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Sample records for bacterial genus pseudoalteromonas

  1. Bioactivity and phylogeny of the marine bacterial genus Pseudoalteromonas

    DEFF Research Database (Denmark)

    Vynne, Nikolaj Grønnegaard

    -associated strains were significantly more likely to possess stable antibacterial activity and be pigmented. Pseudoalteromonas strains are known as prolific producers of bioactive secondary metabolites; hence screening the global strain collection for production of novel antibiotics was initiated. Novel quinolone...... was obtained during the research cruise “Galathea 3”, which circumnavigated the Earth while screening marine bacteria for the ability to inhibit Vibrio anguillarum 90-11-287. Pseudoalteromonas strains were one of the most frequently isolated genera. The Pseudoalteromonas strains were evaluated for...... was not unequivocally reflected in the secondary metabolite profile, possibly due to the limited resolving power of the 16S rRNA gene. The species P. luteoviolacea showed an interesting pattern indicative of phylotype specific antibiotic production strains. Detailed phylogenetic analysis of an...

  2. Pseudoalteromonas spp. Serve as Initial Bacterial Attractants in Mesocosms of Coastal Waters but Have Subsequent Antifouling Capacity in Mesocosms and when Embedded in Paint

    DEFF Research Database (Denmark)

    Bernbom, Nete; Ng, Yin; Møller, Stefan;

    2013-01-01

    . Larger fouling organisms were observed on all plates precoated with Pseudoalteromonas; however, plates coated only with sterile growth medium were dominated by a bacterial biofilm. Suspensions of a P. piscicida strain and a P. tunicata strain were incorporated into ship paints (Hempasil x3 87500 and...

  3. Pseudoalteromonas aestuariivivens sp. nov., isolated from a tidal flat.

    Science.gov (United States)

    Park, Sooyeon; Jung, Yong-Taek; Park, Doo-Sang; Yoon, Jung-Hoon

    2016-05-01

    A Gram-stain-negative, aerobic, motile, rod-shaped or ovoid bacterial strain, designated DB-2T, was isolated from a tidal flat of the Yellow Sea in South Korea, and subjected to a taxonomic study using a polyphasic approach. Strain DB-2T grew optimally at 30 °C, at pH 7.0-8.0 and in the presence of 2.0-3.0 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences showed that strain DB-2T belonged to the genus Pseudoalteromonas. Strain DB-2T exhibited 16S rRNA gene sequence similarities of 97.17-97.36 % to the type strains of Pseudoalteromonas mariniglutinosa, Pseudoalteromonas spongiae and Pseudoalteromonas tetraodonis and of 93.79-96.99 % to the type strains of the other species of the genus Pseudoalteromonas. Strain DB-2T contained Q-8 as the predominant ubiquinone and C16 : 0, C18 : 1ω7c, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C12 : 0 3-OH as the major fatty acids. The major polar lipids detected in strain DB-2T were phosphatidylglycerol, phosphatidylethanolamine, two unidentified glycolipids, an unidentified phospholipid and an unidentified aminolipid. The DNA G+C content of strain DB-2T was 54.9 ± 0.2 mol% and mean DNA-DNA relatedness values with the type strains of P. mariniglutinosa, P. spongiae and P. tetraodonis were 10-17 %. Differential phenotypic properties, together with phylogenetic and genetic distinctiveness, revealed that strain DB-2T is separated from recognized species of the genus Pseudoalteromonas. On the basis of these data, strain DB-2T is considered to represent a novel species of the genus Pseudoalteromonas, for which the name Pseudoalteromonas aestuariivivens sp. nov. is proposed. The type strain is DB-2T ( = KCTC 42779T = CECT 8945T). PMID:26921230

  4. Spotlight on Antimicrobial Metabolites from the Marine Bacteria Pseudoalteromonas: Chemodiversity and Ecological Significance

    Directory of Open Access Journals (Sweden)

    Clément Offret

    2016-07-01

    Full Text Available This review is dedicated to the antimicrobial metabolite-producing Pseudoalteromonas strains. The genus Pseudoalteromonas hosts 41 species, among which 16 are antimicrobial metabolite producers. To date, a total of 69 antimicrobial compounds belonging to 18 different families have been documented. They are classified into alkaloids, polyketides, and peptides. Finally as Pseudoalteromonas strains are frequently associated with macroorganisms, we can discuss the ecological significance of antimicrobial Pseudoalteromonas as part of the resident microbiota.

  5. Bacterial small RNAs in the Genus Rickettsia

    OpenAIRE

    Schroeder, Casey L. C.; Narra, Hema P.; Rojas, Mark; Sahni, Abha; Patel, Jignesh; Khanipov, Kamil; Wood, Thomas G.; Fofanov, Yuriy; Sahni, Sanjeev K.

    2015-01-01

    Background Rickettsia species are obligate intracellular Gram-negative pathogenic bacteria and the etiologic agents of diseases such as Rocky Mountain spotted fever (RMSF), Mediterranean spotted fever, epidemic typhus, and murine typhus. Genome sequencing revealed that R. prowazekii has ~25 % non-coding DNA, the majority of which is thought to be either “junk DNA” or pseudogenes resulting from genomic reduction. These characteristics also define other Rickettsia genomes. Bacterial small RNAs,...

  6. Antibacterial activity of Pseudoalteromonas in the coral holobiont.

    Science.gov (United States)

    Shnit-Orland, Maya; Sivan, Alex; Kushmaro, Ariel

    2012-11-01

    Corals harbor diverse and abundant prokaryotic populations. Bacterial communities residing in the coral mucus layer may be either pathogenic or symbiotic. Some species may produce antibiotics as a method of controlling populations of competing microbial species. The present study characterizes cultivable Pseudoalteromonas sp. isolated from the mucus layer of different coral species from the northern Gulf of Eilat, Red Sea, Israel. Six mucus-associated Pseudoalteromonas spp. obtained from different coral species were screened for antibacterial activity against 23 tester strains. Five of the six Pseudoalteromonas strains demonstrated extracellular antibacterial activity against Gram-positive-but not Gram-negative-tester strains. Active substances secreted into the cell-free supernatant are heat-tolerant and inhibit growth of Bacillus cereus, Staphylococcus aureus, and of ten endogenous Gram-positive marine bacteria isolated from corals. The Pseudoalteromonas spp. isolated from Red sea corals aligned in a phylogenetic tree with previously isolated Pseudoalteromonas spp. of marine origin that demonstrated antimicrobial activity. These results suggest that coral mucus-associated Pseudoalteromonas may play a protective role in the coral holobiont's defense against potential Gram-positive coral pathogens. PMID:22767125

  7. Metalloid reducing bacteria isolated from deep ocean hydrothermal vents of the Juan de Fuca Ridge, Pseudoalteromonas telluritireducens sp. nov. and Pseudoalteromonas spiralis sp. nov.

    Science.gov (United States)

    Rathgeber, Christopher; Yurkova, Natalia; Stackebrandt, Erko; Schumann, Peter; Humphrey, Elaine; Beatty, J Thomas; Yurkov, Vladimir

    2006-11-01

    Five strains of Gram-negative, rod, curved rod and spiral-shaped bacteria were isolated from the vicinity of deep ocean hydrothermal vents along the Main Endeavour Segment of the Juan de Fuca Ridge in the Pacific Ocean. All strains showed remarkable resistance to high levels of toxic metalloid oxyanions, and were capable of reducing the oxyanions tellurite and selenite to their less toxic elemental forms. Phylogenetic analysis of four strains identified these isolates as close relatives of the genus Pseudoalteromonas within the class Gammaproteobacteria. Pseudoalteromonas agarivorans was the closest relative of strains Te-1-1 and Se-1-2-redT, with, respectively, 99.5 and 99.8% 16S rDNA sequence similarity. Strain Te-2-2T was most closely related to Pseudoalteromonas paragorgicola, with 99.8% 16S rDNA sequence similarity. The DNA G+C base composition was 39.6 to 41.8 mol%, in agreement with other members of the genus Pseudoalteromonas. However, the isolates showed important morphological and physiological differences from previously described species of this genus, with one group forming rod-shaped bacteria typical of Pseudoalteromonas and the other forming vibrioid- to spiral-shaped cells. Based on these differences, and on phylogenetic data, we propose the creation of the new species Pseudoalteromonas telluritireducens sp. nov., with strain Se-1-2-redT (DSMZ = 16098T = VKM B-2382T) as the type strain, and Pseudoalteromonas spiralis sp. nov., with strain Te-2-2T (DSMZ = 16099T = VKM B-2383T) as the type strain. PMID:17066332

  8. Complete genome sequence of Pseudoalteromonas rubra SCSIO 6842, harboring a putative conjugative plasmid pMBL6842.

    Science.gov (United States)

    Li, Baiyuan; Wang, Pengxia; Zeng, Zhenshun; Cai, Xingsheng; Wang, Guanghua; Wang, Xiaoxue

    2016-04-20

    Pseudoalteromonas is a genus of Gram-negative and is ubiquitously distributed in the ocean. Many Pseudoalteromonas species are capable of producing pigments, which can serve as an alternative source to replace synthetic pigments used in the food industry. Prodigiosins belong to a family of secondary metabolite characterized by a common pyrrolyl pyrromethane skeleton, and have been successfully applied to yogurt, milk and carbonated drinks as substitutes for synthetic additives. The strain Pseudoalteromonas rubra SCSIO 6842 can produce cycloprodigiosin and harbors a conjugative plasmid. Here we report the complete genome of P. rubra SCSIO 6842 for a better understanding of the molecular basis of cycloprodigiosin production and regulation. PMID:26970053

  9. Characterization of the pigment xanthomonadin in the bacterial genus Xanthomonas using micro- and resonance Raman spectroscopy

    Science.gov (United States)

    Paret, Mathews L.; Sharma, Shiv K.; Misra, Anupam K.; Acosta, Tayro; deSilva, Asoka S.; Vowell, Tomie; Alvarez, Anne M.

    2012-06-01

    We used micro- and resonance Raman spectroscopy with 785 nm and 514.5 nm laser excitation, respectively, to characterize a plant pathogenic bacteria, Xanthomonas axonopodis pv. dieffenbachiae D150. The bacterial genus Xathomonas is closely related to bacterial genus Stenotrophomonas that causes an infection in humans. This study has identified for the first time the unique Raman spectra of the carotenoid-like pigment xanthomonadin of the Xanthomonas strain. Xanthomonadin is a brominated aryl-polyene pigment molecule similar to carotenoids. Further studies were conducted using resonance Raman spectroscopy with 514.5 nm laser excitation on several strains of the bacterial genus Xanthomonas isolated from numerous plants from various geographical locations. The current study revealed that the Raman bands representing the vibrations (v1, v2, v3) of the polyene chain of xanthomonadin are 1003-1005 (v3), 1135-1138 (v2), and 1530 (v1). Overtone bands representing xanthomonadin were identified as 2264-2275 (2v2), and combinational bands at 2653-2662 (v1+ v2). The findings from this study validate our previous finding that the Raman fingerprints of xanthomonadin are unique for the genus Xanthomonas. This facilitates rapid identification (~5 minutes) of Xanthomonas spp. from bacterial culture plates. The xanthomonadin marker is different from Raman markers of many other bacterial genus including Agrobacterium, Bacillus, Clavibacter, Enterobacter, Erwinia, Microbacterium, Paenibacillus, and Ralstonia. This study also identified Xanthomonas spp. from bacterial strains isolated from a diseased wheat sample on a culture plate.

  10. Characterization of a cryptic plasmid pSM429 and its application for heterologous expression in psychrophilic Pseudoalteromonas

    Directory of Open Access Journals (Sweden)

    Chen Bo

    2011-05-01

    Full Text Available Abstract Background Pseudoalteromonas is an important genus widespread in marine environment, and a lot of psychrophilic Pseudoalteromonas strains thrive in deep sea and polar sea. By now, there are only a few genetic systems for Pseudoalteromonas reported and no commercial Pseudoalteromonas genetic system is available, which impedes the study of Pseudoalteromonas, especially for psychrophilic strains. The aim of this study is to develop a heterologous expression system for psychrophilic Pseudoalteromonas. Results A cryptic plasmid pSM429 isolated from psychrophilic Pseudoalteromonas sp. BSi20429 from the Arctic sea ice, was sequenced and characterized. The plasmid pSM429 is 3874 bp in length, with a G+C content of 28%. Four putative open reading frames (ORFs were identified on pSM429. Based on homology, the ORF4 was predicted to encode a replication initiation (Rep protein. A shuttle vector (Escherichia coli, Pseudoalteromonas, pWD, was constructed by ligating pSM429 and pUC19 and inserting a chloramphenicol acetyl transferase (CAT cassette conferring chloramphenicol resistance. To determine the minimal replicon of pSM429 and to check the functionality of identified ORFs, various pWD derivatives were constructed. All derivatives except the two smallest ones were shown to allow replication in Pseudoalteromonas sp. SM20429, a plasmid-cured strain of Pseudoalteromonas sp. BSi20429, suggesting that the orf4 and its flanking intergenic regions are essential for plasmid replication. Although not essential, the sequence including some repeats between orf1 and orf2 plays important roles in segregational stability of the plasmid. With the aid of pWD-derived plasmid pWD2, the erythromycin resistance gene and the cd gene encoding the catalytic domain of a cold-adapted cellulase were successfully expressed in Pseudoalteromonas sp. SM20429. Conclusions Plasmid pSM429 was isolated and characterized, and the regions essential for plasmid replication and

  11. MALDI-TOF Mass Spectrometry Discriminates Known Species and Marine Environmental Isolates of Pseudoalteromonas

    Science.gov (United States)

    Emami, Kaveh; Nelson, Andrew; Hack, Ethan; Zhang, Jinwei; Green, David H.; Caldwell, Gary S.; Mesbahi, Ehsan

    2016-01-01

    The genus Pseudoalteromonas constitutes an ecologically significant group of marine Gammaproteobacteria with potential biotechnological value as producers of bioactive compounds and of enzymes. Understanding their roles in the environment and bioprospecting for novel products depend on efficient ways of identifying environmental isolates. Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) biotyping has promise as a rapid and reliable method of identifying and distinguishing between different types of bacteria, but has had relatively limited application to marine bacteria and has not been applied systematically to Pseudoalteromonas. Therefore, we constructed a MALDI-TOF MS database of 31 known Pseudoalteromonas species, to which new isolates can be compared by MALDI-TOF biotyping. The ability of MALDI-TOF MS to distinguish between species was scrutinized by comparison with 16S rRNA gene sequencing. The patterns of similarity given by the two approaches were broadly but not completely consistent. In general, the resolution of MALDI-TOF MS was greater than that of 16S rRNA gene sequencing. The database was tested with 13 environmental Pseudoalteromonas isolates from UK waters. All of the test strains could be identified to genus level by MALDI-TOF MS biotyping, but most could not be definitely identified to species level. We conclude that several of these isolates, and possibly most, represent new species. Thus, further taxonomic investigation of Pseudoalteromonas is needed before MALDI-TOF MS biotyping can be used reliably for species identification. It is, however, a powerful tool for characterizing and distinguishing among environmental isolates and can make an important contribution to taxonomic studies. PMID:26903983

  12. MALDI-TOF Mass Spectrometry Discriminates Known Species and Marine Environmental Isolates of Pseudoalteromonas.

    Science.gov (United States)

    Emami, Kaveh; Nelson, Andrew; Hack, Ethan; Zhang, Jinwei; Green, David H; Caldwell, Gary S; Mesbahi, Ehsan

    2016-01-01

    The genus Pseudoalteromonas constitutes an ecologically significant group of marine Gammaproteobacteria with potential biotechnological value as producers of bioactive compounds and of enzymes. Understanding their roles in the environment and bioprospecting for novel products depend on efficient ways of identifying environmental isolates. Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) biotyping has promise as a rapid and reliable method of identifying and distinguishing between different types of bacteria, but has had relatively limited application to marine bacteria and has not been applied systematically to Pseudoalteromonas. Therefore, we constructed a MALDI-TOF MS database of 31 known Pseudoalteromonas species, to which new isolates can be compared by MALDI-TOF biotyping. The ability of MALDI-TOF MS to distinguish between species was scrutinized by comparison with 16S rRNA gene sequencing. The patterns of similarity given by the two approaches were broadly but not completely consistent. In general, the resolution of MALDI-TOF MS was greater than that of 16S rRNA gene sequencing. The database was tested with 13 environmental Pseudoalteromonas isolates from UK waters. All of the test strains could be identified to genus level by MALDI-TOF MS biotyping, but most could not be definitely identified to species level. We conclude that several of these isolates, and possibly most, represent new species. Thus, further taxonomic investigation of Pseudoalteromonas is needed before MALDI-TOF MS biotyping can be used reliably for species identification. It is, however, a powerful tool for characterizing and distinguishing among environmental isolates and can make an important contribution to taxonomic studies. PMID:26903983

  13. Comparative genomics of the bacterial genus Listeria: Genome evolution is characterized by limited gene acquisition and limited gene loss

    OpenAIRE

    den Bakker, Henk C.; Cummings, Craig A.; Ferreira, Vania; Vatta, Paolo; Orsi, Renato H.; Degoricija, Lovorka; Barker, Melissa; Petrauskene, Olga; Furtado, Manohar R; Wiedmann, Martin

    2010-01-01

    Background The bacterial genus Listeria contains pathogenic and non-pathogenic species, including the pathogens L. monocytogenes and L. ivanovii, both of which carry homologous virulence gene clusters such as the prfA cluster and clusters of internalin genes. Initial evidence for multiple deletions of the prfA cluster during the evolution of Listeria indicates that this genus provides an interesting model for studying the evolution of virulence and also presents practical challenges with rega...

  14. What Makes a Bacterial Species Pathogenic?:Comparative Genomic Analysis of the Genus Leptospira.

    Directory of Open Access Journals (Sweden)

    Derrick E Fouts

    2016-02-01

    Full Text Available Leptospirosis, caused by spirochetes of the genus Leptospira, is a globally widespread, neglected and emerging zoonotic disease. While whole genome analysis of individual pathogenic, intermediately pathogenic and saprophytic Leptospira species has been reported, comprehensive cross-species genomic comparison of all known species of infectious and non-infectious Leptospira, with the goal of identifying genes related to pathogenesis and mammalian host adaptation, remains a key gap in the field. Infectious Leptospira, comprised of pathogenic and intermediately pathogenic Leptospira, evolutionarily diverged from non-infectious, saprophytic Leptospira, as demonstrated by the following computational biology analyses: 1 the definitive taxonomy and evolutionary relatedness among all known Leptospira species; 2 genomically-predicted metabolic reconstructions that indicate novel adaptation of infectious Leptospira to mammals, including sialic acid biosynthesis, pathogen-specific porphyrin metabolism and the first-time demonstration of cobalamin (B12 autotrophy as a bacterial virulence factor; 3 CRISPR/Cas systems demonstrated only to be present in pathogenic Leptospira, suggesting a potential mechanism for this clade's refractoriness to gene targeting; 4 finding Leptospira pathogen-specific specialized protein secretion systems; 5 novel virulence-related genes/gene families such as the Virulence Modifying (VM (PF07598 paralogs proteins and pathogen-specific adhesins; 6 discovery of novel, pathogen-specific protein modification and secretion mechanisms including unique lipoprotein signal peptide motifs, Sec-independent twin arginine protein secretion motifs, and the absence of certain canonical signal recognition particle proteins from all Leptospira; and 7 and demonstration of infectious Leptospira-specific signal-responsive gene expression, motility and chemotaxis systems. By identifying large scale changes in infectious (pathogenic and intermediately

  15. What Makes a Bacterial Species Pathogenic?:Comparative Genomic Analysis of the Genus Leptospira.

    Science.gov (United States)

    Fouts, Derrick E; Matthias, Michael A; Adhikarla, Haritha; Adler, Ben; Amorim-Santos, Luciane; Berg, Douglas E; Bulach, Dieter; Buschiazzo, Alejandro; Chang, Yung-Fu; Galloway, Renee L; Haake, David A; Haft, Daniel H; Hartskeerl, Rudy; Ko, Albert I; Levett, Paul N; Matsunaga, James; Mechaly, Ariel E; Monk, Jonathan M; Nascimento, Ana L T; Nelson, Karen E; Palsson, Bernhard; Peacock, Sharon J; Picardeau, Mathieu; Ricaldi, Jessica N; Thaipandungpanit, Janjira; Wunder, Elsio A; Yang, X Frank; Zhang, Jun-Jie; Vinetz, Joseph M

    2016-02-01

    Leptospirosis, caused by spirochetes of the genus Leptospira, is a globally widespread, neglected and emerging zoonotic disease. While whole genome analysis of individual pathogenic, intermediately pathogenic and saprophytic Leptospira species has been reported, comprehensive cross-species genomic comparison of all known species of infectious and non-infectious Leptospira, with the goal of identifying genes related to pathogenesis and mammalian host adaptation, remains a key gap in the field. Infectious Leptospira, comprised of pathogenic and intermediately pathogenic Leptospira, evolutionarily diverged from non-infectious, saprophytic Leptospira, as demonstrated by the following computational biology analyses: 1) the definitive taxonomy and evolutionary relatedness among all known Leptospira species; 2) genomically-predicted metabolic reconstructions that indicate novel adaptation of infectious Leptospira to mammals, including sialic acid biosynthesis, pathogen-specific porphyrin metabolism and the first-time demonstration of cobalamin (B12) autotrophy as a bacterial virulence factor; 3) CRISPR/Cas systems demonstrated only to be present in pathogenic Leptospira, suggesting a potential mechanism for this clade's refractoriness to gene targeting; 4) finding Leptospira pathogen-specific specialized protein secretion systems; 5) novel virulence-related genes/gene families such as the Virulence Modifying (VM) (PF07598 paralogs) proteins and pathogen-specific adhesins; 6) discovery of novel, pathogen-specific protein modification and secretion mechanisms including unique lipoprotein signal peptide motifs, Sec-independent twin arginine protein secretion motifs, and the absence of certain canonical signal recognition particle proteins from all Leptospira; and 7) and demonstration of infectious Leptospira-specific signal-responsive gene expression, motility and chemotaxis systems. By identifying large scale changes in infectious (pathogenic and intermediately pathogenic

  16. Ultralong C100 mycolic acids support the assignment of Segniliparus as a new bacterial genus.

    Directory of Open Access Journals (Sweden)

    Sunhee Hong

    Full Text Available Mycolic acid-producing bacteria isolated from the respiratory tract of human and non-human mammals were recently assigned as a distinct genus, Segniliparus, because they diverge from rhodococci and mycobacteria in genetic and chemical features. Using high accuracy mass spectrometry, we determined the chemical composition of 65 homologous mycolic acids in two Segniliparus species and separately analyzed the three subclasses to measure relative chain length, number and stereochemistry of unsaturations and cyclopropyl groups within each class. Whereas mycobacterial mycolate subclasses are distinguished from one another by R groups on the meromycolate chain, Segniliparus species synthesize solely non-oxygenated α-mycolates with high levels of cis unsaturation. Unexpectedly Segniliparus α-mycolates diverge into three subclasses based on large differences in carbon chain length with one bacterial culture producing mycolates that range from C58 to C100. Both the overall chain length (C100 and the chain length diversity (C42 are larger than previously seen for mycolic acid-producing organisms and provide direct chemical evidence for assignment of Segniliparus as a distinct genus. Yet, electron microscopy shows that the long and diverse mycolates pack into a typical appearing membrane. Therefore, these new and unexpected extremes of mycolic acid chemical structure raise questions about the modes of mycolic acid packing and folding into a membrane.

  17. Promiscuous and specific bacterial symbiont acquisition in the amoeboid genus Nuclearia (Opisthokonta).

    Science.gov (United States)

    Dirren, Sebastian; Posch, Thomas

    2016-08-01

    We isolated 17 strains of the amoeboid genus Nuclearia (Opisthokonta) from five Swiss lakes. Eight of these nucleariid isolates were associated with bacterial endosymbionts and/or ectosymbionts. Amoebae were characterized morphologically and by their 18S rRNA genes. Phylogeny based on molecular data resulted in four established monophyletic branches and two new clusters. A heterogeneous picture emerged by highlighting nucleariids with associated bacteria. Apart from one cluster which consisted of only isolates with and three groups of amoebae without symbionts, we also found mixed clusters. The picture got even more 'blurred' by regarding the phylogeny of symbiotic bacteria. Although seven different bacterial strains could be identified, it seems that we still are only scratching the surface of symbionts' diversity. Furthermore, types of symbioses might be different depending on host species. Strains of Nuclearia thermophila harboured the same endosymbiont even when isolated from different lakes. This pointed to a specific and obligate interaction. However, two isolates of N. delicatula were associated with different endosymbiotic bacteria. Here the symbiont acquisition seemed to be rather promiscuous. This behaviour regarding symbiotic associations is especially remarkable considering the phylogenetic position of these basal opisthokonts. PMID:27199347

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

    Science.gov (United States)

    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

  19. Beneficial biofilms in marine aquaculture? Linking points of biofilm formation mechanisms in Pseudomonas aeruginosa and Pseudoalteromonas species

    Directory of Open Access Journals (Sweden)

    Wiebke Wesseling

    2015-07-01

    Full Text Available For marine aquaculture it is suggested that a specific substrate coated with a beneficial biofilm could prevent fish egg clutches from pathogenic infestations and improve the water quality and health of adult fish while, at the same time, minimising the need for the application of antibiotics. In marine biotopes, the habitat of Pseudoalteromonas species (a strain with suggested beneficial properties, biofilms are mostly discussed in the context of fouling processes. Hence research focuses on unravelling the mechanisms of biofilm formation aiming to prevent formation or to destroy existing biofilms. Initially in this review, particular components of biofilm formation in Pseudomonas aeruginosa, a gram-negative model organism that is responsible for nosocomial infections and considered as a food spoiling agent, are described (extracellular appendages, role of matrix components, cell-cell signalling to get an advanced understanding of biofilm formation. The aim of this treatise is to seek linking points for biofilm formation of P. aeruginosa and Pseudoalteromonas sp., respectively. Furthermore, approaches are discussed for how biofilm formation can be realized to improve fish (larvae rearing by species of the genus Pseudoalteromonas.

  20. Multilocus Sequence Analysis of the Marine Bacterial Genus Tenacibaculum Suggests Parallel Evolution of Fish Pathogenicity and Endemic Colonization of Aquaculture Systems

    OpenAIRE

    Habib, Christophe; Houel, Armel; Lunazzi, Aurélie; Bernardet, Jean-François; Olsen, Anne Berit; Nilsen, Hanne; Toranzo, Alicia E.; Castro, Nuria; Nicolas, Pierre; Duchaud, Eric

    2014-01-01

    The genus Tenacibaculum, a member of the family Flavobacteriaceae, is an abundant component of marine bacterial ecosystems that also hosts several fish pathogens, some of which are of serious concern for marine aquaculture. Here, we applied multilocus sequence analysis (MLSA) to 114 representatives of most known species in the genus and of the worldwide diversity of the major fish pathogen Tenacibaculum maritimum. Recombination hampers precise phylogenetic reconstruction, but the data indicat...

  1. What Makes a Bacterial Species Pathogenic?:Comparative Genomic Analysis of the Genus Leptospira

    OpenAIRE

    Fouts, Derrick E.; Matthias, Michael A.; Adhikarla, Haritha; Adler, Ben; Amorim-Santos, Luciane; Berg, Douglas E.; Bulach, Dieter; Buschiazzo, Alejandro; Chang, Yung-Fu; Galloway, Renee L.; Haake, David A.; Haft, Daniel H.; Hartskeerl, Rudy; Ko, Albert I.; Levett, Paul N

    2016-01-01

    Leptospirosis, caused by spirochetes of the genus Leptospira, is a globally widespread, neglected and emerging zoonotic disease. While whole genome analysis of individual pathogenic, intermediately pathogenic and saprophytic Leptospira species has been reported, comprehensive cross-species genomic comparison of all known species of infectious and non-infectious Leptospira, with the goal of identifying genes related to pathogenesis and mammalian host adaptation, remains a key gap in the field....

  2. Bacterial diversity and composition in the fluid of pitcher plants of the genus Nepenthes.

    Science.gov (United States)

    Takeuchi, Yayoi; Chaffron, Samuel; Salcher, Michaela M; Shimizu-Inatsugi, Rie; Kobayashi, Masaki J; Diway, Bibian; von Mering, Christian; Pernthaler, Jakob; Shimizu, Kentaro K

    2015-07-01

    Pitchers are modified leaves used by carnivorous plants for trapping prey. Their fluids contain digestive enzymes from the plant and they harbor abundant microbes. In this study, the diversity of bacterial communities was assessed in Nepenthes pitcher fluids and the composition of the bacterial community was compared to that in other environments, including the phyllosphere of Arabidopsis, animal guts and another pitcher plant, Sarracenia. Diversity was measured by 454 pyrosequencing of 16S rRNA gene amplicons. A total of 232,823 sequences were obtained after chimera and singleton removal that clustered into 3260 distinct operational taxonomic units (OTUs) (3% dissimilarity), which were taxonomically distributed over 17 phyla, 25 classes, 45 orders, 100 families, and 195 genera. Pyrosequencing and fluorescence in situ hybridization yielded similar estimates of community composition. Most pitchers contained high proportions of unique OTUs, and only 22 OTUs (<0.6%) were shared by ≥14/16 samples, suggesting a unique bacterial assemblage in each pitcher at the OTU level. Diversity analysis at the class level revealed that the bacterial communities of both opened and unopened pitchers were most similar to that of Sarracenia and to that in the phyllosphere. Therefore, the bacterial community in pitchers may be formed by environmental filtering and/or by phyllosphere bacteria. PMID:26138047

  3. Denitrifying bacteria from the genus Rhodanobacter dominate bacterial communities in the highly contaminated subsurface of a nuclear legacy waste site

    Energy Technology Data Exchange (ETDEWEB)

    Green, Stefan [Florida State University; Prakash, Om [Florida State University; Jasrotia, Puja [Florida State University; Overholt, Will [Florida State University; Cardenas, Erick [Michigan State University, East Lansing; Hubbard, Daniela [Florida State University; Tiedje, James M. [Michigan State University, East Lansing; Watson, David B [ORNL; Schadt, Christopher Warren [ORNL; Brooks, Scott C [ORNL; Kostka, Joel [Florida State University

    2011-01-01

    The effect of long-term mixed-waste contamination, particularly uranium and nitrate, on the microbial community in the terrestrial subsurface was investigated at the field scale at the Oak Ridge Integrated Field Research Challenge (ORIFRC) site in Oak Ridge, TN. The abundance, community composition, and distribution of groundwater microorganisms were examined across the site during two seasonal sampling events. At representative locations, subsurface sediment was also examined from two boreholes, one sampled from the most heavily contaminated area of the site and another from an area with low contamination. A suite of DNA- and RNA-based molecular tools were employed for community characterization, including quantitative PCR of ribosomal RNA and nitrite reductase genes, community composition fingerprinting analysis, and high-throughput pyrotag sequencing of rRNA genes. The results demonstrate that pH is a major driver of the subsurface microbial community structure, and denitrifying bacteria from the genus Rhodanobacter (class Gammaproteobacteria) dominate at low pH. The relative abundance of bacteria from this genus was positively correlated with lower pH conditions, and these bacteria were abundant and active in the most highly contaminated areas. Other factors, such as concentration of nitrogen species, oxygen and sampling season did not appear to strongly influence the distribution of Rhodanobacter. Results indicate that these organisms are acid-tolerant denitrifiers, well suited to the acidic, nitrate-rich subsurface conditions, and pH is confirmed as a dominant driver of bacterial community structure in this contaminated subsurface environment.

  4. Host and Environmental Specificity in Bacterial Communities Associated to Two Highly Invasive Marine Species (Genus Asparagopsis)

    Science.gov (United States)

    Aires, Tânia; Serrão, Ester A.; Engelen, Aschwin H.

    2016-01-01

    As habitats change due to global and local pressures, population resilience, and adaptive processes depend not only on their gene pools but also on their associated bacteria communities. The hologenome can play a determinant role in adaptive evolution of higher organisms that rely on their bacterial associates for vital processes. In this study, we focus on the associated bacteria of the two most invasive seaweeds in southwest Iberia (coastal mainland) and nearby offshore Atlantic islands, Asparagopsis taxiformis and Asparagopsis armata. Bacterial communities were characterized using 16S rRNA barcoding through 454 next generation sequencing and exploratory shotgun metagenomics to provide functional insights and a backbone for future functional studies. The bacterial community composition was clearly different between the two species A. taxiformis and A. armata and between continental and island habitats. The latter was mainly due to higher abundances of Acidimicrobiales, Sphingomonadales, Xanthomonadales, Myxococcales, and Alteromonadales on the continent. Metabolic assignments for these groups contained a higher number of reads in functions related to oxidative stress and resistance to toxic compounds, more precisely heavy metals. These results are in agreement with their usual association with hydrocarbon degradation and heavy-metals detoxification. In contrast, A. taxiformis from islands contained more bacteria related to oligotrophic environments which might putatively play a role in mineralization of dissolved organic matter. The higher number of functional assignments found in the metagenomes of A. taxiformis collected from Cape Verde Islands suggest a higher contribution of bacteria to compensate nutrient limitation in oligotrophic environments. Our results show that Asparagopsis-associated bacterial communities have host-specificity and are modulated by environmental conditions. Whether this environmental effect reflects the host's selective requirements or

  5. Host and Environmental Specificity in Bacterial Communities Associated to Two Highly Invasive Marine Species (Genus Asparagopsis).

    Science.gov (United States)

    Aires, Tânia; Serrão, Ester A; Engelen, Aschwin H

    2016-01-01

    As habitats change due to global and local pressures, population resilience, and adaptive processes depend not only on their gene pools but also on their associated bacteria communities. The hologenome can play a determinant role in adaptive evolution of higher organisms that rely on their bacterial associates for vital processes. In this study, we focus on the associated bacteria of the two most invasive seaweeds in southwest Iberia (coastal mainland) and nearby offshore Atlantic islands, Asparagopsis taxiformis and Asparagopsis armata. Bacterial communities were characterized using 16S rRNA barcoding through 454 next generation sequencing and exploratory shotgun metagenomics to provide functional insights and a backbone for future functional studies. The bacterial community composition was clearly different between the two species A. taxiformis and A. armata and between continental and island habitats. The latter was mainly due to higher abundances of Acidimicrobiales, Sphingomonadales, Xanthomonadales, Myxococcales, and Alteromonadales on the continent. Metabolic assignments for these groups contained a higher number of reads in functions related to oxidative stress and resistance to toxic compounds, more precisely heavy metals. These results are in agreement with their usual association with hydrocarbon degradation and heavy-metals detoxification. In contrast, A. taxiformis from islands contained more bacteria related to oligotrophic environments which might putatively play a role in mineralization of dissolved organic matter. The higher number of functional assignments found in the metagenomes of A. taxiformis collected from Cape Verde Islands suggest a higher contribution of bacteria to compensate nutrient limitation in oligotrophic environments. Our results show that Asparagopsis-associated bacterial communities have host-specificity and are modulated by environmental conditions. Whether this environmental effect reflects the host's selective requirements or

  6. Intestine Bacterial Composition of the Chromosomal forms of genus Nannospalax and Comparison of Some Rodent Species

    OpenAIRE

    Coşkun, Yüksel; El-Namee, Ausama; KAYA, Alaettin

    2013-01-01

    In this study, five selected different rodent species, Meriones tristrami (karyotype 2n=72 from Mardin/Turkey), Nannospalax ehrenbergi (karyotype 2n=52 from Diyarbakır/Turkey and Mosul/Iraq), Nannospalax nehringi (karyotype 2n = 60 from Sivas/Turkey), Rattus rattus (karyotype 2n=42 from Diyarbakır/Turkey), Sciurus anomalus (karyotype 2n=40 from Bingöl/Turkey) were studied in respect to bacterial species.The results showed the presence of two types of bacteria Pantoea agglomerans and Serratia ...

  7. The uncultured luminous symbiont of Anomalops katoptron (Beryciformes: Anomalopidae) represents a new bacterial genus.

    Science.gov (United States)

    Hendry, Tory A; Dunlap, Paul V

    2011-12-01

    Flashlight fishes (Beryciformes: Anomalopidae) harbor luminous symbiotic bacteria in subocular light organs and use the bacterial light for predator avoidance, feeding, and communication. Despite many attempts anomalopid symbionts have not been brought into laboratory culture, which has restricted progress in understanding their phylogenetic relationships with other luminous bacteria, identification of the genes of their luminescence system, as well as the nature of their symbiotic interactions with their fish hosts. To begin addressing these issues, we used culture-independent analysis of the bacteria symbiotic with the anomalopid fish, Anomalops katoptron, to characterize the phylogeny of the bacteria and to identify the genes of their luminescence system including those involved in the regulation of luminescence. Analysis of the 16S rRNA, atpA, gapA, gyrB, pyrH, recA, rpoA, and topA genes resolved the A. katoptron symbionts as a clade nested within and deeply divergent from other members of Vibrionaceae. The bacterial luminescence (lux) genes were identified as a contiguous set (luxCDABEG), as found for the lux operons of other luminous bacteria. Phylogenetic analysis based on the lux genes confirmed the housekeeping gene phylogenetic placement. Furthermore, genes flanking the lux operon in the A. katoptron symbionts differed from those flanking lux operons of other genera of luminous bacteria. We therefore propose the candidate name Candidatus Photodesmus (Greek: photo = light, desmus = servant) katoptron for the species of bacteria symbiotic with A. katoptron. Results of a preliminary genomic analysis for genes regulating luminescence in other bacteria identified only a Vibrio harveyi-type luxR gene. These results suggest that expression of the luminescence system might be continuous in P. katoptron. PMID:21864694

  8. Development of a Cold-Adapted Pseudoalteromonas Expression System for the Pseudoalteromonas Proteins Intractable for the Escherichia coli System.

