of novel multifunctional histamine H3 receptor antagonists has clearly increased. Since histamine H3 receptor antagonists in clinical development have been tested for a variety of different indications, the combination of pharmacological properties in one molecule for improved pharmacological effects and reduced unwanted side-effects is rationally based on the increasing knowledge on the complex neurotransmitter regulations. The polypharmacological approaches on histamine H3 receptor antagonists on different G-protein coupled receptors, transporters, enzymes as well as on NO-signaling mechanism are described, supported with some lead structures. PMID:27303254

  9. PAF receptor and "Cache-oreilles" effect. Simple PAF antagonists.

    PubMed

    Lamotte-Brasseur, J; Heymans, F; Dive, G; Lamouri, A; Batt, J P; Redeuilh, C; Hosford, D; Braquet, P; Godfroid, J J

    1991-12-01

    Nine simple and structurally flexible PAF antagonists were synthesized and their inhibitory effects on PAF induced platelet aggregation were measured. Compounds with PAF antagonistic activity exhibited a negative electrostatic potential generated by two trimethoxyphenyl groups (isocontour at -10 Kcal/mole) at various distances between the negative clouds. The optimal distance between the atoms generating the "cache-oreilles" system for exhibiting potent PAF antagonistic activity is estimated to be 11-13 A. In the flexible molecules studied, the dispersion of the electronic distribution is not necessarily favorable for anti-PAF activity. The data support the simple bipolarized model for the PAF receptor that has been proposed by the authors.

  10. Behavioral effects of a calcium channel antagonist: nifedipine.

    PubMed

    Tazi, A; Farh, M; Hakkou, F

    1991-01-01

    A series of experiments investigated the behavioral effects of a calcium channel antagonist, nifedipine. This antagonist has facilitatory effects on learning and memory as assessed by the active and passive avoidance tests respectively. In the forced swimming test, nifedipine at a dose of 5 mg/kg had an inhibitory effect on immobilization. Finally, nifedipine (2.5 and 5.0 mg/kg) induced an anxiolytic effect in the water consumption test in a novel environment. These findings are discussed with respect to other findings in the same field and to the neurochemical changes known to be induced by calcium channel antagonists.

  11. Multiple Targeting Approaches on Histamine H3 Receptor Antagonists.

    PubMed

    Khanfar, Mohammad A; Affini, Anna; Lutsenko, Kiril; Nikolic, Katarina; Butini, Stefania; Stark, Holger

    2016-01-01

    With the very recent market approval of pitolisant (Wakix®), the interest in clinical applications of novel multifunctional histamine H3 receptor antagonists has clearly increased. Since histamine H3 receptor antagonists in clinical development have been tested for a variety of different indications, the combination of pharmacological properties in one molecule for improved pharmacological effects and reduced unwanted side-effects is rationally based on the increasing knowledge on the complex neurotransmitter regulations. The polypharmacological approaches on histamine H3 receptor antagonists on different G-protein coupled receptors, transporters, enzymes as well as on NO-signaling mechanism are described, supported with some lead structures. PMID:27303254

  12. Isolation of a Bacterium Capable of Degrading Peanut Hull Lignin

    PubMed Central

    Kerr, Thomas J.; Kerr, Robert D.; Benner, Ronald

    1983-01-01

    Thirty-seven bacterial strains capable of degrading peanut hull lignin were isolated by using four types of lignin preparations and hot-water-extracted peanut hulls. One of the isolates, tentatively identified as Arthrobacter sp., was capable of utilizing all four lignin preparations as well as extracted peanut hulls as a sole source of carbon. The bacterium was also capable of degrading specifically labeled [14C]lignin-labeled lignocellulose and [14C]cellulose-labeled lignocellulose from the cordgrass Spartina alterniflora and could also degrade [14C]Kraft lignin from slash pine. After 10 days of incubation with [14C]cellulose-labeled lignocellulose or [14C]lignin-labeled lignocellulose from S. alterniflora, the bacterium mineralized 6.5% of the polysaccharide component and 2.9% of the lignin component. Images PMID:16346424

  13. A Streamlined Strategy for Biohydrogen Production with an Alkaliphilic Bacterium

    SciTech Connect

    Elias, Dwayne A; Wall, Judy D.; Mormile, Dr. Melanie R.; Begemann, Matthew B

    2012-01-01

    Biofuels are anticipated to enable a shift from fossil fuels for renewable transportation and manufacturing fuels, with biohydrogen considered attractive since it could offer the largest reduction of global carbon budgets. Currently, biohydrogen production remains inefficient and heavily fossil fuel-dependent. However, bacteria using alkali-treated biomass could streamline biofuel production while reducing costs and fossil fuel needs. An alkaliphilic bacterium, Halanaerobium strain sapolanicus, is described that is capable of biohydrogen production at levels rivaling neutrophilic strains, but at pH 11 and hypersaline conditions. H. sapolanicus ferments a variety of 5- and 6- carbon sugars derived from hemicellulose and cellulose including cellobiose, and forms the end products hydrogen and acetate. Further, it can also produce biohydrogen from switchgrass and straw pretreated at temperatures far lower than any previously reported and in solutions compatible with growth. Hence, this bacterium can potentially increase the efficiency and efficacy of biohydrogen production from renewable biomass resources.

  14. Isolation of the Legionnaires' disease bacterium from environmental samples.

    PubMed

    Morris, G K; Patton, C M; Feeley, J C; Johnson, S E; Gorman, G; Martin, W T; Skaliy, P; Mallison, G F; Politi, B D; Mackel, D C

    1979-04-01

    We analyzed 24 environmental samples collected in or near the Indiana Memorial Union, where an epidemic of Legionnaires' disease occurred in early 1978. We conducted fluorescent antibody analyses and culture on F-G and charcoal yeast extract agars of each sample directly; splenic tissue of guinea pigs inoculated with the sample; and yolk sacs from embryonated eggs inoculated with splenic tissue of guinea pigs injected with the sample. Legionnaires' disease (LD) bacterium was isolated from seven of the 24 samples: one water sample from the air-conditioner cooling tower of the Union; three water samples from a stream near the Union; and three mud samples from the same stream. The LD bacterium strains were of three different serotypes. These findings indicate that LD bacteria may be widespread in nature. PMID:373549

  15. Isolation of a bacterium capable of degrading peanut hull lignin

    SciTech Connect

    Kerr, T.A.; Kerr, R.D.; Benner, R.

    1983-11-01

    Thirty-seven bacterial strains capable of degrading peanut hull lignin were isolated by using four types of lignin preparations and hot-water-extracted peanut hulls. One of the isolates, tentatively identified as Arthrobacter species, was capable of utilizing all four lignin preparations as well as extracted peanut hulls as a sole source of carbon. The bacterium was also capable of degrading specifically labeled (/sup 14/C) lignin-labeled lignocellulose and (/sup 14/C)cellulose-labeled lignocellulose from the cordgrass Spartina alterniflora and could also degrade (/sup 14/C) Kraft lignin from slash pine. After 10 days of incubation with (/sup 14/C) cellulose-labeled lignocellulose or (/sup 14/C) lignin-labeled lignocellulose from S. alterniflora, the bacterium mineralized 6.5% of the polysaccharide component and 2.9% of the lignin component. (Refs. 24).

  16. Trichloroethylene Biodegradation by a Methane-Oxidizing Bacterium

    PubMed Central

    Little, C. Deane; Palumbo, Anthony V.; Herbes, Stephen E.; Lidstrom, Mary E.; Tyndall, Richard L.; Gilmer, Penny J.

    1988-01-01

    Trichloroethylene (TCE), a common groundwater contaminant, is a suspected carcinogen that is highly resistant to aerobic biodegradation. An aerobic, methane-oxidizing bacterium was isolated that degrades TCE in pure culture at concentrations commonly observed in contaminated groundwater. Strain 46-1, a type I methanotrophic bacterium, degraded TCE if grown on methane or methanol, producing CO2 and water-soluble products. Gas chromatography and 14C radiotracer techniques were used to determine the rate, methane dependence, and mechanism of TCE biodegradation. TCE biodegradation by strain 46-1 appears to be a cometabolic process that occurs when the organism is actively metabolizing a suitable growth substrate such as methane or methanol. It is proposed that TCE biodegradation by methanotrophs occurs by formation of TCE epoxide, which breaks down spontaneously in water to form dichloroacetic and glyoxylic acids and one-carbon products. Images PMID:16347616

  17. Biotechnology of marine fungi.

    PubMed

    Damare, Samir; Singh, Purnima; Raghukumar, Seshagiri

    2012-01-01

    Filamentous fungi are the most widely used eukaryotes in industrial and pharmaceutical applications. Their biotechnological uses include the production of enzymes, vitamins, polysaccharides, pigments, lipids and others. Marine fungi are a still relatively unexplored group in biotechnology. Taxonomic and habitat diversity form the basis for exploration of marine fungal biotechnology. This review covers what is known of the potential applications of obligate and marine-derived fungi obtained from coastal to the oceanic and shallow water to the deep-sea habitats. Recent studies indicate that marine fungi are potential candidates for novel enzymes, bioremediation, biosurfactants, polysaccharides, polyunsaturated fatty acids and secondary metabolites. Future studies that focus on culturing rare and novel marine fungi, combined with knowledge of their physiology and biochemistry will provide a firm basis for marine mycotechnology. PMID:22222837

  18. Single exposure of dopamine D1 antagonist prevents and D2 antagonist attenuates methylphenidate effect

    PubMed Central

    Claussen, Catherine M; Witte, Lindsey J; Dafny, Nachum

    2015-01-01

    Methylphenidate (MPD) is a readily prescribed drug for the treatment of attention deficit hyperactivity disorder (ADHD) and moreover is used illicitly by youths for its cognitive-enhancing effects and recreation. MPD exposure in rodents elicits increased locomotor activity. Repetitive MPD exposure leads to further augmentation of their locomotor activity. This behavioral response is referred to as behavioral sensitization. Behavioral sensitization is used as an experimental marker for a drug’s ability to elicit dependence. There is evidence that dopamine (DA) is a key player in the acute and chronic MPD effect; however, the role of DA in the effects elicited by MPD is still debated. The objective of this study was to investigate the role of D1 and/or D2 DA receptors in the acute and chronic effect of MPD on locomotor activity. The study lasted for 12 consecutive days. Seven groups of male Sprague Dawley® rats were used. A single D1 or D2 antagonist was given before and after acute and chronic MPD administration. Single injection of D1 DA antagonist was able to significantly attenuate the locomotor activity when given prior to the initial MPD exposure and after repetitive MPD exposure, while the D2 DA antagonist partially attenuated the locomotor activity only when given before the second MPD exposure. The results show the role, at least in part, of the D1 DA receptor in the mechanism of behavioral sensitization, whereas the D2 DA receptor only partially modulates the response to acute and chronic MPD. PMID:27186140

  19. The chemical cue tetrabromopyrrole from a biofilm bacterium induces settlement of multiple Caribbean corals.

    PubMed

    Sneed, Jennifer M; Sharp, Koty H; Ritchie, Kimberly B; Paul, Valerie J

    2014-07-01

    Microbial biofilms induce larval settlement for some invertebrates, including corals; however, the chemical cues involved have rarely been identified. Here, we demonstrate the role of microbial biofilms in inducing larval settlement with the Caribbean coral Porites astreoides and report the first instance of a chemical cue isolated from a marine biofilm bacterium that induces complete settlement (attachment and metamorphosis) of Caribbean coral larvae. Larvae settled in response to natural biofilms, and the response was eliminated when biofilms were treated with antibiotics. A similar settlement response was elicited by monospecific biofilms of a single bacterial strain, Pseudoalteromonas sp. PS5, isolated from the surface biofilm of a crustose coralline alga. The activity of Pseudoalteromonas sp. PS5 was attributed to the production of a single compound, tetrabromopyrrole (TBP), which has been shown previously to induce metamorphosis without attachment in Pacific acroporid corals. In addition to inducing settlement of brooded larvae (P. astreoides), TBP also induced larval settlement for two broadcast-spawning species, Orbicella (formerly Montastraea) franksi and Acropora palmata, indicating that this compound may have widespread importance among Caribbean coral species. PMID:24850918

  20. Architecture of a flagellar apparatus in the fast-swimming magnetotactic bacterium MO-1

    PubMed Central

    Ruan, Juanfang; Kato, Takayuki; Santini, Claire-Lise; Miyata, Tomoko; Kawamoto, Akihiro; Zhang, Wei-Jia; Bernadac, Alain; Wu, Long-Fei; Namba, Keiichi

    2012-01-01

    The bacterial flagellum is a motility organelle that consists of a rotary motor and a helical propeller. The flagella usually work individually or by forming a loose bundle to produce thrust. However, the flagellar apparatus of marine bacterium MO-1 is a tight bundle of seven flagellar filaments enveloped in a sheath, and it has been a mystery as to how the flagella rotate smoothly in coordination. Here we have used electron cryotomography to visualize the 3D architecture of the sheathed flagella. The seven filaments are enveloped with 24 fibrils in the sheath, and their basal bodies are arranged in an intertwined hexagonal array similar to the thick and thin filaments of vertebrate skeletal muscles. This complex and exquisite architecture strongly suggests that the fibrils counter-rotate between flagella in direct contact to minimize the friction of high-speed rotation of individual flagella in the tight bundle within the sheath to enable MO-1 cells to swim at about 300 µm/s. PMID:23184985

  1. Genomic analysis reveals versatile heterotrophic capacity of a potentially symbiotic sulfur-oxidizing bacterium in sponge.