    Directory of Open Access Journals (Sweden)

    Zi-Chao Yu

    Full Text Available Although the Escherichia coli expression system is the most commonly used expression system, some proteins are still difficult to be expressed by this system, such as proteins with high thermolability and enzymes that cannot mature by autoprocessing. Therefore, it is necessary to develop alternative expression systems. In this study, a cold-adapted Pseudoalteromonas expression system was developed. A shuttle vector was constructed, and a conjugational transfer system between E. coli and psychrophilic strain Pseudoalteromonas sp. SM20429 was established. Based on the shuttle vector, three reporter vectors were constructed to compare the strength of the cloned promoters at low temperature. The promoter of xylanase gene from Pseudoalteromonas sp. BSi20429 was chosen due to its high activity at 10-15°C. An expression vector pEV containing the chosen promoter, multiple cloning sites and a His tag was constructed for protein expression and purification. With pEV as expression vector and SM20429 as the host, a cold-adapted protease, pseudoalterin, which cannot be maturely expressed in E. coli, was successfully expressed as an active extracellular enzyme when induced by 2% oat spelt xylan at 15°C for 48 h. Recombinant pseudoalterin purified from the culture by Ni affinity chromatography had identical N-terminal sequence, similar molecular mass and substrate specificity as the native pseudoalterin. In addition, another two cold-adapted enzymes were also successfully expressed by this system. Our results indicate that this cold-adapted Pseudoalteromonas expression system will provide an alternative choice for protein expression, especially for the Pseudoalteromonas proteins intractable for the E. coli system.

  9. Development of a Cold-Adapted Pseudoalteromonas Expression System for the Pseudoalteromonas Proteins Intractable for the Escherichia coli System.

    Science.gov (United States)

    Yu, Zi-Chao; Tang, Bai-Lu; Zhao, Dian-Li; Pang, Xiuhua; Qin, Qi-Long; Zhou, Bai-Cheng; Zhang, Xi-Ying; Chen, Xiu-Lan; Zhang, Yu-Zhong

    2015-01-01

    Although the Escherichia coli expression system is the most commonly used expression system, some proteins are still difficult to be expressed by this system, such as proteins with high thermolability and enzymes that cannot mature by autoprocessing. Therefore, it is necessary to develop alternative expression systems. In this study, a cold-adapted Pseudoalteromonas expression system was developed. A shuttle vector was constructed, and a conjugational transfer system between E. coli and psychrophilic strain Pseudoalteromonas sp. SM20429 was established. Based on the shuttle vector, three reporter vectors were constructed to compare the strength of the cloned promoters at low temperature. The promoter of xylanase gene from Pseudoalteromonas sp. BSi20429 was chosen due to its high activity at 10-15°C. An expression vector pEV containing the chosen promoter, multiple cloning sites and a His tag was constructed for protein expression and purification. With pEV as expression vector and SM20429 as the host, a cold-adapted protease, pseudoalterin, which cannot be maturely expressed in E. coli, was successfully expressed as an active extracellular enzyme when induced by 2% oat spelt xylan at 15°C for 48 h. Recombinant pseudoalterin purified from the culture by Ni affinity chromatography had identical N-terminal sequence, similar molecular mass and substrate specificity as the native pseudoalterin. In addition, another two cold-adapted enzymes were also successfully expressed by this system. Our results indicate that this cold-adapted Pseudoalteromonas expression system will provide an alternative choice for protein expression, especially for the Pseudoalteromonas proteins intractable for the E. coli system. PMID:26333173

  10. Development of a Cold-Adapted Pseudoalteromonas Expression System for the Pseudoalteromonas Proteins Intractable for the Escherichia coli System

    OpenAIRE

    Zi-Chao Yu; Bai-Lu Tang; Dian-Li Zhao; Xiuhua Pang; Qi-Long Qin; Bai-Cheng Zhou; Xi-Ying Zhang; Xiu-Lan Chen; Yu-Zhong Zhang

    2015-01-01

    Although the Escherichia coli expression system is the most commonly used expression system, some proteins are still difficult to be expressed by this system, such as proteins with high thermolability and enzymes that cannot mature by autoprocessing. Therefore, it is necessary to develop alternative expression systems. In this study, a cold-adapted Pseudoalteromonas expression system was developed. A shuttle vector was constructed, and a conjugational transfer system between E. coli and psych...

  11. Liquid Chromatography-Mass Spectrometry-Based Rapid Secondary-Metabolite Profiling of Marine Pseudoalteromonas sp. M2

    Directory of Open Access Journals (Sweden)

    Woo Jung Kim

    2016-01-01

    Full Text Available The ocean is a rich resource of flora, fauna, and food. A wild-type bacterial strain showing confluent growth on marine agar with antibacterial activity was isolated from marine water, identified using 16S rDNA sequence analysis as Pseudoalteromonas sp., and designated as strain M2. This strain was found to produce various secondary metabolites including quinolone alkaloids. Using high-resolution mass spectrometry (MS and nuclear magnetic resonance (NMR analysis, we identified nine secondary metabolites of 4-hydroxy-2-alkylquinoline (pseudane-III, IV, V, VI, VII, VIII, IX, X, and XI. Additionally, this strain produced two novel, closely related compounds, 2-isopentylqunoline-4-one and 2-(2,3-dimetylbutylqunoline-4-(1H-one, which have not been previously reported from marine bacteria. From the metabolites produced by Pseudoalteromonas sp. M2, 2-(2,3-dimethylbutylquinolin-4-one, pseudane-VI, and pseudane-VII inhibited melanin synthesis in Melan-A cells by 23.0%, 28.2%, and 42.7%, respectively, wherein pseudane-VII showed the highest inhibition at 8 µg/mL. The results of this study suggest that liquid chromatography (LC-MS/MS-based metabolite screening effectively improves the efficiency of novel metabolite discovery. Additionally, these compounds are promising candidates for further bioactivity development.

  12. Production and characterization of an extracellular polysaccharide of antarctic marine bacteria Pseudoalteromonas sp. S-15-13

    Institute of Scientific and Technical Information of China (English)

    LI Jiang; CHEN Kaoshan; LIN Xuezheng; HE Peiqing; LI Guangyou

    2006-01-01

    Twenty-seven antarctic bacteria producing extracellular polysaccharide (EPS) were selected from 57 strains by staining technology. The effects of major environmental factors on the growth and EPS production of Pseudoalteromonas sp. S-15-13 were investigated, and the EPS was separated and purified for characterization analysis. The results showed that the optimal conditions for the EPS production were culture period, 56 h; growth temperature, 8 ℃; carbon source, 1.0% glucose; NaCl concentration, 3.0%; pH 6.0~7.0. The EPS was purified by cold ethanol precipitation, proteins removal, ion exchange chromatography and gel chromatography technology. The molecular mass of EPS-II was 62 kDa as determined by the high performance gel permeation chromatography. Its sugar composition was a homopolymer of mannose analyzed by gas chromatograph spectroscopy. After repeated freezing and thawing of the bacteria biomass in the presence of EPS, the bacterial growth was much higher than that observed after freezing in the absence of EPS and the difference augmented with the increase of freeze-thaw cycles. It is hypothesized that the adaptation of Pseudoalteromonas sp. S-15-13 to the antarctic marine conditions, characterized by low temperature, high NaCl concentration and repeated freeze-thaw cycles, might be related to the EPS production ability.

  13. Exopolysaccharides play a role in the swarming of the benthic bacterium Pseudoalteromonas sp. SM9913

    Directory of Open Access Journals (Sweden)

    Ang eLiu

    2016-04-01

    Full Text Available 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.

  14. Optimization of Fermentation Conditions for the Production of the M23 Protease Pseudoalterin by Deep-Sea Pseudoalteromonas sp. CF6-2 with Artery Powder as an Inducer

    OpenAIRE

    Hui-Lin Zhao; Jie Yang; Xiu-Lan Chen; Hai-Nan Su; Xi-Ying Zhang; Feng Huang; Bai-Cheng Zhou; Bin-Bin Xie

    2014-01-01

    Proteases in the M23 family have specific activities toward elastin and bacterial peptidoglycan. The peptidoglycan-degrading property makes these proteases have potential as novel antimicrobials. Because M23 proteases cannot be maturely expressed in Escherichia coli, it is significant to improve the production of these enzymes in their wild strains. Pseudoalterin is a new M23 protease secreted by the deep-sea bacterium Pseudoalteromonas sp. CF6-2. In this study, the fermentation conditions of ...

  15. Anti-biofilm activity of Pseudoalteromonas flavipulchra SktPp1 against Serratia marcescens SMJ-11

    Science.gov (United States)

    Iqbal, Faiq; Usup, Gires; Ahmad, Asmat

    2015-09-01

    This study aimed to examine the anti-biofilm activity of Pseudoalteromonas flavipulchra SktPp1 crude extract against the biofilm producer, Serratia marcescens. The crude extract of P. flavipulchra SktPp1 was extracted with ethyl acetate. The sub-minimum inhibitory concentration (MIC), 0.1 mg/ml, has been used in this study. The anti-biofilm activity of P. flavipulchra SktPp1 crude extract was assessed against the biofilm of S. marcescens using the crystal violet assay. The growth curve has been used as the indicator of the effect of crude extracts to bacterial growth. The sub-MIC crude extract was tested against two of S. marcescens virulence factors, including the swarming ability and production of prodigiosin using the swarming assay and prodigiosin assay. The growth curves of S. marcescens indicated that the sub-MIC concentration of crude extract did not affect the growth of S. marcescens. The production of prodigiosin was reduced by 44%. The diameter of the swarming area was reduced from 8.7 cm to 0.8 cm. The sub-MIC crude extract inhibits 26.9% of the biofilm production in S. marcescens. This crude extract lost its activity at 50°C and above. In conclusion, crude extract of P. flavipulchra SktPp1 has the ability to inhibit S. marcescens SMJ-11 biofilm formation.

  16. ‘Olegusella massiliensis’ strain KHD7, a new bacterial genus isolated from the female genital tract

    OpenAIRE

    Diop, K.; Diop, A.; Raoult, D.; P.-E. Fournier; Fenollar, F.

    2016-01-01

    We report the main characteristics of ‘Olegusella massiliensis’ gen. nov., sp. nov., strain KHD7 (= CSUR P2268=DSM 101849), a new member of the Coriobacteriaceae family isolated from the vaginal flora of a patient with bacterial vaginosis.

  17. Draft Genome Sequences of Two Pseudoalteromonas Strains Isolated from Roots and Leaf Blades of the Seagrass Zostera marina.

    Science.gov (United States)

    Alexiev, Alexandra; Krusor, Megan L; Jospin, Guillaume; Lang, Jenna M; Eisen, Jonathan A; Coil, David A

    2016-01-01

    Here, we present the draft genome sequences for Pseudoalteromonas sp. strain UCD-33C and Pseudoalteromonas lipolytica UCD-48B. Pseudoalteromonas sp. UCD-33C was isolated from Zostera marina roots and P. lipolytica UCD-48B from Z. marina leaf blades, both collected in Woods Hole, MA. These assemblies contain 4,479,285 bp and 4,592,435 bp, respectively. PMID:26893412

  18. Multilocus sequence analysis of the marine bacterial genus Tenacibaculum suggests parallel evolution of fish pathogenicity and endemic colonization of aquaculture systems.

    Science.gov (United States)

    Habib, Christophe; Houel, Armel; Lunazzi, Aurélie; Bernardet, Jean-François; Olsen, Anne Berit; Nilsen, Hanne; Toranzo, Alicia E; Castro, Nuria; Nicolas, Pierre; Duchaud, Eric

    2014-09-01

    The genus Tenacibaculum, a member of the family Flavobacteriaceae, is an abundant component of marine bacterial ecosystems that also hosts several fish pathogens, some of which are of serious concern for marine aquaculture. Here, we applied multilocus sequence analysis (MLSA) to 114 representatives of most known species in the genus and of the worldwide diversity of the major fish pathogen Tenacibaculum maritimum. Recombination hampers precise phylogenetic reconstruction, but the data indicate intertwined environmental and pathogenic lineages, which suggests that pathogenicity evolved independently in several species. At lower phylogenetic levels recombination is also important, and the species T. maritimum constitutes a cohesive group of isolates. Importantly, the data reveal no trace of long-distance dissemination that could be linked to international fish movements. Instead, the high number of distinct genotypes suggests an endemic distribution of strains. The MLSA scheme and the data described in this study will help in monitoring Tenacibaculum infections in marine aquaculture; we show, for instance, that isolates from tenacibaculosis outbreaks in Norwegian salmon farms are related to T. dicentrarchi, a recently described species. PMID:24973065

  19. ‘Olegusella massiliensis’ strain KHD7, a new bacterial genus isolated from the female genital tract

    Directory of Open Access Journals (Sweden)

    K. Diop

    2016-07-01

    Full Text Available We report the main characteristics of ‘Olegusella massiliensis’ gen. nov., sp. nov., strain KHD7 (= CSUR P2268=DSM 101849, a new member of the Coriobacteriaceae family isolated from the vaginal flora of a patient with bacterial vaginosis.

  20. Biofilm formation by Pseudoalteromonas ruthenica and its removal by chlorine.

    Science.gov (United States)

    Saravanan, Periasamy; Nancharaiah, Y Venkata; Venugopalan, Vayalam P; Rao, T Subba; Jayachandran, Seetharaman

    2006-01-01

    The distribution of a recently described marine bacterium, SBT 033 GenBank Accession No. AY723742), Pseudoalteromonas ruthenica, at the seawater intake point, outfall and mixing point of an atomic power plant is described, and its ability to form biofilm was investigated. The effectiveness of the antifouling biocide chlorine in the inactivation of planktonic as well as biofilm cells of P. ruthenica was studied in the laboratory. The results show that the planktonic cells were more readily inactivated than the cells enclosed in a biofilm matrix. Viable counting showed that P. ruthenica cells in biofilms were up to 10 times more resistant to chlorine than those in liquid suspension. Using confocal laser scanning microscopy it was shown that significant detachment of P. ruthenica biofilm developed on a glass substratum could be accomplished by treatment with a dose of 1 mg l-1 chlorine. Chlorine-induced detachment led to a significant reduction in biofilm thickness (up to 69%) and substratum coverage (up to 61%), after 5-min contact time. The results show that P. ruthenica has a remarkable ability to form biofilms but chlorine, a common biocide, can be used to effectively kill and detach these biofilms. PMID:17178570

  1. Meta-analysis Reveals That the Genus Pseudomonas Can Be a Better Choice of Biological Control Agent against Bacterial Wilt Disease Caused by Ralstonia solanacearum.

    Science.gov (United States)

    Chandrasekaran, Murugesan; Subramanian, Dharaneedharan; Yoon, Ee; Kwon, Taehoon; Chun, Se-Chul

    2016-06-01

    Biological control agents (BCAs) from different microbial taxa are increasingly used to control bacterial wilt caused by Ralstonia solanacearum. However, a quantitative research synthesis has not been conducted on the role of BCAs in disease suppression. Therefore, the present study aimed to meta-analyze the impacts of BCAs on both Ralstonia wilt disease suppression and plant (host) growth promotion. The analysis showed that the extent of disease suppression by BCAs varied widely among studies, with effect size (log response ratio) ranging from -2.84 to 2.13. The disease incidence and severity were significantly decreased on average by 53.7% and 49.3%, respectively. BCAs inoculation also significantly increased fresh and dry weight by 34.4% and 36.1%, respectively on average. Also, BCAs inoculation significantly increased plant yield by 66%. Mean effect sizes for genus Pseudomonas sp. as BCAs were higher than for genus Bacillus spp. Among antagonists tested, P. fluorescens, P. putida, B. cereus, B. subtilis and B. amyloliquefaciens were found to be more effective in general for disease reduction. Across studies, highest disease control was found for P. fluorescens, annual plants, co-inoculation with more than one BCA, soil drench and greenhouse condition were found to be essential in understanding plant responses to R. solanacearum. Our results suggest that more efforts should be devoted to harnessing the potential beneficial effects of these antagonists, not just for plant growth promoting traits but also in mode of applications, BCAs formulations and their field studies should be considered in the future for R. solanacearum wilt disease suppression. PMID:27298597

  2. Bacterial diversity in the intestine of young farmed puffer fish Takifugu rubripes

    Science.gov (United States)

    Li, Yanyu; Zhang, Tao; Zhang, Congyao; Zhu, Ying; Ding, Jianfeng; Ma, Yuexin

    2015-07-01

    The aim of the study was to examine the bacterial community associated with the intestinal mucus of young farmed puffer fish Takifugu rubripes. Polymerase chain reaction and partial 16S rDNA sequencing was performed on DNA from bacteria cultivated on Zobell 2216E medium. All the isolates were classified into two phyla—Proteobacteria and Firmicutes. Proteobacteria were the dominant, culturable intestinal microbiota (68.3%). At the genus level, Vibrio, Enterobacter, Bacillus, Pseudomonas, Exiguobacterium, Staphylococcus, Acinetobacter, Pseudoalteromonas and Shewanella were isolated from the intestine, with representatives of the genera Vibrio, Enterobacter and Bacillus accounting for 70.7% of the total. This is the first report of Enterobacter, Bacillus, Exiguobacterium and Staphylococcus as part of the intestinal bacterial microflora in T. rubripes. The profile of the culturable bacterial community differed between samples collected from the same tank at 2-month intervals, as indicated by Bray-Curtis and Sorensen indices, and the impact on the intestinal physiology and health of puffer fish requires further investigation.

  3. Penetration barrier contributes to bacterial biofilm-associated resistance against only select antibiotics, and exhibits genus-, strain- and antibiotic-specific differences.

    Science.gov (United States)

    Singh, Rachna; Sahore, Simmi; Kaur, Preetinder; Rani, Alka; Ray, Pallab

    2016-08-01

    Bacterial biofilms are implicated in a wide range of implant-based and chronic infections. These infections are often associated with adverse therapeutic outcomes, owing to the decreased antibiotic susceptibility of biofilms compared with their planktonic counterparts. This altered biofilm susceptibility has been attributed to multiple factors, including a reduced antibiotic penetration. Although several studies have addressed the role of penetration barrier in biofilm-associated drug resistance, it remains inconclusive. This study was done to elucidate antibiotic penetration through biofilms formed by Staphylococcus aureus, S. epidermidis, Escherichia coli and Klebsiella pneumoniae, using an agar disk diffusion assay. Penetration capacity of six antimicrobial drugs from different classes (β-lactams, aminoglycosides, tetracyclines, phenicols, fluoroquinolones and glycopeptides) through biofilms formed by standard strains and clinical isolates from catheter-related bloodstream infections (CRBSI) was elucidated by measuring their growth-inhibition zones in lawn cultures on Mueller-Hinton agar, following diffusion of an antibiotic from an overlying disk through their biofilm to the agar medium. Penetration of only select antimicrobials (vancomycin and chloramphenicol) was hindered through biofilms. There was considerable variation in biofilm-permeating capacity depending upon the genus, strain/CRBSI isolate and antibiotic tested. Furthermore, antibiotics failed to kill the biofilm cells independent of penetration, indicating that other factors contributed substantially to biofilm resistance. PMID:27402781

  4. Six Pseudoalteromonas Strains Isolated from Surface Waters of Kabeltonne, Offshore Helgoland, North Sea.

    Science.gov (United States)

    Duhaime, Melissa B; Wichels, Antje; Sullivan, Matthew B

    2016-01-01

    Draft genomes are presented for 6 Pseudoalteromonas sp. strains isolated from surface waters at Kabeltonne, Helgoland, a long-term ecological research station in the North Sea. These strains contribute knowledge of the genomic underpinnings of a developing model system to study phage-host dynamics of a particle-associated ocean copiotroph. PMID:26868390

  5. Draft Genome Sequences of Six Pseudoalteromonas Strains, P1-7a, P1-9, P1-13-1a, P1-16-1b, P1-25, and P1-26, Which Induce Larval Settlement and Metamorphosis in Hydractinia echinata

    OpenAIRE

    Klassen, Jonathan L; Wolf, Thomas; Rischer, Maja; Guo, Huijuan; Shelest, Ekaterina; Clardy, Jon; Beemelmanns, Christine

    2015-01-01

    To gain a broader understanding of the importance of a surface-associated lifestyle and morphogenic capability, we have assembled and annotated the genome sequences of Pseudoalteromonas strains P1-7a, P1-9, P1-13-1a, P1-16-1b, P1-25, and P1-26, isolated from Hydractinia echinata. These genomes will allow detailed studies on bacterial factors mediating interkingdom communication.

  6. PhAP protease from Pseudoalteromonas haloplanktis TAC125: Gene cloning, recombinant production in E. coli and enzyme characterization

    Science.gov (United States)

    de Pascale, D.; Giuliani, M.; De Santi, C.; Bergamasco, N.; Amoresano, A.; Carpentieri, A.; Parrilli, E.; Tutino, M. L.

    2010-08-01

    Cold-adapted proteases have been found to be the dominant activity throughout the cold marine environment, indicating their importance in bacterial acquisition of nitrogen-rich complex organic compounds. However, few extracellular proteases from marine organisms have been characterized so far, and the mechanisms that enable their activity in situ are still largely unknown. Aside from their ecological importance and use as model enzyme for structure/function investigations, cold-active proteolytic enzymes offer great potential for biotechnological applications. Our studies on cold adapted proteases were performed on exo-enzyme produced by the Antarctic marine bacterium Pseudoalteromonas haloplanktis TAC125. By applying a proteomic approach, we identified several proteolytic activities from its culture supernatant. PhAP protease was selected for further investigations. The encoding gene was cloned and the protein was recombinantly produced in E. coli cells. The homogeneous product was biochemically characterised and it turned out that the enzyme is a Zn-dependent aminopeptidase, with an activity dependence from assay temperature typical of psychrophilic enzymes.

  7. Marine Bacteria from Danish Coastal Waters Show Antifouling Activity against the Marine Fouling Bacterium Pseudoalteromonas sp. Strain S91 and Zoospores of the Green Alga Ulva australis Independent of Bacteriocidal Activity

    DEFF Research Database (Denmark)

    Bernbom, Nete; Ng, Yoke Yin; Kjelleberg, Staffan;

    2011-01-01

    , representing the major taxonomic groups, different seasons, and isolation strategies, were tested for antiadhesive effect against the marine biofilm-forming bacterium Pseudoalteromonas sp. strain S91 and zoospores of the green alga Ulva australis. The antiadhesive effects were assessed by quantifying the...... number of strain S91 or Ulva spores attaching to a preformed biofilm of each of the 22 strains. The strongest antifouling activity was found in Pseudoalteromonas strains. Biofilms of Pseudoalteromonas piscicida, Pseudoalteromonas tunicata, and Pseudoalteromonas ulvae prevented Pseudoalteromonas S91 from...

  8. Excision of IS492 Requires Flanking Target Sequences and Results in Circle Formation in Pseudoalteromonas atlantica

    OpenAIRE

    Perkins-Balding, Donna; Duval-Valentin, Guy; Glasgow, Anna C.

    1999-01-01

    The gram-negative marine bacterium Pseudoalteromonas atlantica produces extracellular polysaccharide (EPS) that is important in biofilm formation by this bacterium. Insertion and precise excision of IS492 at a locus essential for extracellular polysaccharide production (eps) controls phase variation of EPS production in P. atlantica. Examination of IS492 transposition in P. atlantica by using a PCR-based assay revealed a circular form of IS492 that may be an intermediate in transposition or a...

  9. Draft Genome Sequences of Two Pseudoalteromonas porphyrae Strains Isolated from Seagrass Sediment.

    Science.gov (United States)

    Lee, Ruth D; Jospin, Guillaume; Lang, Jenna M; Eisen, Jonathan A; Coil, David A

    2016-01-01

    Here, we present the draft genome sequences of Pseudoalteromonas porphyrae UCD-SED9 and UCD-SED14 (phylum Proteobacteria). These strains were isolated from sediment surrounding the roots of the seagrass, Zostera marina, collected near the UC, Davis Bodega Marine Laboratory (Bodega Bay, California). The assemblies contain 4,847,456 bp and 4,817,752 bp, respectively. PMID:26988038

  10. Exopolysaccharide production by a marine Pseudoalteromonas sp. strain isolated from Madeira Archipelago ocean sediments.

    Science.gov (United States)

    Roca, Christophe; Lehmann, Mareen; Torres, Cristiana A V; Baptista, Sílvia; Gaudêncio, Susana P; Freitas, Filomena; Reis, Maria A M

    2016-06-25

    Exopolysaccharides (EPS) are polymers excreted by some microorganisms with interesting properties and used in many industrial applications. A new Pseudoalteromonas sp. strain, MD12-642, was isolated from marine sediments and cultivated in bioreactor in saline culture medium containing glucose as carbon source. Its ability to produce EPS under saline conditions was demonstrated reaching an EPS production of 4.4g/L within 17hours of cultivation, corresponding to a volumetric productivity of 0.25g/Lh, the highest value so far obtained for Pseudoalteromonas sp. strains. The compositional analysis of the EPS revealed the presence of galacturonic acid (41-42mol%), glucuronic acid (25-26mol%), rhamnose (16-22mol%) and glucosamine (12-16mol%) sugar residues. The polymer presents a high molecular weight (above 1000kDa). These results encourage the biotechnological exploitation of strain MD12-642 for the production of valuable EPS with unique composition, using saline by-products/wastes as feedstocks. PMID:26923806

  11. A novel genetic system for recombinant protein secretion in the Antarctic Pseudoalteromonas haloplanktis TAC125

    Directory of Open Access Journals (Sweden)

    Marino Gennaro

    2006-12-01

    Full Text Available Abstract Background The final aim of recombinant protein production is both to have a high specific production rate and a high product quality. It was already shown that using cold-adapted bacteria as host vectors, some "intractable" proteins can be efficiently produced at temperature as low as 4°C. Results A novel genetic system for the production and secretion of recombinant proteins in the Antarctic Gram-negative bacterium Pseudoalteromonas haloplanktis TAC125 was set up. This system aims at combining the low temperature recombinant product production with the advantages of extra-cellular protein targeting. The psychrophilic α-amylase from Pseudoalteromonas haloplanktis TAB23 was used as secretion carrier. Three chimerical proteins were produced by fusing intra-cellular proteins to C-terminus of the psychrophilic α-amylase and their secretion was analysed. Data reported in this paper demonstrate that all tested chimeras were translocated with a secretion yield always higher than 80%. Conclusion Data presented here demonstrate that the "cold" gene-expression system is efficient since the secretion yield of tested chimeras is always above 80%. These secretion performances place the α-amylase derived secretion system amongst the best heterologous secretion systems in Gram-negative bacteria reported so far. As for the quality of the secreted passenger proteins, data presented suggest that the system also allows the correct disulphide bond formation of chimera components, secreting a fully active passenger.

  12. Bioactivity, Chemical Profiling, and 16S rRNA-Based Phylogeny of Pseudoalteromonas Strains Collected on a Global Research Cruise

    DEFF Research Database (Denmark)

    Vynne, Nikolaj Grønnegaard; Månsson, Maria; Nielsen, Kristian Fog;

    2011-01-01

    One hundred one antibacterial Pseudoalteromonas strains that inhibited growth of a Vibrio anguillarum test strain were collected on a global research cruise (Galathea 3), and 51 of the strains repeatedly demonstrated antibacterial activity. Here, we profile secondary metabolites of these strains to...

  13. Involvement of the cell-specific pigment genes pks and sult in bacterial defense response of sea urchins Strongylocentrotus intermedius.

    Science.gov (United States)

    Kiselev, Konstantin V; Ageenko, Natalya V; Kurilenko, Valeria V

    2013-03-26

    Bacterial infections are one of the most important problems in mass aquaculture, causing the loss of millions of juvenile organisms. We isolated 22 bacterial strains from the cavity fluid of the sea urchin Strongylocentrotus pallidus and used phylogenetic analysis based on 16S rRNA gene sequences to separate the bacterial strains into 9 genera (Aliivibrio, Bizionia, Colwellia, Olleya, Paenibacillus, Photobacterium, Pseudoalteromonas, Shewanella, and Vibrio). Incubating Strongylocentrotus intermedius larvae with a strain from each of the 9 bacterial genera, we investigated the viability of the larvae, the amount of pigment cells, and the level of polyketide synthase (pks) and sulfotransferase (sult) gene expression. Results of the assay on sea urchin development showed that all bacterial strains, except Pseudoalteromonas and Bizionia, suppressed sea urchin development (resulting in retardation of the embryos' development with cellular disorders) and reduced cell viability. We found that pks expression in the sea urchin larvae after incubation with the bacteria of 9 tested genera was significantly increased, while the sult expression was increased only after the treatment with Pseudoalteromonas and Shewanella. Shikimic acid, which is known to activate the biosynthesis of naphthoquinone pigments, increased the tolerance of the sea urchin embryos to the bacteria. In conclusion, we show that the cell-specific pigment genes pks and sult are involved in the bacterial defense response of sea urchins. PMID:23548362

  14. The Stable Concordance Genus

    OpenAIRE

    Kearney, M. Kate

    2013-01-01

    The concordance genus of a knot is the least genus of any knot in its concordance class. Although difficult to compute, it is a useful invariant that highlights the distinction between the three-genus and four-genus. In this paper we define and discuss the stable concordance genus of a knot, which describes the behavior of the concordance genus under connected sum.

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

    Directory of Open Access Journals (Sweden)

    Sabine Marie Genicot

    2014-08-01

    Full Text Available 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. Isolation and characterization of Pseudoalteromonas sp. from fermented Korean food, as an antagonist to Vibrio harveyi.

    Science.gov (United States)

    Morya, V K; Choi, Wooyoung; Kim, Eun-Ki

    2014-02-01

    The microbial intervention for sustainable management of aquaculture, especially use of probiotics, is one of the most popular and practical approaches towards controlling pathogens. Vibrio harveyi is a well-known pathogenic bacterium, which is associated to a huge economic loss in the aquaculture system by causing vibriosis. The present study is crafted for screening and characterization of anti-Vibrio strains, which were isolated from various traditional fermented Korean foods. A total of 196 strains have been isolated from soybean paste (78 strains), red chili paste (49 strains), soy sauce (18 strains), jeotgal-a salted fish (34 strains), and the gazami crab-Portunus trituberculatus (17 strains). Fifteen strains showed an inhibitory effect on the growth of V. harveyi when subjected to coculture condition. Among the strains isolated, one has been identified as a significant anti-Vibrio strain. Further biochemical characterization and 16S rDNA sequencing revealed it as Pseudoalteromonas aliena, which had been deposited at the Korean Culture Center of Microorganisms (KCCM), Korea and designated as KCCM 11207P. The culture supernatants did not have any antimicrobial properties either in pure or in coculture condition. The culture supernatant was not toxic when supplemented to the swimming crab, Zoea, and Artemia larvae in aquaculture system. The results were very encouraging and showed a significant reduction in accumulated mortality. Here, we reported that pathogenic vibriosis can be controlled by Pseudoalteromonas sp. under in vitro and in vivo conditions. The results indicated that the biotic treatment offers a promising alternative to the use of antibiotics in crab aquaculture. PMID:23793257

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

    Science.gov (United States)

    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.

  18. Influence of Growth Temperature on Lipid and Phosphate Contents of Surface Polysaccharides from the Antarctic Bacterium Pseudoalteromonas haloplanktis TAC 125

    OpenAIRE

    Corsaro, M. Michela; Lanzetta, Rosa; Parrilli, Ermenegilda; Parrilli, Michelangelo; Tutino, M. Luisa; Ummarino, Salvatore

    2004-01-01

    The chemical structural variations induced by different growth temperatures in the lipooligosaccharide and exopolysaccharide components extracted from the Antarctic bacterium Pseudoalteromonas haloplanktis TAC 125 are described. The increase in phosphorylation with the increase in growth temperature seems to be general, because it happens not only for the lipooligosaccharide but also for the exopolysaccharide. Structural variations in the lipid components of lipid A also occur. In addition, f...

  19. Isolation of moderately halophilic pseudoalteromonas producing extracellular hydrolytic enzymes from persian gulf.

    Science.gov (United States)

    Ardakani, M Roayaie; Poshtkouhian, A; Amoozegar, M A; Zolgharnein, H

    2012-03-01

    Extracellular hydrolytic enzymes such as amylases, proteases, lipases and DNases have quite diverse potential usages in different areas such as food industry, biomedical sciences and chemical industries, also it would be of great importance to have available enzymes showing optimal activities at different values of salt concentrations and temperature. Halophiles are the most likely source of such enzymes, because not only their enzymes are salt-tolerant, but many are also thermotolerant. The purpose of this study was isolation of hydrolytic extracellular enzyme producing halophilic bacteria from water and sediment of the Persian Gulf. Isolated bacteria from water and sediment were inoculated in media with concentration of 0-20% NaCl to determine the optimum salt concentration for growth, isolates were also inoculated in 4 types of solid medium containing substrates of 3 extracellular hydrolytic enzymes including amylase, Protease and Lipase, to determine the quantitative detection of enzyme production, selected strains after more accurate physiological and biochemical studies were identified regarding phylogeny and molecular characteristics using 16S rRNA technique. Isolated enzyme producing bacteria belong to Pseudoalteromonas genera. PMID:23450116

  20. Genome Sequences of Three Pseudoalteromonas Strains (P1-8, P1-11, and P1-30), Isolated from the Marine Hydroid Hydractinia echinata

    OpenAIRE

    Klassen, Jonathan L; Rischer, Maja; Wolf, Thomas; Guo, Huijuan; Shelest, Ekaterina; Clardy, Jon; Beemelmanns, Christine

    2015-01-01

    The genomes of three Pseudoalteromonas strains (P1-8, P1-11, and P1-30) were sequenced and assembled. These genomes will inform future study of the genes responsible for the production of biologically active compounds responsible for these strains’ antimicrobial, biofouling, and algicidal activities.

  1. Draft Genome Sequence of Pseudoalteromonas sp. Strain XI10 Isolated from the Brine-Seawater Interface of Erba Deep in the Red Sea

    KAUST Repository

    Zhang, Guishan

    2016-03-10

    Pseudoalteromonas sp. strain XI10 was isolated from the brine-seawater interface of Erba Deep in the Red Sea, Saudi Arabia. Here, we present the draft genome sequence of strain XI10, a gammaproteobacterium that synthesizes polysaccharides for biofilm formation when grown in liquid culture.

  2. Genus $n$ Banach spaces

    OpenAIRE

    Casazza, Peter G.; Lammers, Mark C.

    1999-01-01

    We show that the classification problem for genus $n$ Banach spaces can be reduced to the unconditionally primary case and that the critical case there is $n=2$. It is further shown that a genus $n$ Banach space is unconditionally primary if and only if it contains a complemented subspace of genus $(n-1)$. We begin the process of classifying the genus 2 spaces by showing they have a strong decomposition property.

  3. Genus four superstring measures

    OpenAIRE

    Cacciatori, Sergio L.; Piazza, Francesco Dalla; Geemen, Bert van

    2008-01-01

    A main issue in superstring theory are the superstring measures. D'Hoker and Phong showed that for genus two these reduce to measures on the moduli space of curves which are determined by modular forms of weight eight and the bosonic measure. They also suggested a generalisation to higher genus. We showed that their approach works, with a minor modification, in genus three and we announced a positive result also in genus four. Here we give the modular form in genus four explicitly. Recently S...

  4. Fed-batch process for the psychrotolerant marine bacterium Pseudoalteromonas haloplanktis

    Directory of Open Access Journals (Sweden)

    Lalk Michael

    2010-09-01

    Full Text Available Abstract Background Pseudoalteromonas haloplanktis is a cold-adapted γ-proteobacterium isolated from Antarctic sea ice. It is characterized by remarkably high growth rates at low temperatures. P. haloplanktis is one of the model organisms of cold-adapted bacteria and has been suggested as an alternative host for the soluble overproduction of heterologous proteins which tend to form inclusion bodies in established expression hosts. Despite the progress in establishing P. haloplanktis as an alternative expression host the cell densities obtained with this organism, which is unable to use glucose as a carbon source, are still low. Here we present the first fed-batch cultivation strategy for this auspicious alternative expression host. Results The key for the fed-batch cultivation of P. haloplanktis was the replacement of peptone by casamino acids, which have a much higher solubility and allow a better growth control. In contrast to the peptone medium, on which P. haloplanktis showed different growth phases, on a casamino acids-containing, phosphate-buffered medium P. haloplanktis grew exponentially with a constant growth rate until the stationary phase. A fed-batch process was established by feeding of casamino acids with a constant rate resulting in a cell dry weight of about 11 g l-1 (OD540 = 28 which is a twofold increase of the highest densities which have been obtained with P. haloplanktis so far and an eightfold increase of the density obtained in standard shake flask cultures. The cell density was limited in the fed-batch cultivation by the relatively low solubility of casamino acids (about 100 g l-1, which was proven by pulse addition of casamino acid powder which increased the cell density to about 20 g l-1 (OD540 = 55. Conclusion The growth of P. haloplanktis to higher cell densities on complex medium is possible. A first fed-batch fermentation strategy could be established which is feasible to be used in lab-scale or for industrial

  5. Potential for luxS related signalling in marine bacteria and production of autoinducer-2 in the genus Shewanella

    Directory of Open Access Journals (Sweden)

    Wagner-Döbler Irene

    2008-01-01

    Full Text Available Abstract Background The autoinducer-2 (AI-2 group of signalling molecules are produced by both Gram positive and Gram negative bacteria as the by-product of a metabolic transformation carried out by the LuxS enzyme. They are the only non species-specific quorum sensing compounds presently known in bacteria. The luxS gene coding for the AI-2 synthase enzyme was found in many important pathogens. Here, we surveyed its occurrence in a collection of 165 marine isolates belonging to abundant marine phyla using conserved degenerated PCR primers and sequencing of selected positive bands to determine if the presence of the luxS gene is phylogenetically conserved or dependent on the habitat. Results The luxS gene was not present in any of the Alphaproteobacteria (n = 71 and Bacteroidetes strains (n = 29 tested; by contrast, these bacteria harboured the sahH gene, coding for an alternative enzyme for the detoxification of S-adenosylhomocysteine (SAH in the activated methyl cycle. Within the Gammaproteobacteria (n = 76, luxS was found in all Shewanella, Vibrio and Alteromonas isolates and some Pseudoalteromonas and Halomonas species, while sahH was detected in Psychrobacter strains. A number of Gammaproteobacteria (n = 27 appeared to have neither the luxS nor the sahH gene. We then studied the production of AI-2 in the genus Shewanella using the Vibrio harveyi bioassay. All ten species of Shewanella tested produced a pronounced peak of AI-2 towards the end of the exponential growth phase in several media investigated. The maximum of AI-2 activity was different in each Shewanella species, ranging from 4% to 46% of the positive control. Conclusion The data are consistent with those of fully sequenced bacterial genomes and show that the potential for luxS related signalling is dependent on phylogenetic affiliation rather than ecological niche and is largest in certain groups of Gammaproteobacteria in the marine environment. This is the first report on AI-2

  6. Phylogenetic position of the spirochetal genus Cristispira

    DEFF Research Database (Denmark)

    Paster, B.J.; Pelletier, D.A.; Dewhirst, F.E.; Weisburg, W.G.; Fussing, V.; Poulsen, Lars K.; Dannenberg, S.; Schroeder, I.

    1996-01-01

    Comparative sequence analysis of 16S rRNA genes was used to determine the phylogenetic relationship of the genus Cristispira to other spirochetes. Since Cristispira organisms cannot presently be grown in vitro, 16S rRNA genes were amplified directly from bacterial DNA isolated from Cristispira a...... genus within this family. A fluorescently labeled DNA probe designed from the CP1 sequence was used for in situ hybridization experiments to verify that the sequence obtained was derived from the observed Cristispira cells....

  7. Expression, crystallization and preliminary X-ray analysis of an anomeric inverting agarase from Pseudoalteromonas sp. CY24

    International Nuclear Information System (INIS)

    AgaB from Pseudoalterromonas sp. CY24 has been crystallized. The crystals of wild-type enzyme and the selenomethionine derivative diffracted to 1.97 and 2.64 Å, respectively. AgaB from Pseudoalteromonas sp. CY24 is a novel agarase that hydrolyzes agarose to generate products with inverted anomeric configuration and that has been proposed to have a larger catalytic cleft than other β-agarases. Here, the expression, purification, crystallization and data collection of AgaB in both wild-type and selenomethionine-substituted forms is described. The crystals of wild-type AgaB diffracted to 1.97 Å resolution and belonged to space group C2221. The selenomethionine derivative crystallized in space group I222. The phasing problem was solved by the multiwavelength anomalous dispersion (MAD) method. These results will facilitate detailed structural and enzymatic analysis of AgaB

  8. Antibacterial Property of a Coral-Associated Bacterium Pseudoalteromonas luteoviolacea Against Shrimp Pathogenic Vibrio harveyi (In Vitro Study

    Directory of Open Access Journals (Sweden)

    OCKY KARNA RADJASA

    2005-06-01

    Full Text Available A coral-associated bacterium was successfully screened for secondary metabolites production based on PCR amplification of the nonribosomal peptide synthetase gene and was identified as closely related to Pseudoalteromonas luteoviolacea based on its 16S rDNA.The bacterium was found to inhibit the growth of shrimp pathogenic bacterium tested, Vibrio harveyi. To characterize the inhibiting metabolite, a 279 bp long DNA fragment was obtained and the deduced amino acid sequence showed conserved signature regions for peptide synthetases and revealed a high similarity to NosD (40% identity, a multifunctional peptide synthetase from Nostoc sp. GSV224, and NdaB (44% identity, a peptide synthetase module of Nodularia spumigena.

  9. Knots of genus two

    OpenAIRE

    Stoimenow, A.

    2003-01-01

    We classify all knot diagrams of genus two and three, and give applications to positive, alternating and homogeneous knots, including a classification of achiral genus 2 alternating knots, slice or achiral 2-almost positive knots, a proof of the 3- and 4-move conjectures, and the calculation of the maximal hyperbolic volume for weak genus two knots. We also study the values of the link polynomials at roots of unity, extending denseness results of Jones. Using these values, examples of knots w...

  10. Beyond the string genus

    International Nuclear Information System (INIS)

    In an earlier work we used a path integral analysis to propose a higher genus generalization of the elliptic genus. We found a cobordism invariant parametrized by Teichmuller space. Here we simplify the formula and study the behavior of our invariant under the action of the mapping class group of the Riemann surface. We find that our invariant is a modular function with multiplier just as in genus one.

  11. Cloning and characterization of a new κ-carrageenase gene from marine bacterium Pseudoalteromonas sp. QY203

    Science.gov (United States)

    Xu, Xiaoyan; Li, Shangyong; Yang, Xuemei; Yu, Wengong; Han, Feng

    2015-12-01

    κ-carrageenan oligosaccharides exhibit various biological activities. Enzymatic degradation by κ-carrageenase is safe and controllable. Therefore, κ-carrageenases have captured more and more attentions. In this study, a κ-carrageenase encoding gene, cgkX, was cloned from Pseudoalteromonas sp. QY203 with degenerate and inverse PCR. It comprised an ORF of 1194 bp in length, encoding a protein with 397 amino acid residues. CgkX is a new member of glycoside hydrolase family 16. The deduced amino acid sequence shared a high similarity with CgkX of Pseudoalteromonas κ-carrageenase; however, the recombinant CgkX showed different biochemical characteristics. The recombinant enzyme was most active at pH 7.0 and 55°C in the presence of 300 mmol L-1 NaCl. It was stable in a broad range of acidity ranging from pH 3.0 to pH 10.0 when temperature was below 40°C. More than 80% of its activity was maintained after being incubated at pH 3.6-10.0 and 4°C for 24 h. CgkX retained more than 90% of activity after being incubated at 40°C for 1 h. EDTA and SDS (1 mmol L-1) did not inhibit its activity. CgkX hydrolyzed κ-carrageenan into disaccharide and tetrasaccharide as an endo-cleaver. All these characteristics demonstrated that CgkX is applicable to both κ-carrageenan oligosaccharide production and κ-carrageenase structure-function research.

  12. The genus Bipolaris.

    Science.gov (United States)

    Manamgoda, D S; Rossman, A Y; Castlebury, L A; Crous, P W; Madrid, H; Chukeatirote, E; Hyde, K D

    2014-09-01

    The genus Bipolaris includes important plant pathogens with worldwide distribution. Species recognition in the genus has been uncertain due to the lack of molecular data from ex-type cultures as well as overlapping morphological characteristics. In this study, we revise the genus Bipolaris based on DNA sequence data derived from living cultures of fresh isolates, available ex-type cultures from worldwide collections and observation of type and additional specimens. Combined analyses of ITS, GPDH and TEF gene sequences were used to reconstruct the molecular phylogeny of the genus Bipolaris for species with living cultures. The GPDH gene is determined to be the best single marker for species of Bipolaris. Generic boundaries between Bipolaris and Curvularia are revised and presented in an updated combined ITS and GPDH phylogenetic tree. We accept 47 species in the genus Bipolaris and clarify the taxonomy, host associations, geographic distributions and species' synonymies. Modern descriptions and illustrations are provided for 38 species in the genus with notes provided for the other taxa when recent descriptions are available. Bipolaris cynodontis, B. oryzae, B. victoriae, B. yamadae and B. zeicola are epi- or neotypified and a lectotype is designated for B. stenospila. Excluded and doubtful species are listed with notes on taxonomy and phylogeny. Seven new combinations are introduced in the genus Curvularia to accomodate the species of Bipolaris transferred based on the phylogenetic analysis. A taxonomic key is provided for the morphological identification of species within the genus. PMID:25492990

  13. Chemical and pharmacological studies of the plants from genus Celastrus.

    Science.gov (United States)

    Su, Xiao-Hui; Zhang, Man-Li; Zhan, Wen-Hong; Huo, Chang-Hong; Shi, Qing-Wen; Gu, Yu-Cheng; Kiyota, Hiromasa

    2009-02-01

    The plants of genus Celastrus, distributed in Asia, have been used as natural insecticides and folk medicines to treat fever, chill, joint pain, edema, rheumatoid arthritis, and bacterial infection in China for a long time. This contribution reviews the chemical constituents, isolated from the plants in genus Celastrus in the past few decades, and their biological activities. The compounds listed are sesquiterpenes (beta-agarofurans), diterpenes, triterpenes, alkaloids, and flavonoids. PMID:19235157

  14. Bacterial gastroenteritis

    Science.gov (United States)

    Infectious diarrhea - bacterial gastroenteritis; Acute gastroenteritis; Gastroenteritis - bacterial ... Bacterial gastroenteritis can affect 1 person or a group of people who all ate the same food. It is ...

  15. Minimal Genus One Curves

    OpenAIRE

    Sadek, Mohammad

    2010-01-01

    In this paper we consider genus one equations of degree $n$, namely a (generalised) binary quartic when $n=2$, a ternary cubic when $n=3$, and a pair of quaternary quadrics when $n=4$. A new definition for the minimality of genus one equations of degree $n$ over local fields is introduced. The advantage of this definition is that it does not depend on invariant theory of genus one curves. We prove that this definition coincides with the classical definition of minimality for all $n\\le4$. As a...

  16. Unimodality and genus distributions

    OpenAIRE

    Wan, Liangxia

    2014-01-01

    New criteria are shown that certain combinations of finite unimodal polynomials are unimodal. %Given unimodal polynomials with explicit expressions and dependent recursion relations, we propose an approach to determine their modes. As applications, unimodality of several polynomial sequences satisfying dependent recurrence relations and their modes are provided. Then unimodality of genus distributions for some ladders and crosses can be determined. As special cases, that of genus distribution...

  17. Effects of Pseudoalteromonas sp. BC228 on digestive enzyme activity and immune response of juvenile sea cucumber ( Apostichopus japonicus)

    Science.gov (United States)

    Ma, Yuexin; Sun, Feixue; Zhang, Congyao; Bao, Pengyun; Cao, Shuqing; Zhang, Meiyan

    2014-12-01

    A marine bacterium, Pseudoalteromonas sp. BC228 was supplemented to feed in a feeding experiment aiming to determine its ability of enhancing the digestive enzyme activity and immune response of juvenile Apostichopus japonicus. Sea cucumber individuals were fed with the diets containing 0 (control), 105, 107 and 109 CFU g-1 diet of BC228 for 45 days. Results showed that intestinal trypsin and lipase activities were significantly enhanced by 107 and 109 CFU g-1 diet of BC228 in comparison with control ( P < 0.01). The phagocytic activity in the coelomocytes of sea cucumber fed the diet supplemented with 107 CFU g-1 diet of BC228 was significantly higher than that of those fed control diet ( P < 0.05). In addition, 105 and 107 CFU g-1 diet of BC228 significantly enhanced lysozyme and phenoloxidase activities in the coelomic fluid of sea cucumber, respectively, in comparison with other diets ( P < 0.01). Sea cucumbers, 10 each diet, were challenged with Vibrio splendidus NB13 after 45 days of feeding. It was found that the cumulative incidence and mortality of sea cucumber fed with BC228 containing diets were lower than those of animals fed control diet. Our findings evidenced that BC228 supplemented in diets improved the digestive enzyme activity of juvenile sea cucumber, stimulated its immune response and enhanced its resistance to the infection of V. splendidus.

  18. Cloning, Expression, Purification, and Characterization of Glutaredoxin from Antarctic Sea-Ice Bacterium Pseudoalteromonas sp. AN178

    Directory of Open Access Journals (Sweden)

    Quanfu Wang

    2014-01-01

    Full Text Available Glutaredoxins (Grxs are small ubiquitous redox enzymes that catalyze glutathione-dependent reactions to reduce protein disulfide. In this study, a full-length Grx gene (PsGrx with 270 nucleotides was isolated from Antarctic sea-ice bacterium Pseudoalteromonas sp. AN178. It encoded deduced 89 amino acid residues with the molecular weight 9.8 kDa. Sequence analysis of the amino acid sequence revealed the catalytic motif CPYC. Recombinant PsGrx (rPsGrx stably expressed in E. coli BL21 was purified to apparent homogeneity by Ni-affinity chromatography. rPsGrx exhibited optimal activity at 30°C and pH 8.0 and showed 25.5% of the activity at 0°C. It retained 65.0% of activity after incubation at 40°C for 20 min and still exhibited 37.0% activity in 1.0 M NaCl. These results indicated that rPsGrx was a typical cold active protein with low thermostability.

  19. A coralline algal-associated bacterium, pseudoalteromonas strain J010, yields five new korormicins and a bromopyrrole.

    Science.gov (United States)

    Tebben, Jan; Motti, Cherie; Tapiolas, Dianne; Thomas-Hall, Peter; Harder, Tilmann

    2014-05-01

    The ethanol extract of Pseudoalteromonas strain J010, isolated from the surface of the crustose coralline alga Neogoniolithon fosliei, yielded thirteen natural products. These included a new bromopyrrole, 4'-((3,4,5-tribromo-1H-pyrrol-2-yl) methyl)phenol (1) and five new korormicins G-K (2-6). Also isolated was the known inducer of coral larval metamorphosis, tetrabromopyrrole (TBP), five known korormicins (A-E, previously named 1, 1a-c and 3) and bromoalterochromide A (BAC-A). Structures of the new compounds were elucidated through interpretation of spectra obtained after extensive NMR and MS investigations and comparison with literature values. The antibacterial, antifungal and antiprotozoal potential of 1-6, TBP and BAC-A was assessed. Compounds 1-6 showed antibacterial activity while BAC-A exhibited antiprotozoal properties against Tetrahymena pyriformis. TBP was found to have broad-spectrum activity against all bacteria, the protozoan and the fungus Candida albicans. PMID:24828288

  20. A Coralline Algal-Associated Bacterium, Pseudoalteromonas Strain J010, Yields Five New Korormicins and a Bromopyrrole

    Directory of Open Access Journals (Sweden)

    Jan Tebben

    2014-05-01

    Full Text Available The ethanol extract of Pseudoalteromonas strain J010, isolated from the surface of the crustose coralline alga Neogoniolithon fosliei, yielded thirteen natural products. These included a new bromopyrrole, 4′-((3,4,5-tribromo-1H-pyrrol-2-yl methylphenol (1 and five new korormicins G–K (2–6. Also isolated was the known inducer of coral larval metamorphosis, tetrabromopyrrole (TBP, five known korormicins (A–E, previously named 1, 1a–c and 3 and bromoalterochromide A (BAC-A. Structures of the new compounds were elucidated through interpretation of spectra obtained after extensive NMR and MS investigations and comparison with literature values. The antibacterial, antifungal and antiprotozoal potential of 1–6, TBP and BAC-A was assessed. Compounds 1–6 showed antibacterial activity while BAC-A exhibited antiprotozoal properties against Tetrahymena pyriformis. TBP was found to have broad-spectrum activity against all bacteria, the protozoan and the fungus Candida albicans.

  1. The human genus.

    Science.gov (United States)

    Wood, B; Collard, M

    1999-04-01

    A general problem in biology is how to incorporate information about evolutionary history and adaptation into taxonomy. The problem is exemplified in attempts to define our own genus, Homo. Here conventional criteria for allocating fossil species to Homo are reviewed and are found to be either inappropriate or inoperable. We present a revised definition, based on verifiable criteria, for Homo and conclude that two species, Homo habilis and Homo rudolfensis, do not belong in the genus. The earliest taxon to satisfy the criteria is Homo ergaster, or early African Homo erectus, which currently appears in the fossil record at about 1.9 million years ago. PMID:10102822

  2. Isolation, chemical characteristics and immunity activity of an extracellular polysaccharide EPSⅠ isolated from Antarctic bacterium Pseudoalteromonas sp. S-15-13

    Institute of Scientific and Technical Information of China (English)

    Li Jiang; Chen Kaoshan; Sun Xiuqin; Song Jinping; Li Guangyou

    2007-01-01

    A new extracelluar polysaccharide (EPS) was isolated and purified from Antarctic bacterium S-15-13, identified as Pseudoalteromonas sp. After being separated and purified by DEAE-Sephadex A-50 ionexchange and Sephadex G-100 gel chromatography, two mains fractions (EPSⅠ and EPSⅡ ) were obtained. EPSⅠ was composed of mannose, glucose and galactose with a molecular weight of 23kDa and EPSⅡ was composed of mannose only with a molecular weight of 62kDa. The effect of the polysaccharide EPSⅠ on the cellular immune response of mice was investigated. Results demonstrated that EPSⅠ could markedly facilitate lymphocyte proliferation, and might be a strong immunomodulator.

  3. Genus I. Leptospira

    Science.gov (United States)

    Leptospira comprise a diverse group of bacteria. Some species cause serious infections in animals and humans. These bacteria are aerobes that consume long-chain fatty acids and alcohols as carbon and energy sources. This genus is distinguished from Leptonema or Turneriella by lack of similarity u...

  4. The genus Lagenophora (Compositae)

    NARCIS (Netherlands)

    Cabrera, Angel L.

    1966-01-01

    The genus Lagenophora was first described by Cassini under the name Lagenifera (in Bull. Soc. Philomat. 12, 1816, 199) with the following diagnosis: ‘Ce genre, de la tribus des astérées, comprend le calendula magellanicá, Willd. et le bellis stipitata, Labill. Son principal caractère reside dans la

  5. Dynamics of bacterial community during the bloom caused by Skeletonema costatum and Akashiwo sanguinea in Xiamen sea area%厦门海域2011年中肋骨条藻和血红哈卡藻赤潮期间细菌群落结构变化

    Institute of Scientific and Technical Information of China (English)

    李祎; 杨彩云; 李东; 田蕴; 郑天凌

    2012-01-01

    two bloom sites and one non-bloom site were evaluated by PCR-DGGE ( Denaturing gradient gel electrophoresis, DGGE). The genetic diversity of bacterial community was analyzed based on the DGGE fingerprint. The correlation between bacterial community and environmental parameters was studied by Canoco. [Results] The bacterial community was largely related to pH and N/P during the start-up stage of the bloom; while in the demise stage, it was mostly correlated to salinity and temperature. According to the results of sequence analysis of DGGE dominant bands, Gammaproteobacteria accounted for 47.7% during the bloom and Pseudoalteromonas, Pseudomonas, Alteromonas, Hydrogenophaga, Actibacter and Oleibacter were dominant genus in bacterial community. The Shannon-Weaver diversity index showed that the diversity of bacterial community in bloom site increased firstly and then decreased during this bloom. Hydrogenophaga was dominant in the start-up stage of bloom, while Pseudomonas and Pseudoalteromonas were dominant in the demise stage of bloom. The diversity of attached bacteria and free-living bacteria in bloom sites reached maximum in the same day (the concentration of algae was high) , both of them changed greatly during the bloom while the environment factors which correlated with the two communities were different. [Conclusion] It is the first report about dynamics of bacterial community during the bloom caused by several algae together. This work is helpful to understand the dynamics of bacterial community during the bloom, and provides a theoretical basis for bloom's control in the future.

  6. What is the genus?

    CERN Document Server

    Popescu-Pampu, Patrick

    2016-01-01

    Exploring several of the evolutionary branches of the mathematical notion of genus, this book traces the idea from its prehistory in problems of integration, through algebraic curves and their associated Riemann surfaces, into algebraic surfaces, and finally into higher dimensions. Its importance in analysis, algebraic geometry, number theory and topology is emphasized through many theorems. Almost every chapter is organized around excerpts from a research paper in which a new perspective was brought on the genus or on one of the objects to which this notion applies. The author was motivated by the belief that a subject may best be understood and communicated by studying its broad lines of development, feeling the way one arrives at the definitions of its fundamental notions, and appreciating the amount of effort spent in order to explore its phenomena.

  7. Spiky higher genus strings

    International Nuclear Information System (INIS)

    This paper reports that it is clear from both the non-perturbative and perturbative approaches to two-dimensional quantum gravity that a new strong coupling regime is setting in at d = 1, independent of the genus of the worldsheet being considered. It has been suggested that a Kosterlitz-Thouless (KT) phase transition in the Liouville theory is the cause of this behavior. However, it has recently been pointed out that the XY-model, which displays a KT transition on the plane and the sphere, is always in the strong coupling, disordered phase on a surface of constant negative curvature. A higher genus worldsheet can be represented as a fundamental region on just such a surface, which might seem to suggest that the KT picture predicts a strong coupling region for arbitrary d, contradicting the known results. The authors resolve the apparent paradox

  8. The genus Syncolostemon (Lamiaceae

    Directory of Open Access Journals (Sweden)

    L. E. Codd

    1976-12-01

    Full Text Available The genus  Syncolostemon E. Mey. ex Benth. is revised and its relationship with  Hemizygia (Benth. Briq.f is discussed. A new species,  S. comptonii Codd is described and the following new combinations are made: S. parviflorus var. lanceolatus (Guerke Codd  (= S . lanceolatus Guerke and  S. latidens (N.E. Br. Codd ( = Orthosiphon latidens N.E. Br..

  9. [Bacterial diseases of rape].

    Science.gov (United States)

    Zakharova, O M; Mel'nychuk, M D; Dankevych, L A; Patyka, V P

    2012-01-01

    Bacterial destruction of the culture was described and its agents identified in the spring and winter rape crops. Typical symptoms are the following: browning of stem tissue and its mucilagization, chlorosis of leaves, yellowing and beginning of soft rot in the place of leaf stalks affixion to stems, loss of pigmentation (violet). Pathogenic properties of the collection strains and morphological, cultural, physiological, and biochemical properties of the agents of rape's bacterial diseases isolated by the authors have been investigated. It was found that all the isolates selected by the authors are highly or moderately aggressive towards different varieties of rape. According to the complex of phenotypic properties 44% of the total number of isolates selected by the authors are related to representatives of the genus Pseudomonas, 37% - to Xanthomonas and 19% - to Pectobacterium. PMID:23293826

  10. Regulation of bacterial communities through antimicrobial activity by the coral holobiont.

    Science.gov (United States)

    Kvennefors, E Charlotte E; Sampayo, Eugenia; Kerr, Caroline; Vieira, Genyess; Roff, George; Barnes, Andrew C

    2012-04-01

    Interactions between corals and associated bacteria and amongst these bacterial groups are likely to play a key role in coral health. However, the complexity of these interactions is poorly understood. We investigated the functional role of specific coral-associated bacteria in maintaining microbial communities on the coral Acropora millepora (Ehrenberg 1834) and the ability of coral mucus to support or inhibit bacterial growth. Culture-independent techniques were used to assess bacterial community structures whilst bacterial culture was employed to assess intra- and inter-specific antimicrobial activities of bacteria. Members of Pseudoalteromonas and ribotypes closely related to Vibrio coralliilyticus displayed potent antimicrobial activity against a range of other cultured isolates and grew readily on detached coral mucus. Although such bacterial ribotypes would be expected to have a competitive advantage, they were rare or absent on intact and healthy coral colonies growing in situ (analysed using denaturing gradient gel electrophoresis and 16S rRNA gene sequencing). The most abundant bacterial ribotypes found on healthy corals were Gammaproteobacteria, previously defined as type A coral associates. Our results indicate that this group of bacteria and specific members of the Alphaproteobacteria described here as 'type B associates' may be important functional groups for coral health. We suggest that bacterial communities on coral are kept in check by a combination of host-derived and microbial interactions and that the type A associates in particular may play a key role in maintaining stability of microbial communities on healthy coral colonies. PMID:21984347

  11. The genus Gelsemium: An update

    OpenAIRE

    Dutt, V.; Thakur, S.; V J Dhar; Sharma, A.

    2010-01-01

    The review includes 103 references on the genus Gelsemium, and comprises ethnopharmacology, morphology, phytoconstituents, pharmacological reports, clinical studies and toxicology of the prominent species of Gelsemium. Alkaloids and iridoids constitute major classes of phytoconstituents of the genus. Most popular species of the genus are the Asian G. elegans and the two North American related species, G. sempervirens and G. rankinii. Gelsemium species are categorized under medicinal as well a...

  12. Genus two trisections are standard

    OpenAIRE

    Meier, Jeffrey; Zupan, Alexander

    2014-01-01

    We show that the only closed 4-manifolds admitting genus two trisections are $S^2 \\times S^2$ and connected sums of $S^1 \\times S^3$, $\\mathbb{CP}^2$, and $\\overline{\\mathbb{CP}}^2$ with two summands. Moreover, each of these manifolds admits a unique genus two trisection up to diffeomorphism. The proof relies heavily on the combinatorics of genus two Heegaard diagrams of $S^3$. As a corollary, we classify two-component links contained in a genus two Heegaard surface for $S^3$ with a surface-s...

  13. Bioactivities from Marine Algae of the Genus Gracilaria

    OpenAIRE

    José M. Barbosa-Filho; Maria de Fátima V. de Souza; Luis C. Rodrigues; Athayde-Filho, Petrônio F.; Lira, Narlize S.; Camila De A. Montenegro; Lima, Gedson R. de M.; Batista, Leônia M.; Falcão, Heloina de S.; de Almeida, Cynthia Layse F.

    2011-01-01

    Seaweeds are an important source of bioactive metabolites for the pharmaceutical industry in drug development. Many of these compounds are used to treat diseases like cancer, acquired immune-deficiency syndrome (AIDS), inflammation, pain, arthritis, as well as viral, bacterial, and fungal infections. This paper offers a survey of the literature for Gracilaria algae extracts with biological activity, and identifies avenues for future research. Nineteen species of this genus that were tested fo...

  14. Phylogenetic position of the spirochetal genus Cristispira

    DEFF Research Database (Denmark)

    Paster, B.J.; Pelletier, D.A.; Dewhirst, F.E.;

    1996-01-01

    a cell-laden crystalline styles of the oyster Crassostrea virginica. The amplified products were then cloned into Escherichia coli plasmids. Sequence comparisons of the gene coding for 16S rRNA (rDNA) insert of one clone, designated CP1, indicated that it was spirochetal. The sequence of the 16S rDNA...... insert of another clone was mycoplasmal. The CP1 sequence possessed most of the individual base signatures that are unique to 16S rRNA (or rDNA) sequences of known spirochetes. CP1 branched deeply among other spirochetal genera within the family Spirochaetaceae, and accordingly, it represents a separate......Comparative sequence analysis of 16S rRNA genes was used to determine the phylogenetic relationship of the genus Cristispira to other spirochetes. Since Cristispira organisms cannot presently be grown in vitro, 16S rRNA genes were amplified directly from bacterial DNA isolated from Cristispira...

  15. The Genus Alpinia:A Review of Its Phytochemistry and Pharmacology

    Institute of Scientific and Technical Information of China (English)

    Wei-Jie Zhang; Jian-Guang Luo; Ling-Yi Kong

    2016-01-01

    Genus Alpinia consists of over 250 species, which are widely distributed in south and southeast Asia. Many plants of genus Alpinia have been used for thousands of years to treat digestive system diseases and as anti-inflammatory drugs. Phytochemical research on this genus has led to the isolation of different kinds of diarylheptanoids, terpenes triterpenoids, phenylbutanoids, lignans, and flavonoids. Experimental evidences revealed that both the crude extracts and pure constituents isolated from the genus Alpinia exhibit a wide range of bioactivities such as anti-cancer, anti-oxidant, anti-bacterial, anti-viral, cardiovascular, and digestive system protective effects. Here, we summarize the phytochemistry and pharmacology investigation of the genus Alpinia, which can provide reference for further research and drug development.

  16. Effect of bacterial epiflora on egg hatching of the Atlantic sardine (Sardina pilchardus).

    Science.gov (United States)

    Míguez, Beatriz; Combarro, María Pilar; Guisande, Cástor; Vergara, Alba Ruth; Riveiro, Isabel

    2004-11-01

    The aim of this work was to study the influence of bacterial epiflora on egg hatching of the sardine (Sardina pilchardus) obtained from a natural environment (Ría de Vigo, Spain) during the spawning season of the sardine (from January to June). Total bacteria, viable bacteria or the presence of specific potential pathogens for eggs, such as Pseudoalteromonas piscicida and Tenacibaculum (Flexibacter) ovolyticus, did not affect the viability of sardine eggs. Additionally, no relationship was observed between the presence of Vibrio spp., pathogenic for fish larvae, and the egg hatching. This was probably because the amount of bacteria associated with the eggs were between 10(2) and 10(4) orders lower than those found so far on the eggs of different fish species in rearing systems. Therefore, epiphytic bacteria did not affect the wild sardine eggs and, hence, in the area studied, it is probably not an important factor affecting annual recruitment success of this pelagic fish species. PMID:19712369

  17. The genus Vitex: A review

    Directory of Open Access Journals (Sweden)

    Anita Rani

    2013-01-01

    Full Text Available The review includes 161 references on the genus Vitex, and comprises ethnopharmacology, morphology and microscopy, phytoconstituents, pharmacological reports, clinical studies, and toxicology of the prominent species of Vitex. Essential oils, flavonoids, iridoid glycosides, diterpenoides and ligans constitute major classes of phytoconstituents of the genus. A few species of this genus have medicinal value, among these, leaves and fruits of V. agnus-castus Linn. (Verbenaceae has been traditionally used in treatment of women complaints. V. agnus-castus has also been included in herbal remedies, which are in clinical use to regulate the menstrual cycle, reduce premenstrual symptom tension and anxiety, treat some menopausal symptoms as well as to treat hormonally induced acne. Despite a long tradition of use of some species, the genus has not been explored properly. In the concluding part, the future scope of Vitex species has been emphasized with a view to establish their multifarious biological activities and mode of action.

  18. Abelian Duality at Higher Genus

    CERN Document Server

    Beasley, Chris

    2014-01-01

    In three dimensions, a free, periodic scalar field is related by duality to an abelian gauge field. Here I explore aspects of this duality when both theories are quantized on a Riemann surface of genus g. At higher genus, duality involves an identification of winding with momentum on the Jacobian variety of the Riemann surface. I also consider duality for monopole and loop operators on the surface and exhibit the operator algebra, a refinement of the Wilson-'t Hooft algebra.

  19. The Concordance Genus of 11--Crossing Knots

    OpenAIRE

    Kearney, M. Kate

    2012-01-01

    The concordance genus of a knot is the least genus of any knot in its concordance class. It is bounded above by the genus of the knot, and bounded below by the slice genus, two well-studied invariants. In this paper we consider the concordance genus of 11--crossing prime knots. This analysis resolves the concordance genus of 533 of the 552 prime 11--crossing knots. The appendix to the paper gives concordance diagrams for 59 knots found to be concordant to knots of lower genus, including null-...

  20. A descendent relation in genus 2

    OpenAIRE

    Belorousski, Pasha; Pandharipande, Rahul

    1998-01-01

    A new codimension 2 relation among descendent strata in the moduli space of stable, 3-pointed, genus 2 curves is found. The space of pointed admissible double covers is used in the calculation. The resulting differential equations satisfied by the genus 2 gravitational potentials of varieties in Gromov-Witten theory are described. These are analogous to the WDVV-equations in genus 0 and Getzler's equations in genus 1. As an application, genus 2 descendent invariants of the projective plane ar...

  1. Bacterial Vaginosis

    Science.gov (United States)

    ... 586. Related Content STDs during Pregnancy Fact Sheet Pregnancy and HIV, Viral Hepatitis, and STD Prevention Pelvic Inflammatory Disease ( ... Bacterial Vaginosis (BV) Chlamydia Gonorrhea Genital Herpes Hepatitis HIV/AIDS & STDs Human Papillomavirus ... STDs See Also Pregnancy Reproductive ...

  2. Bacterial Meningitis

    Science.gov (United States)

    ... Schedules Preteen & Teen Vaccines Meningococcal Disease Sepsis Bacterial Meningitis Recommend on Facebook Tweet Share Compartir On this ... serious disease. Laboratory Methods for the Diagnosis of Meningitis This manual summarizes laboratory methods used to isolate, ...

  3. Prostatitis - bacterial

    Science.gov (United States)

    Any bacteria that can cause a urinary tract infection can cause acute bacterial prostatitis. Infections spread through sexual contact can cause prostatitis. These include chlamydia and gonorrhea . Sexually transmitted ...

  4. Bacterial Conjunctivitis

    OpenAIRE

    Köhle, Ülkü; Kükner, Şahap

    2003-01-01

    Conjunctivitis is an infection of the conjunctiva, generally characterized by irritation, itching, foreign body sensation, tearing and discharge. Bacterial conjunctivitis may be distinguished from other types of conjunctivitis by the presence of yellow–white mucopurulent discharge. It is the most common form of ocular infection all around the world. Staphylococcus species are the most common bacterial pathogenes, followed by Streptococcus pneumoniae and Haemophilus i...

  5. Phylogenetic diversity and position of the genus Campylobacter

    Science.gov (United States)

    Lau, P. P.; DeBrunner-Vossbrinck, B.; Dunn, B.; Miotto, K.; MacDonnell, M. T.; Rollins, D. M.; Pillidge, C. J.; Hespell, R. B.; Colwell, R. R.; Sogin, M. L.; Fox, G. E.

    1987-01-01

    RNA sequence analysis has been used to examine the phylogenetic position and structure of the genus Campylobacter. A complete 5S rRNA sequence was determined for two strains of Campylobacter jejuni and extensive partial sequences of the 16S rRNA were obtained for several strains of C. jejuni and Wolinella succinogenes. In addition limited partial sequence data were obtained from the 16S rRNAs of isolates of C. coli, C. laridis, C. fetus, C. fecalis, and C. pyloridis. It was found that W. succinogenes is specifically related to, but not included, in the genus Campylobacter as presently constituted. Within the genus significant diversity was noted. C. jejuni, C. coli and C. laridis are very closely related but the other species are distinctly different from one another. C. pyloridis is without question the most divergent of the Campylobacter isolates examined here and is sufficiently distinct to warrant inclusion in a separate genus. In terms of overall position in bacterial phylogeny, the Campylobacter/Wolinella cluster represents a deep branching most probably located within an expanded version of the Division containing the purple photosynthetic bacteria and their relatives. The Campylobacter/Wolinella cluster is not specifically includable in either the alpha, beta or gamma subdivisions of the purple bacteria.

  6. Gene cloning and sequence analysis of the cold-adapted chaperones DnaK and DnaJ from deep-sea psychrotrophic bacterium Pseudoalteromonas sp. SM9913

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Pseudoalteromonas sp. SM9913 is a phychrotrophic bacterium isolated from the deep-sea sediment. The genes encoding chaperones DnaJ and DnaK of P. sp. SM9913 were cloned by normal PCR and TAIL-PCR (GenBank accession Nos DQ640312, DQ504163). The chaperones DnaJ and DnaK from the strain SM9913 contain such conserved domains as those of many other bacteria, and show some cold-adapted characteristics in their structures when compared with those from psychro-, meso-and themophilic bacteria. It is indicated that chaperones DnaJ and DnaK of P. sp. SM9913 may be adapted to low temperature in deep-sea and function well in assisting folding, assembling and translocation of proteins at low temperature. This research lays a foundation for the further study on the cold-adapted mechanism of chaperones DnaJ and DnaK of cold-adapted microorganisms.

  7. Structural and functional characterization of mature forms of metalloprotease E495 from Arctic sea-ice bacterium Pseudoalteromonas sp. SM495.

    Directory of Open Access Journals (Sweden)

    Hai-Lun He

    Full Text Available E495 is the most abundant protease secreted by the Arctic sea-ice bacterium Pseudoalteromonas sp. SM495. As a thermolysin family metalloprotease, E495 was found to have multiple active forms in the culture of strain SM495. E495-M (containing only the catalytic domain and E495-M-C1 (containing the catalytic domain and one PPC domain were two stable mature forms, and E495-M-C1-C2 (containing the catalytic domain and two PPC domains might be an intermediate. Compared to E495-M, E495-M-C1 had similar affinity and catalytic efficiency to oligopeptides, but higher affinity and catalytic efficiency to proteins. The PPC domains from E495 were expressed as GST-fused proteins. Both of the recombinant PPC domains were shown to have binding ability to proteins C-phycocyanin and casein, and domain PPC1 had higher affinity to C-phycocyanin than domain PPC2. These results indicated that the domain PPC1 in E495-M-C1 could be helpful in binding protein substrate, and therefore, improving the catalytic efficiency. Site-directed mutagenesis on the PPC domains showed that the conserved polar and aromatic residues, D26, D28, Y30, Y/W65, in the PPC domains played key roles in protein binding. Our study may shed light on the mechanism of organic nitrogen degradation in the Arctic sea ice.

  8. Improving Protein Crystal Quality by the Without-Oil Microbatch Method: Crystallization and Preliminary X-ray Diffraction Analysis of Glutathione Synthetase from Pseudoalteromonas haloplanktis

    Directory of Open Access Journals (Sweden)

    Antonella Albino

    2011-09-01

    Full Text Available Glutathione synthetases catalyze the ATP-dependent synthesis of glutathione from L-γ-glutamyl-L-cysteine and glycine. Although these enzymes have been sequenced and characterized from a variety of biological sources, their exact catalytic mechanism is not fully understood and nothing is known about their adaptation at extremophilic environments. Glutathione synthetase from the Antarctic eubacterium Pseudoalteromonas haloplanktis (PhGshB has been expressed, purified and successfully crystallized. An overall improvement of the crystal quality has been obtained by adapting the crystal growth conditions found with vapor diffusion experiments to the without-oil microbatch method. The best crystals of PhGshB diffract to 2.34 Å resolution and belong to space group P212121, with unit-cell parameters a = 83.28 Å, b = 119.88 Å, c = 159.82 Å. Refinement of the model, obtained using phases derived from the structure of the same enzyme from Escherichia coli by molecular replacement, is in progress. The structural determination will provide the first structural characterization of a psychrophilic glutathione synthetase reported to date.

  9. Chemistry of the Genus Plectranthus

    Directory of Open Access Journals (Sweden)

    S. M. Batterjee

    2002-02-01

    Full Text Available This review presents the phytochemical constituents of the genus Plectranthus reported up to 1999. Only a tetrameric derivative of caffeic acid was isolated from P. japonicus, but a group of long-chain alkylphenols, of possible taxonomic significance in the genus, was also isolated. As a genus of the subfamily Nepetoideae, Plectranthus is free from iridoid glycosides and rich in essential oil (i.e. > 0.5% volatile oil on a dry weight basis. Diterpenoids are the more common secondary metabolites in Plectranthus. The majority of them are highly modified abietanoids. This seems to be similar to the pattern of diterpenoids observed for Salvia, but no clerodane diterpenoids were found in Plectranthus.

  10. On genus expansion of superpolynomials

    CERN Document Server

    Mironov, A; Sleptsov, A; Smirnov, A

    2013-01-01

    Recently it was shown that the (Ooguri-Vafa) generating function of HOMFLY polynomials is the Hurwitz partition function, i.e. that the dependence of the HOMFLY polynomials on representation is naturally captured by symmetric group characters (cut-and-join eigenvalues). The genus expansion and expansion through Vassiliev invariants explicitly demonstrate this phenomenon. In the present letter we claim that the superpolynomials are not functions of such a type: symmetric group characters do not provide an adequate linear basis for their expansions. Deformation to superpolynomials is, however, straightforward in the multiplicative basis:the Casimir operators are beta-deformed to Hamiltonians of the Calogero-Moser-Sutherland system. Applying this trick to the genus and Vassiliev expansions, we observe that the deformation is rather straightforward only for the thin knots. Beyond this family additional algebraically independent terms appear in the Vassiliev and genus expansions. This can suggest that the superpol...