    PubMed

    Tian, Ren-Mao; Wang, Yong; Bougouffa, Salim; Gao, Zhao-Ming; Cai, Lin; Bajic, Vladimir; Qian, Pei-Yuan

    2014-11-01

    Sulfur-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB) play essential roles in marine sponges. However, the detailed characteristics and physiology of the bacteria are largely unknown. Here, we present and analyse the first genome of sponge-associated SOB using a recently developed metagenomic binning strategy. The loss of transposase and virulence-associated genes and the maintenance of the ancient polyphosphate glucokinase gene suggested a stabilized SOB genome that might have coevolved with the ancient host during establishment of their association. Exclusive distribution in sponge, bacterial detoxification for the host (sulfide oxidation) and the enrichment for symbiotic characteristics (genes-encoding ankyrin) in the SOB genome supported the bacterial role as an intercellular symbiont. Despite possessing complete autotrophic sulfur oxidation pathways, the bacterium developed a much more versatile capacity for carbohydrate uptake and metabolism, in comparison with its closest relatives (Thioalkalivibrio) and to other representative autotrophs from the same order (Chromatiales). The ability to perform both autotrophic and heterotrophic metabolism likely results from the unstable supply of reduced sulfur in the sponge and is considered critical for the sponge-SOB consortium. Our study provides insights into SOB of sponge-specific clade with thioautotrophic and versatile heterotrophic metabolism relevant to its roles in the micro-environment of the sponge body.

  2. Interactions of the algicidal bacterium Kordia algicida with diatoms: regulated protease excretion for specific algal lysis.

    PubMed

    Paul, Carsten; Pohnert, Georg

    2011-01-01

    Interactions of planktonic bacteria with primary producers such as diatoms have great impact on plankton population dynamics. Several studies described the detrimental effect of certain bacteria on diatoms but the biochemical nature and the regulation mechanism involved in the production of the active compounds remained often elusive. Here, we investigated the interactions of the algicidal bacterium Kordia algicida with the marine diatoms Skeletonema costatum, Thalassiosira weissflogii, Phaeodactylum tricornutum, and Chaetoceros didymus. Algicidal activity was only observed towards the first three of the tested diatom species while C. didymus proved to be not susceptible. The cell free filtrate and the >30 kDa fraction of stationary K. algicida cultures is fully active, suggesting a secreted algicidal principle. The active supernatant from bacterial cultures exhibited high protease activity and inhibition experiments proved that these enzymes are involved in the observed algicidal action of the bacteria. Protease mediated interactions are not controlled by the presence of the alga but dependent on the cell density of the K. algicida culture. We show that protease release is triggered by cell free bacterial filtrates suggesting a quorum sensing dependent excretion mechanism of the algicidal protein. The K. algicida / algae interactions in the plankton are thus host specific and under the control of previously unidentified factors. PMID:21695044

  3. Interactions of the Algicidal Bacterium Kordia algicida with Diatoms: Regulated Protease Excretion for Specific Algal Lysis

    PubMed Central

    Paul, Carsten; Pohnert, Georg

    2011-01-01

    Interactions of planktonic bacteria with primary producers such as diatoms have great impact on plankton population dynamics. Several studies described the detrimental effect of certain bacteria on diatoms but the biochemical nature and the regulation mechanism involved in the production of the active compounds remained often elusive. Here, we investigated the interactions of the algicidal bacterium Kordia algicida with the marine diatoms Skeletonema costatum, Thalassiosira weissflogii, Phaeodactylum tricornutum, and Chaetoceros didymus. Algicidal activity was only observed towards the first three of the tested diatom species while C. didymus proved to be not susceptible. The cell free filtrate and the >30 kDa fraction of stationary K. algicida cultures is fully active, suggesting a secreted algicidal principle. The active supernatant from bacterial cultures exhibited high protease activity and inhibition experiments proved that these enzymes are involved in the observed algicidal action of the bacteria. Protease mediated interactions are not controlled by the presence of the alga but dependent on the cell density of the K. algicida culture. We show that protease release is triggered by cell free bacterial filtrates suggesting a quorum sensing dependent excretion mechanism of the algicidal protein. The K. algicida / algae interactions in the plankton are thus host specific and under the control of previously unidentified factors. PMID:21695044

  4. Characterization of recombinant glutathione reductase from the psychrophilic Antarctic bacterium Colwellia psychrerythraea.

    PubMed

    Ji, Mikyoung; Barnwell, Callie V; Grunden, Amy M

    2015-07-01

    Glutathione reductases catalyze the reduction of oxidized glutathione (glutathione disulfide, GSSG) using NADPH as the substrate to produce reduced glutathione (GSH), which is an important antioxidant molecule that helps maintain the proper reducing environment of the cell. A recombinant form of glutathione reductase from Colwellia psychrerythraea, a marine psychrophilic bacterium, has been biochemically characterized to determine its molecular and enzymatic properties. C. psychrerythraea glutathione reductase was shown to be a homodimer with a molecular weight of 48.7 kDa using SDS-PAGE, MALDI-TOF mass spectrometry and gel filtration. The C. psychrerythraea glutathione reductase sequence shows significant homology to that of Escherichia coli glutathione reductase (66 % identity), and it possesses the FAD and NADPH binding motifs, as well as absorption spectrum features which are characteristic of flavoenzymes such as glutathione reductase. The psychrophilic C. psychrerythraea glutathione reductase exhibits higher k cat and k cat/K m at lower temperatures (4 °C) compared to mesophilic Baker's yeast glutathione reductase. However, C. psychrerythraea glutathione reductase was able to complement an E. coli glutathione reductase deletion strain in oxidative stress growth assays, demonstrating the functionality of C. psychrerythraea glutathione reductase over a broad temperature range, which suggests its potential utility as an antioxidant enzyme in heterologous systems. PMID:26101017

  5. The chemical cue tetrabromopyrrole from a biofilm bacterium induces settlement of multiple Caribbean corals

    PubMed Central

    Sneed, Jennifer M.; Sharp, Koty H.; Ritchie, Kimberly B.; Paul, Valerie J.

    2014-01-01

    Microbial biofilms induce larval settlement for some invertebrates, including corals; however, the chemical cues involved have rarely been identified. Here, we demonstrate the role of microbial biofilms in inducing larval settlement with the Caribbean coral Porites astreoides and report the first instance of a chemical cue isolated from a marine biofilm bacterium that induces complete settlement (attachment and metamorphosis) of Caribbean coral larvae. Larvae settled in response to natural biofilms, and the response was eliminated when biofilms were treated with antibiotics. A similar settlement response was elicited by monospecific biofilms of a single bacterial strain, Pseudoalteromonas sp. PS5, isolated from the surface biofilm of a crustose coralline alga. The activity of Pseudoalteromonas sp. PS5 was attributed to the production of a single compound, tetrabromopyrrole (TBP), which has been shown previously to induce metamorphosis without attachment in Pacific acroporid corals. In addition to inducing settlement of brooded larvae (P. astreoides), TBP also induced larval settlement for two broadcast-spawning species, Orbicella (formerly Montastraea) franksi and Acropora palmata, indicating that this compound may have widespread importance among Caribbean coral species. PMID:24850918

  6. Thermostable purified endoglucanase from thermophilic bacterium acidothermus cellulolyticus

    DOEpatents

    Tucker, Melvin P.; Grohmann, Karel; Himmel, Michael E.; Mohagheghi, Ali

    1992-01-01

    A substantially purified high molecular weight cellulase enzyme having a molecular weight of between about 156,000 to about 203,400 daltons isolated from the bacterium Acidothermus cellulolyticus (ATCC 43068) and a method of producing it are disclosed. The enzyme is water soluble, possesses both C.sub.1 and C.sub.x types of enzymatic activity, has a high degree of stability toward heat and exhibits both a high optimum temperature activity and high inactivation characteristics.

  7. Targeting Nuclear Receptors with Marine Natural Products

    PubMed Central

    Yang, Chunyan; Li, Qianrong; Li, Yong

    2014-01-01

    Nuclear receptors (NRs) are important pharmaceutical targets because they are key regulators of many metabolic and inflammatory diseases, including diabetes, dyslipidemia, cirrhosis, and fibrosis. As ligands play a pivotal role in modulating nuclear receptor activity, the discovery of novel ligands for nuclear receptors represents an interesting and promising therapeutic approach. The search for novel NR agonists and antagonists with enhanced selectivities prompted the exploration of the extraordinary chemical diversity associated with natural products. Recent studies involving nuclear receptors have disclosed a number of natural products as nuclear receptor ligands, serving to re-emphasize the translational possibilities of natural products in drug discovery. In this review, the natural ligands of nuclear receptors will be described with an emphasis on their mechanisms of action and their therapeutic potentials, as well as on strategies to determine potential marine natural products as nuclear receptor modulators. PMID:24473166

  8. Targeting nuclear receptors with marine natural products.

    PubMed

    Yang, Chunyan; Li, Qianrong; Li, Yong

    2014-01-27

    Nuclear receptors (NRs) are important pharmaceutical targets because they are key regulators of many metabolic and inflammatory diseases, including diabetes, dyslipidemia, cirrhosis, and fibrosis. As ligands play a pivotal role in modulating nuclear receptor activity, the discovery of novel ligands for nuclear receptors represents an interesting and promising therapeutic approach. The search for novel NR agonists and antagonists with enhanced selectivities prompted the exploration of the extraordinary chemical diversity associated with natural products. Recent studies involving nuclear receptors have disclosed a number of natural products as nuclear receptor ligands, serving to re-emphasize the translational possibilities of natural products in drug discovery. In this review, the natural ligands of nuclear receptors will be described with an emphasis on their mechanisms of action and their therapeutic potentials, as well as on strategies to determine potential marine natural products as nuclear receptor modulators.

  9. Marine Indole Alkaloids

    PubMed Central

    Netz, Natalie; Opatz, Till

    2015-01-01

    Marine indole alkaloids comprise a large and steadily growing group of secondary metabolites. Their diverse biological activities make many compounds of this class attractive starting points for pharmaceutical development. Several marine-derived indoles were found to possess cytotoxic, antineoplastic, antibacterial and antimicrobial activities, in addition to the action on human enzymes and receptors. The newly isolated indole alkaloids of marine origin since the last comprehensive review in 2003 are reported, and biological aspects will be discussed. PMID:26287214

  10. An on-bacterium flow cytometric immunoassay for protein quantification.

    PubMed

    Lan, Wen-Jun; Lan, Wei; Wang, Hai-Yan; Yan, Lei; Wang, Zhe-Li

    2013-09-01

    The polystyrene bead-based flow cytometric immunoassay has been widely reported. However, the preparation of functional polystyrene bead is still inconvenient. This study describes a simple and easy on-bacterium flow cytometric immunoassay for protein quantification, in which Staphylococcus aureus (SAC) is used as an antibody-antigen carrier to replace the polystyrene bead. The SAC beads were prepared by carboxyfluorescein diacetate succinimidyl ester (CFSE) labeling, paraformaldehyde fixation and antibody binding. Carcinoembryonic antigen (CEA) and cytokeratin-19 fragment (CYFRA 21-1) proteins were used as models in the test system. Using prepared SAC beads, biotinylated proteins, and streptavidin-phycoerythrin (SA-PE), the on-bacterium flow cytometric immunoassay was validated by quantifying CEA and CYFRA 21-1 in sample. Obtained data demonstrated a concordant result between the logarithm of the protein concentration and the logarithm of the PE mean fluorescence intensity (MFI). The limit of detection (LOD) in this immunoassay was at least 0.25 ng/ml. Precision and accuracy assessments appeared that either the relative standard deviation (R.S.D.) or the relative error (R.E.) was <10%. The comparison between this immunoassay and a polystyrene bead-based flow cytometric immunoassay showed a correlation coefficient of 0.998 for serum CEA or 0.996 for serum CYFRA 21-1. In conclusion, the on-bacterium flow cytometric immunoassay may be of use in the quantification of serum protein. PMID:23739299

  11. Detection of Pathogenic Leptospira Bacteria in Pinniped Populations via PCR and Identification of a Source of Transmission for Zoonotic Leptospirosis in the Marine Environment

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Leptospirosis, caused by the spirochete bacterium Leptospira, is a geographically widespread disease that affects a broad range of mammals, including marine mammals. During 2004 an outbreak of leptospirosis occurred among select pinniped populations along the West Coast of North America, with cases...