  11. The genus Gelsemium: An update

    Directory of Open Access Journals (Sweden)

    V Dutt

    2010-01-01

    Full Text Available The review includes 103 references on the genus Gelsemium, and comprises ethnopharmacology, morphology, phytoconstituents, pharmacological reports, clinical studies and toxicology of the prominent species of Gelsemium. Alkaloids and iridoids constitute major classes of phytoconstituents of the genus. Most popular species of the genus are the Asian G. elegans and the two North American related species, G. sempervirens and G. rankinii. Gelsemium species are categorized under medicinal as well as poisonous plants. Amongst various species, G. elegans and G. sempervirens possess medicinal value, and have been traditionally used as nervous system relaxant. These plants have been explored exhaustively for their anticancer activity. In the concluding part, the future scope of Gelsemium species has been emphasized with a view to establish their multifarious biological activities and mode of actions

  12. Bacterial carbonatogenesis

    International Nuclear Information System (INIS)

    Several series of experiments in the laboratory as well as in natural conditions teach that the production of carbonate particles by heterotrophic bacteria follows different ways. The 'passive' carbonatogenesis is generated by modifications of the medium that lead to the accumulation of carbonate and bicarbonate ions and to the precipitation of solid particles. The 'active' carbonatogenesis is independent of the metabolic pathways. The carbonate particles are produced by ionic exchanges through the cell membrane following still poorly known mechanisms. Carbonatogenesis appears to be the response of heterotrophic bacterial communities to an enrichment of the milieu in organic matter. The active carbonatogenesis seems to start first. It is followed by the passive one which induces the growth of initially produced particles. The yield of heterotrophic bacterial carbonatogenesis and the amounts of solid carbonates production by bacteria are potentially very high as compared to autotrophic or chemical sedimentation from marine, paralic or continental waters. Furthermore, the bacterial processes are environmentally very ubiquitous; they just require organic matter enrichment. Thus, apart from purely evaporite and autotrophic ones, all Ca and/or Mg carbonates must be considered as from heterotrophic bacterial origin. By the way, the carbon of carbonates comes from primary organic matter. Such considerations ask questions about some interpretations from isotopic data on carbonates. Finally, bacterial heterotrophic carbonatogenesis appears as a fundamental phase in the relationships between atmosphere and lithosphere and in the geo-biological evolution of Earth. (author)

  13. Isolation and antimicrobial acitivity of anthraquinones from some species of the lichen genus Xanthoria

    Directory of Open Access Journals (Sweden)

    LJ. KRSTIC

    2000-08-01

    Full Text Available The isolation of six anthraquinones, erythroglaucin, physcion, xanthorin, emodin, fallacinal and teloschistin, from three species of the lichen genus Xanthoria (X. fallax, X. elegans and X. policarpa is reported. Physcion is the dominant anthraquinone in all species. the anthraquinones showed broad-spectrum antifingal activity and selective activity against some phytopathogenic bacterial species.

  14. Evidence for Vertical Inheritance and Loss of the Leukotoxin Operon in Genus Mannheimia

    DEFF Research Database (Denmark)

    Larsen, Jesper; Pedersen, Anders Gorm; Christensen, Henrik; Bisgaard, Magne; Angen, Øystein; Ahrens, Peter; Olsen, John E.

    2007-01-01

    The Mannheimia subclades belong to the same bacterial genus but have taken divergent paths toward their distinct lifestyles. M. haemolytica + M. glucosida are potential pathogens of the respiratory tract in the mammalian suborder Ruminantia, whereas M. ruminalis, the supposed sister group, lives as...

  15. Twists of genus three Jacobians

    OpenAIRE

    Meagher, Stephen

    2007-01-01

    We give a criterion to distinguish between a genus three Jacobian and its [-1] twist in terms of the product of the 36 even theta nulls. We also express the product of the 36 theta nulls in terms of the discriminant of a genus three curve. The results are arithmetic in nature and thus add to previous work over C on the product of the even theta nulls. They generalize previous work of Ritzenthaler and Lachaud for Abelian threefolds which are (2,2,2) isogenous to a product of elliptic curves. T...

  16. Pseudovirgaria, a fungicolous hyphomycete genus

    NARCIS (Netherlands)

    Braun, U.; Crous, P.W.; Groenewald, J.Z.; Scheuer, C.

    2011-01-01

    The genus Pseudovirgaria, based on P. hyperparasitica, was recently introduced for a mycoparasite of rust sori of various species of Frommeella, Pucciniastrum and Phragmidium in Korea. In the present study, an older name introduced by Saccardo based on European material, Rhinotrichum griseum, is sho

  17. Pseudovirgaria, a fungicolous hyphomycete genus

    NARCIS (Netherlands)

    Braun, U.; Crous, P.W.; Groenewald, J.Z.; Scheuer, C.

    2011-01-01

    The genus Pseudovirgaria, based on P. hyperparasitica, was recently introduced for a mycoparasite of rust sori of various species of Frommeëlla, Pucciniastrum and Phragmidium in Korea. In the present study, an older name introduced by Saccardo based on European material, Rhinotrichum griseum, is sho

  18. Bioactivities from Marine Algae of the Genus Gracilaria

    Directory of Open Access Journals (Sweden)

    José M. Barbosa-Filho

    2011-07-01

    Full Text Available Seaweeds are an important source of bioactive metabolites for the pharmaceutical industry in drug development. Many of these compounds are used to treat diseases like cancer, acquired immune-deficiency syndrome (AIDS, inflammation, pain, arthritis, as well as viral, bacterial, and fungal infections. This paper offers a survey of the literature for Gracilaria algae extracts with biological activity, and identifies avenues for future research. Nineteen species of this genus that were tested for antibacterial, antiviral, antifungal, antihypertensive, cytotoxic, spermicidal, embriotoxic, and anti-inflammatory activities are cited from the 121 references consulted.

  19. Bacterial Adhesion & Blocking Bacterial Adhesion

    DEFF Research Database (Denmark)

    Vejborg, Rebecca Munk

    2008-01-01

    parameters, which influence the transition from a planktonic lifestyle to a sessile lifestyle, have been studied. Protein conditioning film formation was found to influence bacterial adhesion and subsequent biofilm formation considerable, and an aqueous extract of fish muscle tissue was shown to...... tract to the microbial flocs in waste water treatment facilities. Microbial biofilms may however also cause a wide range of industrial and medical problems, and have been implicated in a wide range of persistent infectious diseases, including implantassociated microbial infections. Bacterial adhesion is...... the first committing step in biofilm formation, and has therefore been intensely scrutinized. Much however, still remains elusive. Bacterial adhesion is a highly complex process, which is influenced by a variety of factors. In this thesis, a range of physico-chemical, molecular and environmental...

  20. Bacterial lipases

    NARCIS (Netherlands)

    Jaeger, Karl-Erich; Ransac, Stéphane; Dijkstra, Bauke W.; Colson, Charles; Heuvel, Margreet van; Misset, Onno

    1994-01-01

    Many different bacterial species produce lipases which hydrolyze esters of glycerol with preferably long-chain fatty acids. They act at the interface generated by a hydrophobic lipid substrate in a hydrophilic aqueous medium. A characteristic property of lipases is called interfacial activation, mea

  1. Bacterial Ecology

    DEFF Research Database (Denmark)

    Fenchel, Tom

    2011-01-01

    Bacterial ecology is concerned with the interactions between bacteria and their biological and nonbiological environments and with the role of bacteria in biogeochemical element cycling. Many fundamental properties of bacteria are consequences of their small size. Thus, they can efficiently exploit...

  2. Fiber sums of genus 2 Lefschetz fibrations

    OpenAIRE

    Auroux, Denis

    2003-01-01

    Using the recent results of Siebert and Tian about the holomorphicity of genus 2 Lefschetz fibrations with irreducible singular fibers, we show that any genus 2 Lefschetz fibration becomes holomorphic after fiber sum with a holomorphic fibration.

  3. Genus Reducing Knots in 3-Manifolds

    OpenAIRE

    Rieck, Yo’av

    2001-01-01

    A genus reducing knot is a knot that has infinitely many surgeries after which the Heegaard genus of the manifold reduces. We study certain aspects of this question, in particular solving it for totally orientable Seifert Fibered Spaces, where we find examples of manifolds of arbitrarily high genus containing no such knot.

  4. Singular elliptic genus of normal surfaces

    OpenAIRE

    Waelder, Robert

    2007-01-01

    We define the singular elliptic genus for arbitrary normal surfaces, prove that it is a birational invariant, and show that it generalizes the singular elliptic genus of Borisov and Libgober and the stringy $\\chi_y$ genus of Batyrev and Veys.

  5. Genetics and Genomics of the Genus Amycolatopsis.

    Science.gov (United States)

    Kumari, Rashmi; Singh, Priya; Lal, Rup

    2016-09-01

    Actinobacteria are gram-positive filamentous bacteria which contains some of the most deadly human pathogens (Mycobacterium tuberculosis, M. leprae, Corynebacterium diphtheriae, Nocardia farcinica), plant pathogens (Streptomyces scabies, Leifsonia xyli) along with organisms that produces antibiotic (Streptomycetes, Amycolatopsis, Salinospora). Interestingly, these bacteria are equipped with an extraordinary capability of producing antibiotics and other metabolites which have medicinal properties. With the advent of inexpensive genome sequencing techniques and their clinical importance, many genomes of Actinobacteria have been successfully sequenced. These days, with the constant increasing number of drug-resistant bacteria, the urgent need for discovering new antibiotics has emerged as a major scientific challenge. And, unfortunately the traditional method of screening bacterial strains for the production of antibiotics has decreased leading to a paradigm shift in the planning and execution of discovery of novel biosynthetic gene clusters via genome mining process. The entire focus has shifted to the evaluation of genetic capacity of organisms for metabolite production and activation of cryptic gene clusters. This has been made possible only due to the availability of genome sequencing and has been augmented by genomic studies and new biotechnological approaches. Through this article, we present the analysis of the genomes of species belonging to the genus Amycolatopsis, sequenced till date with a focus on completely sequenced genomes and their application for further studies. PMID:27407288

  6. On the concordance genus of topologically slice knots

    OpenAIRE

    Hom, Jennifer

    2012-01-01

    The concordance genus of a knot K is the minimum Seifert genus of all knots smoothly concordant to K. Concordance genus is bounded below by the 4-ball genus and above by the Seifert genus. We give a lower bound for the concordance genus of K coming from the knot Floer complex of K. As an application, we prove that there are topologically slice knots with 4-ball genus equal to one and arbitrarily large concordance genus.

  7. The genus Enterococcus as probiotic: safety concerns

    Directory of Open Access Journals (Sweden)

    Tatiane Ferreira Araújo

    2013-06-01

    Full Text Available Species from the genus Enterococcus have been used as probiotic for humans or animals, although this genus is not considered "generally recognized as safe" (GRAS. While enterococci are considered "positive" in food technology, isolates of this genus have emerged as opportunistic pathogens for the humans. The aim of this review is to summarize the characteristics that can determine the use of this genus as probiotics. According to the guidelines used to define the genus Enterococcus strains as probiotic a case-by-case evaluation of each potential technological strain is presented and research perspectives for using enterococci as probiotic is also discussed.

  8. [Bacterial vaginosis].

    Science.gov (United States)

    Romero Herrero, Daniel; Andreu Domingo, Antonia

    2016-07-01

    Bacterial vaginosis (BV) is the main cause of vaginal dysbacteriosis in the women during the reproductive age. It is an entity in which many studies have focused for years and which is still open for discussion topics. This is due to the diversity of microorganisms that cause it and therefore, its difficult treatment. Bacterial vaginosis is probably the result of vaginal colonization by complex bacterial communities, many of them non-cultivable and with interdependent metabolism where anaerobic populations most likely play an important role in its pathogenesis. The main symptoms are an increase of vaginal discharge and the unpleasant smell of it. It can lead to serious consequences for women, such as an increased risk of contracting sexually transmitted infections including human immunodeficiency virus and upper genital tract and pregnancy complications. Gram stain is the gold standard for microbiological diagnosis of BV, but can also be diagnosed using the Amsel clinical criteria. It should not be considered a sexually transmitted disease but it is highly related to sex. Recurrence is the main problem of medical treatment. Apart from BV, there are other dysbacteriosis less characterized like aerobic vaginitis of which further studies are coming slowly but are achieving more attention and consensus among specialists. PMID:27474242

  9. On genus expansion of superpolynomials

    OpenAIRE

    Mironov, Andrei; Morozov, Alexei; Sleptsov, Alexei; Smirnov, Andrey(ITEP, Moscow, 117218, Russia)

    2013-01-01

    Recently it was shown that the (Ooguri-Vafa) generating function of HOMFLY polynomials is the Hurwitz partition function, i.e. that the dependence of the HOMFLY polynomials on representation R is naturally captured by symmetric group characters (cut-and-join eigenvalues). The genus expansion and expansion through Vassiliev invariants explicitly demonstrate this phenomenon. In the present letter we claim that the superpolynomials are not functions of such a type: symmetric group characters do ...

  10. CYANOBACTERIA OF THE GENUS PROCHLOROTHRIX

    Directory of Open Access Journals (Sweden)

    NataliaValeryevnaIvanikova

    2012-05-01

    Full Text Available Green cyanobacteria are distinguished from blue-green ones by the possession of a chlorophyll-containing light harvesting antenna. Three genera of green cyanobacteria, namely Acaryochloris, Prochlorococcus and Prochloron, are unicellular and of marine habitat; Prochlorococcus marinus attracts most attention due to its outstanding role in prime productivity. The fourth genus, Prochlorothrix, is represented by filamentous freshwater strains. Unlike the rest of green cyanobacteria, Prochlorothrix is paradoxically rare: it has been isolated from two European locations only. Taking into account fluctuating blooms, morphological resemblance with Planktothrix and Pseudanabaena, and unsuccessful enrichment of Prochlorothrix, the preferred strategy of search for this cyanobacterium is based on PCR with natural DNA and specific primers. This approach already demonstrates a broader distribution of Prochlorothrix: marker genes have been found in at least two additional locations. Despite the growing evidence for naturally occurring Prochlorothrix, there are only a few cultivated strains, and only one of them (PCC 9006 is claimed to be axenic. In multixenic cultures, Prochlorothrix is accompanied by heterotrophic bacteria, indicating a consortium-type association. The genus Prochlorothrix includes two species: P. hollandica and P. scandica based on distinctions in genomic DNA, cell size, temperature optimum, and fatty acid composition of membrane lipids. In this short review, the properties of cyanobacteria of the genus Prochlorothrix are described, and the evolutionary scenario of green cyanobacteria, especially taking into account their role in the origin of simple chloroplast is given.

  11. On genus expansion of superpolynomials

    Energy Technology Data Exchange (ETDEWEB)

    Mironov, Andrei, E-mail: mironov@itep.ru [Lebedev Physics Institute, Moscow 119991 (Russian Federation); ITEP, Moscow 117218 (Russian Federation); National Research Nuclear University MEPhI, Moscow 115409 (Russian Federation); Morozov, Alexei, E-mail: morozov@itep.ru [ITEP, Moscow 117218 (Russian Federation); National Research Nuclear University MEPhI, Moscow 115409 (Russian Federation); Sleptsov, Alexei, E-mail: sleptsov@itep.ru [ITEP, Moscow 117218 (Russian Federation); Laboratory of Quantum Topology, Chelyabinsk State University, Chelyabinsk 454001 (Russian Federation); KdVI, University of Amsterdam (Netherlands); Smirnov, Andrey, E-mail: asmirnov@math.columbia.edu [ITEP, Moscow 117218 (Russian Federation); Columbia University, Department of Mathematics, New York (United States)

    2014-12-15

    Recently it was shown that the (Ooguri–Vafa) generating function of HOMFLY polynomials is the Hurwitz partition function, i.e. that the dependence of the HOMFLY polynomials on representation R is naturally captured by symmetric group characters (cut-and-join eigenvalues). The genus expansion and expansion through Vassiliev invariants explicitly demonstrate this phenomenon. In the present paper we claim that the superpolynomials are not functions of such a type: symmetric group characters do not provide an adequate linear basis for their expansions. Deformation to superpolynomials is, however, straightforward in the multiplicative basis: the Casimir operators are β-deformed to Hamiltonians of the Calogero–Moser–Sutherland system. Applying this trick to the genus and Vassiliev expansions, we observe that the deformation is fully straightforward only for the thin knots. Beyond the family of thin knots additional algebraically independent terms appear in the Vassiliev and genus expansions. This can suggest that the superpolynomials do in fact contain more information about knots than the colored HOMFLY and Kauffman polynomials. However, even for the thin knots the beta-deformation is non-innocent: already in the simplest examples it seems inconsistent with the positivity of colored superpolynomials in non-(anti)symmetric representations, which also happens in I. Cherednik's (DAHA-based) approach to the torus knots.

  12. On genus expansion of superpolynomials

    International Nuclear Information System (INIS)

    Recently it was shown that the (Ooguri–Vafa) generating function of HOMFLY polynomials is the Hurwitz partition function, i.e. that the dependence of the HOMFLY polynomials on representation R is naturally captured by symmetric group characters (cut-and-join eigenvalues). The genus expansion and expansion through Vassiliev invariants explicitly demonstrate this phenomenon. In the present paper we claim that the superpolynomials are not functions of such a type: symmetric group characters do not provide an adequate linear basis for their expansions. Deformation to superpolynomials is, however, straightforward in the multiplicative basis: the Casimir operators are β-deformed to Hamiltonians of the Calogero–Moser–Sutherland system. Applying this trick to the genus and Vassiliev expansions, we observe that the deformation is fully straightforward only for the thin knots. Beyond the family of thin knots additional algebraically independent terms appear in the Vassiliev and genus expansions. This can suggest that the superpolynomials do in fact contain more information about knots than the colored HOMFLY and Kauffman polynomials. However, even for the thin knots the beta-deformation is non-innocent: already in the simplest examples it seems inconsistent with the positivity of colored superpolynomials in non-(anti)symmetric representations, which also happens in I. Cherednik's (DAHA-based) approach to the torus knots

  13. Bacterial community structure in aquifers corresponds to stratigraphy

    Science.gov (United States)

    Beyer, Andrea; Möller, Silke; Neumann, Stefan; Burow, Katja; Gutmann, Falko; Lindner, Julia; Müsse, Steffen; Kothe, Erika; Büchel, Georg

    2014-05-01

    So far, groundwater microbiology with respect to different host rocks has not been well described in the literature. However, factors influencing the communities would be of interest to provide a tool for mapping groundwater paths. The Thuringian Basin (Germany) studied here, contains formations of the Permian (Zechstein) and also Triassic period of Buntsandstein, Muschelkalk and Keuper, all of which can be found to crop out at the surface in different regions. We analyzed the bacterial community of nine natural springs and sixteen groundwater wells of the respective rock formations as well as core material from the Zechstein salts. For that we sampled in a mine 3 differnet salt rock samples (carnallitite, halite and sylvinitite). To validate the different approaches, similar rock formations were compared and a consistent microbial community for Buntsandstein could be verified. Similary, for Zechstein, the presence of halophiles was seen with cultivation, isolation directly from the rock material and also in groundwater with DNA-dependent approaches. A higher overlap between sandstone- and limestone-derived communities was visible as if compared to the salt formations. Principal component analysis confirmed formation specific patterns for Muschelkalk, Buntsandstein and Zechstein for the bacterial taxa present, with some overlaps. Bacilli and Gammaproteobacteria were the major groups, with the genera Pseudomonas, Marinomonas, Bacillus, Marinobacter and Pseudoalteromonas representing the communities. The bacteria are well adapted to their respective environment with survival strategies including a wide range of salinity which makes them suitable as tracers for fluid movement below the ground. The results indicate the usefulness and robustness of the approach taken here to investigate aquifer community structures in dependence of the stratigraphy of the groundwater reservoir.

  14. Vortices on higher genus surfaces

    International Nuclear Information System (INIS)

    We consider the topological interactions of vortices on general surfaces. If the genus of the surface is greater than zero, the handles can carry magnetic flux. The classical state of the vortices and the handles can be described by a mapping from the fundamental group to the unbroken gauge group. The allowed configurations must satisfy a relation induced by the fundamental group. Upon quantization, the handles can carry ''Cheshire charge.'' The motion of the vortices can be described by the braid group of the surface. How the motion of the vortices affects the state is analyzed in detail

  15. NSR superstring measures in genus 5

    International Nuclear Information System (INIS)

    Currently there are two proposed ansätze for NSR superstring measures: the Grushevsky ansatz and the OPSMY ansatz, which for genera g⩽4 are known to coincide. However, neither the Grushevsky nor the OPSMY ansatz leads to a vanishing two-point function in genus four, which can be constructed from the genus five expressions for the respective ansätze. This is inconsistent with the known properties of superstring amplitudes. In the present paper we show that the Grushevsky and OPSMY ansätze do not coincide in genus five. Then, by combining these ansätze, we propose a new ansatz for genus five, which now leads to a vanishing two-point function in genus four. We also show that one cannot construct an ansatz from the currently known forms in genus 6 that satisfies all known requirements for superstring measures

  16. Integrable systems in the infinite genus limit

    OpenAIRE

    Gesztesy, Fritz

    2001-01-01

    We provide an elementary approach to integrable systems associated with hyperelliptic curves of infinite genus. In particular, we explore the extent to which the classical Burchnall-Chaundy theory generalizes in the infinite genus limit, and systematically study the effect of Darboux transformations for the KdV hierarchy on such infinite genus curves. Our approach applies to complex-valued periodic solutions of the KdV hierarchy and naturally identifies the Riemann surface familiar from stand...

  17. Geometric Registration of High-genus Surfaces

    OpenAIRE

    Wen, Chengfeng; Lui, Lok Ming

    2013-01-01

    This paper presents a method to obtain geometric registrations between high-genus ($g\\geq 1$) surfaces. Surface registration between simple surfaces, such as simply-connected open surfaces, has been well studied. However, very few works have been carried out for the registration of high-genus surfaces. The high-genus topology of the surface poses great challenge for surface registration. A possible approach is to partition surfaces into simply-connected patches and registration is done patch ...

  18. The genus Lolium; taxonomy and genetic resources.

    OpenAIRE

    Loos, B.P.

    1994-01-01

    Several aspects of variation within the genus Lolium, and more in detail within Lolium perenne (perennial ryegrass) have been highlighted. As the results are extensively discussed in each chapter, the general discussion is focused on two aspects of the research.SpeciationIt is clear that the genus Lolium is a very variable genus. The variation within the species reduces the clarity of separation of the species. Stebbins (1956) found the differences between Lolium and Festuca not sufficient to...

  19. Phylogenetic Analysis of the Genus Pistacia (Anacardiaceae)

    OpenAIRE

    AL-Saghir, Mohannad Ghazi

    2006-01-01

    Pistacia is an economically important genus because it contains the pistachio crop, P. vera, which has edible seeds of considerable commercial importance. The evolutionary history of the genus and the taxonomic relationships among the species are controversial and not well understood. This study that has been conducted on this genus to refine taxonomic and evolutionary relationship utilizing different types of data (including morphology, anatomy and molecular) The studied species were the fol...

  20. On the slice genus of links

    OpenAIRE

    Florens, Vincent; Gilmer, Patrick M.

    2003-01-01

    We define Casson-Gordon sigma-invariants for links and give a lower bound of the slice genus of a link in terms of these invariants. We study as an example a family of two component links of genus h and show that their slice genus is h, whereas the Murasugi-Tristram inequality does not obstruct this link from bounding an annulus in the 4-ball.

  1. The genus chenopodium: Phytochemistry, ethnopharmacology and pharmacology

    OpenAIRE

    Zlatina Kokanova-Nedialkova, , , , , and; Paraskev T Nedialkov; Stefan D. Nikolov

    2009-01-01

    The review includes 154 references on the genus Chenopodium covered up to December 2008 and has been compiled using references mainly from Chemical Abstracts and Pubmed. This article briefly reviews the phytochemistry, ethnopharmacology and pharmacology of Chenopodium genus. Three hundred seventy nine compounds isolated from different species are reported. Fenolics, flavonoids, saponins, ecdysteroids and triterpenoids were the major classes of phytoconstituents of this genus. The detailed dis...

  2. Bacterial hydrodynamics

    CERN Document Server

    Lauga, Eric

    2015-01-01

    Bacteria predate plants and animals by billions of years. Today, they are the world's smallest cells yet they represent the bulk of the world's biomass, and the main reservoir of nutrients for higher organisms. Most bacteria can move on their own, and the majority of motile bacteria are able to swim in viscous fluids using slender helical appendages called flagella. Low-Reynolds-number hydrodynamics is at the heart of the ability of flagella to generate propulsion at the micron scale. In fact, fluid dynamic forces impact many aspects of bacteriology, ranging from the ability of cells to reorient and search their surroundings to their interactions within mechanically and chemically-complex environments. Using hydrodynamics as an organizing framework, we review the biomechanics of bacterial motility and look ahead to future challenges.

  3. Bacterial Diversity in Çamalti Saltern, Turkey.

    Science.gov (United States)

    Mutlu, Mehmet Burçin; Güven, Kiymet

    2015-01-01

    A combination of culture-dependent and culture-independent approaches was employed to identify the bacterial diversity of Çamalti solar saltern in Turkey. The bacterial communities of Çamalti Saltern were analyzed by molecular techniques that included denaturing gradient gel electrophoresis of 16S rRNA gene fragments PCR amplified from DNA extracted from the water samples of the saltern and 16S rRNA gene library analysis. A total of 42 isolates were identified at the genus/species level and 17 of them were found to belong to the Bacteria domain. All bacterial isolates were phylogenetically related to Halobacillus, Virgibacillus and Halomonas genus. A total of 50 clones from 16S rRNA gene library were analyzed by ARDRA. 16S rRNA sequence analysisof these clones revealed that most (85%) of the bacterial clones were related to Salinibacter genus members of the Bacteroidetes. The sequences of DGGE bands were related to the uncultured Salinibacter, uncultured halophilic bacterium and Halomonas sp. This work highlights the halophilic bacterial diversity of Çamalti marine solar saltern. PMID:26094314

  4. Spatial and Species Variations in Bacterial Communities Associated with Corals from the Red Sea as Revealed by Pyrosequencing

    KAUST Repository

    Lee, O. O.

    2012-08-03

    Microbial associations with corals are common and are most likely symbiotic, although their diversity and relationships with environmental factors and host species remain unclear. In this study, we adopted a 16S rRNA gene tag-pyrosequencing technique to investigate the bacterial communities associated with three stony Scleractinea and two soft Octocorallia corals from three locations in the Red Sea. Our results revealed highly diverse bacterial communities in the Red Sea corals, with more than 600 ribotypes detected and up to 1,000 species estimated from a single coral species. Altogether, 21 bacterial phyla were recovered from the corals, of which Gammaproteobacteria was the most dominant group, and Chloroflexi, Chlamydiae, and the candidate phylum WS3 were reported in corals for the first time. The associated bacterial communities varied greatly with location, where environmental conditions differed significantly. Corals from disturbed areas appeared to share more similar bacterial communities, but larger variations in community structures were observed between different coral species from pristine waters. Ordination methods identified salinity and depth as the most influential parameters affecting the abundance of Vibrio, Pseudoalteromonas, Serratia, Stenotrophomonas, Pseudomonas, and Achromobacter in the corals. On the other hand, bacteria such as Chloracidobacterium and Endozoicomonas were more sensitive to the coral species, suggesting that the host species type may be influential in the associated bacterial community, as well. The combined influences of the coral host and environmental factors on the associated microbial communities are discussed. This study represents the first comparative study using tag-pyrosequencing technology to investigate the bacterial communities in Red Sea corals.

  5. [Immunochemical Detection of Azospirilla in Soil with Genus-Specific Antibodies].

    Science.gov (United States)

    Shirokov, A A; Krasov, A I; Selivanov, N Yu; Burygin, G L; Shchegolev, S Yu; Matora, L Yu

    2015-01-01

    Immunoelectrophoresis and immunodiffusion analysis with antibodies to whole intact cells of the type strain of nitrogen-fixing soil bacteria Azospirillum brasilense Sp7 revealed at least three conservative surface immunogenic proteins of azospirilla. Cross-reactions with these proteins made it possible to use the above antibodies for detection of azospirilla as a genus-specific probe conjugated with horseradish peroxidase as an enzymatic label. Direct immune-enzyme analysis of soil suspensions (typical chernozem, Saratov oblast) confirmed applicability of the conjugates based on genus-specific antibodies to the surface proteins of azospirilla for direct detection of this bacterial genus in environmental samples. These results provide a basis for broad application of this method for analysis of Azospirillum occurrence in soil. PMID:26263631

  6. Multidrug Efflux Pumps in the Genus Erwinia: Physiology and Regulation of Efflux Pump Gene Expression.

    Science.gov (United States)

    Thekkiniath, J; Ravirala, R; San Francisco, M

    2016-01-01

    Plant pathogens belonging to the genus Erwinia cause diseases in several economically important plants. Plants respond to bacterial infection with a powerful chemical arsenal and signaling molecules to rid themselves of the microbes. Although our understanding of how Erwinia initiate infections in plants has become clear, a comprehensive understanding of how these bacteria rid themselves of noxious antimicrobial agents during the infection is important. Multidrug efflux pumps are key factors in bacterial resistance toward antibiotics by reducing the level of antimicrobial compounds in the bacterial cell. Erwinia induce the expression of efflux pump genes in response to plant-derived antimicrobials. The capability of Erwinia to co-opt plant defense signaling molecules such as salicylic acid to trigger multidrug efflux pumps might have developed to ensure bacterial survival in susceptible host plants. In this review, we discuss the developments in Erwinia efflux pumps, focusing in particular on efflux pump function and the regulation of efflux pump gene expression. PMID:27571694

  7. Generating the genus g+1 Goeritz group of a genus g handlebody

    OpenAIRE

    Scharlemann, Martin

    2011-01-01

    A specific set of 4g+1 elements is shown to generate the Goeritz group of the genus g+1 Heegaard splitting of a genus g handlebody. These generators are consistent with Powell's proposed generating set for the Goeritz group of the genus g+1 splitting of S^3. There are two proofs: one using purely classical techniques and one using thin position.

  8. Development of a recA Gene-Based Identification Approach for the Entire Burkholderia Genus

    OpenAIRE

    Payne, George W.; Vandamme, Peter; Morgan, Sara H.; LiPuma, John J.; Coenye, Tom; Weightman, Andrew J.; Jones, T. Hefin; Mahenthiralingam, Eshwar

    2005-01-01

    Burkholderia is an important bacterial genus containing species of ecological, biotechnological, and pathogenic interest. With their taxonomy undergoing constant revision and the phenotypic similarity of several species, correct identification of Burkholderia is difficult. A genetic scheme based on the recA gene has greatly enhanced the identification of Burkholderia cepacia complex species. However, the PCR developed for the latter approach was limited by its specificity for the complex. By ...

  9. Distribution of Naturally Occurring Anthraquinones, Iridoids and Flavonoids from Morinda genus: Chemistry and Biological activity

    OpenAIRE

    Phakhodee, Wong

    2012-01-01

    The present review covers chemistry and bioactivities of anthraquinones, iridoids, and flavonoids from the Morinda genus. The plants of Morinda species, belonging to the Rubiaceae family, have been used as traditional folk medicine with anti-bacterial, anti-fungal, anti-tumor, anti-helmin, analgesic, anti-inflammatory, and immune enhancing effects. They are rich sources of anthraquinones and iridoids. The relevant 2-methoxy-1,3,6-trihydroxyanthraquinone is one of the most potent quinone reduc...

  10. Conjugation genes are common throughout the genus Rickettsia and are transmitted horizontally

    OpenAIRE

    Weinert, Lucy A.; Welch, John J.; Jiggins, Francis M.

    2009-01-01

    Rickettsia are endosymbionts of arthropods, some of which are vectored to vertebrates where they cause disease. Recently, it has been found that some Rickettsia strains harbour conjugative plasmids and others encode some conjugative machinery within the bacterial genome. We investigated the distribution of these conjugation genes in a phylogenetically diverse collection of Rickettsia isolated from arthropods. We found that these genes are common throughout the genus and, in stark contrast to ...

  11. Evolution of the Genus Homo

    Science.gov (United States)

    Tattersall, Ian; Schwartz, Jeffrey H.

    2009-05-01

    Definition of the genus Homo is almost as fraught as the definition of Homo sapiens. We look at the evidence for “early Homo,” finding little morphological basis for extending our genus to any of the 2.5-1.6-myr-old fossil forms assigned to “early Homo” or Homo habilis/rudolfensis. We also point to heterogeneity among “early African Homo erectus,” and the lack of apomorphies linking these fossils to the Asian Homo erectus group, a cohesive regional clade that shows some internal variation, including brain size increase over time. The first truly cosmopolitan Homo species is Homo heidelbergensis, known from Africa, Europe, and China following 600 kyr ago. One species sympatric with it included the >500-kyr-old Sima de los Huesos fossils from Spain, clearly distinct from Homo heidelbergensis and the oldest hominids assignable to the clade additionally containing Homo neanderthalensis. This clade also shows evidence of brain size expansion with time; but although Homo neanderthalensis had a large brain, it left no unequivocal evidence of the symbolic consciousness that makes our species unique. Homo sapiens clearly originated in Africa, where it existed as a physical entity before it began (also in that continent) to show the first stirrings of symbolism. Most likely, the biological underpinnings of symbolic consciousness were exaptively acquired in the radical developmental reorganization that gave rise to the highly characteristic osteological structure of Homo sapiens, but lay fallow for tens of thousands of years before being “discovered” by a cultural stimulus, plausibly the invention of language.

  12. Changes in bacterial community metabolism and composition during the degradation of dissolved organic matter from the jellyfish Aurelia aurita in a Mediterranean coastal lagoon.

    Science.gov (United States)

    Blanchet, Marine; Pringault, Olivier; Bouvy, Marc; Catala, Philippe; Oriol, Louise; Caparros, Jocelyne; Ortega-Retuerta, Eva; Intertaglia, Laurent; West, Nyree; Agis, Martin; Got, Patrice; Joux, Fabien

    2015-09-01

    Spatial increases and temporal shifts in outbreaks of gelatinous plankton have been observed over the past several decades in many estuarine and coastal ecosystems. The effects of these blooms on marine ecosystem functioning and particularly on the dynamics of the heterotrophic bacteria are still unclear. The response of the bacterial community from a Mediterranean coastal lagoon to the addition of dissolved organic matter (DOM) from the jellyfish Aurelia aurita, corresponding to an enrichment of dissolved organic carbon (DOC) by 1.4, was assessed for 22 days in microcosms (8 l). The high bioavailability of this material led to (i) a rapid mineralization of the DOC and dissolved organic nitrogen from the jellyfish and (ii) the accumulation of high concentrations of ammonium and orthophosphate in the water column. DOM from jellyfish greatly stimulated heterotrophic prokaryotic production and respiration rates during the first 2 days; then, these activities showed a continuous decay until reaching those measured in the control microcosms (lagoon water only) at the end of the experiment. Bacterial growth efficiency remained below 20%, indicating that most of the DOM was respired and a minor part was channeled to biomass production. Changes in bacterial diversity were assessed by tag pyrosequencing of partial bacterial 16S rRNA genes, DNA fingerprints, and a cultivation approach. While bacterial diversity in control microcosms showed little changes during the experiment, the addition of DOM from the jellyfish induced a rapid growth of Pseudoalteromonas and Vibrio species that were isolated. After 9 days, the bacterial community was dominated by Bacteroidetes, which appeared more adapted to metabolize high-molecular-weight DOM. At the end of the experiment, the bacterial community shifted toward a higher proportion of Alphaproteobacteria. Resilience of the bacterial community after the addition of DOM from the jellyfish was higher for metabolic functions than diversity

  13. Three New Species of the Genus Ochroconis

    OpenAIRE

    Samerpitak, K.; Gerrits van den Ende, A. H. G.; Menken, S.B.J.; Hoog, de, G.S.

    2015-01-01

    Ochroconis bacilliformis, O. phaeophora and O. robusta, three novel species of the melanized genus Ochroconis (Sympoventuriaceae, Venturiales), are described, illustrated and distinguished phenotypically and molecularly from previously described species in the genus Ochroconis. Their potential significance for infection of cold-blooded vertebrates is discussed.

  14. Positive curvature and the elliptic genus

    OpenAIRE

    Weisskopf, Nicolas

    2013-01-01

    We prove several results about the vanishing of the elliptic genus on positively curved Spin manifolds with logarithmic symmetry rank. The proofs are based on the rigidity of the elliptic genus and Kennard's improvement of the Connectedness Lemma for transversely intersecting, totally geodesic submanifolds.

  15. Revision of the genus Labisia (Myrsinaceae)

    OpenAIRE

    Sunarno, B.

    2005-01-01

    The genus Labisia (Myrsinaceae) is revised for the Flora Malesiana region. Seven species are recognised. Several earlier described species are synonymous to L. pumila and reduced to varieties of that species: var. alata, var. lanceolata, var. neriifolia and var. sessilifolia. A new record of L. longistyla is mentioned. Labisia malouiana and L. obtusifolia are excluded from the genus.

  16. Phenetic relationships in the genus Myotis

    NARCIS (Netherlands)

    Findley, James S.

    1970-01-01

    The genus Myotis is of interest to the evolutionist because of its diversity and because of its nearly cosmopolitan distribution. An understanding of the biology of this remarkable genus may provide insight into its success, as well as the success of other expansive groups of mammals. As part of an

  17. The elliptic genus and Hidden symmetry

    International Nuclear Information System (INIS)

    We study the elliptic genus (a partition function) in certain interacting, twist quantum field theories. Without twists, these theories have N=2 supersymmetry. The twists provide a regularization, and also partially break the supersymmetry. In spite of the regularization, one can establish a homotopy of the elliptic genus in a coupling parameter. Our construction relies on a priori estimates and other methods from constructive quantum field theory; this mathematical underpinning allows us to justify evaluating the elliptic genus at one endpoint of the homotopy. We obtain a version of Witten's proposed formula for the elliptic genus in terms of classical theta functions. As a consequence, the elliptic genus has a hidden SL(2,Z) symmetry characteristic of conformal theory, even though the underlying theory is not conformal. (orig.)