  12. Characterizing Marine Soundscapes.

    PubMed

    Erbe, Christine; McCauley, Robert; Gavrilov, Alexander

    2016-01-01

    The study of marine soundscapes is becoming widespread and the amount of data collected is increasing rapidly. Data owners (typically academia, industry, government, and defense) are negotiating data sharing and generating potential for data syntheses, comparative studies, analyses of trends, and large-scale and long-term acoustic ecology research. A problem is the lack of standards and commonly agreed protocols for the recording of marine soundscapes, data analysis, and reporting that make a synthesis and comparison of results difficult. We provide a brief overview of the components in a marine soundscape, the hard- and software tools for recording and analyzing marine soundscapes, and common reporting formats. PMID:26610968

  13. Parasites and marine invasions

    USGS Publications Warehouse

    Torchin, M.E.; Lafferty, K.D.; Kuris, A.M.

    2002-01-01

    Introduced marine species are a major environmental and economic problem. The rate of these biological invasions has substantially increased in recent years due to the globalization of the world's economies. The damage caused by invasive species is often a result of the higher densities and larger sizes they attain compared to where they are native. A prominent hypothesis explaining the success of introduced species is that they are relatively free of the effects of natural enemies. Most notably, they may encounter fewer parasites in their introduced range compared to their native range. Parasites are ubiquitous and pervasive in marine systems, yet their role in marine invasions is relatively unexplored. Although data on parasites of marine organisms exist, the extent to which parasites can mediate marine invasions, or the extent to which invasive parasites and pathogens are responsible for infecting or potentially decimating native marine species have not been examined. In this review, we present a theoretical framework to model invasion success and examine the evidence for a relationship between parasite presence and the success of introduced marine species. For this, we compare the prevalence and species richness of parasites in several introduced populations of marine species with populations where they are native. We also discuss the potential impacts of introduced marine parasites on native ecosystems.

  14. Complications of TNF-α antagonists and iron homeostasis

    EPA Science Inventory

    TNF-α is a central regulator of inflammation and its blockade downregulates other proinflammatory cytokines, chemokines, and growth factors. Subsequently, TNF-α antagonists are currently used in treatment regimens directed toward several inflammatory diseases. Despite a beneficia...

  15. Anthropomorphic finger antagonistically actuated by SMA plates.

    PubMed

    Engeberg, Erik D; Dilibal, Savas; Vatani, Morteza; Choi, Jae-Won; Lavery, John

    2015-10-01

    Most robotic applications that contain shape memory alloy (SMA) actuators use the SMA in a linear or spring shape. In contrast, a novel robotic finger was designed in this paper using SMA plates that were thermomechanically trained to take the shape of a flexed human finger when Joule heated. This flexor actuator was placed in parallel with an extensor actuator that was designed to straighten when Joule heated. Thus, alternately heating and cooling the flexor and extensor actuators caused the finger to flex and extend. Three different NiTi based SMA plates were evaluated for their ability to apply forces to a rigid and compliant object. The best of these three SMAs was able to apply a maximum fingertip force of 9.01N on average. A 3D CAD model of a human finger was used to create a solid model for the mold of the finger covering skin. Using a 3D printer, inner and outer molds were fabricated to house the actuators and a position sensor, which were assembled using a multi-stage casting process. Next, a nonlinear antagonistic controller was developed using an outer position control loop with two inner MOSFET current control loops. Sine and square wave tracking experiments demonstrated minimal errors within the operational bounds of the finger. The ability of the finger to recover from unexpected disturbances was also shown along with the frequency response up to 7 rad s(-1). The closed loop bandwidth of the system was 6.4 rad s(-1) when operated intermittently and 1.8 rad s(-1) when operated continuously. PMID:26292164

  16. Identification of M-CSF agonists and antagonists

    SciTech Connect

    Pandit, Jayvardhan; Jancarik, Jarmila; Kim, Sung-Hou; Koths, Kirston; Halenbeck, Robert; Fear, Anna Lisa; Taylor, Eric; Yamamoto, Ralph; Bohm, Andrew

    2000-02-15

    The present invention is directed to methods for crystallizing macrophage colony stimulating factor. The present invention is also directed to methods for designing and producing M-CSF agonists and antagonists using information derived from the crystallographic structure of M-CSF. The invention is also directed to methods for screening M-CSF agonists and antagonists. In addition, the present invention is directed to an isolated, purified, soluble and functional M-CSF receptor.

  17. Azogabazine; a photochromic antagonist of the GABAA receptor.

    PubMed

    Huckvale, Rosemary; Mortensen, Martin; Pryde, David; Smart, Trevor G; Baker, James R

    2016-07-12

    The design and synthesis of azogabazine is described, which represents a highly potent (IC50 = 23 nM) photoswitchable antagonist of the GABAA receptor. An azologization strategy is adopted, in which a benzyl phenyl ether in a high affinity gabazine analogue is replaced by an azobenzene, with resultant retention of antagonist potency. We show that cycling from blue to UV light, switching between trans and cis isomeric forms, leads to photochemically controlled antagonism of the GABA ion channel. PMID:27327397

  18. Magnet-Facilitated Selection of Electrogenic Bacteria from Marine Sediment

    PubMed Central

    Kiseleva, Larisa; Briliute, Justina; Khilyas, Irina V.; Simpson, David J. W.; Fedorovich, Viacheslav; Cohen, M.; Goryanin, Igor

    2015-01-01

    Some bacteria can carry out anaerobic respiration by depositing electrons on external materials, such as electrodes, thereby creating an electrical current. Into the anode chamber of microbial fuel cells (MFCs) having abiotic air-cathodes we inoculated microorganisms cultured from a magnetic particle-enriched portion of a marine tidal sediment, reasoning that since some external electron acceptors are ferromagnetic, electrogenic bacteria should be found in their vicinity. Two MFCs, one inoculated with a mixed bacterial culture and the other with an axenic culture of a helical bacterium isolated from the magnetic particle enrichment, termed strain HJ, were operated for 65 d. Both MFCs produced power, with production from the mixed culture MFC exceeding that of strain HJ. Strain HJ was identified as a Thalassospira sp. by transmission electron microscopic analysis and 16S rRNA gene comparisons. An MFC inoculated with strain HJ and operated in open circuit produced 47% and 57% of the maximal power produced from MFCs inoculated with the known electrogen Geobacter daltonii and the magnetotactic bacterium Desulfamplus magnetomortis, respectively. Further investigation will be needed to determine whether bacterial populations associated with magnetic particles within marine sediments are enriched for electrogens. PMID:26504814

  19. Magnet-Facilitated Selection of Electrogenic Bacteria from Marine Sediment.

    PubMed

    Kiseleva, Larisa; Briliute, Justina; Khilyas, Irina V; Simpson, David J W; Fedorovich, Viacheslav; Cohen, M; Goryanin, Igor

    2015-01-01

    Some bacteria can carry out anaerobic respiration by depositing electrons on external materials, such as electrodes, thereby creating an electrical current. Into the anode chamber of microbial fuel cells (MFCs) having abiotic air-cathodes we inoculated microorganisms cultured from a magnetic particle-enriched portion of a marine tidal sediment, reasoning that since some external electron acceptors are ferromagnetic, electrogenic bacteria should be found in their vicinity. Two MFCs, one inoculated with a mixed bacterial culture and the other with an axenic culture of a helical bacterium isolated from the magnetic particle enrichment, termed strain HJ, were operated for 65 d. Both MFCs produced power, with production from the mixed culture MFC exceeding that of strain HJ. Strain HJ was identified as a Thalassospira sp. by transmission electron microscopic analysis and 16S rRNA gene comparisons. An MFC inoculated with strain HJ and operated in open circuit produced 47% and 57% of the maximal power produced from MFCs inoculated with the known electrogen Geobacter daltonii and the magnetotactic bacterium Desulfamplus magnetomortis, respectively. Further investigation will be needed to determine whether bacterial populations associated with magnetic particles within marine sediments are enriched for electrogens. PMID:26504814

  20. "Marinating" Our Urban Youth.

    ERIC Educational Resources Information Center

    Ascher, Alan

    1981-01-01

    Describes marine education programs at the elementary and secondary levels in the New York City area. The city's extensive coastline and numerous learning centers comprise one of the richest educational resources in the country for studying the marine environment. (Author/WB)

  1. Marine Attitude Survey

    ERIC Educational Resources Information Center

    Hounshell, Paul B.; Hampton, Carolyn

    This 22-item Marine Attitude Survey was developed for use in elementary/middle schools to measure students' attitudes about various aspects of marine science. Students are asked if they agree, are not sure, or disagree with such items as: (1) the seashore is a fun place to visit; (2) if all sharks were killed, the world would be a better place;…

  2. Monitoring Marine Microbial Fouling

    NASA Technical Reports Server (NTRS)

    Colwell, R.

    1985-01-01

    Two techniques developed for studying marine fouling. Methods originally developed to study fouling of materials used in Space Shuttle solid fuel booster rockets. Methods used to determine both relative fouling rates and efficacy of cleaning methods to remove fouling on various surfaces including paints, metals, and sealants intended for marine use.

  3. CXCR3 antagonist VUF10085 binds to an intrahelical site distinct from that of the broad spectrum antagonist TAK–779

    PubMed Central

    Nedjai, Belinda; Viney, Jonathan M; Li, Hubert; Hull, Caroline; Anderson, Caroline A; Horie, Tomoki; Horuk, Richard; Vaidehi, Nagarajan; Pease, James E

    2015-01-01

    Background and Purpose The chemokine receptor CXCR3 is implicated in a variety of clinically important diseases, notably rheumatoid arthritis and atherosclerosis. Consequently, antagonists of CXCR3 are of therapeutic interest. In this study, we set out to characterize binding sites of the specific low MW CXCR3 antagonist VUF10085 and the broad spectrum antagonist TAK-779 which blocks CXCR3 along with CCR2 and CCR5. Experimental Approach Molecular modelling of CXCR3, followed by virtual ligand docking, highlighted several CXCR3 residues likely to contact either antagonist, notably a conserved aspartate in helix 2 (Asp-1122:63), which was postulated to interact with the quaternary nitrogen of TAK-779. Validation of modelling was carried out by site-directed mutagenesis of CXCR3, followed by assays of cell surface expression, ligand binding and receptor activation. Key Results Mutation of Asn-1323.33, Phe-207 and Tyr-2716.51 within CXCR3 severely impaired both ligand binding and chemotactic responses, suggesting that these residues are critical for maintenance of a functional CXCR3 conformation. Contrary to our hypothesis, mutation of Asp-1122:63 had no observable effects on TAK-779 activity, but clearly decreased the antagonist potency of VUF 10085. Likewise, mutations of Phe-1313.32, Ile-2796.59 and Tyr-3087.43 were well tolerated and were critical for the antagonist activity of VUF 10085 but not for that of TAK-779. Conclusions and Implications This more detailed definition of a binding pocket within CXCR3 for low MW antagonists should facilitate the rational design of newer CXCR3 antagonists, with obvious clinical potential. PMID:25425280

  4. Marin Tsunami (video)

    USGS Publications Warehouse

    Filmed and edited by: Loeffler, Kurt; Gesell, Justine

    2010-01-01

    Tsunamis are a constant threat to the coasts of our world. Although tsunamis are infrequent along the West coast of the United States, it is possible and necessary to prepare for potential tsunami hazards to minimize loss of life and property. Community awareness programs are important, as they strive to create an informed society by providing education and training. The Marin coast could be struck by a tsunami. Whether you live in Marin County, visit the beaches, or rent or own a home near the coast, it is vital to understand the tsunami threat and take preparation seriously. Marin Tsunami tells the story of what several West Marin communities are doing to be prepared. This video was produced by the US Geological Survey (USGS) in cooperation with the Marin Office of Emergency Services.

  5. Neurotoxic marine poisoning.

    PubMed

    Isbister, Geoffrey K; Kiernan, Matthew C

    2005-04-01

    Marine poisoning results from the ingestion of marine animals that contain toxic substances and causes substantial illness in coastal regions. Three main clinical syndromes of marine poisoning have important neurological symptoms-ciguatera, tetrodotoxin poisoning, and paralytic shellfish poisoning. Ciguatera is the commonest syndrome of marine poisoning and is characterised by moderate to severe gastrointestinal effects (vomiting, diarrhoea, and abdominal cramps) and neurological effects (myalgia, paraesthesia, cold allodynia, and ataxia), but is rarely lethal. Tetrodotoxin poisoning and paralytic shellfish poisoning are less common but have a higher fatality rate than ciguatera. Mild gastrointestinal effects and a descending paralysis are characteristic of these types of poisoning. In severe poisoning, paralysis rapidly progresses to respiratory failure. Diagnosis of all types of marine poisoning is made from the circumstances of ingestion (type of fish and location) and the clinical effects. Because there are no antidotes, supportive care, including mechanical ventilation in patients with severe paralysis, is the mainstay of treatment.