  18. Beneficial and harmful roles of bacteria from the Clostridium genus.

    Science.gov (United States)

    Samul, Dorota; Worsztynowicz, Paulina; Leja, Katarzyna; Grajek, Włodzimierz

    2013-01-01

    Bacteria of the Clostridium genus are often described only as a biological threat and a foe of mankind. However, many of them have positive properties and thanks to them they may be used in many industry branches (e.g., in solvents and alcohol production, in medicine, and also in esthetic cosmetology). During the last 10 years interest in application of C. botulinum and C. tetani in medicine significantly increased. Currently, the structure and biochemical properties of neurotoxins produced by these bacterial species, as well as possibilities of application of such toxins as botulinum as a therapeutic factor in humans, are being intensely researched. The main aim of this article is to demonstrate that bacteria from Clostridium spp. are not only pathogens and the enemy of humanity but they also have many important beneficial properties which make them usable among many chemical, medical, and cosmetic applications. PMID:24432307

  19. Evolution of the leukotoxin promoter in genus Mannheimia

    DEFF Research Database (Denmark)

    Larsen, Jesper; Pedersen, Anders Gorm; Davies, Robert L;

    2009-01-01

    Background: The Mannheimia species encompass a wide variety of bacterial lifestyles, including opportunistic pathogens and commensals of the ruminant respiratory tract, commensals of the ovine rumen, and pathogens of the ruminant integument. Here we present a scenario for the evolution of the...... leukotoxin promoter among representatives of the five species within genus Mannheimia. We also consider how the evolution of the leukotoxin operon fits with the evolution and maintenance of virulence. Results: The alignment of the intergenic regions upstream of the leukotoxin genes showed significant...... sequence and positional conservation over a 225-bp stretch immediately proximal to the transcriptional start site of the IktC gene among all Mannheimia strains. However, in the course of the Mannheimia genome evolution, the acquisition of individual noncoding regions upstream of the conserved promoter...

  20. Surface proteins of bacteria of the genus Bifidobacterium 

    Directory of Open Access Journals (Sweden)

    Ewa Dylus

    2013-05-01

    Full Text Available Beneficial effects due to the presence of probiotic bacteria of the genus Bifidobacterium in the human intestinal tract are still an interesting object of study. So far activities have been confirmed of bifidobacteria in stimulation of the host immune system, stimulation of tumor cell apoptosis, improvement of bowel motility, alleviation of symptoms of lactose intolerance, cholesterol lowering capacity, prevention and treatment of diarrhea and irritable bowel syndrome, alleviation of allergy or atopic dermatitis, maintenance of homeostasis of the intestine, and stimulation of the development of normal intestinal microflora in infants. A multitude of therapeutic properties encourages researchers to investigate the possibility of using the potential of Bifidobacterium in the prevention and treatment of other conditions such as rheumatoid arthritis and depression. Although it is known that the beneficial effects are due to intestinal mucosal colonization by these bacteria, the cell components responsible for the colonization are still not determined. In addition to the beneficial effects of probiotic administration, there were also negative effects including sepsis. Therefore research has been directed to identify specific components of Bifidobacterium responsible for probiotic effects. Currently researchers are focused on identifying, isolating and evaluating the properties of surface proteins that are probably involved in the adhesion of bacterial cells to the intestinal epithelium, improving colonization. This paper is an overview of current knowledge on Bifidobacterium surface proteins. The ways of transport and anchoring proteins in Gram-positive bacterial cells, the assembly of cell wall, and a description of the genus Bifidobacterium are presented.

  1. The genus chenopodium: Phytochemistry, ethnopharmacology and pharmacology

    Directory of Open Access Journals (Sweden)

    Zlatina Kokanova-Nedialkova

    2009-01-01

    Full Text Available The review includes 154 references on the genus Chenopodium covered up to December 2008 and has been compiled using references mainly from Chemical Abstracts and Pubmed. This article briefly reviews the phytochemistry, ethnopharmacology and pharmacology of Chenopodium genus. Three hundred seventy nine compounds isolated from different species are reported. Fenolics, flavonoids, saponins, ecdysteroids and triterpenoids were the major classes of phytoconstituents of this genus. The detailed distribution of these compounds among the different Chenopodium species with the related references is given in tables. In addition, this review discusses the traditional medicinal uses of different Chenopodium species as well as recent developments done in this aspect.

  2. Pyrosequencing analysis of bacterial diversity in dental unit waterlines.

    Science.gov (United States)

    Costa, Damien; Mercier, Anne; Gravouil, Kevin; Lesobre, Jérôme; Delafont, Vincent; Bousseau, Anne; Verdon, Julien; Imbert, Christine

    2015-09-15

    Some infections cases due to exposure to output water from dental unit waterlines (DUWL) have been reported in the literature. However, this type of healthcare-associated risk has remained unclear and up until now the overall bacterial composition of DUWL has been poorly documented. In this study, 454 high-throughput pyrosequencing was used to investigate the bacterial community in seven dental offices (N = 7) and to identify potential bacterial pathogenic sequences. Dental unit waters (DUW) were collected from the tap water supplying units (Incoming Water; IW) to the output exposure point of the turbine handpiece (Output water; OW) following a stagnation period (OWS), and immediately after the last patient of the sampling day (OWA). A high bacterial diversity was revealed in DUW with 394 operational taxonomic units detected at the genus level. In addition to the inter-unit variability observed, results showed increased total bacterial cell concentration and shifts in bacterial community composition and abundance at the genus level, mainly within the Gamma- and Alpha-Proteobacteria class, as water circulated in the dental unit (DU). Results showed that 96.7%, 96.8% and 97.4% of the total sequences from IW, OWS and OWA respectively were common to the 3 defined water groups, thereby highlighting a common core microbiome. Results also suggested that stagnation and DU maintenance practices were critical to composition of the bacterial community. The presence of potentially pathogenic genera was detected, including Pseudomonas and Legionella spp. Emerging and opportunistic pathogenic genera such as Mycobacterium, Propionibacterium and Stenotrophomonas were likewise recovered in DUW. For the first time, an exhaustive evaluation of the bacterial communities present in DUW was performed taking into account the circulation of water within the DU. This study highlights an ignored diversity of the DUWL bacterial community. Our findings also contribute to a better

  3. Larval settlement of the common Australian sea urchin Heliocidaris erythrogramma in response to bacteria from the surface of coralline algae.

    Science.gov (United States)

    Huggett, Megan J; Williamson, Jane E; de Nys, Rocky; Kjelleberg, Staffan; Steinberg, Peter D

    2006-10-01

    Bacterial biofilms are increasingly seen as important for the successful settlement of marine invertebrate larvae. Here we tested the effects of biofilms on settlement of the sea urchin Heliocidaris erythrogramma. Larvae settled on many surfaces including various algal species, rocks, sand and shells. Settlement was reduced by autoclaving rocks and algae, and by treatment of algae with antibiotics. These results, and molecular and culture-based analyses, suggested that the bacterial community on plants was important for settlement. To test this, approximately 250 strains of bacteria were isolated from coralline algae, and larvae were exposed to single-strain biofilms. Many induced rates of settlement comparable to coralline algae. The genus Pseudoalteromonas dominated these highly inductive strains, with representatives from Vibrio, Shewanella, Photobacterium and Pseudomonas also responsible for a high settlement response. The settlement response to different bacteria was species specific, as low inducers were also dominated by species in the genera Pseudoalteromonas and Vibrio. We also, for the first time, assessed settlement of larvae in response to characterised, monospecific biofilms in the field. Larvae metamorphosed in higher numbers on an inducing biofilm, Pseudoalteromonas luteoviolacea, than on either a low-inducing biofilm, Pseudoalteromonas rubra, or an unfilmed control. We conclude that the bacterial community on the surface of coralline algae is important as a settlement cue for H. erythrogramma larvae. This study is also an example of the emerging integration of molecular microbiology and more traditional marine eukaryote ecology. PMID:16794830

  4. Revision of the African genus Uvariastrum (Annonaceae).

    Science.gov (United States)

    Couvreur, Thomas L P

    2014-01-01

    The genus Uvariastrum (Annonaceae) is restricted to continental Africa and is characterized by sepals with folded margins, few carpels and numerous stamens. The genus is mainly found in the tropical lowland rain forests of Africa, with one species growing in a drier woodland habitat. The species name Uvariastrum pynaertii De Wild is reduced into synonymy with Uvariastrum zenkeri Engl. & Diels. Uvaraistrum neglectum Paiva and Uvariastrum modestum Dielsare transferred to the genus Uvaria leading to two new combinations: Uvaria modesta (Diels) Couvreur, comb. nov. and Uvaria paivana Couvreur, nom. nov. Five species are currently recognized in Uvariastrum. The present revision, the first of the genus for over 100 years, provides an overview of previously published information and discussions on morphology, taxonomy and palynology. Preliminary conservation status assessments are provided for each species, as well as diagnostic keys for fruiting and flowering material as well as detailed species descriptions. Furthermore, all species are illustrated by line drawings and all species are mapped. PMID:24526846

  5. Synaptospory in the fern genus Pyrrosia (Polypodiaceae)

    NARCIS (Netherlands)

    Uffelen, van Gerda A.

    1983-01-01

    The correlation between sporoderm sculpture and life form of the sporophyte as postulated by Kramer (1977) is investigated for the fern genus Pyrrosia. This correlation is not found in Pyrrosia but may be present in other fern groups.

  6. The geometric genus of hypersurface singularities

    OpenAIRE

    Andras Nemethi; Baldur Sigurdsson

    2014-01-01

    Using the path lattice cohomology we provide a conceptual topological characterization of the geometric genus for certain complex normal surface singularities with rational homology sphere links, which is uniformly valid for all superisolated and Newton non--degenerate hypersurface singularities.

  7. Evolutionary history of the genus Trisopterus.

    Science.gov (United States)

    Gonzalez, Elena G; Cunha, Regina L; Sevilla, Rafael G; Ghanavi, Hamid R; Krey, Grigorios; Bautista, José M

    2012-03-01

    The group of small poor cods and pouts from the genus Trisopterus, belonging to the Gadidae family, comprises four described benthopelagic species that occur across the North-eastern Atlantic, from the Baltic Sea to the coast of Morocco, and the Mediterranean. Here, we combined molecular data from mitochondrial (cytochrome b) and nuclear (rhodopsin) genes to confirm the taxonomic status of the described species and to disentangle the evolutionary history of the genus. Our analyses supported the monophyly of the genus Trisopterus and confirmed the recently described species Trisopterus capelanus. A relaxed molecular clock analysis estimated an Oligocene origin for the group (~30 million years ago; mya) indicating this genus as one of the most ancestral within the Gadidae family. The closure and re-opening of the Strait of Gibraltar after the Messinian Salinity Crisis (MSC) probably triggered the speciation process that resulted in the recently described T. capelanus. PMID:22178361

  8. The genus Calappa in the Ionian Sea

    Energy Technology Data Exchange (ETDEWEB)

    Pastore, M. [Consiglio Nazionale delle Ricerche, Taranto (Italy). Ist. Sperimentale Talassografico

    1995-12-31

    Until now the genus Calappa in the Mediterranean sea was represented by Calappa granulata (l., 1758). With the present paper, two new species, Calappa rissoana and Calappa tuerkajana and Calappa pelii Herklots (1851) too, are signaled in such basin.

  9. Pollen morphology of the genus Malus Mill.

    Directory of Open Access Journals (Sweden)

    Irina Dyakova

    2014-04-01

    Full Text Available The study of pollen morphology of some species of the genus Malus (Rosaceae was carried out. All investigated species are characterized by tricolpate pollen grains, but differ by their size and coloration.

  10. Draft Genome Sequence of Criibacterium bergeronii gen. nov., sp. nov., Strain CCRI-22567T, Isolated from a Vaginal Sample from a Woman with Bacterial Vaginosis.

    Science.gov (United States)

    Maheux, Andrée F; Bérubé, Ève; Boudreau, Dominique K; Raymond, Frédéric; Corbeil, Jacques; Roy, Paul H; Boissinot, Maurice; Omar, Rabeea F

    2016-01-01

    Criibacterium bergeronii gen. nov., sp. nov., CCRI-22567 is the type strain of the new genus Criibacterium The strain was isolated from a woman with bacterial vaginosis. The genome assembly comprised 2,384,460 bp, with 34.4% G+C content. This is the first genome announcement of a strain belonging to the genus Criibacterium. PMID:27587833

  11. A Brief Chronicle of the Genus Cordyceps Fr., the Oldest Valid Genus in Cordycipitaceae (Hypocreales, Ascomycota)

    OpenAIRE

    Shrestha, Bhushan; Tanaka, Eiji; Han, Jae-Gu; Oh, Junsang; Han, Sang-Kuk; Lee, Kang-Hyo; Sung, Gi-Ho

    2014-01-01

    The earliest pre-Linnaean fungal genera are briefly discussed here with special emphasis on the nomenclatural connection with the genus Cordyceps Fr. Since its valid publication under the basidiomycetous genus Clavaria Vaill. ex L. (Clavaria militaris L. Sp. Pl. 2:1182, 1753), the genus Cordyceps has undergone nomenclatural changes in the post-Linnaean era, but has stood firmly for approximately 200 years. Synonyms of Cordyceps were collected from different literature sources and analyzed bas...

  12. Standardized gene nomenclature for the Brassica genus

    OpenAIRE

    King Graham J; Østergaard Lars

    2008-01-01

    Abstract The genus Brassica (Brassicaceae, Brassiceae) is closely related to the model plant Arabidopsis, and includes several important crop plants. Against the background of ongoing genome sequencing, and in line with efforts to standardize and simplify description of genetic entities, we propose a standard systematic gene nomenclature system for the Brassica genus. This is based upon concatenating abbreviated categories, where these are listed in descending order of significance from left ...

  13. Symmetry of Embedded Genus-One Helicoids

    OpenAIRE

    Bernstein, Jacob; Breiner, Christine

    2010-01-01

    In this note, we use the Lopez-Ros deformation introduced in [9] to show that any embedded genus-one helicoid must be symmetric with respect to rotation by 180 degrees around a normal line. This partially answers a conjecture of Bobenko from [3]. We also show this symmetry holds for an embedded genus-k helicoid $\\Sigma$, provided the underlying conformal structure of $\\Sigma$ is hyperelliptic.

  14. Cosmetic crossings of genus one knots

    CERN Document Server

    Balm, Cheryl

    2011-01-01

    We show that for genus one knots the Alexander polynomial and the homology of the double cover branching over the knot provide obstructions to cosmetic crossings. As an application we prove the nugatory crossing conjecture for the negatively twisted, positive Whitehead doubles of all knots. We also verify the conjecture for several families of pretzel knots and all genus one knots with up to 10 crossings.

  15. Constructing Numerical Semigroups of a Given Genus

    OpenAIRE

    Zhao, Yufei

    2009-01-01

    Let n_g denote the number of numerical semigroups of genus g. Bras-Amoros conjectured that n_g possesses certain Fibonacci-like properties. Almost all previous attempts at proving this conjecture were based on analyzing the semigroup tree. We offer a new, simpler approach to counting numerical semigroups of a given genus. Our method gives direct constructions of families of numerical semigroups, without referring to the generators or the semigroup tree. In particular, we give an improved asym...

  16. Remarks on Superstring amplitudes in higher genus

    OpenAIRE

    Manni, Riccardo Salvati

    2008-01-01

    Very recently, Grushevsky continued D'Hoker and Phong's program of finding the chiral superstring measure from first principles by constructing modular forms satisfying certain factorization constraints. He has proposed an ansatz in genus 4 and conjectured a possible formula for the superstring measure in any genus, subject to the condition that certain modular forms admit holomorphic roots. In this note we want to give some evidence that Grushevsky's approach seems to be very fruitful.

  17. Kops genus - en værkstedsrapport

    DEFF Research Database (Denmark)

    Gudiksen, Asgerd

     Inden for Ømålsområdet optræder ordet kop både i genus femininum, masku­linum og neutrum. På Sjælland, hvor trekønssystemet er under af­vikling, kan ordet desuden være genus commune. Der kan konstateres en vis dialektgeografisk fordeling af de tre (fire) genera, men især på Sjælland er...

  18. Phylogeography of genus Squalius in Albania

    OpenAIRE

    Radek Šanda; Miroslav Švátora

    2015-01-01

    This study is focused on the issue of the Squalius genus phylogeography in Albania in the Balkan region. Phylogenetic analyses of sequence variation at mitochondrial DNA (cytochrome b gene) were used to examine these issues for the freshwater fish of the genus Squalius from various river systems in the Adriatic Sea region. There were identified three genetic lineages of unclear taxonomic position, where the genetic variation between identified clades range from 1.6 to 2.1 %. The first lineage...

  19. Revision of the genus Gymnacranthera (Myristicaceae)

    OpenAIRE

    Schouten, R.T.A.

    1986-01-01

    In Gymnacranthera, a small genus of Southeast Asian Myristicaceae, at present 7 species have been accepted, one (G. forbesii) with 2 and another ( G. farquhariana) with 4 varieties. One species, G. canarica, occurs in S. India, the remainder of the species is distributed in the area from S. Thailand east to E. New Guinea and the Bismarck Archipelago; the genus is absent from Java and the Lesser Sunda Islands. Species distinction is difficult because the androecium, which provides good charact...

  20. Effect of Bacillus spp. on seed germination of selected species of the genus Cuscuta (Convolvulaceae

    Directory of Open Access Journals (Sweden)

    Fatemeh Hadizadeh

    2014-04-01

    Full Text Available Species of the genus Cuscuta are annual angiospermic rootless and leafless (achlorophyllous parasitic plants. Bacillus is an example of PGPR bacteria exhibiting plant growth promoting activity. In this study the effects of bacterial suspension on germination of dodder’s seed has been determinated. Seeds of three Cuscuta species were collected from field for evaluating effects of three different Bacillus on its germination. Results show that seed germination of the C. monogyna and C. campestris is inhibited by all three bacterial species. Based on Tukey analysis, the highest inhibitory activity on seed germination of C. monogyna was shown with B. pumilus (68.88%; as well as C. campestris with B. megaterium (95.76% and B. pumilus (91.53%, whilst seed germination of C. europaea was almost identically inhibited by all three bacterial species. This paper reports the variable effects of Bacillus species on the seed germination of selected Cuscuta species.

  1. Genus 2 Curves with Complex Multiplication

    CERN Document Server

    Goren, Eyal Z

    2010-01-01

    Genus 2 curves are useful in cryptography for both discrete-log based and pairing-based systems, but a method is required to compute genus 2 curves such that the Jacobian has a given number of points. Currently, all known methods involve constructing genus 2 curves with complex multiplication via computing their three Igusa class polynomials. These polynomials have rational coefficients and require extensive computation and precision to compute. Both the computation and the complexity analysis of these algorithms can be improved by a more precise understanding of the denominators of the coefficients of the polynomials. The main goal of this paper is to give a bound on the denominators of Igusa class polynomials of genus 2 curves with CM by a primitive quartic CM field. We give an overview of Igusa's results on the moduli space of genus two curves and the method to construct genus 2 curves via their Igusa invariants. We also give a complete characterization of the reduction type of a CM abelian surface, for bi...

  2. Mechanism of uranium (VI) removal by two anaerobic bacterial communities

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Monica [Centro de Ciencias do Mar, Universidade do Algarve, FCT-DQF (edificio 8), Campus de Gambelas, 8005-139 Faro (Portugal); Faleiro, Maria Leonor [IBB - Centro de Biomedicina Molecular e Estrutural, Universidade do Algarve, FCT, Campus de Gambelas, 8005-139 Faro (Portugal); Costa, Ana M. Rosa da [Centro de Investigacao em Quimica do Algarve, Universidade do Algarve, FCT, DQF, Campus de Gambelas, 8005-139 Faro (Portugal); Chaves, Sandra; Tenreiro, Rogerio [Universidade de Lisboa, Faculdade de Ciencias, Centro de Biodiversidade, Genomica Integrativa e Funcional (BioFIG), Campus de FCUL, Campo Grande, 1749-016 Lisboa (Portugal); Matos, Antonio Pedro [Servico de Anatomia Patologica, Hospital Curry Cabral, Lisboa (Portugal); Costa, Maria Clara, E-mail: mcorada@ualg.pt [Centro de Ciencias do Mar, Universidade do Algarve, FCT-DQF (edificio 8), Campus de Gambelas, 8005-139 Faro (Portugal)

    2010-12-15

    The mechanism of uranium (VI) removal by two anaerobic bacterial consortia, recovered from an uncontaminated site (consortium A) and other from an uranium mine (consortium U), was investigated. The highest efficiency of U (VI) removal by both consortia (97%) occurred at room temperature and at pH 7.2. Furthermore, it was found that U (VI) removal by consortium A occurred by enzymatic reduction and bioaccumulation, while the enzymatic process was the only mechanism involved in metal removal by consortium U. FTIR analysis suggested that after U (VI) reduction, U (IV) could be bound to carboxyl, phosphate and amide groups of bacterial cells. Phylogenetic analysis of 16S rRNA showed that community A was mainly composed by bacteria closely related to Sporotalea genus and Rhodocyclaceae family, while community U was mainly composed by bacteria related to Clostridium genus and Rhodocyclaceae family.

  3. Mechanism of uranium (VI) removal by two anaerobic bacterial communities

    International Nuclear Information System (INIS)

    The mechanism of uranium (VI) removal by two anaerobic bacterial consortia, recovered from an uncontaminated site (consortium A) and other from an uranium mine (consortium U), was investigated. The highest efficiency of U (VI) removal by both consortia (97%) occurred at room temperature and at pH 7.2. Furthermore, it was found that U (VI) removal by consortium A occurred by enzymatic reduction and bioaccumulation, while the enzymatic process was the only mechanism involved in metal removal by consortium U. FTIR analysis suggested that after U (VI) reduction, U (IV) could be bound to carboxyl, phosphate and amide groups of bacterial cells. Phylogenetic analysis of 16S rRNA showed that community A was mainly composed by bacteria closely related to Sporotalea genus and Rhodocyclaceae family, while community U was mainly composed by bacteria related to Clostridium genus and Rhodocyclaceae family.

  4. A bacterial quorum-sensing precursor induces mortality in the marine coccolithophore, Emiliania huxleyi

    Directory of Open Access Journals (Sweden)

    Elizabeth L Harvey

    2016-02-01

    Full Text Available Interactions between phytoplankton and bacteria play a central role in mediating biogeochemical cycling and food web structure in the ocean. However, deciphering the chemical drivers of these interspecies interactions remains challenging. Here we report the isolation of 2-heptyl-4-quinolone (HHQ, released by Pseudoalteromonas piscicida, a marine gamma-proteobacteria previously reported to induce phytoplankton mortality through a hitherto unknown algicidal mechanism. HHQ functions as both an antibiotic and a bacterial signaling molecule in cell-cell communication in clinical infection models. Co-culture of the bloom-forming coccolithophore, Emiliania huxleyi with both live P. piscicida and cell-free filtrates caused a significant decrease in algal growth. Investigations of the P. piscicida exometabolome revealed HHQ, at nanomolar concentrations, induced mortality in three strains of E. huxleyi. Mortality of E. huxleyi in response to HHQ occurred slowly, implying static growth rather than a singular loss event (e.g. rapid cell lysis. In contrast, the marine chlorophyte, Dunaliella tertiolecta and diatom, Phaeodactylum tricornutum were unaffected by HHQ exposures. These results suggest that HHQ mediates the type of interkingdom interactions that cause shifts in phytoplankton population dynamics. These chemically mediated interactions, and other like it, ultimately influence large-scale oceanographic processes.

  5. Isolation of bacterial endophytes from germinated maize kernels.

    Science.gov (United States)

    Rijavec, Tomaz; Lapanje, Ales; Dermastia, Marina; Rupnik, Maja

    2007-06-01

    The germination of surface-sterilized maize kernels under aseptic conditions proved to be a suitable method for isolation of kernel-associated bacterial endophytes. Bacterial strains identified by partial 16S rRNA gene sequencing as Pantoea sp., Microbacterium sp., Frigoribacterium sp., Bacillus sp., Paenibacillus sp., and Sphingomonas sp. were isolated from kernels of 4 different maize cultivars. Genus Pantoea was associated with a specific maize cultivar. The kernels of this cultivar were often overgrown with the fungus Lecanicillium aphanocladii; however, those exhibiting Pantoea growth were never colonized with it. Furthermore, the isolated bacterium strain inhibited fungal growth in vitro. PMID:17668041

  6. Bacterial Nail Infection (Paronychia)

    Science.gov (United States)

    ... of nail infection is often caused by a bacterial infection but may also be caused by herpes, a ... to a type of yeast called Candida , or bacterial infection, and this may lead to abnormal nail growth. ...

  7. Potato suberin induces differentiation and secondary metabolism in the genus Streptomyces.

    Science.gov (United States)

    Lerat, Sylvain; Forest, Martin; Lauzier, Annie; Grondin, Gilles; Lacelle, Serge; Beaulieu, Carole

    2012-01-01

    Bacteria of the genus Streptomyces are soil microorganisms with a saprophytic life cycle. Previous studies have revealed that the phytopathogenic agent S. scabiei undergoes metabolic and morphological modifications in the presence of suberin, a complex plant polymer. This paper investigates morphological changes induced by the presence of potato suberin in five species of the genus Streptomyces, with emphasis on S. scabiei. Streptomyces scabiei, S. acidiscabies, S. avermitilis, S. coelicolor and S. melanosporofaciens were grown both in the presence and absence of suberin. In all species tested, the presence of the plant polymer induced the production of aerial hyphae and enhanced resistance to mechanical lysis. The presence of suberin in liquid minimal medium also induced the synthesis of typical secondary metabolites in S. scabiei and S. acidiscabies (thaxtomin A), S. coelicolor (actinorhodin) and S. melanosporofaciens (geldanamycin). In S. scabiei, the presence of suberin modified the fatty acid composition of the bacterial membrane, which translated into higher membrane fluidity. Moreover, suberin also induced thickening of the bacterial cell wall. The present data indicate that suberin hastens cellular differentiation and triggers the onset of secondary metabolism in the genus Streptomyces. PMID:22129602

  8. Bacterial community survey of sediments at Naracoorte Caves, Australia

    OpenAIRE

    Ball Andrew S.; Kirby Greg; Bourne Steven; Cao Xiangsheng; Mazaheri Nezhad Fard Ramin; Adetutu Eric M.; Shahsavari Esamaeil; Thorpe Krystal

    2012-01-01

    Bacterial diversity in sediments at UNESCO World Heritage listed Naracoorte Caves was surveyed as part of an investigation carried out in a larger study on assessing microbial communities in caves. Cave selection was based on tourist accessibility; Stick Tomato and Alexandra Cave (> 15000 annual visits) and Strawhaven Cave was used as control (no tourist access). Microbial analysis showed that Bacillus was the most commonly detected microbial genus by culture dependent and independent survey ...

  9. Bacterial versus fungal laccase: potential for micropollutant degradation

    OpenAIRE

    Margot, Jonas; Bennati-Granier, Chloé; Maillard, Julien; Blánquez, Paqui; Barry, David Andrew; Holliger, Christof

    2013-01-01

    Relatively high concentrations of micropollutants in municipal wastewater treatment plant (WWTP) effluents underscore the necessity to develop additional treatment steps prior to discharge of treated wastewater. Microorganisms that produce unspecific oxidative enzymes such as laccases are a potential means to improve biodegradation of these compounds. Four strains of the bacterial genus Streptomyces (S. cyaneus, S. ipomoea, S. griseus and S. psammoticus) and the white-rot fungus Trametes vers...

  10. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that....... As such, adhesion represents the Achilles heel of crucial pathogenic functions. It follows that interference with adhesion can reduce bacterial virulence. Here, we illustrate this important topic with examples of techniques being developed that can inhibit bacterial adhesion. Some of these will...

  11. The genus Isodon (Schrad. ex Benth. Spach in Africa and a new genus Rabdosiella Codd (Lamiaceae

    Directory of Open Access Journals (Sweden)

    L. E. Codd

    1984-12-01

    Full Text Available The typification of the genus Isodon (Schrad. ex Benth. Spach and its occurrence in Africa are discussed; an allied genus Rabdosiella Codd is described and the combinations R. calycina (Benth. Codd and R. ternifolia (D.Don Codd (the latter an Indian species are effected.

  12. The Genus Coelocrania and the Resurrection of the Genus Pseudosastra (Coleoptera: Chrysomelidae: Galerucinae)

    OpenAIRE

    Mohamed S. Mohamedsaid

    1993-01-01

    The genus Coelocrania Jacoby is reviewed, with the resurrection of the genus Pseudosastra Jacoby. Four new species are herein described from Malaysia: Pseudosastra depressa, P. ghazallyi , P. indah, and P. latiffi. Keys to the species of Coelocrania and Pseudosastra are provided.

  13. Higher-genus Gromov-Witten invariants as genus 0 invariants of symmetric products

    OpenAIRE

    Costello, Kevin

    2003-01-01

    I prove a formula expressing the descendent genus g Gromov-Witten invariants of a projective variety X in terms of genus 0 invariants of its symmetric product stack S^{g+1}(X). When X is a point, the latter are structure constants of the symmetric group, and we obtain a new way of calculating the Gromov-Witten invariants of a point.

  14. Bacterial Symbionts of a Devastating Coffee Plant Pest, the Stinkbug Antestiopsis thunbergii (Hemiptera: Pentatomidae)

    OpenAIRE

    Matsuura, Yu; Hosokawa, Takahiro; Serracin, Mario; Tulgetske, Genet M.; Miller, Thomas A.; Fukatsu, Takema

    2014-01-01

    Stinkbugs of the genus Antestiopsis, so-called antestia bugs or variegated coffee bugs, are notorious pests of coffee plants in Africa. We investigated the symbiotic bacteria associated with Antestiopsis thunbergii, a major coffee plant pest in Rwanda. PCR, cloning, sequencing, and phylogenetic analysis of bacterial genes identified four distinct bacterial lineages associated with A. thunbergii: a gammaproteobacterial gut symbiont and symbionts representing the genera Sodalis, Spiroplasma, an...

  15. A Genus Oblivious Approach to Cross Parameterization

    Energy Technology Data Exchange (ETDEWEB)

    Bennett, J C; Pascucci, V; Joy, K I

    2008-06-16

    In this paper we present a robust approach to construct a map between two triangulated meshes, M and M{prime} of arbitrary and possibly unequal genus. We introduce a novel initial alignment scheme that allows the user to identify 'landmark tunnels' and/or a 'constrained silhouette' in addition to the standard landmark vertices. To describe the evolution of non-landmark tunnels we automatically derive a continuous deformation from M to M{prime} using a variational implicit approach. Overall, we achieve a cross parameterization scheme that is provably robust in the sense that it can map M to M{prime} without constraints on their relative genus. We provide a number of examples to demonstrate the practical effectiveness of our scheme between meshes of different genus and shape.

  16. The genus curve of the Abell clusters

    Science.gov (United States)

    Rhoads, James E.; Gott, J. Richard, III; Postman, Marc

    1994-01-01

    We study the topology of large-scale structure through a genus curve measurement of the recent Abell catalog redshift survey of Postman, Huchra, and Geller (1992). The structure is found to be spongelike near median density and to exhibit isolated superclusters and voids at high and low densities, respectively. The genus curve shows a slight shift toward 'meatball' topology, but remains consistent with the hypothesis of Gaussian random phase initial conditions. The amplitude of the genus curve corresponds to a power-law spectrum with index n = 0.21(sub -0.47 sup +0.43) on scales of 48/h Mpc or to a cold dark matter power spectrum with omega h = 0.36(sub -0.17 sup +0.46).

  17. Matrix models as CFT: Genus expansion

    International Nuclear Information System (INIS)

    We show how the formulation of the matrix models as conformal field theories on a Riemann surfaces can be used to compute the genus expansion of the observables. Here we consider the simplest example of the Hermitian matrix model, where the classical solution is described by a hyperelliptic Riemann surface. To each branch point of the Riemann surface we associate an operator which represents a twist field dressed by the modes of the twisted boson. The partition function of the matrix model is computed as a correlation function of such dressed twist fields. The perturbative construction of the dressing operators yields a set of Feynman rules for the genus expansion, which involve vertices, propagators and tadpoles. The vertices are universal, the propagators and the tadpoles depend on the Riemann surface. As a demonstration we evaluate the genus-two free energy using the Feynman rules.

  18. The lichen genus parmotrema in South Korea.

    Science.gov (United States)

    Jayalal, Udeni; Divakar, Pradeep K; Joshi, Santosh; Oh, Soon-Ok; Koh, Young Jin; Hur, Jae-Seoun

    2013-03-01

    Parmotrema A. Massal. is a common lichen genus scattered throughout the Korean Peninsula; however, no detailed taxonomic or revisionary study of this genus has been conducted for nearly two decades. Therefore, this study revised the taxonomy of this genus based on specimens deposited in the lichen herbarium at the Korean Lichen Research Institute and samples wereidentified using recent literature. In this revisionary study, a total of eighteen species of Parmotrema including eight new records [Parmotrema cetratum (Ach.) Hale, Parmotrema cristiferum (Taylor) Hale, Parmotrema grayanum (Hue) Hale, Parmotrema defectum (Hale) Hale, Parmotrema dilatatum (Vain.) Hale, Parmotrema margaritatum (Hue) Hale, Parmotrema pseudocrinitum (Abbayes) Hale, and Parmotrema subsumptum (Nyl.) Hale] are documented. Detailed descriptions of each species with their morphological, anatomical and chemical characteristics are also given and a key to the known Parmotrema species of the Korean Peninsula is presented. PMID:23610536

  19. Genus Mikania: chemical composition and phytotherapeutical activity

    Directory of Open Access Journals (Sweden)

    Luciane C. Rufatto

    2012-12-01

    Full Text Available The genus Mikania ranks high in the list of best-selling natural products in the world. Its main distribution is in South America, but some species are found in Asia, North America and Africa. It is used for treating fever, rheumatism, colds and respiratory diseases, as well as snake bites and scorpion stings, due to its broad spectrum of action. There are approximately 430 species of this genus and only 12% have been studied, highlighting their chemical and pharmacological diversity. The main chemical groups are: coumarins and derivatives, sesquiterpenes, sesquiterpenes lactones, diterpenes, phytosterols/terpenoids and flavonoids. This review aims to supply useful references for scientists interested in natural products and the search for new compounds, from over the 300 already described for the genus.

  20. Specific detection and real-time PCR quantification of potentially mycophagous bacteria belonging to the genus Collimonas in different soil ecosystems

    NARCIS (Netherlands)

    Höppener-Ogawa, S.; Leveau, J.H.J.; Smant, W.; Van Veen, J.A.; De Boer, W.

    2007-01-01

    The bacterial genus Collimonas has the remarkable characteristic that it grows at the expense of living fungal hyphae under laboratory conditions. Here, we report the first field inventory of the occurrence and abundance of Collimonas in soils (n = 45) with naturally different fungal densities, whic

  1. The toroidal block and the genus expansion

    CERN Document Server

    Kashani-Poor, Amir-Kian

    2012-01-01

    We study the correspondence between four-dimensional supersymmetric gauge theories and two-dimensional conformal field theories in the case of N=2* gauge theory. We emphasize the genus expansion on the gauge theory side, as obtained via geometric engineering from the topological string. This point of view uncovers modular properties of the one-point conformal block on a torus with complexified intermediate momenta: in the large intermediate weight limit, it is a power series whose coefficients are quasi-modular forms. The all-genus viewpoint that the conformal field theory approach lends to the topological string yields insight into the analytic structure of the topological string partition function.

  2. Constructing Numerical Semigroups of a Given Genus

    CERN Document Server

    Zhao, Yufei

    2009-01-01

    Let n_g denote the number of numerical semigroups of genus g. Bras-Amoros conjectured that n_g possesses certain Fibonacci-like properties. Almost all previous attempts at proving this conjecture were based on analyzing the semigroup tree. We offer a new, simpler approach to counting numerical semigroups of a given genus. Our method gives direct constructions of families of numerical semigroups, without referring to the generators or the semigroup tree. In particular, we give an improved asymptotic lower bound for n_g.

  3. Identification and nomenclature of the genus Penicillium

    DEFF Research Database (Denmark)

    Visagie, C.M.; Houbraken, J.; Frisvad, Jens Christian;

    2014-01-01

    Penicillium is a diverse genus occurring worldwide and its species play important roles as decomposers of organic materials and cause destructive rots in the food industry where they produce a wide range of mycotoxins. Other species are considered enzyme factories or are common indoor air allergens...... on each accepted species MycoBank number, living ex-type strains and provide GenBank accession numbers to ITS, β-tubulin, calmodulin and RPB2 sequences, thereby supplying a verified set of sequences for each species of the genus. In addition to the nomenclatural list, we recommend a standard working...

  4. Slope equalities for genus 5 surface fibrations

    CERN Document Server

    Tenni, Elisa

    2010-01-01

    K. Konno proved a slope equality for fibred surfaces with fibres of odd genus and general fibre of maximal gonality. More precisely he found a relation between the invariants of the fibration and certain weights of special fibres (called the Horikawa numbers). We give an alternative and more geometric proof in the case of a genus 5 fibration, under generality assumptions. In our setting we are able to prove that the fibre with positive Horikawa numbers are precisely the trigonal ones, we compute their weights explicitly and thus we exhibit explicit examples of regular surfaces with assigned invariants and Horikawa numbers.

  5. The genus of curve, pants and flip graphs

    OpenAIRE

    Parlier, Hugo; Petri, Bram

    2014-01-01

    This article is about the graph genus of certain well studied graphs in surface theory: the curve, pants and flip graphs. We study both the genus of these graphs and the genus of their quotients by the mapping class group. The full graphs, except for in some low complexity cases, all have infinite genus. The curve graph once quotiented by the mapping class group has the genus of a complete graph so its genus is well known by a theorem of Ringel and Youngs. For the other two graphs we are able...