  6. Effects of H1 and H2 receptor antagonists on Tetrahymena.

    PubMed

    Csaba, G; László, V; Darvas, Z

    1978-01-01

    In Tetrahymena pyriformis the phagocytotic rate increases in response to histamine, but neither the H1 antagonist phenindamine nor the H2 antagonist metiamide stimulate phagocytosis. The H1 antagonist counteracts the effect of histamine, whereas the H2 antagonist does not. The histamine receptor of Tetrahymena is of H1-type, since it cannot distinguish between histamine and antagonists which are closely related to it chemically. It does, however, distinguish between histamine and the chemically unrelated H1 antagonist, phenindamine. The H2 antagonist does not interact with the receptor.

  7. Early Illustrations of Geste Antagoniste in Cervical and Generalized Dystonia

    PubMed Central

    Broussolle, Emmanuel; Laurencin, Chloé; Bernard, Emilien; Thobois, Stéphane; Danaila, Teodor; Krack, Paul

    2015-01-01

    Background Geste antagoniste, or sensory trick, is a voluntary maneuver that temporarily reduces the severity of dystonic postures or movements. We present a historical review of early reports and illustrations of geste antagoniste. Results In 1894, Brissaud described this phenomenon in Paris in patients with torticollis. He noted that a violent muscular contraction could be reversed by a minor voluntary action. He considered the improvement obtained by what he called “simple mannerisms, childish behaviour or fake pathological movements” was proof of the psychogenic origin of what he named mental torticollis. This concept was supported by photographical illustrations of the patients. The term geste antagoniste was used by Brissaud’s pupils, Meige and Feindel, in their 1902 monograph on movement disorders. Other reports and illustrations of this sign were published in Europe between 1894 and 1906. Although not mentioned explicitly, geste antagoniste was also illustrated in a case report of generalized dystonia in Oppenheim’s 1911 seminal description of dystonia musculorum deformans in Berlin. Discussion Brissaud-Meige’s misinterpretation of the geste antagoniste unfortunately anchored the psychogenic origin of dystonia for decades. In New York, Herz brought dystonia back into the realm of organic neurology in 1944. Thereafter, it was given prominence by other authors, notably Fahn and Marsden in the 1970–1980s. Nowadays, neurologists routinely investigate for geste antagoniste when a dystonic syndrome is suspected, because it provides a further argument in favor of dystonia. The term alleviating maneuver was proposed in 2014 to replace sensory trick or geste antagoniste. This major sign is now part of the motor phenomenology of the 2013 Movement Disorder Society’s classification of dystonia. PMID:26417535

  8. Fast Neutron Irradiation of the Highly Radioresistant Bacterium Deinococcus Radiodurans

    NASA Astrophysics Data System (ADS)

    Case, Diane Louise

    Fast neutron dose survival curves were generated for the bacterium Deinococcus radiodurans, which is renowned for its unusually high resistance to gamma, x-ray, and ultraviolet radiation, but for which fast neutron response was unknown. The fast neutrons were produced by the University of Massachusetts Lowell 5.5-MV, type CN Van de Graaff accelerator through the ^7Li(p,n)^7 Be reaction by bombarding a thick metallic lithium target with a 4-MeV proton beam. The bacteria were uniformly distributed on 150-mm agar plates and were exposed to the fast neutron beam under conditions of charged particle equilibrium. The plates were subdivided into concentric rings of increasing diameter from the center to the periphery of the plate, within which the average neutron dose was calculated as the product of the precisely known neutron fluence at the average radius of the ring and the neutron energy dependent kerma factor. The neutron fluence and dose ranged from approximately 3 times 1013 n cm^ {-2} to 1 times 1012 n cm^ {-2}, and 200 kilorad to 5 kilorad, respectively, from the center to the periphery of the plate. Percent survival for Deinococcus radiodurans as a function of fast neutron dose was derived from the ability of the irradiated cells to produce visible colonies within each ring compared to that of a nonirradiated control population. The bacterium Escherichia coli B/r (CSH) was irradiated under identical conditions for comparative purposes. The survival response of Deinococcus radiodurans as a result of cumulative fast neutron exposures was also investigated. The quantification of the ability of Deinococcus radiodurans to survive cellular insult from secondary charged particles, which are produced by fast neutron interactions in biological materials, will provide valuable information about damage and repair mechanisms under extreme cellular stress, and may provide new insight into the origin of this bacterium's unprecedented radiation resistance.

  9. Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens

    SciTech Connect

    Daniel P. Molloy

    2004-02-24

    The specific purpose of this research project was to identify factors that affect zebra mussel kill by the bacterium Pseudomonas fluorescens. Test results obtained during this three-year project identified the following key variables as affecting mussel kill: treatment concentration, treatment duration, mussel siphoning activity, dissolved oxygen concentration, water temperature, and naturally suspended particle load. Using this latter information, the project culminated in a series of pipe tests which achieved high mussel kill inside power plants under once-through conditions using service water in artificial pipes.

  10. Triazine herbicide resistance in the photosynthetic bacterium Rhodopseudomonas sphaeroides

    SciTech Connect

    Brown, A.E.; Gilbert, C.W.; Guy, R.; Arntzen, C.J.

    1984-10-01

    The photoaffinity herbicide azidoatrazine (2-azido-4-ethylamino-6-isopropylamino-s-triazine) selectively labels the L subunit of the reaction center of the photosynthetic bacterium Rhodopseudomonas sphaeroides. Herbicide-resistant mutants retain the L subunit and have altered binding properties for methylthio- and chloro-substituted triazines as well as altered equilibrium constants for electron transfer between primary and secondary electron acceptors. We suggest that a subtle alteration in the L subunit is responsible for herbicide resistance and that the L subunit is the functional analog of the 32-kDa Q/sub B/ protein of chloroplast membranes. 42 references, 6 figures, 1 table.

  11. CORNEAL REACTIONS TO BACTERIUM GRANULOSIS AND OTHER MICROORGANISMS

    PubMed Central

    Olitsky, Peter K.; Knutti, Ralph E.; Tyler, Joseph R.

    1932-01-01

    The conclusions which may be drawn from the results of the experiments here presented are: 1. The cornea of the rabbit is highly sensitive to the action of various injected bacteria. The lesions vary from insignificant, transient changes to severe, destructive panophthalmitis, with fine gradations from the mildest to the violent form of inflammation. Moreover, animals that receive the same organisms show like changes. 2. The varying degree of inflammatory reaction is related to the pathogenicity of the special culture employed; as, for example, is shown by the reactions to Type I pneumococci and to Bacterium granulosis. It is evident that when a microorganism having a certain degree of virulence is used, a lesion of localized vasculonebulous keratitis resembling pannus tenuis or vasculosus of human trachoma can be induced. Thus Bacterium granulosis, Bacillus xerosis, Hemophilus influenzae, Pneumococcus Type II, Streptococcus viridans, and gonococcus can cause the pannus-like corneal changes in the rabbit. Of these organisms, however, only Bacterium granulosis induces early, uncomplicated and enduring keratitic lesions; the others cause first, diffuse keratitis with suppurative lesions; then, as a residual effect, transient, localized, vasculonebulous changes in the cornea. These changes, in contradistinction to the granulosis lesions, are, therefore delayed, complicated, and transient. When, on the other hand, the invasiveness and infecting power of the organisms are low, as is the case with the filtrable, Gram-negative bacillus and the small, Gram-negative bacilli ultimately derived from cases of folliculosis, no marked effect is produced by their intracorneal inoculation. If the pathogenicity of bacteria is high (as shown by Pneumococcus Type I, hemolytic streptococcus, and the remaining bacteria), intracorneal inoculation of the microorganisms leads to serious suppurative or destructive changes. 3. The results of experiments with monkeys indicate that while

  12. Magnetic guidance of the magnetotactic bacterium Magnetospirillum gryphiswaldense.

    PubMed

    Loehr, Johannes; Pfeiffer, Daniel; Schüler, Dirk; Fischer, Thomas M

    2016-04-21

    Magnetospirillum gryphiswaldense is a magnetotactic bacterium with a permanent magnetic moment capable of swimming using two bipolarly located flagella. In their natural environment these bacteria swim along the field lines of the homogeneous geomagnetic field in a typical run and reversal pattern and thereby create non-differentiable trajectories with sharp edges. In the current work we nevertheless achieve stable guidance along curved lines of mechanical instability by using a heterogeneous magnetic field of a garnet film. The successful guidance of the bacteria depends on the right balance between motility and the magnetic moment of the magnetosome chain. PMID:26972517

  13. Marine fragrance chemistry.

    PubMed

    Hügel, Helmut M; Drevermann, Britta; Lingham, Anthony R; Marriott, Philip J

    2008-06-01

    The main marine message in perfumery is projected by Calone 1951 (7-methyl-2H-1,5-benzodioxepin-3(4H)-one). Kraft (Givaudan) and Gaudin (Firmenich) further maximized the marine fragrance molecular membership by extending the carbon chain of the 7-Me group. Our research targeted the polar group of the benzodioxepinone parent compound to investigate how this region of molecular makeup resonates with the dominant marine fragrance of the Calone 1951 structure. The olfactory evaluation of analogues prepared by chemical modification or removal of the CO group resulted in the introduction of aldehydic, sweet and floral-fruity notes with a diluted/diminished potency of the marine odor. To further analyze the olfactory properties of benzodioxepinones containing a diverse range of aromatic ring substituents, a novel synthesis route was developed. We found that a 7-alkyl group in Calone 1951 was essential for the maintenance of the significant marine odor characteristic, and our studies support the concept that the odorant structure occupying the hydrophobic binding pocket adjacent to the aromatic ring-binding site of the olfactory receptor is pivotal in the design and discovery of more potent and characteristic marine fragrances. How the structure of benzodioxepinones connects to marine sea-breeze fragrances is our continuing challenging research focus at the chemistry-biology interface.

  14. Antibiofilm and Anti-Infection of a Marine Bacterial Exopolysaccharide Against Pseudomonas aeruginosa.

    PubMed

    Wu, Shimei; Liu, Ge; Jin, Weihua; Xiu, Pengyuan; Sun, Chaomin

    2016-01-01

    Pseudomonas aeruginosa is a well-known pathogenic bacterium that forms biofilms and produces virulence factors, thus leading to major problems in many fields, such as clinical infection, food contamination, and marine biofouling. In this study, we report the purification and characterization of an exopolysaccharide EPS273 from the culture supernatant of marine bacterium P. stutzeri 273. The exopolysaccharide EPS273 not only effectively inhibits biofilm formation but also disperses preformed biofilm of P. aeruginosa PAO1. High performance liquid chromatography traces of the hydrolyzed polysaccharides shows that EPS273 primarily consists of glucosamine, rhamnose, glucose and mannose. Further investigation demonstrates that EPS273 reduces the production of the virulence factors pyocyanin, exoprotease, and rhamnolipid, and the virulence of P. aeruginosa PAO1 to human lung cells A549 and zebrafish embryos is also obviously attenuated by EPS273. In addition, EPS273 also greatly reduces the production of hydrogen peroxide (H2O2) and extracellular DNA (eDNA), which are important factors for biofilm formation. Furthermore, EPS273 exhibits strong antioxidant potential by quenching hydroxyl and superoxide anion radicals. Notably, the antibiofouling activity of EPS273 is observed in the marine environment up to 2 weeks according to the amounts of bacteria and diatoms in the glass slides submerged in the ocean. Taken together, the properties of EPS273 indicate that it has a promising prospect in combating bacterial biofilm-associated infection, food-processing contamination and marine biofouling. PMID:26903981

  15. The anti-biofilm activity secreted by a marine Pseudoalteromonas strain.

    PubMed

    Klein, Géraldine L; Soum-Soutéra, Emmanuelle; Guede, Zakoua; Bazire, Alexis; Compère, Chantal; Dufour, Alain

    2011-09-01

    Bacterial biofilms occur on all submerged structures in marine environments. The authors previously reported that the marine bacterium Pseudoalteromonas sp. 3J6 secretes antibiofilm activity. Here, it was discovered that another Pseudoalteromonas sp. strain, D41, inhibited the development of strain 3J6 in mixed biofilms. Confocal laser scanning microscope observations revealed that the culture supernatant of strain D41 impaired biofilm formation of strain 3J6 and another marine bacterium. A microtiter plate assay of the antibiofilm activity was set up and validated with culture supernatants of Pseudoalteromonas sp. 3J6. This assay was used to determine the spectra of action of strains D41 and 3J6. Each culture supernatant impaired the biofilm development of 13 marine bacteria out of 18. However, differences in the spectra of action and the physical behaviours of the antibiofilm molecules suggest that the latter are not identical. They nevertheless share the originality of being devoid of antibacterial activity against planktonic bacteria. PMID:21895460