  6. Phylogenetic analysis of symbionts in feather-feeding lice of the genus Columbicola: evidence for repeated symbiont replacements

    OpenAIRE

    Smith, Wendy A; Oakeson, Kelly F.; Johnson, Kevin P.; Reed, David L; Carter, Tamar; Smith, Kari L; Koga, Ryuichi; Fukatsu, Takema; Clayton, Dale H.; Dale, Colin

    2013-01-01

    Background Many groups of insects have obligate bacterial symbionts that are vertically transmitted. Such associations are typically characterized by the presence of a monophyletic group of bacteria living in a well-defined host clade. In addition the phylogeny of the symbiotic bacteria is typically congruent with that of the host, signifying co-speciation. Here we show that bacteria living in a single genus of feather lice, Columbicola (Insecta: Phthiraptera), present an exception to this ty...

  7. The psychrophilic bacterium Pseudoalteromonas halosplanktis TAC125 possesses a gene coding for a cold-adapted feruloyl esterase activity that shares homology with esterase enzymes from gamma-proteobacteria and yeast.

    Science.gov (United States)

    Aurilia, Vincenzo; Parracino, Antonietta; Saviano, Michele; Rossi, Mose'; D'Auria, Sabato

    2007-08-01

    The complete genome of the psychrophilic bacteria Pseudoalteromonas haloplanktis TAC 125, recently published, owns a gene coding for a putative esterase activity corresponding to the ORF PSHAa1385, also classified in the Carbohydrate Active Enzymes database (CAZY) belonging to family 1 of carbohydrate esterase proteins. This ORF is 843 bp in length and codes for a protein of 280 amino acid residues. In this study we characterized and cloned the PSHAa1385 gene in Escherichia coli. We also characterized the recombinant protein by biochemical and biophysical methodologies. The PSHAa1385 gene sequence showed a significant homology with several carboxyl-esterase and acetyl-esterase genes from gamma-proteobacteria genera and yeast. The recombinant protein exhibited a significant activity towards pNP-acetate, alpha-and beta-naphthyl acetate as generic substrates, and 4-methylumbelliferyl p-trimethylammonio cinnamate chloride (MUTMAC) as a specific substrate, indicating that the protein exhibits a feruloyl esterase activity that it is displayed by similar enzymes present in other organisms. Finally, a three-dimensional model of the protein was built and the amino acid residues involved in the catalytic function of the protein were identified. PMID:17543477

  8. Bacterial Succession in the Broiler Gastrointestinal Tract.

    Science.gov (United States)

    Ranjitkar, Samir; Lawley, Blair; Tannock, Gerald; Engberg, Ricarda M

    2016-04-15

    A feeding trial was performed with broilers receiving a diet of wheat-based feed (WBF), maize-based feed (MBF), or maize-based concentrates supplemented with 15% or 30% crimped kernel maize silage (CKMS-15 or CKMS-30, respectively). The aim of the study was to investigate the bacterial community compositions of the crop, gizzard, ileum, and cecum contents in relation to the feeding strategy and age (8, 15, 22, 25, 29, or 36 days). Among the four dietary treatments, bacterial diversity was analyzed for MBF and CKMS-30 by 454 pyrosequencing of the 16S rRNA gene. Since the diets had no significant influence on bacterial diversity, data were pooled for downstream analysis. With increasing age, a clear succession of bacterial communities and increased bacterial diversity were observed.Lactobacillaceae(belonging mainly to the genusLactobacillus) represented most of theFirmicutesat all ages and in all segments of the gut except the cecum. The development of a "mature" microbiota in broilers occurred during the period from days 15 to 22. Striking increases in the relative abundances ofLactobacillus salivarius(17 to 36%) and clostridia (11 to 18%), and a concomitant decrease in the relative abundance ofLactobacillus reuteri, were found in the ileum after day 15. The concentration of deconjugated bile salts increased in association with the increased populations ofL. salivariusand clostridia. BothL. salivariusand clostridia deconjugate bile acids, and increases in the abundances of these bacteria might be associated with growth reduction and gastrointestinal (GI) disorders occurring in the critical period of broiler life between days 20 and 30. PMID:26873323

  9. Evolutionary Relationships of “Candidatus Endobugula” Bacterial Symbionts and Their Bugula Bryozoan Hosts▿

    OpenAIRE

    Lim-Fong, Grace E.; Regali, Lindsay A.; Haygood, Margo G.

    2008-01-01

    Ribosomal gene sequences were obtained from bryozoans in the genus Bugula and their bacterial symbionts; analyses of host and symbiont phylogenetic trees did not support a history of strict cospeciation. Symbiont-derived compounds known to defend host larvae from predation were only detected in two out of four symbiotic Bugula species.

  10. Palynology of the Genus Stachytarpheta Vahl. (Verbenaceae

    Directory of Open Access Journals (Sweden)

    Olubukola ADEDEJI

    2010-12-01

    Full Text Available The exine morphology of pollen grains of Stachytarpheta indica (Linn. Vahl, Stachytarpheta cayennensis (Rich. Vahl and Stachytarpheta angustifolia (Mill. Vahl is reported. This study was carried out with a light microscope. Pollen grains from fresh anthers were collected and aceolysed. Statistical analysis used to analyse the data collected include cluster analysis, correlation analysis, similarity and distance indices. The pollen grains are spheroidal to oblate to sub-oblate in shape. They are aperturate, both colpate and porate. Tricolpate types occur most frequently, acolpate, monocolpate, bicolpate and tetracolpate types less frequently. The multicolpate and multiporate attributes in all the species indicate that the genus is not primitive in evolutionary history and this species probably, evolved around in the same time. According to the size, the pollen grains of the genus falls into groups permagna (pollen diameter 100-200 ?m and giganta (pollen diameter greater than 200 ?m. S. cayennensis and S. anguistifolia belong to group permagna and S. indica only in the group giganta. This separates S. indica from the other two species. The large pollen grain size in the genus clearly supports the fact that the flowers in the genus are more insect-and-bird pollinated than wind pollinated. The similarity and distance indices of the species showed that S. cayennensis and S. angustifolia are the closest. S. indica is closer to S. angustifolia but farther from S. cayennensis.

  11. Revision of the African genus Uvariastrum (Annonaceae

    Directory of Open Access Journals (Sweden)

    Thomas Couvreur

    2014-01-01

    Full Text Available The genus Uvariastrum (Annonaceae is restricted to continental Africa and is characterized by sepals with folded margins, few carpels and numerous stamens. The genus is mainly found in the tropical lowland rain forests of Africa, with one species growing in a drier woodland habitat. The species name U. pynaertii De Wild is reduced into synonymy with U. zenkeri Engl. & Diels. Uvaraistrum neglectum Paiva and U. modestum Diels are transferred to the genus Uvaria leading to two new combinations: Uvaria modesta (Diels Couvreur, comb. nov. and Uvaria paivana Couvreur, nom. nov.. Five species are currently recognized in Uvariastrum. The present revision, the first of the genus for over 100 years, provides an overview of previously published information and discussions on morphology, taxonomy and palynology. Preliminary conservation status assessments are provided for each species, as well as diagnostic keys for fruiting and flowering material as well as detailed species descriptions. Furthermore, all species are illustrated by line drawings and all species are mapped.

  12. The genus Lolium; taxonomy and genetic resources.

    NARCIS (Netherlands)

    Loos, B.P.

    1994-01-01

    Several aspects of variation within the genus Lolium, and more in detail within Lolium perenne (perennial ryegrass) have been highlighted. As the results are extensively discussed in each chapter, the general discussion is focused on two aspects of the research.SpeciationIt is clear that the

  13. Polyphasic taxonomy of the genus Talaromyces

    DEFF Research Database (Denmark)

    Yilmaz, N.; Visagie, C.M.; Houbraken, J.;

    2014-01-01

    The genus Talaromyces was described by Benjamin in 1955 as a sexual state of Penicillium that produces soft walled ascomata covered with interwoven hyphae. Phylogenetic information revealed that Penicillium subgenus Biverticillium and Talaromyces form a monophyletic clade distinct from the other ...

  14. Counting plane curves of any genus

    OpenAIRE

    Caporaso, Lucia; Harris, Joe

    1996-01-01

    We obtain a recursive formula answering the following question: How many irreducible, plane curves of degree d and (geometric) genus g pass through 3d-1+g general points in the plane? The formula is proved by studying suitable degenerations of plane curves.

  15. Chemotaxonomy of the genus Nuxia (Buddlejaceae)

    DEFF Research Database (Denmark)

    Jensen, Søren Rosendal

    An investigation of two species of Nuxia (Buddlejaceae) showed that this genus is characterised by the presence of the eight-carbon iridoid glucoside unedoside and/or its derivatives. From N. floribunda was isolated unedoside, nuxioside (6-O-a-L-rhamnopyranosyl-unedoside) and 2''-acetyl-3...

  16. Eremophilane Sesquiterpenes from the Genus Ligularia.

    Science.gov (United States)

    Wu, Ling; Liao, Zhixin; Liu, Chao; Jia, Haiyang; Sun, Jinyue

    2016-06-01

    Ligularia speices are widely used in Asian folk medicines for the treatment of various human diseases. Eremophilane-type sesquiterpenes are abundant and typical secondary metabolites found in this genus. Over 500 eremophilanes reported from members of Ligularia are reviewed in this article together with bioactivity data in an effort to highlight the development in this field. PMID:27161126

  17. The genus Echinostelium (Myxomycetes in Lithuania

    Directory of Open Access Journals (Sweden)

    Gražina Adamonytė

    2013-12-01

    Full Text Available Seven species of the genus – Echinostelium apitectum, E. arboreum, E. brooksii, E. colliculosum, E. corynophorum, E. aff. elachiston, E. minutum – are reported from Lithuania. Their morphological peculiarities are discussed; a key to the species, pictures and distribution maps are given.

  18. The genus Echinostelium (Myxomycetes) in Lithuania

    OpenAIRE

    Gražina Adamonytė

    2013-01-01

    Seven species of the genus – Echinostelium apitectum, E. arboreum, E. brooksii, E. colliculosum, E. corynophorum, E. aff. elachiston, E. minutum – are reported from Lithuania. Their morphological peculiarities are discussed; a key to the species, pictures and distribution maps are given.

  19. The genus Alocasia (Araceae) in Australasia

    NARCIS (Netherlands)

    Hay, A.; Wise, Rosemary

    1991-01-01

    The genus Alocasia (Araceae) is revised for Australasia. Thirteen species are recognised and keyed; eleven are endemic to and one is thought to be introduced to and escaped in Papuasia; A. brisbanensis (F.M. Bailey) Domin is endemic to Australia, and is redescribed; five are new to science. The genu

  20. A study in the genus Vulpia

    NARCIS (Netherlands)

    Henrard, J.Th.

    1937-01-01

    In conclusion, we propose the following nomenclatural alterations. For a good classification, the genus Vulpia is to be accepted as a member of the Festuceae. Various names of Vulpia are fixed according to our present rules of nomenclature, viz. V. bromoides (L.) GRAY, V. membranacea (L.) LINK, V. g

  1. Cosmetic surgeries on genus one knots

    OpenAIRE

    Wang, Jiajun

    2005-01-01

    In this paper, we prove that there are no truly cosmetic surgeries on genus one classical knots. If the two surgery slopes have the same sign, we give the only possibilities of reflectively cosmetic surgeries. The result is an application of Heegaard Floer theory and number theory.

  2. Sarawakodendron, a new genus of Celastraceae

    NARCIS (Netherlands)

    Hou, Ding

    1967-01-01

    During my trip to Malaysia in 1966, sponsored by the Netherlands Foundation for the Advancement of Tropical Research (WOTRO), for doing field work on Anacardiaceae, a new tree genus was found in Sarawak belonging to the family Celastraceae which I have revised for the Flora Malesiana series I, volum

  3. Revision of the genus Fordia (Papilionaceae: Millettieae)

    NARCIS (Netherlands)

    Buijsen, J.R.M.

    1988-01-01

    In Fordia, a small genus of Southeast Asian Papilionaceae, 8 species are accepted and 2 subspecies, one of which is newly described (F. splendidissima subsp. rheophytica). The name of F. splendidissima is a new combination of an old name proposed by Miquel. Six names (among which F. coriacea, F. gib

  4. Revision of the genus Gymnacranthera (Myristicaceae)

    NARCIS (Netherlands)

    Schouten, R.T.A.

    1986-01-01

    In Gymnacranthera, a small genus of Southeast Asian Myristicaceae, at present 7 species have been accepted, one (G. forbesii) with 2 and another ( G. farquhariana) with 4 varieties. One species, G. canarica, occurs in S. India, the remainder of the species is distributed in the area from S. Thailand

  5. Nomenclatural changes in the genus Bremeria (Rubiaceae)

    NARCIS (Netherlands)

    Davis, A.P.; Razafimandimbison, S.G.; Andriambololonera, S.

    2011-01-01

    Five new combinations are made in the genus Bremeria: B. arachnocarpa, B. eriantha, B. scabrella, B. landia var. holosericea, and B. landia var. stadmanii. Bremeria gerrardii is conspecific with Gaertnera phanerophlebia, and thus excluded from Bremeria. Lectotypes are designated for Mussaenda erecti

  6. Tunnel number one, genus one fibered knots

    OpenAIRE

    Baker, Kenneth L.; Johnson, Jesse E.; Klodginski, Elizabeth A.

    2006-01-01

    We determine the genus one fibered knots in lens spaces that have tunnel number one. We also show that every tunnel number one, once-punctured torus bundle is the result of Dehn filling a component of the Whitehead link in the 3-sphere.

  7. Vimentin in Bacterial Infections

    DEFF Research Database (Denmark)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    -vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial......Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate...... filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge...

  8. Genus two Heegaard splittings of exteriors of 1-genus 1-bridge knots II

    CERN Document Server

    Goda, Hiroshi

    2010-01-01

    A knot K is called a 1-genus 1-bridge knot in a 3-manifold M if (M,K) has a Heegaard splitting (V_1,t_1)\\cup (V_2,t_2) where V_i is a solid torus and t_i is a boundary parallel arc properly embedded in V_i. If the exterior of a knot has a genus 2 Heegaard splitting, we say that the knot has an unknotting tunnel. Naturally the exterior of a 1-genus 1-bridge knot K allows a genus 2 Heegaard splitting, i.e., K has an unknotting tunnel. But, in general, there are unknotting tunnels which are not derived form this procedure. Some of them may be levelled with the torus \\partial V_1=\\partial V_2, whose case was studied in our previous paper. In this paper, we consider the remaining case.

  9. Demonstrating Bacterial Flagella.

    Science.gov (United States)

    Porter, John R.; And Others

    1992-01-01

    Describes an effective laboratory method for demonstrating bacterial flagella that utilizes the Proteus mirabilis organism and a special harvesting technique. Includes safety considerations for the laboratory exercise. (MDH)

  10. A New Genus of Macropsinae (Hemiptera: Cicadellidae) From Madagascar

    OpenAIRE

    Yang, Liyuan; Dietrich, C.H.; Zhang, Yalin

    2016-01-01

    Paragalboa acuta gen. & sp. n. is described and illustrated from Madagascar. The new genus shows morphological affinities to the Macropsini genus Galboa Distant recorded from Seychelles. A checklist of all known genera of Macropsinae is provided.

  11. Genus Phyllanthus for chronic hepatitis B virus infection

    DEFF Research Database (Denmark)

    Liu, J; Lin, Haili; McIntosh, H

    2001-01-01

    To evaluate the efficacy and safety of genus Phyllanthus for chronic hepatitis B virus (HBV) infection we performed a systematic review of randomized clinical trials. Randomized trials comparing genus Phyllanthus vs. placebo, no intervention, general nonspecific treatment, other herbal medicine, ...

  12. Certhiasomus, a new genus of woodcreeper (Aves: Passeriformes: Dendrocolaptidae)

    Science.gov (United States)

    Derryberry, Elizabeth; Claramunt, Santiago; Chesser, R. Terry; Aleixo, Alexandre; Cracraft, Joel; Moyle, Robert G.; Brumfield, Robb T.

    2010-01-01

    Phylogenetic analysis of the family Dendrocolaptidae (Aves: Passeriformes) indicates that the two species traditionally placed in the genus Deconychura are not sister taxa. Certhiasomus, a new genus of woodcreeper, is described for one of these species, C. stictolaemus.

  13. Elliptic genus of phases of N=2 theories

    OpenAIRE

    Libgober, A.

    2014-01-01

    We discuss an algebro-geometric description of Witten's phases of N=2 theories and propose a definition of their elliptic genus provided some conditions on singularities of the phases are met. For Landau-Ginzburg phase one recovers elliptic genus of LG models proposed in physics literature in early 90s. For certain transitions between phases we derive invariance of elliptic genus from an equivariant form of McKay correspondence for elliptic genus. As special cases one obtains Landau-Giznburg/...

  14. A review on phytochemistry and ethnopharmacological aspects of genus Calendula

    OpenAIRE

    Disha Arora; Anita Rani; Anupam Sharma

    2013-01-01

    This review includes 84 references on the genus Calendula (Asteraceae) and comprises ethnopharmacology, morphology and microscopy, phytoconstituents, pharmacological reports, clinical studies and toxicology of the prominent species of Calendula. Triterpene alcohols, triterpene saponins, flavonoids, carotenoids and polysaccharides constitute major classes of phytoconstituents of the genus. A few species of this genus have medicinal value, among these Calendula officinalis Linn., has been tradi...

  15. The strong symmetric genus of the finite Coxeter groups

    OpenAIRE

    Jackson, Michael A.

    2004-01-01

    The strong symmetric genus of a finite group G is the smallest genus of a closed orientable topological surface on which G acts faithfully as a group of orientation preserving automorphisms. In this paper we complete the calculation of the strong symmetric genus for each finite Coxeter group excluding the group E8.

  16. Positive braid knots of maximal topological 4-genus

    OpenAIRE

    Liechti, Livio

    2015-01-01

    We show that a positive braid knot has maximal topological 4-genus exactly if it has maximal signature invariant. As an application, we determine all positive braid knots with maximal topological 4-genus and compute the topological 4-genus for all positive braid knots with up to 12 crossings.

  17. Redefinition of the genus Triophtydeus Thor, 1932 (Acari: Actinedida)

    OpenAIRE

    André, H.M.

    1985-01-01

    The genus Triophtydeus Thor, 1932 is redefined from the study of the type-species, T. triophthalmus (Oudemans, 1929). The genus Metatriophtydeus André, 1980 is a junior synonym of Triophtydeus. Species belonging or likely to belong to the genus Triophtydeus are listed and generic and specific characters are discussed.

  18. Limit groups, positive-genus towers and measure equivalence

    OpenAIRE

    Bridson, Martin R.; Tweedale, Michael; Wilton, Henry

    2005-01-01

    By definition, an $\\omega$-residually free tower is positive-genus if all surfaces used in its construction are of positive genus. We prove that every limit group is virtually a subgroup of a positive-genus $\\omega$-residually free tower. By combining this with results of Gaboriau, we prove that elementarily free groups are measure equivalent to free groups.

  19. A taxonomic revision of the genus Ixonanthes (Linaceae)

    OpenAIRE

    Kool, R.

    1980-01-01

    In this revision 3 species are recognized for the Southeast Asian, mainly Malesian, genus Ixonanthes Jack (Linaceae). No new species are described, while 29 names have been placed into synonymy. It is proposed to unite the African genus Phyllocosmus Klotzsch with the American genus Ochthocosmus Benth.

  20. Create the genus Pelarspovirus in the family Tombusviridae

    Science.gov (United States)

    In 2014 we submitted a proposal to create this new genus with six members. The Executive Committee (EC) of the ICTV did not support its creation at that time due to the placement of the pelarspovirus genus branch within a larger monophyletic lineage of many of the members of the carmovirus genus wh...

  1. Crossoliparis - a new genus of Malaxidinae (Orchidaceae, Malaxideae), from neotropic

    OpenAIRE

    Hanna B. Margońska

    2011-01-01

    A new genus Crossoliparis of the subtribe Malaxidinae (Orchidaceae), from tropical area of Central America is proposed. The new genus type species is described and illustrated. Keys to species of genus Crossoliparis and its close related genera of subtribe Malaxidinae from Americas, is added.

  2. Crossoliparis - a new genus of Malaxidinae (Orchidaceae, Malaxideae, from neotropic

    Directory of Open Access Journals (Sweden)

    Hanna B. Margońska

    2011-04-01

    Full Text Available A new genus Crossoliparis of the subtribe Malaxidinae (Orchidaceae, from tropical area of Central America is proposed. The new genus type species is described and illustrated. Keys to species of genus Crossoliparis and its close related genera of subtribe Malaxidinae from Americas, is added.

  3. Topological classification and enumeration of RNA structures by genus

    DEFF Research Database (Denmark)

    Andersen, Jørgen Ellegaard; Penner, Robert; Reidys, C. M.; Waterman, M.S.

    2013-01-01

    To an RNA pseudoknot structure is naturally associated a topological surface, which has its associated genus, and structures can thus be classified by the genus. Based on earlier work of Harer-Zagier, we compute the generating function for the number of those structures of fixed genus and minimum...

  4. Pseudasthenes, a new genus of ovenbird (Aves: Passeriformes: Furnariidae)

    Science.gov (United States)

    Derryberry, Elizabeth; Claramunt, Santiago; O'Quin, Kelly E.; Aleixo, Alexandre; Chesser, R. Terry; Remsen, J.V., Jr.; Brumfield, Robb T.

    2010-01-01

    Phylogenetic analysis of the family Furnariidae (Aves: Passeriformes) indicates that the genus Asthenes is polyphyletic, consisting of two groups that are not sister taxa. Pseudasthenes, a new genus of ovenbird, is described for one of these groups. The four species included in the new genus, formerly placed in Asthenes, are P. humicola, P. patagonica, P. steinbachi, and P. cactorum.

  5. Comparative analysis of bacterial community-metagenomics in coastal Gulf of Mexico sediment microcosms following exposure to Macondo oil (MC252)

    KAUST Repository

    Koo, Hyunmin

    2014-09-10

    The indigenous bacterial communities in sediment microcosms from Dauphin Island (DI), Petit Bois Island (PB) and Perdido Pass (PP) of the coastal Gulf of Mexico were compared following treatment with Macondo oil (MC252) using pyrosequencing and culture-based approaches. After quality-based trimming, 28,991 partial 16S rRNA sequence reads were analyzed by rarefaction, confirming that analyses of bacterial communities were saturated with respect to species diversity. Changes in the relative abundances of Proteobacteria, Bacteroidetes and Firmicutes played an important role in structuring bacterial communities in oil-treated sediments. Proteobacteria were dominant in oil-treated samples, whereas Firmicutes and Bacteroidetes were either the second or the third most abundant taxa. Tenericutes, members of which are known for oil biodegradation, were detected shortly after treatment, and continued to increase in DI and PP sediments. Multivariate statistical analyses (ADONIS) revealed significant dissimilarity of bacterial communities between oil-treated and untreated samples and among locations. In addition, a similarity percentage analysis showed the contribution of each species to the contrast between untreated and oil-treated samples. PCR amplification using DNA from pure cultures of Exiguobacterium,  Pseudoalteromonas,  Halomonas and Dyadobacter, isolated from oil-treated microcosm sediments, produced amplicons similar to polycyclic aromatic hydrocarbon-degrading genes. In the context of the 2010 Macondo blowout, the results from our study demonstrated that the indigenous bacterial communities in coastal Gulf of Mexico sediment microcosms responded to the MC252 oil with altered community structure and species composition. The rapid proliferation of hydrocarbonoclastic bacteria suggests their involvement in the degradation of the spilt oil in the Gulf of Mexico ecosystem.

  6. Bacterial flora of spices and its control by gamma irradiation

    International Nuclear Information System (INIS)

    The bacterial contamination was tested in 26 samples of spices. Chili, allspice and paprika were the most contaminated spices by bacteria. Five bacterial genera were isolated, namely bacillus, staphylococcus, streptococcus, micrococcus, and coccobacillus, all being gram-positive. Most isolates have been related to the genus bacillus. The bacterial isolates were identified as B. alvei, B. circulans, B. megaterium, B. pasteurii, B. pumilus, B. thuringiensis, B. sphaericus, B. incertaesedis, Micrococcus luteus, staphylococcus aureus, streptococcus sp. and coccobacillus sp. Irradiation of spices led to a significant decrease in the bacterial count of all samples. The dose required to inhibit completely the natural bacterial flora was 25 KGY. The most radioresistant isolates were staphylococcus aureus and micrococcus luteus which were subjected to sublethal doses of 15 and 20 KGY respectively. The dose response curves of the 2 most radioresistant isolates showed simple exponential relationship. The D 10-value of S. aureus and M. luteus were 0.9 and 1.1 KGY, respectively. The effect of storage period on the bacterial load of, as well as, the antibacterial activity of the tested spices were investigated. (author)

  7. Shuffling bacterial metabolomes

    OpenAIRE

    Thomason, Brendan; Read, Timothy D.

    2006-01-01

    Horizontal gene transfer (HGT) has a far more significant role than gene duplication in bacterial evolution. This has recently been illustrated by work demonstrating the importance of HGT in the emergence of bacterial metabolic networks, with horizontally acquired genes being placed in peripheral pathways at the outer branches of the networks.

  8. Vimentin in Bacterial Infections.

    Science.gov (United States)

    Mak, Tim N; Brüggemann, Holger

    2016-01-01

    Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs). IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection. PMID:27096872

  9. Prevention of bacterial adhesion

    DEFF Research Database (Denmark)

    Klemm, Per; Vejborg, Rebecca Munk; Hancock, Viktoria

    2010-01-01

    Management of bacterial infections is becoming increasingly difficult due to the emergence and increasing prevalence of bacterial pathogens that are resistant to available antibiotics. Conventional antibiotics generally kill bacteria by interfering with vital cellular functions, an approach that ...... become valuable weapons for preventing pathogen contamination and fighting infectious diseases in the future....

  10. Vimentin in Bacterial Infections

    Directory of Open Access Journals (Sweden)

    Tim N. Mak

    2016-04-01

    Full Text Available Despite well-studied bacterial strategies to target actin to subvert the host cell cytoskeleton, thus promoting bacterial survival, replication, and dissemination, relatively little is known about the bacterial interaction with other components of the host cell cytoskeleton, including intermediate filaments (IFs. IFs have not only roles in maintaining the structural integrity of the cell, but they are also involved in many cellular processes including cell adhesion, immune signaling, and autophagy, processes that are important in the context of bacterial infections. Here, we summarize the knowledge about the role of IFs in bacterial infections, focusing on the type III IF protein vimentin. Recent studies have revealed the involvement of vimentin in host cell defenses, acting as ligand for several pattern recognition receptors of the innate immune system. Two main aspects of bacteria-vimentin interactions are presented in this review: the role of vimentin in pathogen-binding on the cell surface and subsequent bacterial invasion and the interaction of cytosolic vimentin and intracellular pathogens with regards to innate immune signaling. Mechanistic insight is presented involving distinct bacterial virulence factors that target vimentin to subvert its function in order to change the host cell fate in the course of a bacterial infection.

  11. An ortholog of the Leptospira interrogans lipoprotein LipL32 aids in the colonization of Pseudoalteromonas tunicata to host surfaces

    Directory of Open Access Journals (Sweden)

    SuhelenEgan

    2014-07-01

    Full Text Available The bacterium P. tunicata is a common surface colonizer of marine eukaryotes, including the macroalga Ulva australis. Genomic analysis of P. tunicata identified genes potentially involved in surface colonization, including genes with homology to bacterial virulence factors that mediate attachment. Of particular interest is the presence of a gene, designated ptlL32, encoding an ortholog to the Leptospira lipoprotein LipL32, which has been shown to facilitate the interaction of Leptospira sp. with host extracellular matrix (ECM structures and is thought to be an important virulence trait for pathogenic Leptospira. To investigate the role of PtlL32 in the colonization by P. tunicata we constructed and characterized a ΔptlL32 mutant strain. Whilst P. tunicata ΔptlL32 bound to an abiotic surface with the same capacity as the wild type strain, it had a marked effect on the ability of P. tunicata to bind to ECM, suggesting a specific role in attachment to biological surfaces. Loss of PtlL32 also significantly reduced the capacity for P. tunciata to colonize the host algal surface demonstrating a clear role for this protein as a host-colonization factor. PtlL32 appears to have a patchy distribution across specific groups of environmental bacteria and phylogenetic analysis of PtlL32 orthologous proteins from non-Leptospira species suggests it may have been acquired via horizontal gene transfer between distantly related lineages. This study provides the first evidence for an attachment function for a LipL32- like protein outside the Leptospira and thereby contributes to the understanding of host colonization in ecologically distinct bacterial species.

  12. Dynamic bacterial communities on reverse-osmosis membranes in a full-scale desalination plant.

    Science.gov (United States)

    Manes, C-L de O; West, N; Rapenne, S; Lebaron, P

    2011-01-01

    To better understand biofouling of seawater reverse osmosis (SWRO) membranes, bacterial diversity was characterized in the intake water, in subsequently pretreated water and on SWRO membranes from a full-scale desalination plant (FSDP) during a 9 month period. 16S rRNA gene fingerprinting and sequencing revealed that bacterial communities in the water samples and on the SWRO membranes were very different. For the different sampling dates, the bacterial diversity of the active and the total bacterial fractions of the water samples remained relatively stable over the sampling period whereas the bacterial community structure on the four SWRO membrane samples was significantly different. The richness and evenness of the SWRO membrane bacterial communities increased with usage time with an increase in the Shannon diversity index of 2.2 to 3.7. In the oldest SWRO membrane (330 days), no single operational taxonomic unit (OTU) dominated and the majority of the OTUs fell into the Alphaproteobacteria or the Planctomycetes. In striking contrast, a Betaproteobacteria OTU affiliated to the genus Ideonella was dominant and exclusively found in the membrane used for the shortest time (10 days). This suggests that bacteria belonging to this genus could be one of the primary colonizers of the SWRO membrane. Knowledge of the dominant bacterial species on SWRO membranes and their dynamics should help guide culture studies for physiological characterization of biofilm forming species. PMID:21108068

  13. The toroidal block and the genus expansion

    Science.gov (United States)

    Kashani-Poor, Amir-Kian; Troost, Jan

    2013-03-01

    We study the correspondence between four-dimensional supersymmetric gauge theories and two-dimensional conformal field theories in the case of {N}={2^{*}} gauge theory. We emphasize the genus expansion on the gauge theory side, as obtained via geometric engineering from the topological string. This point of view uncovers modular properties of the one-point conformal block on a torus with complexified intermediate momenta: in the large intermediate weight limit, it is a power series whose coefficients are quasimodular forms. The all-genus viewpoint that the conformal field theory approach lends to the topological string yields insight into the analytic structure of the topological string partition function in the field theory limit.

  14. On the genus of a maximal curve

    OpenAIRE

    Korchmaros, Gabor; Torres, Fernando

    2000-01-01

    Previous results on genera g of F_{q^2}-maximal curves are improved: (1) Either g\\leq (q^2-q+4)/6, or g=\\lfloor(q-1)^2/4\\rfloor, or g=q(q-1)/2; (2) The hypothesis on the existence of a particular Weierstrass point in \\cite{at} is proved; (3) For q\\equiv 1\\pmod{3}, q\\ge 13, no F_{q^2}-maximal curve of genus (q-1)(q-2)/3 exists; (4) For q\\equiv 2\\pmod{3}, q\\ge 11, the non-singular F_{q^2}-model of the plane curve of equation y^q+y=x^{(q+1)/3} is the unique F_{q^2}-maximal curve of genus g=(q-1)...

  15. Phylogeny and taxonomy of the genus Gliocephalotrichum.

    Science.gov (United States)

    Lombard, L; Serrato-Diaz, L M; Cheewangkoon, R; French-Monar, R D; Decock, C; Crous, P W

    2014-06-01

    Species in the genus Gliocephalotrichum (= Leuconectria) (Hypocreales, Nectriaceae) are soilborne fungi, associated with post-harvest fruit spoilage of several important tropical fruit crops. Contemporary taxonomic studies of these fungi have relied on morphology and DNA sequence comparisons of the internal transcribed spacer region of the nuclear rDNA (ITS) and the β-tubulin gene regions. Employing DNA sequence data from four loci (β-tubulin, histone H3, ITS, and translation elongation factor 1-alpha) and morphological comparisons, the taxonomic status of the genus Gliocephalotrichum was re-evaluated. As a result five species are newly described, namely G. humicola (Taiwan, soil), G. mexicanum (rambutan fruit from Mexico), G. nephelii (rambutan fruit from Guatemala), G. queenslandicum (Australia, endophytic isolations) and G. simmonsii (rambutan fruit from Guatemala). Although species of Gliocephalotrichum are generally not regarded as important plant pathogens, their ability to cause post-harvest fruit rot could have an impact on fruit export and storage. PMID:25264387

  16. Elliptic Genus of Phases of N = 2 Theories

    Science.gov (United States)

    Libgober, Anatoly

    2015-12-01

    We discuss an algebro-geometric description of Witten's phases of N = 2 theories and propose a definition of their elliptic genus provided some conditions on singularities of the phases are met. For Landau-Ginzburg phase one recovers elliptic genus of LG models proposed in physics literature in early 1990s. For certain transitions between phases we derive invariance of elliptic genus from an equivariant form of McKay correspondence for elliptic genus. As special cases one obtains Landau-Giznburg/Calabi-Yau correspondence for elliptic genus of weighted homogeneous potentials as well as certain hybrid/CY correspondences.

  17. Chemical Constituents of Plants from the Genus Ixora.

    Science.gov (United States)

    Chen, Li-Jun; Zhang, Yan; Chen, Ye-Gao

    2016-03-01

    Ixora is a genus of ca. 400 species in the family Rubiaceae. Since the 1940s, eighty-one compounds including phenolics, peptides, terpenoids, and sterols have been isolated from six species of the genus Ixora. Pharmacological studies have shown that these compounds and extracts from the Ixora genus have extensive activities, such as antitumor, chemoprotective, and antioxidant activities. In this review, we summarize the phytochemical progress and list the compounds isolated from the genus Ixora. The biological activities of this genus are also covered. PMID:26916522

  18. Perturbations of quadratic centers of genus one

    OpenAIRE

    Gautier, Sebastien; Gavrilov, Lubomir; Iliev, Iliya D.

    2007-01-01

    We propose a program for finding the cyclicity of period annuli of quadratic systems with centers of genus one. As a first step, we classify all such systems and determine the essential one-parameter quadratic perturbations which produce the maximal number of limit cycles. We compute the associated Poincare-Pontryagin-Melnikov functions whose zeros control the number of limit cycles. To illustrate our approach, we determine the cyclicity of the annuli of two particular reversible systems.

  19. Cyanobacteria of the Genus Prochlorothrix †

    OpenAIRE

    Pinevich, Alexander; Velichko, Natalia; Ivanikova, Natalia

    2012-01-01

    Green cyanobacteria differ from the blue–green cyanobacteria by the possession of a chlorophyll-containing light-harvesting antenna. Three genera of the green cyanobacteria namely Acaryochloris, Prochlorococcus, and Prochloron are unicellular and inhabit marine environments. Prochlorococcus marinus attracts most attention due to its prominent role in marine primary productivity. The fourth genus Prochlorothrix is represented by the filamentous freshwater strains. Unlike the other green cyanob...

  20. The toroidal block and the genus expansion

    OpenAIRE

    Kashani-Poor, Amir-Kian; Troost, Jan

    2012-01-01

    We study the correspondence between four-dimensional supersymmetric gauge theories and two-dimensional conformal field theories in the case of N=2* gauge theory. We emphasize the genus expansion on the gauge theory side, as obtained via geometric engineering from the topological string. This point of view uncovers modular properties of the one-point conformal block on a torus with complexified intermediate momenta: in the large intermediate weight limit, it is a power series whose coefficient...

  1. The diatom genus Proboscia in subarctic waters

    OpenAIRE

    Takahashi, Kozo; Jordan, Richard; Priddle, Julian

    1994-01-01

    A study of modem pelagic subarctic Pacific phytoplankton has revealed the presence of three distinct species of Proboscia Sundstrom, including the type species P. alata and two new species with historical complications, P. subarctica (= Rhizosolenia alata f. curvirostris Gran) is markedly different in proboscis and valve morphology from the type species and in fact bears more resemblance to fossil members of the genus. P. eumorpha (= R. obtusa Hensen sensu Ostenfeld) resembles the austral spe...

  2. Phylogeny and taxonomy of the genus Gliocephalotrichum

    OpenAIRE

    Lombard, L.; Serrato-Diaz, L.M.; Cheewangkoon, R.; French-Monar, R.D.; Decock, C.; Crous, P.W.

    2014-01-01

    Species in the genus Gliocephalotrichum (= Leuconectria) (Hypocreales, Nectriaceae) are soilborne fungi, associated with post-harvest fruit spoilage of several important tropical fruit crops. Contemporary taxonomic studies of these fungi have relied on morphology and DNA sequence comparisons of the internal transcribed spacer region of the nuclear rDNA (ITS) and the β-tubulin gene regions. Employing DNA sequence data from four loci (β-tubulin, histone H3, ITS, and translation elongation facto...

  3. Concordance of Bing Doubles and Boundary Genus

    Science.gov (United States)

    Livingston, Charles; van Cott, Cornelia A.

    2011-11-01

    Cha and Kim proved that if a knot K is not algebraically slice, then no iterated Bing double of K is concordant to the unlink. We prove that if K has nontrivial signature $\\sigma$, then the n-iterated Bing double of K is not concordant to any boundary link with boundary surfaces of genus less than $2^{n-1}\\sigma$. The same result holds with $\\sigma$ replaced by $2\\tau$, twice the Ozsvath-Szabo knot concordance invariant.

  4. The genus Crataegus: chemical and pharmacological perspectives

    OpenAIRE

    Dinesh Kumar; Vikrant Arya; Zulfiqar Ali Bhat; Nisar Ahmad Khan; Deo Nandan Prasad

    2012-01-01

    Traditional drugs have become a subject of world importance, with both medicinal and economical implications. A regular and widespread use of herbs throughout the world has increased serious concerns over their quality, safety and efficacy. Thus, a proper scientific evidence or assessment has become the criteria for acceptance of traditional health claims. Plants of the genus Crataegus, Rosaceae, are widely distributed and have long been used in folk medicine for the treatment of various ailm...