  16. Antibiofilm and Anti-Infection of a Marine Bacterial Exopolysaccharide Against Pseudomonas aeruginosa

    PubMed Central

    Wu, Shimei; Liu, Ge; Jin, Weihua; Xiu, Pengyuan; Sun, Chaomin

    2016-01-01

    Pseudomonas aeruginosa is a well-known pathogenic bacterium that forms biofilms and produces virulence factors, thus leading to major problems in many fields, such as clinical infection, food contamination, and marine biofouling. In this study, we report the purification and characterization of an exopolysaccharide EPS273 from the culture supernatant of marine bacterium P. stutzeri 273. The exopolysaccharide EPS273 not only effectively inhibits biofilm formation but also disperses preformed biofilm of P. aeruginosa PAO1. High performance liquid chromatography traces of the hydrolyzed polysaccharides shows that EPS273 primarily consists of glucosamine, rhamnose, glucose and mannose. Further investigation demonstrates that EPS273 reduces the production of the virulence factors pyocyanin, exoprotease, and rhamnolipid, and the virulence of P. aeruginosa PAO1 to human lung cells A549 and zebrafish embryos is also obviously attenuated by EPS273. In addition, EPS273 also greatly reduces the production of hydrogen peroxide (H2O2) and extracellular DNA (eDNA), which are important factors for biofilm formation. Furthermore, EPS273 exhibits strong antioxidant potential by quenching hydroxyl and superoxide anion radicals. Notably, the antibiofouling activity of EPS273 is observed in the marine environment up to 2 weeks according to the amounts of bacteria and diatoms in the glass slides submerged in the ocean. Taken together, the properties of EPS273 indicate that it has a promising prospect in combating bacterial biofilm-associated infection, food-processing contamination and marine biofouling. PMID:26903981

  17. Regulation of Cell Death by IAPs and Their Antagonists.

    PubMed

    Vasudevan, Deepika; Ryoo, Hyung Don

    2015-01-01

    Inhibitors of apoptosis (IAPs) family of genes encode baculovirus IAP-repeat domain-containing proteins with antiapoptotic function. These proteins also contain RING or UBC domains and act by binding to major proapoptotic factors and ubiquitylating them. High levels of IAPs inhibit caspase-mediated apoptosis. For these cells to undergo apoptosis, IAP function must be neutralized by IAP-antagonists. Mammalian IAP knockouts do not exhibit obvious developmental phenotypes, but the cells are more sensitized to apoptosis in response to injury. Loss of the mammalian IAP-antagonist ARTS results in reduced stem cell apoptosis. In addition to the antiapoptotic properties, IAPs regulate the innate immune response, and the loss of IAP function in humans is associated with immunodeficiency. The roles of IAPs in Drosophila apoptosis regulation are more apparent, where the loss of IAP1, or the expression of IAP-antagonists in Drosophila cells, is sufficient to trigger apoptosis. In this organism, apoptosis as a fate is conferred by the transcriptional induction of the IAP-antagonists. Many signaling pathways often converge on shared enhancer regions of IAP-antagonists. Cell death sensitivity is further regulated by posttranscriptional mechanisms, including those regulated by kinases, miRs, and ubiquitin ligases. These mechanisms are employed to eliminate damaged or virus-infected cells, limit neuroblast (neural stem cell) numbers, generate neuronal diversity, and sculpt tissue morphogenesis.

  18. Gonadotrophin releasing hormone antagonist in IVF/ICSI

    PubMed Central

    MS, Kamath; AM, Mangalraj; KM, Muthukumar; K, George

    2008-01-01

    OBJECTIVE: To study the efficacy of gonadotrophin releasing hormone (GnRH) antagonist in In-vitro-fertilization/Intracytoplasmic sperm injection (IVF/ICSI) cycles. TYPE OF STUDY: Observational study. SETTING: Reproductive Medicine Unit, Christian Medical College Hospital, Vellore, Tamil Nadu. MATERIALS AND METHODS: GnRH antagonists were introduced into our practice in November 2005. Fifty-two women undergoing the antagonist protocol were studied and information gathered regarding patient profile, treatment parameters (total gonadotrophin dosage, duration of treatment, and oocyte yield), and outcomes in terms of embryological parameters (cleavage rates, implantation rates) and clinical pregnancy. These parameters were compared with 121 women undergoing the standard long protocol. The costs between the two groups were also compared. MAIN OUTCOME: Clinical pregnancy rate. RESULTS: The clinical pregnancy rate per embryo transfer in the antagonist group was 31.7% which was comparable to the clinical pregnancy rate in women undergoing the standard long protocol (30.63%). The costs between the two groups were comparable. CONCLUSIONS: GnRH antagonist protocol was found to be effective and comparable to the standard long protocol regimen. In addition it was simple, convenient, and patient friendly. PMID:19562061

  19. 75 FR 68605 - Marine Mammals

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-08

    ... Register (75 FR 39915) that a request for a permit to conduct research on gray whales (Eschrictius robustus... National Oceanic and Atmospheric Administration RIN 0648-XX23 Marine Mammals AGENCY: National Marine... Marine Science Center, Newport, OR has been issued a permit to conduct research on marine...

  20. Vector potential of houseflies for the bacterium Aeromonas caviae.

    PubMed

    Nayduch, D; Noblet, G Pittman; Stutzenberger, F J

    2002-06-01

    Houseflies, Musca domestica Linnaeus (Diptera: Muscidae), have been implicated as vectors or transporters of numerous gastrointestinal pathogens encountered during feeding and ovipositing on faeces. The putative enteropathogen Aeromonas caviae (Proteobacteria: Aeromonadaceae) may be present in faeces of humans and livestock. Recently A. caviae was detected in houseflies by PCR and isolated by culture methods. In this study, we assessed the vector potential of houseflies for A. caviae relative to multiplication and persistence of the bacterium in the fly and to contamination of other flies and food materials. In experimentally fed houseflies, the number of bacteria increased up to 2 days post-ingestion (d PI) and then decreased significantly 3 d PI. A large number of bacteria was detected in the vomitus and faeces of infected flies at 2-3 d PI. The bacteria persisted in flies for up to 8 d PI, but numbers were low. Experimentally infected flies transmitted A. caviae to chicken meat, and transmissibility was directly correlated with exposure time. Flies contaminated the meat for up to 7 d PI; however, a significant decrease in contamination was observed 2-3 d PI. In the fly-to-fly transmission experiments, the transmission of A. caviae was observed and was apparently mediated by flies sharing food. These results support houseflies as potential vectors for A. caviae because the bacterium multiplied, persisted in flies for up to 8 d PI, and could be transmitted to human food items.

  1. Polysaccharide degradation systems of the saprophytic bacterium Cellvibrio japonicus

    DOE PAGESBeta

    Gardner, Jeffrey G.

    2016-06-04

    Study of recalcitrant polysaccharide degradation by bacterial systems is critical for understanding biological processes such as global carbon cycling, nutritional contributions of the human gut microbiome, and the production of renewable fuels and chemicals. One bacterium that has a robust ability to degrade polysaccharides is the Gram-negative saprophyte Cellvibrio japonicus. A bacterium with a circuitous history, C. japonicus underwent several taxonomy changes from an initially described Pseudomonas sp. Most of the enzymes described in the pre-genomics era have also been renamed. Furthermore, this review aims to consolidate the biochemical, structural, and genetic data published on C. japonicus and its remarkablemore » ability to degrade cellulose, xylan, and pectin substrates. Initially, C. japonicus carbohydrate-active enzymes were studied biochemically and structurally for their novel polysaccharide binding and degradation characteristics, while more recent systems biology approaches have begun to unravel the complex regulation required for lignocellulose degradation in an environmental context. Also included is a discussion for the future of C. japonicus as a model system, with emphasis on current areas unexplored in terms of polysaccharide degradation and emerging directions for C. japonicus in both environmental and biotechnological applications.« less

  2. Molybdate Reduction to Molybdenum Blue by an Antarctic Bacterium

    PubMed Central

    Ahmad, S. A.; Shukor, M. Y.; Shamaan, N. A.; Mac Cormack, W. P.; Syed, M. A.

    2013-01-01

    A molybdenum-reducing bacterium from Antarctica has been isolated. The bacterium converts sodium molybdate or Mo6+ to molybdenum blue (Mo-blue). Electron donors such as glucose, sucrose, fructose, and lactose supported molybdate reduction. Ammonium sulphate was the best nitrogen source for molybdate reduction. Optimal conditions for molybdate reduction were between 30 and 50 mM molybdate, between 15 and 20°C, and initial pH between 6.5 and 7.5. The Mo-blue produced had a unique absorption spectrum with a peak maximum at 865 nm and a shoulder at 710 nm. Respiratory inhibitors such as antimycin A, sodium azide, potassium cyanide, and rotenone failed to inhibit the reducing activity. The Mo-reducing enzyme was partially purified using ion exchange and gel filtration chromatography. The partially purified enzyme showed optimal pH and temperature for activity at 6.0 and 20°C, respectively. Metal ions such as cadmium, chromium, copper, silver, lead, and mercury caused more than 95% inhibition of the molybdenum-reducing activity at 0.1 mM. The isolate was tentatively identified as Pseudomonas sp. strain DRY1 based on partial 16s rDNA molecular phylogenetic assessment and the Biolog microbial identification system. The characteristics of this strain would make it very useful in bioremediation works in the polar and temperate countries. PMID:24381945

  3. Molybdate reduction to molybdenum blue by an Antarctic bacterium.

    PubMed

    Ahmad, S A; Shukor, M Y; Shamaan, N A; Mac Cormack, W P; Syed, M A

    2013-01-01

    A molybdenum-reducing bacterium from Antarctica has been isolated. The bacterium converts sodium molybdate or Mo⁶⁺ to molybdenum blue (Mo-blue). Electron donors such as glucose, sucrose, fructose, and lactose supported molybdate reduction. Ammonium sulphate was the best nitrogen source for molybdate reduction. Optimal conditions for molybdate reduction were between 30 and 50 mM molybdate, between 15 and 20°C, and initial pH between 6.5 and 7.5. The Mo-blue produced had a unique absorption spectrum with a peak maximum at 865 nm and a shoulder at 710 nm. Respiratory inhibitors such as antimycin A, sodium azide, potassium cyanide, and rotenone failed to inhibit the reducing activity. The Mo-reducing enzyme was partially purified using ion exchange and gel filtration chromatography. The partially purified enzyme showed optimal pH and temperature for activity at 6.0 and 20°C, respectively. Metal ions such as cadmium, chromium, copper, silver, lead, and mercury caused more than 95% inhibition of the molybdenum-reducing activity at 0.1 mM. The isolate was tentatively identified as Pseudomonas sp. strain DRY1 based on partial 16s rDNA molecular phylogenetic assessment and the Biolog microbial identification system. The characteristics of this strain would make it very useful in bioremediation works in the polar and temperate countries. PMID:24381945

  4. Mariner-Venus 1967

    NASA Technical Reports Server (NTRS)

    1971-01-01

    Detailed information on the spacecraft performance, mission operations, and tracking and data acquisition is presented for the Mariner Venus 1967 and Mariner Venus 1967 extension projects. Scientific and engineering results and conclusions are discussed, and include the scientific mission, encounter with Venus, observations near Earth, and cruise phase of the mission. Flight path analysis, spacecraft subsystems, and mission-related hardware and computer program development are covered. The scientific experiments carried by Mariner 5 were ultraviolet photometer, solar plasma probe, helium magnetometer, trapped radiation detector, S-band radio occultation, dual-frequency radio propagation, and celestial mechanics. The engineering experience gained by converting a space Mariner Mars 1964 spacecraft into one flown to Venus is also described.

  5. Marine Life Study

    NASA Technical Reports Server (NTRS)

    1988-01-01

    As a result of widespread ocean dumping and other pollution problems, marine scientists at Morgan State University are studying the populations of various marine organisms to determine the effects of pollution. They are also compiling data on the aging of marine organisms. There now exists a new method of determining the age of the surf clam. They are applying digital image processing to clam aging investigations. Computer creates digitized images of clam sections with annual rings. The image is enhanced -- manipulated to emphasize certain features in order to improve and amplify the information that can be extracted from the image. Also useful in other marine organisms that have growth bands making it easier to get an accurate count.

  6. Marine medicinal glycomics

    PubMed Central

    Pomin, Vitor H.

    2014-01-01

    Glycomics is an international initiative aimed to understand the structure and function of the glycans from a given type of cell, tissue, organism, kingdom or even environment, as found under certain conditions. Glycomics is one of the latest areas of intense biological research. Glycans of marine sources are unique in terms of structure and function. They differ considerably from those of terrestrial origin. This review discusses the most known marine glycans of potential therapeutic properties. They are chitin, chitosan, and sulfated polysaccharides named glycosaminoglycans, sulfated fucans, and sulfated galactans. Their medical actions are very broad. When certain structural requirements are found, these glycans can exhibit beneficial effects in inflammation, coagulation, thrombosis, cancer growth/metastasis, and vascular biology. Both structure and therapeutic mechanisms of action of these marine glycans are discussed here in straight context with the current glycomic age through a project suggestively named marine medicinal glycomics. PMID:24524028

  7. Marine Natural Products Revisited.

    ERIC Educational Resources Information Center

    Chang, Clifford W. J.

    1978-01-01

    Reports the chemistry of saxitoxin, a paralytic shellfish poison, and other toxins, including the structure of aplysiatoxins. Discusses the chemical signals and defense agents used in intra- and inter- species communication; anticancer agents; and organometallics in the marine environment. (MA)

  8. Neuroprotective Effects of Glutamate Antagonists and Extracellular Acidity

    NASA Astrophysics Data System (ADS)

    Kaku, David A.; Giffard, Rona G.; Choi, Dennis W.

    1993-06-01

    Glutamate antagonists protect neurons from hypoxic injury both in vivo and in vitro, but in vitro studies have not been done under the acidic conditions typical of hypoxia-ischemia in vivo. Consistent with glutamate receptor antagonism, extracellular acidity reduced neuronal death in murine cortical cultures that were deprived of oxygen and glucose. Under these acid conditions, N-methyl-D-aspartate and α-amino-3-hydroxy-5-methyl-4-isox-azolepropionate-kainate antagonists further reduced neuronal death, such that some neurons tolerated prolonged oxygen and glucose deprivation almost as well as did astrocytes. Neuroprotection induced by this combination exceeded that induced by glutamate antagonists alone, suggesting that extracellular acidity has beneficial effects beyond the attenuation of ionotropic glutamate receptor activation.

  9. Marine & hydrokinetic technology development.

    SciTech Connect

    LiVecchi, Al; Jepsen, Richard Alan

    2010-06-01

    The Wind and Water Power Program supports the development of marine and hydrokinetic devices, which capture energy from waves, tides, ocean currents, the natural flow of water in rivers, and marine thermal gradients, without building new dams or diversions. The program works closely with industry and the Department of Energy's national laboratories to advance the development and testing of marine and hydrokinetic devices. In 2008, the program funded projects to develop and test point absorber, oscillating wave column, and tidal turbine technologies. The program also funds component design, such as techniques for manufacturing and installing coldwater pipes critical for ocean thermal energy conversion (OTEC) systems. Rigorous device testing is necessary to validate and optimize prototypes before beginning full-scale demonstration and deployment. The program supports device testing by providing technology developers with information on testing facilities. Technology developers require access to facilities capable of simulating open-water conditions in order to refine and validate device operability. The program has identified more than 20 tank testing operators in the United States with capabilities suited to the marine and hydrokinetic technology industry. This information is available to the public in the program's Hydrodynamic Testing Facilities Database. The program also supports the development of open-water, grid-connected testing facilities, as well as resource assessments that will improve simulations done in dry-dock and closed-water testing facilities. The program has established two university-led National Marine Renewable Energy Centers to be used for device testing. These centers are located on coasts and will have open-water testing berths, allowing researchers to investigate marine and estuary conditions. Optimal array design, development, modeling and testing are needed to maximize efficiency and electricity generation at marine and hydrokinetic power

  10. Marine biodiversity characteristics.

    PubMed

    Boeuf, Gilles

    2011-05-01

    Oceans contain the largest living volume of the "blue" planet, inhabited by approximately 235-250,000 described species, all groups included. They only represent some 13% of the known species on the Earth, but the marine biomasses are really huge. Marine phytoplankton alone represents half the production of organic matter on Earth while marine bacteria represent more than 10%. Life first appeared in the oceans more than 3.8 billion years ago and several determining events took place that changed the course of life, ranging from the development of the cell nucleus to sexual reproduction going through multi-cellular organisms and the capture of organelles. Of the 31 animal phyla currently listed, 12 are exclusively marine phyla and have never left the ocean. An interesting question is to try to understand why there are so few marine species versus land species? This pattern of distribution seems pretty recent in the course of Evolution. From an exclusively marine world, since the beginning until 440 million years ago, land number of species much increased 110 million years ago. Specific diversity and ancestral roles, in addition to organizational models and original behaviors, have made marine organisms excellent reservoirs for identifying and extracting molecules (>15,000 today) with pharmacological potential. They also make particularly relevant models for both fundamental and applied research. Some marine models have been the source of essential discoveries in life sciences. From this diversity, the ocean provides humankind with renewable resources, which are highly threatened today and need more adequate management to preserve ocean habitats, stocks and biodiversity. PMID:21640952

  11. Development and Characterization of High Affinity Leptins and Leptin Antagonists*

    PubMed Central

    Shpilman, Michal; Niv-Spector, Leonora; Katz, Meirav; Varol, Chen; Solomon, Gili; Ayalon-Soffer, Michal; Boder, Eric; Halpern, Zamir; Elinav, Eran; Gertler, Arieh

    2011-01-01

    Leptin is a pleiotropic hormone acting both centrally and peripherally. It participates in a variety of biological processes, including energy metabolism, reproduction, and modulation of the immune response. So far, structural elements affecting leptin binding to its receptor remain unknown. We employed random mutagenesis of leptin, followed by selection of high affinity mutants by yeast surface display and discovered that replacing residue Asp-23 with a non-negatively charged amino acid leads to dramatically enhanced affinity of leptin for its soluble receptor. Rational mutagenesis of Asp-23 revealed the D23L substitution to be most effective. Coupling the Asp-23 mutation with alanine mutagenesis of three amino acids (L39A/D40A/F41A) previously reported to convert leptin into antagonist resulted in potent antagonistic activity. These novel superactive mouse and human leptin antagonists (D23L/L39A/D40A/F41A), termed SMLA and SHLA, respectively, exhibited over 60-fold increased binding to leptin receptor and 14-fold higher antagonistic activity in vitro relative to the L39A/D40A/F41A mutants. To prolong and enhance in vivo activity, SMLA and SHLA were monopegylated mainly at the N terminus. Administration of the pegylated SMLA to mice resulted in a remarkably rapid, significant, and reversible 27-fold more potent increase in body weight (as compared with pegylated mouse leptin antagonist), because of increased food consumption. Thus, recognition and mutagenesis of Asp-23 enabled construction of novel compounds that induce potent and reversible central and peripheral leptin deficiency. In addition to enhancing our understanding of leptin interactions with its receptor, these antagonists enable in vivo study of the role of leptin in metabolic and immune processes and hold potential for future therapeutic use in disease pathologies involving leptin. PMID:21119198

  12. Development and characterization of high affinity leptins and leptin antagonists.

    PubMed

    Shpilman, Michal; Niv-Spector, Leonora; Katz, Meirav; Varol, Chen; Solomon, Gili; Ayalon-Soffer, Michal; Boder, Eric; Halpern, Zamir; Elinav, Eran; Gertler, Arieh

    2011-02-11

    Leptin is a pleiotropic hormone acting both centrally and peripherally. It participates in a variety of biological processes, including energy metabolism, reproduction, and modulation of the immune response. So far, structural elements affecting leptin binding to its receptor remain unknown. We employed random mutagenesis of leptin, followed by selection of high affinity mutants by yeast surface display and discovered that replacing residue Asp-23 with a non-negatively charged amino acid leads to dramatically enhanced affinity of leptin for its soluble receptor. Rational mutagenesis of Asp-23 revealed the D23L substitution to be most effective. Coupling the Asp-23 mutation with alanine mutagenesis of three amino acids (L39A/D40A/F41A) previously reported to convert leptin into antagonist resulted in potent antagonistic activity. These novel superactive mouse and human leptin antagonists (D23L/L39A/D40A/F41A), termed SMLA and SHLA, respectively, exhibited over 60-fold increased binding to leptin receptor and 14-fold higher antagonistic activity in vitro relative to the L39A/D40A/F41A mutants. To prolong and enhance in vivo activity, SMLA and SHLA were monopegylated mainly at the N terminus. Administration of the pegylated SMLA to mice resulted in a remarkably rapid, significant, and reversible 27-fold more potent increase in body weight (as compared with pegylated mouse leptin antagonist), because of increased food consumption. Thus, recognition and mutagenesis of Asp-23 enabled construction of novel compounds that induce potent and reversible central and peripheral leptin deficiency. In addition to enhancing our understanding of leptin interactions with its receptor, these antagonists enable in vivo study of the role of leptin in metabolic and immune processes and hold potential for future therapeutic use in disease pathologies involving leptin.

  13. Antinociceptive effects of MSVIII-19, a functional antagonist of the GluK1 kainate receptor.

    PubMed

    Qiu, Chang-Shen; Lash-Van Wyhe, Leanne; Sasaki, Makoto; Sakai, Ryuichi; Swanson, Geoffrey T; Gereau, Robert W

    2011-05-01

    The ionotropic glutamate receptor subunit, GluK1 (GluR5), is expressed in many regions of the nervous system related to sensory transmission. Recently, a selective ligand for the GluK1 receptor, MSVIII-19 (8,9-dideoxy-neodysiherbaine), was synthesized as a derivative of dysiherbaine, a toxin isolated from the marine sponge Lendenfeldia chondrodes. MSVIII-19 potently desensitizes GluK1 receptors without channel activation, rendering it useful as a functional antagonist. Given the high selectivity for GluK1 and the proposed role for this glutamate receptor in nociception, we sought to test the analgesic potential of MSVIII-19 in a series of models of inflammatory, neuropathic, and visceral pain in mice. MSVIII-19 delivered intrathecally dose-dependently reduced formalin-induced spontaneous behaviors and reduced thermal hypersensitivity 3 hours after formalin injection and 24 hours after complete Freund's adjuvant-induced inflammation, but had no effect on mechanical sensitivity in the same models. Intrathecal MSVIII-19 significantly reduced both thermal hyperalgesia and mechanical hypersensitivity in the chronic constriction injury model of neuropathic pain, but had no effect in the acetic acid model of visceral pain. Peripheral administration of MSVIII-19 had no analgesic efficacy in any of these models. Finally, intrathecal MSVIII-19 did not alter responses in Tail-flick tests or performance on the accelerating RotaRod. These data suggest that spinal administration of MSVIII-19 reverses hypersensitivity in several models of pain in mice, supporting the clinical potential of GluK1 antagonists for the management of pain. PMID:21324591

  14. Characterization of a Novel Subtilisin-like Protease Myroicolsin from Deep Sea Bacterium Myroides profundi D25 and Molecular Insight into Its Collagenolytic Mechanism*

    PubMed Central

    Ran, Li-Yuan; Su, Hai-Nan; Zhou, Ming-Yang; Wang, Lei; Chen, Xiu-Lan; Xie, Bin-Bin; Song, Xiao-Yan; Shi, Mei; Qin, Qi-Long; Pang, Xiuhua; Zhou, Bai-Cheng; Zhang, Yu-Zhong; Zhang, Xi-Ying

    2014-01-01

    Collagen is an insoluble protein that widely distributes in the extracellular matrix of marine animals. Collagen degradation is an important step in the marine nitrogen cycle. However, the mechanism of marine collagen degradation is still largely unknown. Here, a novel subtilisin-like collagenolytic protease, myroicolsin, which is secreted by the deep sea bacterium Myroides profundi D25, was purified and characterized, and its collagenolytic mechanism was studied. Myroicolsin displays low identity (<30%) to previously characterized subtilisin-like proteases, and it contains a novel domain structure. Protein truncation indicated that the Pro secretion system C-terminal sorting domain in the precursor protein is involved in the cleavage of the N-propeptide, and the linker is required for protein folding during myroicolsin maturation. The C-terminal β-jelly roll domain did not bind insoluble collagen fiber, suggesting that myroicolsin may degrade collagen without the assistance of a collagen-binding domain. Myroicolsin had broad specificity for various collagens, especially fish-insoluble collagen. The favored residue at the P1 site was basic arginine. Scanning electron microscopy and atomic force microscopy, together with biochemical analyses, confirmed that collagen fiber degradation by myroicolsin begins with the hydrolysis of proteoglycans and telopeptides in collagen fibers and fibrils. Myroicolsin showed strikingly different cleavage patterns between native and denatured collagens. A collagen degradation model of myroicolsin was proposed based on our results. Our study provides molecular insight into the collagen degradation mechanism and structural characterization of a subtilisin-like collagenolytic protease secreted by a deep sea bacterium, shedding light on the degradation mechanism of deep sea sedimentary organic nitrogen. PMID:24429289

  15. Genetically modified Vibrio harveyi strains as potential bioindicators of mutagenic pollution of marine environments

    SciTech Connect

    Czyz, A.; Jasiecki, J.; Bogdan, A.; Szpilewska, H.; Wegrzyn, G.

    2000-02-01

    For biodetection of mutagenic pollution of marine environments, an organism naturally occurring in these habitats should be used. The authors found that marine bacterium Vibrio harveyi may be an appropriate bioindicator of mutagenic pollution. For positive selection of mutants, they developed a simple method for isolation of V. harveyi mutants resistant to neomycin. The authors constructed genetically modified V. harveyi strains that produce significantly more neomycin-resistant mutants upon treatment with low concentrations of mutagens than the wild-type counterpart. The sensitivity of the mutagenicity test with the V. harveyi strains is at least comparable to (if not higher than) that of the commonly used Ames test, which uses Salmonella enterica serovar Typhimurium strains. Therefore, the authors consider that the V. harveyi strains described in this report could be used as potential bioindicators of mutagenic pollution of marine environments.