  5. Genomic characterization of the Taylorella genus

    OpenAIRE

    Hebert, Laurent; Moumen, Bouziane; Pons, Nicolas; Duquesne, Fabien; Breuil, Marie-France; Goux, Didier; Batto, Jean-Michel; Laugier, Claire; Renault, Pierre; Petry, Sandrine

    2012-01-01

    The Taylorella genus comprises two species: Taylorella equigenitalis, which causes contagious equine metritis, and Taylorella asinigenitalis, a closely-related species mainly found in donkeys. We herein report on the first genome sequence of T. asinigenitalis, analyzing and comparing it with the recently-sequenced T. equigenitalis genome. The T. asinigenitalis genome contains a single circular chromosome of 1,638,559 bp with a 38.3% GC content and 1,534 coding sequences (CDS). While 212 CDSs ...

  6. Operators and higher genus mirror curves

    CERN Document Server

    Codesido, Santiago; Marino, Marcos

    2016-01-01

    We perform further tests of the correspondence between spectral theory and topological strings, focusing on mirror curves of genus greater than one with nontrivial mass parameters. In particular, we analyze the geometry relevant to the SU(3) relativistic Toda lattice, and the resolved C^3/Z_6 orbifold. Furthermore, we give evidence that the correspondence holds for arbitrary values of the mass parameters, where the quantization problem leads to resonant states. We also explore the relation between this correspondence and cluster integrable systems.

  7. The genus Crataegus: chemical and pharmacological perspectives

    Directory of Open Access Journals (Sweden)

    Dinesh Kumar

    2012-10-01

    Full Text Available Traditional drugs have become a subject of world importance, with both medicinal and economical implications. A regular and widespread use of herbs throughout the world has increased serious concerns over their quality, safety and efficacy. Thus, a proper scientific evidence or assessment has become the criteria for acceptance of traditional health claims. Plants of the genus Crataegus, Rosaceae, are widely distributed and have long been used in folk medicine for the treatment of various ailments such as heart (cardiovascular disorders, central nervous system, immune system, eyes, reproductive system, liver, kidney etc. It also exhibits wide range of cytotoxic, gastroprotective, anti-inflammatory, anti-HIV and antimicrobial activities. Phytochemicals like oligomeric procyanidins, flavonoids, triterpenes, polysaccharides, catecholamines have been identified in the genus and many of these have been evaluated for biological activities. This review presents comprehensive information on the chemistry and pharmacology of the genus together with the traditional uses of many of its plants. In addition, this review discusses the clinical trials and regulatory status of various Crataegus plants along with the scope for future research in this aspect.

  8. Phylogeography of genus Squalius in Albania

    Directory of Open Access Journals (Sweden)

    Radek Šanda

    2015-11-01

    Full Text Available This study is focused on the issue of the Squalius genus phylogeography in Albania in the Balkan region. Phylogenetic analyses of sequence variation at mitochondrial DNA (cytochrome b gene were used to examine these issues for the freshwater fish of the genus Squalius from various river systems in the Adriatic Sea region. There were identified three genetic lineages of unclear taxonomic position, where the genetic variation between identified clades range from 1.6 to 2.1 %. The first lineage is distributed in the Neretva River drainage in Bosnia and Hercegovina, i.e. north of Albania and in the whole remaining Periadriatic regions, whereas the second lineage is especially spread in the northern part of Albania and the third lineage occurs especially in the zone of the European ancient lake systems on the Balkan Peninsula (lakes Ohrid and Prespa, from where expands to the southern part of Albania. Both lineages sympatrically coincide in the hydrological river-lake system of Ohrid-Drin-Skadar. The phylogenetic and taxonomic position of the Squalius genus in the region seems to be interesting topic for subsequent and more detailed study.

  9. The genus Capsicum (Solanaceae in Africa

    Directory of Open Access Journals (Sweden)

    W. H. Eshbaugh

    1983-12-01

    Full Text Available The genus Capsicum (Solanaceae includes approximately 20 wild species and 4-5 domesticated taxa commonly referred to as ‘chilies’ or ‘peppers’. The pre-Colombian distribution of the genus was New World. The evolutionary history of the genus is now envisaged as including three distinct lines leading to the domesticated taxa. The route of Capsicum to the Old World is thought to have followed three different courses. First, explorers introduced it to Europe with secondary introduction into Africa via further exploratory expeditions; second, botanical gardens played a major role in introduction; and third, introduction followed the slave trade routes. Today, pepper production in Africa is of two types, vegetable and spice. Statistical profiles on production are difficult to interpret, but the data available indicate that Nigeria, Egypt, Tunisia and Ghana are the leading producers. Production is mainly a local phenomenon and large acreage is seldom devoted to the growing of peppers. The primary peppers in Africa are C.  annuum and C.  frutescens.

  10. Standardized gene nomenclature for the Brassica genus

    Directory of Open Access Journals (Sweden)

    King Graham J

    2008-05-01

    Full Text Available Abstract The genus Brassica (Brassicaceae, Brassiceae is closely related to the model plant Arabidopsis, and includes several important crop plants. Against the background of ongoing genome sequencing, and in line with efforts to standardize and simplify description of genetic entities, we propose a standard systematic gene nomenclature system for the Brassica genus. This is based upon concatenating abbreviated categories, where these are listed in descending order of significance from left to right (i.e. genus – species – genome – gene name – locus – allele. Indicative examples are provided, and the considerations and recommendations for use are discussed, including outlining the relationship with functionally well-characterized Arabidopsis orthologues. A Brassica Gene Registry has been established under the auspices of the Multinational Brassica Genome Project that will enable management of gene names within the research community, and includes provisional allocation of standard names to genes previously described in the literature or in sequence repositories. The proposed standardization of Brassica gene nomenclature has been distributed to editors of plant and genetics journals and curators of sequence repositories, so that it can be adopted universally.

  11. Identification of signature and primers specific to genus Pseudomonas using mismatched patterns of 16S rDNA sequences

    OpenAIRE

    Kapley A; Raje DV; Purohit HJ

    2003-01-01

    Abstract Background Pseudomonas, a soil bacterium, has been observed as a dominant genus that survives in different habitats with wide hostile conditions. We had a basic assumption that the species level variation in 16S rDNA sequences of a bacterial genus is mainly due to substitutions rather than insertion or deletion of bases. Keeping this in view, the aim was to identify a region of 16S rDNA sequence and within that focus on substitution prone stretches indicating species level variation ...

  12. The myxomycete genus Schenella: morphological and DNA sequence evidence for synonymy with the gasteromycete genus Pyrenogaster.

    Science.gov (United States)

    Estrada-Torres, Arturo; Gaither, Thomas W; Miller, Dennis L; Lado, Carlos; Keller, Harold W

    2005-01-01

    The genus Schenella has proven difficult to classify since its description as a new genus in 1911. Macbride placed it with the Myxomycetes but it was unclear with which myxomycete, if any, it should be grouped. Recent identification of abundant samples of Schenella has aided a re-evaluation of its classification as a myxomycete. Morphological evidence based on light and scanning electron microscopy of recently collected specimens and on the type specimen of Macbride suggested that it might be synonymous with the gasteromycete Pyrenogaster Analysis of DNA sequences from freshly isolated samples indicates that the genus Schenella is related closely to an anciently diverged, monophyletic group of fungi that includes several gasteromycete genera, among them Geastrum, Sphaerobolus and Pseudocolus. Comparisons of the morphology and DNA sequences of authentically identified specimens of Pyrenogaster atrogleba indicate that it is synonymous with Schenella simplex. The nomenclatural implications of this discovery are discussed. PMID:16389965

  13. Bizionia arctica sp. nov., isolated from Arctic fjord seawater, and emended description of the genus Bizionia.

    Science.gov (United States)

    Li, Hai; Zhang, Xi-Ying; Liu, Chang; Liu, Ang; Qin, Qi-Long; Su, Hai-Nan; Shi, Mei; Zhou, Bai-Cheng; Chen, Xiu-Lan; Zhang, Yu-Zhong; Xie, Bin-Bin

    2015-09-01

    A Gram-stain-negative, yellow-pigmented, aerobic, non-flagellated, non-gliding bacterial strain, designated SM1203(T), was isolated from surface seawater of Kongsfjorden, Svalbard. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SM1203(T) was affiliated with the genus Bizionia in the family Flavobacteriaceae. The strain shared the highest 16S rRNA gene sequence similarity (>96%) with the type strains of Formosa spongicola (96.8%), Bizionia paragorgiae (96.3%), B. saleffrena (96.3%) and B. echini (96.1%) and 95.4-95.7% sequence similarity with the type strains of other known species of the genus Bizionia. The strain grew at 4-30 °C and in the presence of 1.0-5.0% (w/v) NaCl. The major fatty acids of strain SM1203(T) were iso-C15 : 0, iso-C15 : 1, anteiso-C15 : 0 and C15 : 0 and the main polar lipids were phosphatidylethanolamine and an unidentified lipid. The major respiratory quinone of strain SM1203(T) was menaquinone 6 (MK-6). The genomic DNA G+C content of strain SM1203(T) was 34.8 mol%. Based on the polyphasic characterization of strain SM1203(T) in this study, the strain represents a novel species in the genus Bizionia, for which the name Bizionia arctica sp. nov. is proposed. The type strain is SM1203(T) ( = CGMCC 1.12751(T) = JCM 30333(T)). An emended description of the genus Bizionia is also given. PMID:26016491

  14. Bacterial Wound Culture

    Science.gov (United States)

    ... Home Visit Global Sites Search Help? Bacterial Wound Culture Share this page: Was this page helpful? Also known as: Aerobic Wound Culture; Anaerobic Wound Culture Formal name: Culture, wound Related ...

  15. Bacterial Meningitis in Infants

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2004-04-01

    Full Text Available A retrospective study of 80 infantile patients (ages 30-365 days; 47 male, 33 female with culture-proven bacterial meningitis seen over a 16 year period (1986-2001 is reported from Taiwan.

  16. Exploring the HME and HAE1 efflux systems in the genus Burkholderia

    Directory of Open Access Journals (Sweden)

    Pasca Maria

    2010-06-01

    Full Text Available Abstract Background The genus Burkholderia includes a variety of species with opportunistic human pathogenic strains, whose increasing global resistance to antibiotics has become a public health problem. In this context a major role could be played by multidrug efflux pumps belonging to Resistance Nodulation Cell-Division (RND family, which allow bacterial cells to extrude a wide range of different substrates, including antibiotics. This study aims to i identify rnd genes in the 21 available completely sequenced Burkholderia genomes, ii analyze their phylogenetic distribution, iii define the putative function(s that RND proteins perform within the Burkholderia genus and iv try tracing the evolutionary history of some of these genes in Burkholderia. Results BLAST analysis of the 21 Burkholderia sequenced genomes, using experimentally characterized ceoB sequence (one of the RND family counterpart in the genus Burkholderia as probe, allowed the assembly of a dataset comprising 254 putative RND proteins. An extensive phylogenetic analysis revealed the occurrence of several independent events of gene loss and duplication across the different lineages of the genus Burkholderia, leading to notable differences in the number of paralogs between different genomes. A putative substrate [antibiotics (HAE1 proteins/heavy-metal (HME proteins] was also assigned to the majority of these proteins. No correlation was found between the ecological niche and the lifestyle of Burkholderia strains and the number/type of efflux pumps they possessed, while a relation can be found with genome size and taxonomy. Remarkably, we observed that only HAE1 proteins are mainly responsible for the different number of proteins observed in strains of the same species. Data concerning both the distribution and the phylogenetic analysis of the HAE1 and HME in the Burkholderia genus allowed depicting a likely evolutionary model accounting for the evolution and spreading of HME and HAE

  17. Genus two Heegaard splittings of exteriors of 1-genus 1-bridge knots

    CERN Document Server

    Goda, Hiroshi

    2010-01-01

    A knot K in a closed connected orientable 3-manifold M is called a 1-genus 1-bridge knot if (M,K) has a splitting into two pairs of a solid torus V_i (i=1,2) and a boundary parallel arc in it. The splitting induces a genus two Heegaard splitting of the exterior of K naturally, i.e., K has an unknotting tunnel. However the converse is not true in general. Then we study such general case in this paper. One of the conclusions is that the unknotting tunnel may be levelled with the torus \\partial V_1=\\partial V_2.

  18. Calibrating bacterial evolution

    OpenAIRE

    Ochman, Howard; Elwyn, Susannah; Moran, Nancy A

    1999-01-01

    Attempts to calibrate bacterial evolution have relied on the assumption that rates of molecular sequence divergence in bacteria are similar to those of higher eukaryotes, or to those of the few bacterial taxa for which ancestors can be reliably dated from ecological or geological evidence. Despite similarities in the substitution rates estimated for some lineages, comparisons of the relative rates of evolution at different classes of nucleotide sites indicate no basis for their universal appl...

  19. Genomic characterization of the Taylorella genus.

    Directory of Open Access Journals (Sweden)

    Laurent Hébert

    Full Text Available The Taylorella genus comprises two species: Taylorella equigenitalis, which causes contagious equine metritis, and Taylorella asinigenitalis, a closely-related species mainly found in donkeys. We herein report on the first genome sequence of T. asinigenitalis, analyzing and comparing it with the recently-sequenced T. equigenitalis genome. The T. asinigenitalis genome contains a single circular chromosome of 1,638,559 bp with a 38.3% GC content and 1,534 coding sequences (CDS. While 212 CDSs were T. asinigenitalis-specific, 1,322 had orthologs in T. equigenitalis. Two hundred and thirty-four T. equigenitalis CDSs had no orthologs in T. asinigenitalis. Analysis of the basic nutrition metabolism of both Taylorella species showed that malate, glutamate and alpha-ketoglutarate may be their main carbon and energy sources. For both species, we identified four different secretion systems and several proteins potentially involved in binding and colonization of host cells, suggesting a strong potential for interaction with their host. T. equigenitalis seems better-equipped than T. asinigenitalis in terms of virulence since we identified numerous proteins potentially involved in pathogenicity, including hemagluttinin-related proteins, a type IV secretion system, TonB-dependent lactoferrin and transferrin receptors, and YadA and Hep_Hag domains containing proteins. This is the first molecular characterization of Taylorella genus members, and the first molecular identification of factors potentially involved in T. asinigenitalis and T. equigenitalis pathogenicity and host colonization. This study facilitates a genetic understanding of growth phenotypes, animal host preference and pathogenic capacity, paving the way for future functional investigations into this largely unknown genus.

  20. Bacterial community survey of sediments at Naracoorte Caves, Australia

    Directory of Open Access Journals (Sweden)

    Ball Andrew S.

    2012-07-01

    Full Text Available Bacterial diversity in sediments at UNESCO World Heritage listed Naracoorte Caves was surveyed as part of an investigation carried out in a larger study on assessing microbial communities in caves. Cave selection was based on tourist accessibility; Stick Tomato and Alexandra Cave (> 15000 annual visits and Strawhaven Cave was used as control (no tourist access. Microbial analysis showed that Bacillus was the most commonly detected microbial genus by culture dependent and independent survey of tourist accessible and inaccessible areas of show (tourist accessible and control caves. Other detected sediment bacterial groups were assigned to the Firmicutes, Actinobacteria and Proteobacteria. The survey also showed differences in bacterial diversity in caves with human access compared to the control cave with the control cave having unique microbial sequences (Acinetobacter, Agromyces, Micrococcus and Streptomyces. The show caves had higher bacterial counts, different 16S rDNA based DGGE cluster patterns and principal component groupings compared to Strawhaven. Different factors such as human access, cave use and configurations could have been responsible for the differences observed in the bacterial community cluster patterns (tourist accessible and inaccessible areas of these caves. Cave sediments can therefore act as reservoirs of microorganisms. This might have some implications on cave conservation activities especially if these sediments harbor rock art degrading microorganisms in caves with rock art.

  1. Soil bacterial communities associated with natural and commercial Cyclopia spp.

    Science.gov (United States)

    Postma, Anneke; Slabbert, Etienne; Postma, Ferdinand; Jacobs, Karin

    2016-03-01

    The commercially important plants in the genus Cyclopia spp. are indigenous to the Cape Floristic Region of South Africa and are used to manufacture an herbal tea known as honeybush tea. Growing in the low nutrient fynbos soils, these plants are highly dependent on symbiotic interactions with soil microorganisms for nutrient acquisition. The aim of this study was to investigate the soil bacterial communities associated with two commercially important Cyclopia species, namely C. subternata and C. longifolia. Specific interest was the differences between rhizosphere and bulk soil collected from natural sites and commercially grown plants. Samples were collected on two occasions to include a dry summer and wet winter season. Results showed that the dominant bacterial taxa associated with these plants included Acidobacteria, Actinobacteria, Bacteroidetes and Proteobacteria. Commercial and natural as well as rhizosphere and bulk soil samples were highly similar in bacterial diversity and species richness. Significant differences were detected in bacterial community structures and co-occurrence patterns between the wet and dry seasons. The results of this study improved our knowledge on what effect commercial Cyclopia plantations and seasonal changes can have on soil bacterial communities within the endemic fynbos biome. PMID:26850159

  2. The genus Platychara from the Western Hemisphere

    Science.gov (United States)

    Peck, R.E.; Forester, R.M.

    1979-01-01

    The systematics of four species belonging to the genus Platychara (Charophyta) from the Western Hemisphere is discussed. Three of the species, as defined herein, occur in Cretaceous and Paleocene rocks from Mexico through South America. The type species, P. compressa (Peck and Reker) Grambast, also of Cretaceous and Paleocene age, is herein restricted to deposits north of Mexico. These latter restrictions geographically separate P. compressa and P. perlata as presently defined but the relationship between these two species is still uncertain. A new species, P. grambastii, is proposed for specimens from Maestrichtian sediments in Jamaica. ?? 1979.

  3. Double genus expansion for general Ω background

    Science.gov (United States)

    Prudenziati, Andrea

    2016-07-01

    We will show how the refined holomorphic anomaly equation obeyed by the Nekrasov partition function at generic 𝜖1, 𝜖2 values becomes compatible, in a certain two-parameter expansion, with the assumption that both parameters are associated to genus counting. The underlying worldsheet theory will be analyzed and constrained in various ways, and we will provide both physical interpretation and some alternative evidence for this model. Finally, we will use the Gopakumar-Vafa formulation for the refined topological string in order to give a more quantitative description.

  4. Elliptic Genus of E-strings

    OpenAIRE

    Kim, Joonho; Kim, Seok; Lee, Kimyeong; Park, Jaemo; Vafa, Cumrun

    2014-01-01

    We study a family of 2d N=(0,4) gauge theories which describes at low energy the dynamics of E-strings, the M2-branes suspended between a pair of M5 and M9 branes. The gauge theory is engineered using a duality with type IIA theory, leading to the D2-branes suspended between an NS5-brane and 8 D8-branes on an O8-plane. We compute the elliptic genus of this family of theories, and find agreement with the known results for single and two E-strings. The partition function can in principle be com...

  5. Non-gravitational effects on genus penicillium

    Science.gov (United States)

    Loup, Mackenzie

    1995-01-01

    In September 1994, Shuttle Orbiter Discovery, STS-64, launched into space. Aboard that shuttle was a payload containing Fungi spores, genus Penicillium. With the over looking help of Dr. Audrey Gabel, Associate Professor of Biology at Black Hills State University, investigations on differing media types began. Basis for this experimentation was to determine if there was any differences between the space exposed spores and control spores. Studies concluded that there were differences and those differences were then recorded. It was hypothesized the spores may have been effected causing differences in growth rate, colony size, depth and margins, coloring, germination, and growth on different media.

  6. A review of the genus Curtisia (Curtisiaceae

    Directory of Open Access Journals (Sweden)

    E. YU Yembaturova

    2009-12-01

    Full Text Available A review of the monotypic southern African endemic genus Curtisia Aiton is presented. Detailed studies of the fruit and seed structure provided new evidence in support of a close relationship between the family Curtisiaceae and Comaceae. Comparisons with several other members of the Comales revealed carpological similarities to certain species of Comus s.I., sometimes treated as segregate genera Dendrobenthamia Hutch, and Benthamidia Spach. We also provide information on the history of the assegai tree, Curtisia dentata (Burm.f. C.A.Sm. and its uses, as well as a formal taxonomic revision, including nomenclature, typification, detailed description and geographical distribution.

  7. Adaptation in Toxic Environments: Arsenic Genomic Islands in the Bacterial Genus Thiomonas

    Science.gov (United States)

    Freel, Kelle C.; Krueger, Martin C.; Farasin, Julien; Brochier-Armanet, Céline; Barbe, Valérie; Andrès, Jeremy; Cholley, Pierre-Etienne; Dillies, Marie-Agnès; Jagla, Bernd; Koechler, Sandrine; Leva, Yann; Magdelenat, Ghislaine; Plewniak, Frédéric; Proux, Caroline; Coppée, Jean-Yves; Bertin, Philippe N.; Heipieper, Hermann J.; Arsène-Ploetze, Florence

    2015-01-01

    Acid mine drainage (AMD) is a highly toxic environment for most living organisms due to the presence of many lethal elements including arsenic (As). Thiomonas (Tm.) bacteria are found ubiquitously in AMD and can withstand these extreme conditions, in part because they are able to oxidize arsenite. In order to further improve our knowledge concerning the adaptive capacities of these bacteria, we sequenced and assembled the genome of six isolates derived from the Carnoulès AMD, and compared them to the genomes of Tm. arsenitoxydans 3As (isolated from the same site) and Tm. intermedia K12 (isolated from a sewage pipe). A detailed analysis of the Tm. sp. CB2 genome revealed various rearrangements had occurred in comparison to what was observed in 3As and K12 and over 20 genomic islands (GEIs) were found in each of these three genomes. We performed a detailed comparison of the two arsenic-related islands found in CB2, carrying the genes required for arsenite oxidation and As resistance, with those found in K12, 3As, and five other Thiomonas strains also isolated from Carnoulès (CB1, CB3, CB6, ACO3 and ACO7). Our results suggest that these arsenic-related islands have evolved differentially in these closely related Thiomonas strains, leading to divergent capacities to survive in As rich environments. PMID:26422469

  8. Biosynthesis of bacterial glycogen: activator specificity of the adenosine diphosphate glucose pyrophosphorylases from the genus Rhodospirillum.

    OpenAIRE

    Preiss, J; Greenberg, E

    1981-01-01

    The adenosine diphosphate (ADP) glucose pyrophosphorylases from Rhodospirillum fulvum, Rhodospirillum molischianum, and Rhodospirillum tenue were partially purified, and their kinetic properties were studied. The enzyme from the three organisms was found to be activated by pyruvate and thus was similar to the Rhodospirillum rubrum enzyme that had been previously studied (C. E. Furlong, and J. Preiss, J. Biol. Chem. 244:2539-2548, 1979). The enzymes from R. fulvum, R. molischianum, and R. tenu...

  9. A bacterial pathogen infecting gametophytes of Saccharina japonica (Laminariales, Phaeophyceae)

    Institute of Scientific and Technical Information of China (English)

    PENG Yanting; LI Wei

    2013-01-01

    A newly identified bacterial disease of kelp (Saccharinajaponica) gametophytes was found in clone cultures.It is characterized by swollen gametophyte cells in the early period of infection followed by filamentous fading.An alginolytic marine bacterium referred to as A-1 was isolated from the diseased gametophytes.On the basis of 16S rDNA sequencing and morphological,physiological and biochemical characteristics,the bacterium was identified as a strain of the genus Alteromonas.By testing Koch's postulates,Alteromonas sp.A-1 was further confirmed as the pathogen.The infection process was also investigated using both scanning electron and light microscopy.

  10. Chemodiversity in the genus Aspergillus

    DEFF Research Database (Denmark)

    Frisvad, Jens Christian; Larsen, Thomas Ostenfeld

    2015-01-01

    characterized. The genus Aspergillus is cladistically holophyletic but phenotypically polythetic and very diverse and is associated to quite different sexual states. Following the one fungus one name system, the genus Aspergillus is restricted to a holophyletic clade that include the morphologically different...... biosynthetic family isoextrolites. However, it appears that secondary metabolites from one Aspergillus section have analogous metabolites in other sections (here also called heteroisoextrolites). In this review, we give a genus-wide overview of secondary metabolite production in Aspergillus species. Extrolites...

  11. Yucca: A medicinally significant genus with manifold therapeutic attributes

    OpenAIRE

    Patel, Seema

    2012-01-01

    The genus Yucca comprising of several species is dominant across the chaparrals, canyons and deserts of American South West and Mexico. This genus has long been a source of sustenance and drugs for the Native Americans. In the wake of revived interest in drug discovery from plant sources, this genus has been investigated and startling nutritive and therapeutic capacities have come forth. Apart from the functional food potential, antioxidant, antiinflammation, antiarthritic, anticancer, antidi...

  12. Microsatellites in the genus Xiphophorus, developed in Xiphophorus montezumae

    OpenAIRE

    Seckinger, Jens; Brinkmann, Henner; Meyer, Axel

    2002-01-01

    Species of the genus Xiphophorus (swordtails and platies) are of great interest for the study of evolution of sexually selected traits like the sword, which is an elongation of ventral fin rays of the male caudal fin, that has evolved in several species within this genus. The detection of 10 microsatellites within the genus Xiphophorus will enable studies about the correlation of this trait with sexual reproductive success of males possessing swords of different lengths. These microsatellites...

  13. Variance Analysis of Genus Ipomoea based on Morphological Characters

    OpenAIRE

    DWI PRIYANTO; SURATMAN; AHMAD DWI SETYAWAN

    2000-01-01

    The objective of this research was to find out the variability of morphological characters of genus Ipomoea, including coefficient variance and phylogenetic relationships. Genus Ipomoea has been identified consisting of four species i.e. Ipomoea crassicaulis Rob, Ipomoea aquatica Forsk., Ipomoea reptans Poir and Ipomoea leari. Four species of the genus took from surround the lake inside the campus of Sebelas Maret University, Surakarta. Comparison of species variability was based on the varia...

  14. Elliptic Genus of E-strings

    CERN Document Server

    Kim, Joonho; Lee, Kimyeong; Park, Jaemo; Vafa, Cumrun

    2014-01-01

    We study a family of 2d N=(0,4) gauge theories which describes at low energy the dynamics of E-strings, the M2-branes suspended between a pair of M5 and M9 branes. The gauge theory is engineered using a duality with type IIA theory, leading to the D2-branes suspended between an NS5-brane and 8 D8-branes on an O8-plane. We compute the elliptic genus of this family of theories, and find agreement with the known results for single and two E-strings. The partition function can in principle be computed for arbitrary number of E-strings, and we compute them explicitly for low numbers. We test our predictions against the partially known results from topological strings, as well as from the instanton calculus of 5d Sp(1) gauge theory. Given the relation to topological strings, our computation provides the all genus partition function of the refined topological strings on the canonical bundle over 1/2 K3.

  15. Bacterial diversity at different stages of the composting process

    Directory of Open Access Journals (Sweden)

    Paulin Lars

    2010-03-01

    Full Text Available Abstract Background Composting is an aerobic microbiological process that is facilitated by bacteria and fungi. Composting is also a method to produce fertilizer or soil conditioner. Tightened EU legislation now requires treatment of the continuously growing quantities of organic municipal waste before final disposal. However, some full-scale composting plants experience difficulties with the efficiency of biowaste degradation and with the emission of noxious odours. In this study we examine the bacterial species richness and community structure of an optimally working pilot-scale compost plant, as well as a full-scale composting plant experiencing typical problems. Bacterial species composition was determined by isolating total DNA followed by amplifying and sequencing the gene encoding the 16S ribosomal RNA. Results Over 1500 almost full-length 16S rRNA gene sequences were analysed and of these, over 500 were present only as singletons. Most of the sequences observed in either one or both of the composting processes studied here were similar to the bacterial species reported earlier in composts, including bacteria from the phyla Actinobacteria, Bacteroidetes, Firmicutes, Proteobacteria and Deinococcus-Thermus. In addition, a number of previously undetected bacterial phylotypes were observed. Statistical calculations estimated a total bacterial diversity of over 2000 different phylotypes in the studied composts. Conclusions Interestingly, locally enriched or evolved bacterial variants of familiar compost species were observed in both composts. A detailed comparison of the bacterial diversity revealed a large difference in composts at the species and strain level from the different composting plants. However, at the genus level, the difference was much smaller and illustrated a delay of the composting process in the full-scale, sub-optimally performing plants.

  16. Sensory, chemical and bacteriological changes during storage of iced squid ( Todaropsis eblanae )

    DEFF Research Database (Denmark)

    Paarup, T.; Sanchez, J.A.; Moral, A.; Christensen, H.; Bisgaard, M.; Gram, Lone

    2002-01-01

    Aims: To relate sensory shelf-life of iced whole and gutted squid to bacterial growth and chemical changes. Methods and Results: Cooked mantles from whole and gutted individuals were rejected after 10 and 12 days of storage, respectively, due to ammoniacal off-odours. Rate of production of both...... ammonia and trimethylamine was highest in the whole lot. Agmatine, which was only present in trace amounts in freshly-caught squid, increased rapidly in both lots. The main microflora at the time of sensory rejection of iced whole squid included Gram- negative, motile and non-fermentative rods, which were...... psychrophilic and had a requirement for NaCl. 16S rDNA sequence analyses identified the strains as belonging to the genus Pseudoalteromonas . Shewanella putrefaciens , Pseudoalteromonas sp. and Pseudomonas sp. dominated in spoiled gutted squid. Identification of strains from the stomach and digestive gland of...

  17. Bacterial meningitis in children

    International Nuclear Information System (INIS)

    To demonstrate the epidemiology, clinical manifestations and bacteriological profile of bacterial meningitis in children beyond the neonatal period in our hospital. This was a retrospective descriptive study conducted at Prince Rashid Hospital in Irbid, Jordan. The medical records of 50 children with the diagnosis of bacterial meningitis during 4 years period, were reviewed. The main cause of infection was streptococcus pneumoniae, followed by Haemophilus influenza and Niesseria meningitides. Mortality was higher in infants and meningococcal infection, while complications were more encountered in cases of streptococcus pneumoniae. Cerebrospinal fluid culture was positive in 11 cases and Latex agglutination test in 39. There is a significant reduction of the numbers of bacterial meningitis caused by Haemophilus influenza type B species. (author)

  18. Minimum taxonomic criteria for bacterial genome sequence depositions and announcements.

    Science.gov (United States)

    Bull, Matthew J; Marchesi, Julian R; Vandamme, Peter; Plummer, Sue; Mahenthiralingam, Eshwar

    2012-04-01

    Multiple bioinformatic methods are available to analyse the information encoded within the complete genome sequence of a bacterium and accurately assign its species status or nearest phylogenetic neighbour. However, it is clear that even now in what is the third decade of bacterial genomics, taxonomically incorrect genome sequence depositions are still being made. We outline a simple scheme of bioinformatic analysis and a set of minimum criteria that should be applied to all bacterial genomic data to ensure that they are accurately assigned to the species or genus level prior to database deposition. To illustrate the utility of the bioinformatic workflow, we analysed the recently deposited genome sequence of Lactobacillus acidophilus 30SC and demonstrated that this DNA was in fact derived from a strain of Lactobacillus amylovorus. Using these methods researchers can ensure that the taxonomic accuracy of genome sequence depositions is maintained within the ever increasing nucleic acid datasets. PMID:22366464

  19. Transfer of Methanolobus siciliae to the genus Methanosarcina, naming it Methanosarcina siciliae, and emendation of the genus Methanosarcina

    Science.gov (United States)

    Ni, S.; Woese, C. R.; Aldrich, H. C.; Boone, D. R.

    1994-01-01

    A sequence analysis of the 16S rRNA of Methanolobus siciliae T4/M(T) (T = type strain) showed that this strain is closely related to members of the genus Methanosarcina, especially Methanosarcina acetivorans C2A(T). Methanolobus siciliae T4/M(T) and HI350 were morphologically more similar to members of the genus Methanosarcina than to members of the genus Methanolobus in that they both formed massive cell aggregates with pseudosarcinae. Thus, we propose that Methanolobus siciliae should be transferred to the genus Methanosarcina as Methanosarcina siciliae.

  20. Diagnosis of bacterial vaginosis

    Directory of Open Access Journals (Sweden)

    Đukić Slobodanka

    2013-01-01

    Full Text Available Bacterial vaginosis is a common, complex clinical syndrome characterized by alterations in the normal vaginal flora. When symptomatic, it is associated with a malodorous vaginal discharge and on occasion vaginal burning or itching. Under normal conditions, lactobacilli constitute 95% of the bacteria in the vagina. Bacterial vaginosis is associated with severe reduction or absence of the normal H2O2­producing lactobacilli and overgrowth of anaerobic bacteria and Gardnerella vaginalis, Atopobium vaginae, Mycoplasma hominis and Mobiluncus species. Most types of infectious disease are diagnosed by culture, by isolating an antigen or RNA/DNA from the microbe, or by serodiagnosis to determine the presence of antibodies to the microbe. Therefore, demonstration of the presence of an infectious agent is often a necessary criterion for the diagnosis of the disease. This is not the case for bacterial vaginosis, since the ultimate cause of the disease is not yet known. There are a variety of methods for the diagnosis of bacterial vaginosis but no method can at present be regarded as the best. Diagnosing bacterial vaginosis has long been based on the clinical criteria of Amsel, whereby three of four defined criteria must be satisfied. Nugent’s scoring system has been further developed and includes validation of the categories of observable bacteria structures. Up­to­date molecular tests are introduced, and better understanding of vaginal microbiome, a clear definition for bacterial vaginosis, and short­term and long­term fluctuations in vaginal microflora will help to better define molecular tests within the broader clinical context.

  1. Interfering with bacterial gossip

    DEFF Research Database (Denmark)

    Bjarnsholt, Thomas; Tolker-Nielsen, Tim; Givskov, Michael

    2011-01-01

    defense. Antibiotics exhibit a rather limited effect on biofilms. Furthermore, antibiotics have an ‘inherent obsolescence’ because they select for development of resistance. Bacterial infections with origin in bacterial biofilms have become a serious threat in developed countries. Pseudomonas aeruginosa......, resistance and QS inhibition as future antimicrobial targets, in particular those that would work to minimize selection pressures for the development of resistant bacteria.......Biofilm resilience poses major challenges to the development of novel antimicrobial agents. Biofilm bacteria can be considered small groups of “Special Forces” capable of infiltrating the host and destroying important components of the cellular defense system with the aim of crippling the host...

  2. Chromosome studies in the genus Jatropha L.

    Directory of Open Access Journals (Sweden)

    R.Sasikala and M.Paramathma

    2010-07-01

    Full Text Available The inflorescences of ten species of the genus Jatropha were fixed in Cornoy’s fluid (6:3:1. Acetocarmine stain (2% wasused for staining the pollen mother cells. Seven species exhibited 11 bivalents and 2n =22 and x=11. But the two otherspecies, J.villosa var. villosa and J.villosa var. ramnadensis showed only 10 bivalents and 2n number of 20 chromosomesand x=10. The study concluded the occurrence of two kinds of haploid chromosome numbers of n =10 and n =11. ExceptJatropha tanjorensis, cytological investigation in all species exhibited normal and complete pairing and bivalent formationin metaphase I and equal separation of chromosome in anaphase and indicated that the course of meiosis was normal.Jatropha tanjorensis did not exhibit normal course of meiosis and no proper count of chromosomes could be made. Presentchromosomal studies in Jatropha revealed the existence of two basic chromosomes numbers x = 5 and x = 6.

  3. Anomaly cancelling terms from the elliptic genus

    International Nuclear Information System (INIS)

    We calculate the heterotic string one-loop diagram in 2n+2 dimensions with one external Bμν and n external gravitons and/or gauge bosons. The result is a modular integral over the weight zero terms of the character valued partition function (or elliptic genus) of the theory, and can be directly expressed in terms of the factor which multiplies Tr F2-Tr R2 in the field theory anomaly. The integrands have a non-trivial dependence on the modular parameter τ, reflecting contributions not only from the physical massless states but also from an infinity of 'unphysical' modes. Some of them are identical to integrands which have been discussed recently in relation with Atkin-Lehner symmetry and the cosmological constant. As a corollary we find a method to compute these integrals without using Atkin-Lehner transformations. (orig.)

  4. The genus Schoenoxiphium (Cyperaceae. A preliminary account

    Directory of Open Access Journals (Sweden)

    I. Kukkonen

    1983-12-01

    Full Text Available The genus Schoenoxiphium of the tribe Cariceae of Cyperaceae is conservatively accepted as being restricted to the African continent and Madagascar. The special features of the inflorescence structure are described. The following species are provisionally recognized: S. basutorum Turrill, S. distinctum Kukkonen, S. ecklonii Nees, S.  filiforme Kükenthal, S. gracile Chermezon, S. lanceum (Thunberg Kukenthal, S. lehmannii (Nees Steudel, S.  madagascariense Chermezon, S. perdensum Kukkonen, S. rufum Nees, S. schweickerdtii Merxmiiller & Podlech, and  S. sparteum (Wahlenberg Kukenthal. A key to the species is provided and their distribution is roughly outlined. The morphological variation within the species suggests separation of taxa below specific level, or perhaps even at species level, but this will require more detailed information about the ecology, distribution and the cytology.

  5. The neotropical genus Opeatocerata Melander (Díptera, Empididae

    Directory of Open Access Journals (Sweden)

    Kenneth G. V. Smith

    1989-01-01

    Full Text Available The Neotropical empidid genus Opeatocerata Melander, hitherto known from only a sigle female from Mexico, is redefined in the light of new material, including males. Three new species are described and illustrated, a key provided and the presence of the genus now additionally established in Costa Rica, Panama, Bolivia, Ecuador, Trinidad and Brazil.

  6. Phylogeny of the Peckia-genus group

    DEFF Research Database (Denmark)

    Buenaventura Ruiz, Ingrid Eliana; Pape, Thomas

    2015-01-01

    Peckia is the most species-rich necrophagous genus among the Neotropical sarcophagids, encompassing 67 species distributed in 5 subgenera. Recent phylogenetic studies have challenged the monophyly of this genus with regard to species of the genera Peckiamyia, Titanogrypa, and Villegasia, and the ...

  7. Polyakov relation for the sphere and higher genus surfaces

    CERN Document Server

    Menotti, Pietro

    2015-01-01

    The Polyakov relation, which in the sphere topology gives the changes of the Liouville action under the variation of the position of the sources, in the case of higher genus is related also to the dependence of the action on the moduli of the surface. We write and prove such a relation for genus 1 and for all hyperelliptic surfaces.