  16. Genetically modified Vibrio harveyi strains as potential bioindicators of mutagenic pollution of marine environments.

    PubMed

    Czyz, A; Jasiecki, J; Bogdan, A; Szpilewska, H; Wegrzyn, G

    2000-02-01

    For biodetection of mutagenic pollution of marine environments, an organism naturally occurring in these habitats should be used. We found that marine bacterium Vibrio harveyi may be an appropriate bioindicator of mutagenic pollution. For positive selection of mutants, we developed a simple method for isolation of V. harveyi mutants resistant to neomycin. We constructed genetically modified V. harveyi strains that produce significantly more neomycin-resistant mutants upon treatment with low concentrations of mutagens than the wild-type counterpart. The sensitivity of the mutagenicity test with the V. harveyi strains is at least comparable to (if not higher than) that of the commonly used Ames test, which uses Salmonella enterica serovar Typhimurium strains. Therefore, we consider that the V. harveyi strains described in this report could be used as potential bioindicators of mutagenic pollution of marine environments.

  17. Pharmacokinetic interactions with calcium channel antagonists (Part II).

    PubMed

    Schlanz, K D; Myre, S A; Bottorff, M B

    1991-12-01

    Since calcium channel antagonists are a diverse class of drugs frequently administered in combination with other agents, the potential for clinically significant pharmacokinetic drug interactions exists. These interactions occur most frequently via altered hepatic blood flow and impaired hepatic enzyme activity. Part I of the article, which appeared in the previous issue of the Journal, dealt with interactions between calcium antagonists and marker compounds, theophylline, midazolam, lithium, doxorubicin, oral hypoglycaemics and cardiac drugs. Part II examines interactions with cyclosporin, anaesthetics, carbamazepine and cardiovascular agents. PMID:1782739

  18. Hyperglycemia of Diabetic Rats Decreased by a Glucagon Receptor Antagonist

    NASA Astrophysics Data System (ADS)

    Johnson, David G.; Ulichny Goebel, Camy; Hruby, Victor J.; Bregman, Marvin D.; Trivedi, Dev

    1982-02-01

    The glucagon analog [l-Nα-trinitrophenylhistidine, 12-homoarginine]-glucagon (THG) was examined for its ability to lower blood glucose concentrations in rats made diabetic with streptozotocin. In vitro, THG is a potent antagonist of glucagon activation of the hepatic adenylate cyclase assay system. Intravenous bolus injections of THG caused rapid decreases (20 to 35 percent) of short duration in blood glucose. Continuous infusion of low concentrations of the inhibitor led to larger sustained decreases in blood glucose (30 to 65 percent). These studies demonstrate that a glucagon receptor antagonist can substantially reduce blood glucose levels in diabetic animals without addition of exogenous insulin.

  19. Bradykinin antagonists with dehydrophenylalanine analogues at position 5.

    PubMed

    Greiner, G; Dornberger, U; Paegelow, I; Schölkens, B A; Liebmann, C; Reissmann, S

    1998-04-01

    Continuing the studies on structural requirements of bradykinin antagonists, it has been found that analogues with dehydrophenylalanine (deltaPhe) or its ring-substituted analogues (deltaPhe(X)) at position 5 act as antagonists on guinea pig pulmonary artery, and on guinea pig ileum. Because both organs are considered to be bradykinin B2 receptor tissues, the analogues with deltaPhe or deltaPhe(X) at position 5, but without any replacement at position 7, seem to represent a new structural type of B2 receptor antagonist. All the analogues investigated act as partial antagonists; they inhibit the bradykinin-induced contraction at low concentrations and act as agonists at higher concentrations. Ring substitutions by methyl groups or iodine reduce both the agonistic and antagonistic activity. Only substitution by fluorine gives a high potency. Incorporation of deltaPhe into different representative antagonists with key modifications at position 7 does not enhance the antagonist activity of the basic structures, with one exception. Only the combination of deltaPhe at position 5 with DPhe at position 7 increases the antagonistic potency on guinea pig ileum by about one order of magnitude. Radioligand binding studies indicate the importance of position 5 for the discrimination of B2 receptor subtypes. The binding affinity to the low-affinity binding site (KL) was not significantly changed by replacement of Phe by deltaPhe. In contrast, ring-methylation of deltaPhe results in clearly reduced binding to KL. The affinity to the high-affinity binding site (KH) was almost unchanged by the replacement of Phe in position 5 by deltaPhe, whereas the analogue with 2-methyl-dehydrophenylalanine completely failed to detect the KH-site. The peptides were synthesized on the Wang-resin according to the Fmoc/Bu(t) strategy using Mtr protection for the side chain of Arg. The dehydrophenylalanine analogues were prepared by a strategy involving PyBop couplings of the dipeptide unit Fmoc

  20. Discovery of cannabinoid-1 receptor antagonists by virtual screening.

    PubMed

    Lee, Gil Nam; Kim, Kwang Rok; Ahn, Sung-Hoon; Bae, Myung Ae; Kang, Nam Sook

    2010-09-01

    In this work, we tried to find a new scaffold for a CB1 receptor antagonist using virtual screening. We first analyzed structural features for the known cannabinoid-1 receptor antagonists and, then, we built pharmacophore models using the HipHop concept and carried out a docking study based on our homology CB1 receptor 3D structure. The most active compound, including thiazole-4-one moiety, showed an activity value of 125 nM IC(50), with a good PK profile. PMID:20667724

  1. Discovery of Tertiary Sulfonamides as Potent Liver X Receptor Antagonists

    SciTech Connect

    Zuercher, William J.; Buckholz†, Richard G.; Campobasso, Nino; Collins, Jon L.; Galardi, Cristin M.; Gampe, Robert T.; Hyatt, Stephen M.; Merrihew, Susan L.; Moore, John T.; Oplinger, Jeffrey A.; Reid, Paul R.; Spearing, Paul K.; Stanley, Thomas B.; Stewart, Eugene L.; Willson, Timothy M.

    2010-08-12

    Tertiary sulfonamides were identified in a HTS as dual liver X receptor (LXR, NR1H2, and NR1H3) ligands, and the binding affinity of the series was increased through iterative analogue synthesis. A ligand-bound cocrystal structure was determined which elucidated key interactions for high binding affinity. Further characterization of the tertiary sulfonamide series led to the identification of high affinity LXR antagonists. GSK2033 (17) is the first potent cell-active LXR antagonist described to date. 17 may be a useful chemical probe to explore the cell biology of this orphan nuclear receptor.

  2. Discovery of small molecule antagonists of TRPV1.

    PubMed

    Rami, Harshad K; Thompson, Mervyn; Wyman, Paul; Jerman, Jeffrey C; Egerton, Julie; Brough, Stephen; Stevens, Alexander J; Randall, Andrew D; Smart, Darren; Gunthorpe, Martin J; Davis, John B

    2004-07-16

    Small molecule antagonists of the vanilloid receptor 1 (TRPV1, also known as VR1) are disclosed. Ureas such as 5 (SB-452533) were used to explore the structure activity relationship with several potent analogues identified. Pharmacological studies using electrophysiological and FLIPR Ca(2+) based assays showed compound 5 was an antagonist versus capsaicin, noxious heat and acid mediated activation of TRPV1. Study of a quaternary salt of 5 supports a mode of action in which compounds from this series cause inhibition via an extracellularly accessible binding site on the TRPV1 receptor. PMID:15203132

  3. Discovery of cannabinoid-1 receptor antagonists by virtual screening.

    PubMed

    Lee, Gil Nam; Kim, Kwang Rok; Ahn, Sung-Hoon; Bae, Myung Ae; Kang, Nam Sook

    2010-09-01

    In this work, we tried to find a new scaffold for a CB1 receptor antagonist using virtual screening. We first analyzed structural features for the known cannabinoid-1 receptor antagonists and, then, we built pharmacophore models using the HipHop concept and carried out a docking study based on our homology CB1 receptor 3D structure. The most active compound, including thiazole-4-one moiety, showed an activity value of 125 nM IC(50), with a good PK profile.

  4. Histamine 2 Receptor Antagonists and Proton Pump Inhibitors.

    PubMed

    Brinkworth, Megan D; Aouthmany, Mouhammad; Sheehan, Michael

    2016-01-01

    Within the last 50 years, the pharmacologic market for gastric disease has grown exponentially. Currently, medical management with histamine 2 receptor antagonist and proton pump inhibitors are the mainstay of therapy over surgical intervention. These are generally regarded as safe medications, but there are growing numbers of cases documenting adverse effects, especially those manifesting in the skin. Here we review the pharmacology, common clinical applications, and adverse reactions of both histamine 2 receptor antagonists and proton pump inhibitors with a particular focus on the potential for allergic reactions including allergic contact dermatitis. PMID:27172303

  5. Pantoea agglomerans: a mysterious bacterium of evil and good. Part IV. Beneficial effects.

    PubMed

    Dutkiewicz, Jacek; Mackiewicz, Barbara; Lemieszek, Marta Kinga; Golec, Marcin; Milanowski, Janusz

    2016-06-01

    Pantoea agglomerans, a gammaproteobacterium of plant origin, possesses many beneficial traits that could be used for the prevention and/or treatment of human and animal diseases, combating plant pathogens, promotion of plant growth and bioremediation of the environment. It produces a number of antibiotics (herbicolin, pantocins, microcin, agglomerins, andrimid, phenazine, among others) which could be used for combating plant, animal and human pathogens or for food preservation. Japanese researchers have demonstrated that the low-molecular-mass lipopolysaccharide of P. agglomerans isolated by them and described as 'Immunopotentiator from Pantoea agglomerans 1 (IP-PA1)' reveals the extremely wide spectrum of healing properties, mainly due to its ability for the maintenance of homeostasis by macrophage activation. IP-PA1 was proved to be effective in the prevention and treatment of a broad range of human and animal disorders, such as tumours, hyperlipidaemia, diabetes, ulcer, various infectious diseases, atopic allergy and stress-induced immunosuppression; it also showed a strong analgesic effect. It is important that most of these effects could be achieved by the safe oral administration of IP-PA1. Taking into account that P. agglomerans occurs commonly as a symbiont of many species of insects, including mosquitoes transmitting the Plasmodium parasites causing malaria, successful attempts were made to apply the strategy of paratransgenesis, in which bacterial symbionts are genetically engineered to express and secrete anti-Plasmodium effector proteins. This strategy shows prospects for a successful eradication of malaria, a deadly disease killing annually over one million people, as well as of other vector-borne diseases of humans, animals and plants. Pantoea agglomerans has been identified as an antagonist of many plant pathogens belonging to bacteria and fungi, as a result of antibiotic production, competition mechanisms or induction of plant resistance. Its use as

  6. Pantoea agglomerans: a mysterious bacterium of evil and good. Part IV. Beneficial effects.

    PubMed

    Dutkiewicz, Jacek; Mackiewicz, Barbara; Lemieszek, Marta Kinga; Golec, Marcin; Milanowski, Janusz

    2016-06-01

    Pantoea agglomerans, a gammaproteobacterium of plant origin, possesses many beneficial traits that could be used for the prevention and/or treatment of human and animal diseases, combating plant pathogens, promotion of plant growth and bioremediation of the environment. It produces a number of antibiotics (herbicolin, pantocins, microcin, agglomerins, andrimid, phenazine, among others) which could be used for combating plant, animal and human pathogens or for food preservation. Japanese researchers have demonstrated that the low-molecular-mass lipopolysaccharide of P. agglomerans isolated by them and described as 'Immunopotentiator from Pantoea agglomerans 1 (IP-PA1)' reveals the extremely wide spectrum of healing properties, mainly due to its ability for the maintenance of homeostasis by macrophage activation. IP-PA1 was proved to be effective in the prevention and treatment of a broad range of human and animal disorders, such as tumours, hyperlipidaemia, diabetes, ulcer, various infectious diseases, atopic allergy and stress-induced immunosuppression; it also showed a strong analgesic effect. It is important that most of these effects could be achieved by the safe oral administration of IP-PA1. Taking into account that P. agglomerans occurs commonly as a symbiont of many species of insects, including mosquitoes transmitting the Plasmodium parasites causing malaria, successful attempts were made to apply the strategy of paratransgenesis, in which bacterial symbionts are genetically engineered to express and secrete anti-Plasmodium effector proteins. This strategy shows prospects for a successful eradication of malaria, a deadly disease killing annually over one million people, as well as of other vector-borne diseases of humans, animals and plants. Pantoea agglomerans has been identified as an antagonist of many plant pathogens belonging to bacteria and fungi, as a result of antibiotic production, competition mechanisms or induction of plant resistance. Its use as

  7. Vitroprocines, new antibiotics against Acinetobacter baumannii, discovered from marine Vibrio sp. QWI-06 using mass-spectrometry-based metabolomics approach

    PubMed Central

    Liaw, Chih-Chuang; Chen, Pei-Chin; Shih, Chao-Jen; Tseng, Sung-Pin; Lai, Ying-Mi; Hsu, Chi-Hsin; Dorrestein, Pieter C.; Yang, Yu-Liang

    2015-01-01

    A robust and convenient research strategy integrating state-of-the-art analytical techniques is needed to efficiently discover novel compounds from marine microbial resources. In this study, we identified a series of amino-polyketide derivatives, vitroprocines A-J, from the marine bacterium Vibrio sp. QWI-06 by an integrated approach using imaging mass spectroscopy and molecular networking, as well as conventional bioactivity-guided fractionation and isolation. The structure-activity relationship of vitroprocines against Acinetobacter baumannii is proposed. In addition, feeding experiments with 13C-labeled precursors indicated that a pyridoxal 5′-phosphate-dependent mechanism is involved in the biosynthesis of vitroprocines. Elucidation of amino-polyketide derivatives from a species of marine bacteria for the first time demonstrates the potential of this integrated metabolomics approach to uncover marine bacterial biodiversity. PMID:26238555

  8. Vitroprocines, new antibiotics against Acinetobacter baumannii, discovered from marine Vibrio sp. QWI-06 using mass-spectrometry-based metabolomics approach

    NASA Astrophysics Data System (ADS)

    Liaw, Chih-Chuang; Chen, Pei-Chin; Shih, Chao-Jen; Tseng, Sung-Pin; Lai, Ying-Mi; Hsu, Chi-Hsin; Dorrestein, Pieter C.; Yang, Yu-Liang

    2015-08-01

    A robust and convenient research strategy integrating state-of-the-art analytical techniques is needed to efficiently discover novel compounds from marine microbial resources. In this study, we identified a series of amino-polyketide derivatives, vitroprocines A-J, from the marine bacterium Vibrio sp. QWI-06 by an integrated approach using imaging mass spectroscopy and molecular networking, as well as conventional bioactivity-guided fractionation and isolation. The structure-activity relationship of vitroprocines against Acinetobacter baumannii is proposed. In addition, feeding experiments with 13C-labeled precursors indicated that a pyridoxal 5‧-phosphate-dependent mechanism is involved in the biosynthesis of vitroprocines. Elucidation of amino-polyketide derivatives from a species of marine bacteria for the first time demonstrates the potential of this integrated metabolomics approach to uncover marine bacterial biodiversity.

  9. Viral Density and Virus-to-Bacterium Ratio in Deep-Sea Sediments of the Eastern Mediterranean

    PubMed Central

    Danovaro, Roberto; Serresi, Michela

    2000-01-01

    Viruses are now recognized as a key component in pelagic systems, but their role in marine sediment has yet to be assessed. In this study bacterial and viral densities were determined at nine deep-sea stations selected from three main sites (i.e., the Sporades Basin, the Cretan Sea, and the Ierapetra Trench at depths of 1,232, 1,840, and 4,235 m, respectively) of the Eastern Mediterranean. The three areas were characterized by different phytopigment and biopolymeric carbon concentrations and by changes in the protein and carbohydrate pools. A gradient of increasing trophic conditions was observed from the Sporades Basin (North Aegean) to the Ierapetra Trench (South Aegean). Viral densities (ranging from 1 × 109 to 2 × 109 viruses ml of sediment−1) were significantly correlated to bacterial densities (n = 9, r2 = 0.647) and reached values up to 3 orders of magnitude higher than those generally reported for the water column. However, the virus-to-bacterium density ratio in deep-sea sediments was about 1 order of magnitude lower (range of 2 to 5, with a modal value of 2.6) than in pelagic environments. Virus density decreased vertically with depth in sediment cores at all stations and was below detection limits at the 10-cm depth of the abyssal sediments of the Ierapetra Trench. Virus density in the sediment apparently reflected a gradient of particle fluxes and trophic conditions, displaying the highest values in the Sporades Basin. The low virus-to-bacterium ratios and their inverse relationship with station depth suggest that the role played by viruses in controlling deep-sea benthic bacterial assemblages and biogeochemical cycles is less relevant than in pelagic systems. PMID:10788350

  10. Structural characterization and ecological roles of a novel exopolysaccharide from the deep-sea psychrotolerant bacterium Pseudoalteromonas sp. SM9913.

    PubMed

    Qin, Guokui; Zhu, Lizhi; Chen, Xiulan; Wang, Peng George; Zhang, Yuzhong

    2007-05-01

    Pseudoalteromonas sp. SM9913 is a psychrotolerant bacterium isolated from deep-sea sediment. The structural characterization and ecological roles of the exopolysaccharide (EPS) secreted by this strain were studied in this work. The yield of the EPS increased as the culture temperature decreased in the range 30-10 degrees C, and it reached 5.25 g l(-1) (dry weight) under optimal growth conditions (15 degrees C, 52 h). EPS fraction was purified and its structure was identified by the combination of NMR spectra, high-resolution mass spectrometry (HRMS) analysis and methylation analysis. The ratio of the sugar units, the acetyl group and the ethoxyl group was close to 4 : 5 : 1. The major sugar unit of the EPS was 6-linked glucose (61.8 %); other sugar units present included terminal arabinofuranosyl (11.0 %) and glucopyranosyl (11.2 %) residues and a small amount of other sugar derivatives. Its structure was different from EPSs reported for other marine bacteria. Besides the structural elucidation of the EPS, its ecological roles were studied. This EPS could enhance the stability of the cold-adapted protease MCP-01 secreted by the same strain through preventing its autolysis. It could bind many metal ions, including Fe(2+), Zn(2+), Cu(2+), Co(2+). It was also a very good flocculating agent and could conglomerate colloidal and suspended particles. These results indicated that the EPS secreted by strain SM9913 might help this strain enrich the proteinaceous particles and the trace metals in the deep-sea environment, stabilize the secreted cold-adapted proteases and avoid its diffusion. This is believed to be the first report on the structure of the EPS secreted by a deep-sea psychrotolerant bacterium and its ecological roles. According to these results and other studies, a schematic diagram of the lifestyle of the deep-sea psychrotolerant strain SM9913 is suggested.

  11. Draft Genome Sequence of Ensifer adhaerens M78, a Mineral-Weathering Bacterium Isolated from Soil

    PubMed Central

    Wang, Yuanli; Chen, Wei; He, Linyan; Wang, Qi

    2016-01-01

    Ensifer adhaerens M78, a bacterium isolated from soil, can weather potash feldspar and release Fe, Si, and Al from rock under nutrient-poor conditions. Here, we report the draft genome sequence of strain M78, which may facilitate a better understanding of the molecular mechanism involved in mineral weathering by the bacterium. PMID:27609930

  12. Genome Sequence of the Mycorrhizal Helper Bacterium Pseudomonas fluorescens BBc6R8

    PubMed Central

    Gross, H.; Morin, E.; Karpinets, T.; Utturkar, S.; Mehnaz, S.; Martin, F.; Frey-Klett, P.; Labbé, J.

    2014-01-01

    We report the draft genome sequence of the mycorrhizal helper bacterium Pseudomonas fluorescens strain BBc6R8. This is the first genome of a mycorrhizal helper bacterium. The draft genome contains 6,952,353 bp and is predicted to encode 6,317 open reading frames. Comparative genomic analyses will help to identify helper traits. PMID:24407649

  13. Draft Genome Sequence of Ensifer adhaerens M78, a Mineral-Weathering Bacterium Isolated from Soil.

    PubMed

    Wang, Yuanli; Chen, Wei; He, Linyan; Wang, Qi; Sheng, Xia-Fang

    2016-01-01

    Ensifer adhaerens M78, a bacterium isolated from soil, can weather potash feldspar and release Fe, Si, and Al from rock under nutrient-poor conditions. Here, we report the draft genome sequence of strain M78, which may facilitate a better understanding of the molecular mechanism involved in mineral weathering by the bacterium. PMID:27609930

  14. Draft Genome Sequence of Pseudomonas aeruginosa Strain RB, a Bacterium Capable of Synthesizing Cadmium Selenide Nanoparticles.

    PubMed

    Ayano, Hiroyuki; Kuroda, Masashi; Soda, Satoshi; Ike, Michihiko

    2014-01-01

    Pseudomonas aeruginosa strain RB is a bacterium capable of synthesizing cadmium selenide (CdSe) nanoparticles and was isolated from a soil sample. Here, we present the draft genome sequence of P. aeruginosa strain RB. To the best of our knowledge, this is the first report of a draft genome of a CdSe-synthesizing bacterium.

  15. Kinetic study of trichloroethylene and toluene degradation by a bioluminescent reporter bacterium

    SciTech Connect

    Kelly, C.J.; Sanseverino, J.; Bienkowski, P.R.; Sayler, G.S.

    1995-12-31

    A constructed bioluminescent reporter bacterium, Pseudomonas putida B2, is very briefly described in this paper. The bacterium degrades toluene and trichloroethylene (TCE), and produces light in the presence of toluene. The light response is an indication of cellular viability and expression of the genes encoding toluene and TCE degrading enzymes.

  16. Near-complete genome sequence of the cellulolytic Bacterium Bacteroides (Pseudobacteroides) cellulosolvens ATCC 35603

    DOE PAGESBeta

    Dassa, Bareket; Utturkar, Sagar M.; Hurt, Richard A.; Klingeman, Dawn Marie; Keller, Martin; Xu, Jian; Reddy, Harish Kumar; Borovok, Ilya; Grinberg, Inna Rozman; Lamed, Raphael; et al

    2015-09-24

    We report the single-contig genome sequence of the anaerobic, mesophilic, cellulolytic bacterium, Bacteroides cellulosolvens. The bacterium produces a particularly elaborate cellulosome system, whereas the types of cohesin-dockerin interactions are opposite of other known cellulosome systems: cell-surface attachment is thus mediated via type-I interactions whereas enzymes are integrated via type-II interactions.

  17. Draft Genome Sequence of Ensifer adhaerens M78, a Mineral-Weathering Bacterium Isolated from Soil.

    PubMed

    Wang, Yuanli; Chen, Wei; He, Linyan; Wang, Qi; Sheng, Xia-Fang

    2016-01-01

    Ensifer adhaerens M78, a bacterium isolated from soil, can weather potash feldspar and release Fe, Si, and Al from rock under nutrient-poor conditions. Here, we report the draft genome sequence of strain M78, which may facilitate a better understanding of the molecular mechanism involved in mineral weathering by the bacterium.

  18. Genome Sequence of the Antarctic Psychrophile Bacterium Planococcus antarcticus DSM 14505

    PubMed Central

    Margolles, Abelardo; Gueimonde, Miguel

    2012-01-01

    Planococcus antarcticus DSM 14505 is a psychrophile bacterium that was isolated from cyanobacterial mat samples, originally collected from ponds in McMurdo, Antarctica. This orange-pigmented bacterium grows at 4°C and may possess interesting enzymatic activities at low temperatures. Here we report the first genomic sequence of P. antarcticus DSM 14505. PMID:22843594

  19. Characterization of a novel non-steroidal glucocorticoid receptor antagonist

    SciTech Connect

    Li, Qun-Yi; Zhang, Meng; Hallis, Tina M.; DeRosier, Therese A.; Yue, Jian-Min; Ye, Yang; Mais, Dale E.; Wang, Ming-Wei

    2010-01-15

    Selective antagonists of the glucocorticoid receptor (GR) are desirable for the treatment of hypercortisolemia associated with Cushing's syndrome, psychic depression, obesity, diabetes, neurodegenerative diseases, and glaucoma. NC3327, a non-steroidal small molecule with potent binding affinity to GR (K{sub i} = 13.2 nM), was identified in a high-throughput screening effort. As a full GR antagonist, NC3327 greatly inhibits the dexamethasone (Dex) induction of marker genes involved in hepatic gluconeogenesis, but has a minimal effect on matrix metalloproteinase 9 (MMP-9), a GR responsive pro-inflammatory gene. Interestingly, the compound recruits neither coactivators nor corepressors to the GR complex but competes with glucocorticoids for the interaction between GR and a coactivator peptide. Moreover, NC3327 does not trigger GR nuclear translocation, but significantly blocks Dex-induced GR transportation to the nucleus, and thus appears to be a 'competitive' GR antagonist. Therefore, the non-steroidal compound, NC3327, may represent a new class of GR antagonists as potential therapeutics for a variety of cortisol-related endocrine disorders.

  20. Medium-Induced Antagonistic Behavior in Staphylococcus Aureus.

    ERIC Educational Resources Information Center

    Benathen, Isaiah A.

    1992-01-01

    Antagonism is the production of substances by microorganisms that inhibit or prevent the growth of other bacteria. This paper demonstrates the antagonistic behavior of gram-positive coccus on the B. subtilis and Enterococcus faecalis gram-positive microorganisms, showing that the process of antagonism is sometimes dependent on the nutritional…