  8. The Polyakov relation for the sphere and higher genus surfaces

    Science.gov (United States)

    Menotti, Pietro

    2016-05-01

    The Polyakov relation, which in the sphere topology gives the changes of the Liouville action under the variation of the position of the sources, is also related in the case of higher genus to the dependence of the action on the moduli of the surface. We write and prove such a relation for genus 1 and for all hyperelliptic surfaces.

  9. A path integral derivation of χy-genus

    International Nuclear Information System (INIS)

    The formula for the Hirzebruch χy-genus of complex manifolds is a consequence of the Hirzebruch-Riemann-Roch formula. The classical index formulae for Todd genus, Euler number and signature correspond to the case when the complex variable y=0, -1 and 1 respectively. Here we give a direct derivation of this nice formula based on supersymmetric quantum mechanics

  10. The Polyakov relation for the sphere and higher genus surfaces

    International Nuclear Information System (INIS)

    The Polyakov relation, which in the sphere topology gives the changes of the Liouville action under the variation of the position of the sources, is also related in the case of higher genus to the dependence of the action on the moduli of the surface. We write and prove such a relation for genus 1 and for all hyperelliptic surfaces. (paper)

  11. Tsiangia, a new genus based on Gaertnera Hongkongensis (Rubiaceae)

    OpenAIRE

    But, P. Pui-Hay; Hsue, Hsiang-hao; Li, Ping-T’ao

    1986-01-01

    Detailed examination of the holotype and isotype of Gaertnera hongkongensis Seemann led to the conclusion that this species does not belong to Gaertnera nor to Randia. A new genus, Tsiangia, is proposed to accommodate the new combination Tsiangia hongkongensis. This new genus is retained in Rubiaceae.

  12. Chemical Constituents of Plants from the Genus Psychotria.

    Science.gov (United States)

    Yang, Hongmei; Zhang, Hongmei; Yang, Caiqiong; Chen, Yegao

    2016-07-01

    Psychotria is a genus of ca. 1500 species in the family Rubiaceae. Up to now, 41 species of the Psychotria genus have been chemically investigated, and 159 compounds, including alkaloids of indole, quinoline and benzoquinolizidine type, terpenoids, steroids, phenolics and aliphatic compounds have been isolated. These compounds show potent bioactivities, such as antimicrobial, antiviral, and antiparasitic activities. PMID:27206020

  13. The genus Gloriosa (Colchicaceae) : ethnobotany, phylogeny and taxonomy

    NARCIS (Netherlands)

    Maroyi, A.

    2012-01-01

    This thesis focuses on the ethnobotany, phylogeny and taxonomy of the genus Gloriosa L. over its distributional range. Some Gloriosa species are known to have economic and commercial value, but the genus is also well known for its complex alpha taxonomy. An appropriate taxonomy for this group is of

  14. Quantum field theory on higher-genus Riemann surfaces

    International Nuclear Information System (INIS)

    Quantum field theory for b-c systems is formulated on Riemann surfaces with arbitrary genus. We make use of the formalism recently developed by Krichever and Novikov. Hamiltonian is defined properly, and the Ward-Takahashi identities are derived on higher-genus Riemann surfaces. (author)

  15. A taxonomic revision of the Genus Origanum (Labiatae)

    NARCIS (Netherlands)

    Ietswaart, J.H.

    1980-01-01

    The present study deals with the systematics and taxonomy of the genus Origanum (Labiatae, Saturejeae). As this difficult genus was never before monographed, a revisional study was much needed. The data presented are mainly based on the study of herbarium specimens and in some cases of living ones.

  16. Refined Chern-Simons Theory in Genus Two

    CERN Document Server

    Arthamonov, Semeon

    2015-01-01

    Reshetikhin-Turaev (a.k.a. Chern-Simons) TQFT is a functor that associates vector spaces to two-dimensional genus g surfaces and linear operators to automorphisms of surfaces. The purpose of this paper is to demonstrate that there exists a Macdonald q,t-deformation -- refinement -- of these operators that preserves the defining relations of the mapping class groups beyond genus 1. For this we explicitly construct the refined TQFT representation of the genus 2 mapping class group in the case of rank one TQFT. This is a direct generalization of the original genus 1 construction of arXiv:1105.5117, opening a question if it extends to any genus. Our construction is built upon a q,t-deformation of the square of q-6j symbol of U_q(sl_2), which we define using the Macdonald version of Fourier duality. This allows to compute the refined Jones polynomial for arbitrary knots in genus 2. In contrast with genus 1, the refined Jones polynomial in genus 2 does not appear to agree with the Poincare polynomial of the triply ...

  17. Studies in the Ericoideae. II. The new genus Stokoeanthus

    Directory of Open Access Journals (Sweden)

    E. G. H. Oliver

    1976-12-01

    Full Text Available The new monotypic genus Stokoeanthus is described, its type and only species being the new species S. chionophilus E. G. H. Oliver. The position of the genus in the subfamily, its relationships and the reasons for its establishment are given.

  18. Bacterial populations on brewery filling hall surfaces as revealed by next-generation sequencing.

    Science.gov (United States)

    Priha, Outi; Raulio, Mari; Maukonen, Johanna; Vehviläinen, Anna-Kaisa; Storgårds, Erna

    2016-01-01

    Due to the presence of moisture and nutrients, brewery filling line surfaces are susceptible to unwanted microbial attachment. Knowledge of the attaching microbes will aid in designing hygienic control of the process. In this study the bacterial diversity present on brewery filling line surfaces was revealed by next generation sequencing. The two filling lines studied maintained their characteristic bacterial community throughout three sampling times (13-163 days). On the glass bottle line, γ-proteobacteria dominated (35-82% of all OTUs), whereas on the canning line α-, β- and γ-proteobacteria and actinobacteria were most common. The most frequently detected genera were Acinetobacter, Propinobacterium and Pseudomonas. The halophilic genus Halomonas was commonly detected, which might be due to its tolerance to alkaline foam cleaners. This study has revealed a detailed overall picture of the bacterial groups present on filling line surfaces. Further effort should be given to determine the efficacy of washing procedures on different bacterial groups. PMID:27064426

  19. Bacterial extracellular lignin peroxidase

    Science.gov (United States)

    Crawford, Donald L.; Ramachandra, Muralidhara

    1993-01-01

    A newly discovered lignin peroxidase enzyme is provided. The enzyme is obtained from a bacterial source and is capable of degrading the lignin portion of lignocellulose in the presence of hydrogen peroxide. The enzyme is extracellular, oxidative, inducible by lignin, larch wood xylan, or related substrates and capable of attacking certain lignin substructure chemical bonds that are not degradable by fungal lignin peroxidases.

  20. Bacterial Skin Infections

    Science.gov (United States)

    ... or scraped, the injury should be washed with soap and water and covered with a sterile bandage. Petrolatum may be applied to open areas to keep the tissue moist and to try to prevent bacterial invasion. Doctors recommend that people do not use ...

  1. Bacterial microflora of nectarines

    Science.gov (United States)

    Microflora of fruit surfaces has been the best source of antagonists against fungi causing postharvest decays of fruit. However, there is little information on microflora colonizing surfaces of fruits other than grapes, apples, and citrus fruit. We characterized bacterial microflora on nectarine f...

  2. Diversity of Bacterial Communities of Fitness Center Surfaces in a U.S. Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Nabanita Mukherjee

    2014-12-01

    Full Text Available Public fitness centers and exercise facilities have been implicated as possible sources for transmitting community-acquired bacterial infections. However, the overall diversity of the bacterial community residing on the surfaces in these indoor environments is still unknown. In this study, we investigated the overall bacterial ecology of selected fitness centers in a metropolitan area (Memphis, TN, USA utilizing culture-independent pyrosequencing of the 16S rRNA genes. Samples were collected from the skin-contact surfaces (e.g., exercise instruments, floor mats, handrails, etc. within fitness centers. Taxonomical composition revealed the abundance of Firmicutes phyla, followed by Proteobacter and Actinobacteria, with a total of 17 bacterial families and 25 bacterial genera. Most of these bacterial genera are of human and environmental origin (including, air, dust, soil, and water. Additionally, we found the presence of some pathogenic or potential pathogenic bacterial genera including Salmonella, Staphylococcus, Klebsiella, and Micrococcus. Staphylococcus was found to be the most prevalent genus. Presence of viable forms of these pathogens elevates risk of exposure of any susceptible individuals. Several factors (including personal hygiene, surface cleaning and disinfection schedules of the facilities may be the reasons for the rich bacterial diversity found in this study. The current finding underscores the need to increase public awareness on the importance of personal hygiene and sanitation for public gym users.

  3. Genus Two Zhu Theory for Vertex Operator Algebras

    CERN Document Server

    Gilroy, Thomas

    2015-01-01

    We consider correlation functions for a vertex operator algebra on a genus two Riemann surface formed by sewing two tori together. We describe a generalisation of genus one Zhu recursion expressing an arbitrary genus two $n$--point correlation function in terms of $(n-1)$--point functions. We consider several applications including the correlation functions for the Heisenberg vertex operator algebra and its modules, Virasoro correlation functions and genus two Ward identities. We derive novel differential equations in terms of a differential operator on the genus two Siegel upper half plane for holomorphic $1$--forms, the normalised bidifferential of the second kind and the Heisenberg partition function. We also prove that the holomorphic mapping from the sewing parameter domain to the Siegel upper half plane is injective but not surjective.

  4. Bacterial community analysis of Tatsoi cultivated by hydroponics.

    Science.gov (United States)

    Koo, Ok K; Kim, Hun; Kim, Hyun J; Baker, Christopher A; Ricke, Steven C

    2016-07-01

    Tatsoi (Brassica narinosa) is a popular Asian salad green that is mostly consumed as a source of fresh produce. The purpose of this study was to assess the microbial diversity of Tatsoi cultivated in a hydroponic system and of its ecosystem. Tatsoi leaves, nutrient solution, and perlite/earth samples from a trickle feed system (TFS) and an ebb-and-flow system (EFS) were collected and their microbial communities were analyzed by pyrosequencing analysis. The results showed that most bacteria in the leaves from the TFS contained genus Sporosarcina (99.6%), while Rhizobium (60.4%) was dominant in the leaves from the EFS. Genus Paucibacter (18.21%) and Pelomonas (12.37%) were the most abundant microbiota in the nutrient solution samples of the TFS. In the EFS, the nutrient solution samples contained mostly genus Rhodococcus and Acinetobacter. Potential microbial transfer between the leaves and the ecosystem was observed in the EFS, while samples in the TFS were found to share only one species between the leaves, nutrient solution, and earth. Together, these results show that the bacterial populations in Tatsoi and in its ecosystem are highly diverse based on the cultivation system. PMID:27070460

  5. Inter- and Intraspecific Variations of Bacterial Communities Associated with Marine Sponges from San Juan Island, Washington

    KAUST Repository

    Lee, O. O.

    2009-04-10

    This study attempted to assess whether conspecific or congeneric sponges around San Juan Island, Washington, harbor specific bacterial communities. We used a combination of culture-independent DNA fingerprinting techniques (terminal restriction fragment length polymorphism and denaturing gradient gel electrophoresis [DGGE]) and culture-dependent approaches. The results indicated that the bacterial communities in the water column consisted of more diverse bacterial ribotypes than and were drastically different from those associated with the sponges. High levels of similarity in sponge-associated bacterial communities were found only in Myxilla incrustans and Haliclona rufescens, while the bacterial communities in Halichondria panicea varied substantially among sites. Certain terminal restriction fragments or DGGE bands were consistently obtained for different individuals of M. incrustans and H. rufescens collected from different sites, suggesting that there are stable or even specific associations of certain bacteria in these two sponges. However, no specific bacterial associations were found for H. panicea or for any one sponge genus. Sequencing of nine DGGE bands resulted in recovery of seven sequences that best matched the sequences of uncultured Proteobacteria. Three of these sequences fell into the sponge-specific sequence clusters previously suggested. An uncultured alphaproteobacterium and a culturable Bacillus sp. were found exclusively in all M. incrustans sponges, while an uncultured gammaproteobacterium was unique to H. rufescens. In contrast, the cultivation approach indicated that sponges contained a large proportion of Firmicutes, especially Bacillus, and revealed large variations in the culturable bacterial communities associated with congeneric and conspecific sponges. This study revealed sponge species-specific but not genus- or site-specific associations between sponges and bacterial communities and emphasized the importance of using a combination

  6. Dynamics of bacterial community in the gut of Cornu aspersum

    Directory of Open Access Journals (Sweden)

    ZDRAVKA KOLEVA

    2015-12-01

    Full Text Available The dynamics of the bacterial community in the intestinal tract of Cornu aspersum was investigated during different states of its life cycle. Two approaches were applied – culture and non-culture. The non-culture approach was performed by ARDRA of 16S rDNA using two of the six tested endonucleases. Data were analyzed by hierarchical cluster analysis. The restriction of 16S rDNA samples from the snail of different physiological states with endonucleases HinfI and Csp6I resulted in generation of different profiles depending on the snail states. By the culture approach we found that the total number of cultivable bacteria, representatives of Enterobacteriaceae, lactic acid bacteria, amylolitic and cellulolytic bacteria were the most abundant in active state of the snails. Cellulolytic bacteria were not detected in juveniles of C. aspersum. Escherichia coli, Clostridium perfringens as well as bacteria from the genus Salmonella, Shigella and Pseudomonas were not detected. Bacteria of the genus Aeromonas were found in juveniles of C. aspersum, after that their number decrease and were not found in hibernating snails. On the base of the two applied approaches this study shows that the bacterial flora in the intestinal tract of C. aspersum is affected by the seasonal and environmental variations and undergoes quantitative and qualitative changes during the different states of the life cycle. The snails harbor in their gut intestinal bacteria, which possess biochemical potentiality to degrade the plant components.

  7. The development and characterisation of a bacterial artificial chromosome library for Fragaria vesca

    OpenAIRE

    Abbott Albert G; Monfort Amparo; Muñoz-Torres Monica C; Sargent Daniel J; Girona Elena; Bonet Julio; Arús Pere; Simpson David W; Davik Jahn

    2009-01-01

    Abstract Background The cultivated strawberry Fragaria ×ananassa is one of the most economically-important soft-fruit species. Few structural genomic resources have been reported for Fragaria and there exists an urgent need for the development of physical mapping resources for the genus. The first stage in the development of a physical map for Fragaria is the construction and characterisation of a high molecular weight bacterial artificial chromosome (BAC) library. Methods A BAC library, cons...

  8. Heme uptake in bacterial pathogens

    OpenAIRE

    Contreras, Heidi; Chim, Nicholas; Credali, Alfredo; Goulding, Celia W.

    2014-01-01

    Iron is an essential nutrient for the survival of organisms. Bacterial pathogens possess specialized pathways to acquire heme from their human hosts. In this review, we present recent structural and biochemical data that provide mechanistic insights into several bacterial heme uptake pathways, encompassing the sequestration of heme from human hemoproteins to secreted or membrane-associated bacterial proteins, the transport of heme across bacterial membranes, and the degradation of heme within...

  9. Gram-Negative Bacterial Sensors for Eukaryotic Signal Molecules

    Directory of Open Access Journals (Sweden)

    Olivier Lesouhaitier

    2009-09-01

    Full Text Available Ample evidence exists showing that eukaryotic signal molecules synthesized and released by the host can activate the virulence of opportunistic pathogens. The sensitivity of prokaryotes to host signal molecules requires the presence of bacterial sensors. These prokaryotic sensors, or receptors, have a double function: stereospecific recognition in a complex environment and transduction of the message in order to initiate bacterial physiological modifications. As messengers are generally unable to freely cross the bacterial membrane, they require either the presence of sensors anchored in the membrane or transporters allowing direct recognition inside the bacterial cytoplasm. Since the discovery of quorum sensing, it was established that the production of virulence factors by bacteria is tightly growth-phase regulated. It is now obvious that expression of bacterial virulence is also controlled by detection of the eukaryotic messengers released in the micro-environment as endocrine or neuro-endocrine modulators. In the presence of host physiological stress many eukaryotic factors are released and detected by Gram-negative bacteria which in return rapidly adapt their physiology. For instance, Pseudomonas aeruginosa can bind elements of the host immune system such as interferon-γ and dynorphin and then through quorum sensing circuitry enhance its virulence. Escherichia coli sensitivity to the neurohormones of the catecholamines family appears relayed by a recently identified bacterial adrenergic receptor. In the present review, we will describe the mechanisms by which various eukaryotic signal molecules produced by host may activate Gram-negative bacteria virulence. Particular attention will be paid to Pseudomonas, a genus whose representative species, P. aeruginosa, is a common opportunistic pathogen. The discussion will be particularly focused on the pivotal role played by these new types of pathogen sensors from the sensing to the transduction

  10. Distribution of Naturally Occurring Anthraquinones, Iridoids and Flavonoids from Morinda genus: Chemistry and Biological activity

    Directory of Open Access Journals (Sweden)

    Wong PHAKHODEE

    2012-09-01

    Full Text Available The present review covers chemistry and bioactivities of anthraquinones, iridoids, and flavonoids from the Morinda genus. The plants of Morinda species, belonging to the Rubiaceae family, have been used as traditional folk medicine with anti-bacterial, anti-fungal, anti-tumor, anti-helmin, analgesic, anti-inflammatory, and immune enhancing effects. They are rich sources of anthraquinones and iridoids. The relevant 2-methoxy-1,3,6-trihydroxyanthraquinone is one of the most potent quinone reductase enzyme inducers with no cytotoxicity with normal cells. Damnacanthol-3-O-b-D-primeveroside and lucidin-3-O-b-D-primeveroside displayed a significant reduction of the blood glucose levels in anti-diabetic tests. Additionally, iridoids, 9-epi-6a-methoxy geniposidic acid, scandoside methyl ester, asperulosidic acid, showed a more potent inhibitory effect of melanogenesis than the commercial available depigmented arbutin used in cosmetic industry.

  11. POSSIBLE ROLE OF PROBIOTIC MICROORGANISMS OF BIFIDOBACTERIUM AND LACTOBACILLUS GENUS IN PATHOGENESIS OF AUTOIMMUNE THYROID DISEASES

    Directory of Open Access Journals (Sweden)

    E. P. Kiseleva

    2014-07-01

    Full Text Available It was revealed, that, in blood samples of the patients with autoimmune thyroid diseases, serum antibodies against cell-free fraction of Bifidobacterium bifidum 791 and Lactobacillus plantarum B-01 were detected, respectively, in 71 and 63% of cases, that being two-fold higher than appropriate frequencies in healthy blood donors. An evidence was obtained that presence of some components specifically reacting with autoantibodies against thyroid peroxidase and thyroglobulin on the surface of the microorganisms cells and competing for binding of these immunoglobulins with thyroid antigens. One may also suggest a presence of bacterial components, interacting with thyroid peroxidase. The data obtained let us suggest that probiotic microorganisms of Bifidobacterium and Lactobacillus genus could take part in pathogenesis of autoimmune thyroid diseases, by means of molecular mimicry mechanisms.

  12. Evolutionary transitions in bacterial symbiosis

    OpenAIRE

    Sachs, Joel L.; Skophammer, Ryan G.; Regus, John U.

    2011-01-01

    Diverse bacterial lineages form beneficial infections with eukaryotic hosts. The origins, evolution, and breakdown of these mutualisms represent important evolutionary transitions. To examine these key events, we synthesize data from diverse interactions between bacteria and eukaryote hosts. Five evolutionary transitions are investigated, including the origins of bacterial associations with eukaryotes, the origins and subsequent stable maintenance of bacterial mutualism with hosts, the captur...

  13. Pantoea: insights into a highly versatile and diverse genus within the Enterobacteriaceae.

    Science.gov (United States)

    Walterson, Alyssa M; Stavrinides, John

    2015-11-01

    The bacterial genus Pantoea comprises many versatile species that have been isolated from a multitude of environments. Pantoea was delineated as a genus approximately 25 years ago, but since then, approximately 20 species have been identified having a diversity of characteristics. Isolates from water and soil have been harnessed for industrial purposes including bioremediation, and the degradation of herbicides and other toxic products. Other isolates possess nitrogen fixation and plant growth-promoting capabilities, which are currently being explored for agricultural applications. Some isolates are antibiotic producers, and have been developed into biocontrol agents for the management of plant diseases. Pantoea is also known to form host associations with a variety of hosts, including plants, insects and humans. Although often thought of as a plant pathogen, recent evidence suggests that Pantoea is being frequently isolated from the nosocomial environment, with considerable debate as to its role in human disease. This review will explore this highly versatile group and its capabilities, its known associations, and the underlying genetic and genomic determinants that drive its diversity and adaptability. PMID:26109597

  14. The Geobacillus Pan-Genome: Implications for the Evolution of the Genus

    Science.gov (United States)

    Bezuidt, Oliver K.; Pierneef, Rian; Gomri, Amin M.; Adesioye, Fiyin; Makhalanyane, Thulani P.; Kharroub, Karima; Cowan, Don A.

    2016-01-01

    The genus Geobacillus is comprised of a diverse group of spore-forming Gram-positive thermophilic bacterial species and is well known for both its ecological diversity and as a source of novel thermostable enzymes. Although the mechanisms underlying the thermophilicity of the organism and the thermostability of its macromolecules are reasonably well understood, relatively little is known of the evolutionary mechanisms, which underlie the structural and functional properties of members of this genus. In this study, we have compared 29 Geobacillus genomes, with a specific focus on the elements, which comprise the conserved core and flexible genomes. Based on comparisons of conserved core and flexible genomes, we present evidence of habitat delineation with specific Geobacillus genomes linked to specific niches. Our analysis revealed that Geobacillus and Anoxybacillus share a high proportion of genes. Moreover, the results strongly suggest that horizontal gene transfer is a major factor deriving the evolution of Geobacillus from Bacillus, with genetic contributions from other phylogenetically distant taxa. PMID:27252683

  15. Comparative Genomics of the Ubiquitous, Hydrocarbon-degrading Genus Marinobacter

    Science.gov (United States)

    Singer, E.; Webb, E.; Edwards, K. J.

    2012-12-01

    The genus Marinobacter is amongst the most ubiquitous in the global oceans and strains have been isolated from a wide variety of marine environments, including offshore oil-well heads, coastal thermal springs, Antarctic sea water, saline soils and associations with diatoms and dinoflagellates. Many strains have been recognized to be important hydrocarbon degraders in various marine habitats presenting sometimes extreme pH or salinity conditions. Analysis of the genome of M. aquaeolei revealed enormous adaptation versatility with an assortment of strategies for carbon and energy acquisition, sensation, and defense. In an effort to elucidate the ecological and biogeochemical significance of the Marinobacters, seven Marinobacter strains from diverse environments were included in a comparative genomics study. Genomes were screened for metabolic and adaptation potential to elucidate the strategies responsible for the omnipresence of the Marinobacter genus and their remedial action potential in hydrocarbon-polluted waters. The core genome predominantly encodes for key genes involved in hydrocarbon degradation, biofilm-relevant processes, including utilization of external DNA, halotolerance, as well as defense mechanisms against heavy metals, antibiotics, and toxins. All Marinobacter strains were observed to degrade a wide spectrum of hydrocarbon species, including aliphatic, polycyclic aromatic as well as acyclic isoprenoid compounds. Various genes predicted to facilitate hydrocarbon degradation, e.g. alkane 1-monooxygenase, appear to have originated from lateral gene transfer as they are located on gene clusters of 10-20% lower GC-content compared to genome averages and are flanked by transposases. Top ortholog hits are found in other hydrocarbon degrading organisms, e.g. Alcanivorax borkumensis. Strategies for hydrocarbon uptake encoded by various Marinobacter strains include cell surface hydrophobicity adaptation via capsular polysaccharide biosynthesis and attachment

  16. Genomes-based phylogeny of the genus Xanthomonas

    Directory of Open Access Journals (Sweden)

    Rodriguez-R Luis M

    2012-03-01

    Full Text Available Abstract Background The genus Xanthomonas comprises several plant pathogenic bacteria affecting a wide range of hosts. Despite the economic, industrial and biological importance of Xanthomonas, the classification and phylogenetic relationships within the genus are still under active debate. Some of the relationships between pathovars and species have not been thoroughly clarified, with old pathovars becoming new species. A change in the genus name has been recently suggested for Xanthomonas albilineans, an early branching species currently located in this genus, but a thorough phylogenomic reconstruction would aid in solving these and other discrepancies in this genus. Results Here we report the results of the genome-wide analysis of DNA sequences from 989 orthologous groups from 17 Xanthomonas spp. genomes available to date, representing all major lineages within the genus. The phylogenetic and computational analyses used in this study have been automated in a Perl package designated Unus, which provides a framework for phylogenomic analyses which can be applied to other datasets at the genomic level. Unus can also be easily incorporated into other phylogenomic pipelines. Conclusions Our phylogeny agrees with previous phylogenetic topologies on the genus, but revealed that the genomes of Xanthomonas citri and Xanthomonas fuscans belong to the same species, and that of Xanthomonas albilineans is basal to the joint clade of Xanthomonas and Xylella fastidiosa. Genome reduction was identified in the species Xanthomonas vasicola in addition to the previously identified reduction in Xanthomonas albilineans. Lateral gene transfer was also observed in two gene clusters.

  17. Bacterial proteases and virulence

    DEFF Research Database (Denmark)

    Frees, Dorte; Brøndsted, Lone; Ingmer, Hanne

    Bacterial pathogens rely on proteolysis for variety of purposes during the infection process. In the cytosol, the main proteolytic players are the conserved Clp and Lon proteases that directly contribute to virulence through the timely degradation of virulence regulators and indirectly by providing...... tolerance to adverse conditions such as those experienced in the host. In the membrane, HtrA performs similar functions whereas the extracellular proteases, in close contact with host components, pave the way for spreading infections by degrading host matrix components or interfering with host cell...... cell. These extracellular proteases are activated in complex cascades involving auto-processing and proteolytic maturation. Thus, proteolysis has been adopted by bacterial pathogens at multiple levels to ensure the success of the pathogen in contact with the human host....

  18. Supramolecular bacterial systems

    OpenAIRE

    Sankaran, Shrikrishnan

    2015-01-01

    For nearly over a decade, a wide variety of dynamic and responsive supramolecular architectures have been investigated and developed to address biological systems. Since the non-covalent interactions between individual molecular components in such architectures are similar to the interactions found in living systems, it was possible to integrate chemically-synthesized and naturally-occurring components to create platforms with interesting bioactive properties. Bacterial cells and recombinant ...

  19. Bacterial transformation of terpenoids

    International Nuclear Information System (INIS)

    Data on the bacterial transformation of terpenoids published in the literature in the past decade are analyzed. Possible pathways for chemo-, regio- and stereoselective modifications of terpenoids are discussed. Considerable attention is given to new technological approaches to the synthesis of terpenoid derivatives suitable for the use in the perfume and food industry and promising as drugs and chiral intermediates for fine organic synthesis. The bibliography includes 246 references

  20. Introduction of new carotenoids into the bacterial photosynthetic apparatus by combining the carotenoid biosynthetic pathways of Erwinia herbicola and Rhodobacter sphaeroides.

    OpenAIRE

    Hunter, C N; Hundle, B S; Hearst, J E; Lang, H.P.; Gardiner, A.T.; Takaichi, S; Cogdell, R. J.

    1994-01-01

    Carotenoids have two major functions in bacterial photosynthesis, photoprotection and accessory light harvesting. The genes encoding many carotenoid biosynthetic pathways have now been mapped and cloned in several different species, and the availability of cloned genes which encode the biosynthesis of carotenoids not found in the photosynthetic genus Rhodobacter opens up the possibility of introducing a wider range of foreign carotenoids into the bacterial photosynthetic apparatus than would ...

  1. Notes on hyperelliptic fibrations of genus 3, II

    OpenAIRE

    Murakami, Masaaki

    2013-01-01

    This is the part II of the series under the same title. In part I, using the approach developed by Catanese--Pignatelli arXiv:math/0503294, we gave a structure theorem for hyperelliptic genus 3 fibrations all of whose fibers are 2-connected (arXiv:1209.6278 [math.AG]). In this part II, we shall give a structure theorem for smooth deformation families of these to non-hyperelliptic genus 3 fibrations. As an application, we shall give a set of sufficient conditions for our genus 3 hyperelliptic ...

  2. Bheemamyces, a new genus of the family Asterinaceae (Ascomycetes

    Directory of Open Access Journals (Sweden)

    V.B. Hosagoudar

    2010-11-01

    Full Text Available Bheemamyces with its type B. argyreicola, a new genus and a new species of the family Asterinaceae, collected on the leaves of Argyreia nervosa from the Malabar Botanic Garden, Kozhikode, Kerala, has been described and illustrated in detail. This genus differs from other genera of the family Asterinaceae in having the mycelia originated from the main hyphae, lifted slightly above the host surface, appearing like a ‘whip’, possessing intercalary and sub intercalary or sub lateral appressoria. Another such taxon, Asterina argyreiae Hansf. has been brought under this genus as Bheemamyces argyreiae (Hansf. comb. nov.

  3. The genus Plectranthus in India and its chemistry.

    Science.gov (United States)

    Waldia, Shobha; Joshi, Bipin C; Pathak, Uma; Joshi, Mukesh C

    2011-02-01

    Phytochemical constituents isolated from Indian species of the genus Plectranthus reported up to 2009 are compiled. In India, the genus Plectranthus is found in all the habitats and altitudes, particularly in the Himalaya, the Southern Ghats, and the Nilgiri region. P. amboinicus, P. barbatus, P. caninus, P. mollis, P. coetsa, and P. incanus are the most common species found in India. Phytochemical studies of the genus revealed that Indian Plectranthus species are rich in essential oil, and that the most abundant secondary metabolites are diterpenoids, i.e., labdanes, abietanes, and ent-kauranes, as well as triterpenoids. PMID:21337498

  4. toward a phylogeny of the kukri snakes, genus oligodon

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    the south and southeast asian snake genus oligodon,known for its egg-eating feeding behavior,has been a taxonomically and systematically challenging group.this work provides the first phylogenetic hypothesis for the genus.we use approximately 1900 base pairs of mitochondrial dna sequence data to infer the relationships of these snakes,and we examine congruence between the phylogeny and hemipenial characters.a hypothesis for the position of oligodon within the colubridae is also proposed.we discuss the implications of the phylogeny for previous taxonomic groupings,and consider the usefulness of the trees in analysis of behavior and biogeography of this genus.

  5. Abradeosporangium, a new genus of Mucorales (Fungi: Zygomycetes from India

    Directory of Open Access Journals (Sweden)

    A. Subrahmanyam

    2010-09-01

    Full Text Available Abradeosporangium, a new genus of Mucorales with its type species A. variosporum, is described from India. The new genus is distinct in producing dimorphic sporangia and multispored, acolumellate and globose macrosporangia with persistent, thin peridium. Sparingly, portions of the sporangial wall at the top and bottom of the sporangia are dissolved at maturity to release the sporangiospores whilst, in its close ally Gilbertella, the sporangium breaks open via a longitudinal suture. Further, the smaller sporangia (microsporangia are without a longitudinal suture and produce variable number of spores. The sporangiospores are pale brown, longitudinally striated without any appendages. Besides, the new genus produces neither rhizoids nor zygospores.

  6. Isleria, a new genus of antwren (Aves: Passeriformes: Thamnophilidae)

    Science.gov (United States)

    Bravo, Gustavo A.; Chesser, R. Terry; Brumfield, Robb T.

    2012-01-01

    A comprehensive molecular phylogenetic analysis of the family Thamnophilidae indicated that the genus Myrmotherula is not monophyletic. The clade composed of M. guttata and M. hauxwelli is only distantly related to other members of the genus and should be removed from Myrmotherula. The phenotypic distinctiveness of the clade argues against merging it with its sister group Thamnomanes and no generic name is available for the guttata-hauxwelli clade. Consequently, we describe the genus Isleria for these two species, and designate Myrmothera guttata as its type species.

  7. The mapping glass group for genus 2

    International Nuclear Information System (INIS)

    This article represents joint work with Tullio Regge and essentially concerns the symmetries of the hexagon. When space Σ is a genus 2 Riemann surface the observable of the theory are the gauge-invariant normalized traces of the SL(2,R) matrices which form the spinor representation of π1(Σ). It was extremely difficult to find a suitable notation for the 15 possible traces, in fact we shall simultaneously use two equivalent (and hopefully not too ambiguous) notations which are now described. First, define Bn = c(U1aV1bU2cV2d) where c(x) = 1/2 Tr(x), x element of π1, and n = a + 2b +4c + 8d = 1 . . . 15. There are two exception to ???, namely B3 = c (U1V1-1) and B12 = c(U2V2-1). SL(2,R) identities will reduce all other traces. These can be arranged to fit on a hexagon where each line, internal or on the border, represents one of the Bn. Instead of numbering the lines number the points so that, for example, B1 is equivalent to A12, B5 to A36, with Aij = Aji, where we use different letters A,B, to avoid confusion. This is the second notation. They can be related through the 6 x 6 symmetric matrix Aij whose components are precisely the elements Aij and Aii (no sum) = 1

  8. American Tertiary mollusks of the genus Clementia

    Science.gov (United States)

    Woodring, W.P.

    1927-01-01

    Aside from its value as an aid in determining the age of Tertiary beds, the chief interest of the genus Clementia lies in the anomalous features of its present and former distribution. An attempt is made in this paper to trace its geologic history, to point out its paleobiologic significance, and to describe all the known American Tertiary species. The fossils from Colombia used in preparing this report were collected during explorations made under the direction of Dr. 0. B. Hopkins, chief geologist of the Imperial Oil Co. (Ltd.), who kindly donated them to the United States National Museum. Dr. T. Wayland Vaughan, of the Scripps Institution of Oceanography, furnished information relating to specimens collected by him in Mexico. Dr. Bruce L. Clark, of the University of California; Dr. G. Dallas Hanna, of the California Academy of Sciences; Dr. H. A. Pilsbry, of the Philadelphia Academy of Natural Sciences; and Dr. W. D. Matthew, of the American Museum of Natural History, generously loaned type specimens and other material. Doctor Clark and Doctor Hanna also gave information concerning the Tertiary species from California. Mr. Ralph B. Stewart, of the University of California, read the manuscript, and I have taken advantage of his suggestions. I am also indebted to Mr. L. R. Cox, of the British Museum, for information relating to the fossil species from Persia, Zanzibar, and Burma, and to Dr. Axel A. Olsson, of the International Petroleum Co., for data concerning undescribed Tertiary species from Peru.

  9. The genus Echium (Boraginaceae in southern Africa

    Directory of Open Access Journals (Sweden)

    E. Retief

    1998-12-01

    Full Text Available The genus Echium L. (Boraginaceae comprises about 60 species, mainly from Macaronesia. Europe, western Asia and North Africa. Two species E plantagineum L. and E. vulgare L. were introduced into southern Africa and have become naturalised. The species occur mainly as roadside weeds in the region. Echium is closely related to Lobostemon Lehm. (incl. Echiostachys Levyns, endemic in the southwestern Cape region. Pollen morphology shows a remarkable similarity between these genera, even suggesting that they could be merged. However, other characters, such as bilobed styles (Echium versus undivided ones (Lobostemon and the presence of an annulus, composed of a minute collar or 5-10 minute hairy lobules, at the bottom of the corolla tube inside (Echium, in contrast to hairs and/or scales at the base of the filaments (Lobostemon contradict the pollen structure, and Echium and Lobostemon are therefore regarded as two separate genera. Significant taxonomic characters, an identification key, full descriptions, illustrations and distribution maps of E. plantagineum and E. vulgare are given.

  10. A Cytotaxonomic Study in the Genus Zingiber

    Directory of Open Access Journals (Sweden)

    AHMAD DWI SETYAWAN

    2000-01-01

    Full Text Available The objective of the study was to know the taxonomic structure of the genus of Zingiber based on cytological characters such as ratio of number, shape and size of chromosome. Zingiber specimens were mainly from Bogor botanical garden. There were seven species studied, Z. amaricans Nor., Z. aromaticum Val., Z. cassumunar Roxb., Z. gramineum Bl., Z. officinale Roxb., Z. ottensii Val. and Z. zerumbet (L. J.E. Smith. Z. officinale (local name: Jahe consinsting of 4 varieties, big ginger (jahe gajah, red ginger (jahe merah, small ginger (jahe emprit and blue-dark browny ginger (jahe wulung. Species identification was based on the literature such as of Backer and Bakhuizen van den Brink (1968, Holttum (1950, and Burkill (1935. Semi permanent squash method using acetoorcein dye was used to prepare the sample (Darnaedi, 1991; Okada, 1981; Robert and Short, 1979. The results of the study indicate that the number of chromosomes of all species studied were the same, 2n=32. The length size of the first chromosome pair was about 2m. The shape of the chromosomes was mostly metacentric. Length and shape of each pair of chromosomes were hard to be determined accurately using this method, so that the chromosomal karyotype map unable to be constructed in this study. Giemsa C-banding method might be used to solve the problems. ©

  11. Functional proteomics within the genus Lactobacillus.

    Science.gov (United States)

    De Angelis, Maria; Calasso, Maria; Cavallo, Noemi; Di Cagno, Raffaella; Gobbetti, Marco

    2016-03-01

    Lactobacillus are mainly used for the manufacture of fermented dairy, sourdough, meat, and vegetable foods or used as probiotics. Under optimal processing conditions, Lactobacillus strains contribute to food functionality through their enzyme portfolio and the release of metabolites. An extensive genomic diversity analysis was conducted to elucidate the core features of the genus Lactobacillus, and to provide a better comprehension of niche adaptation of the strains. However, proteomics is an indispensable "omics" science to elucidate the proteome diversity, and the mechanisms of regulation and adaptation of Lactobacillus strains. This review focuses on the novel and comprehensive knowledge of functional proteomics and metaproteomics of Lactobacillus species. A large list of proteomic case studies of different Lactobacillus species is provided to illustrate the adaptability of the main metabolic pathways (e.g., carbohydrate transport and metabolism, pyruvate metabolism, proteolytic system, amino acid metabolism, and protein synthesis) to various life conditions. These investigations have highlighted that lactobacilli modulate the level of a complex panel of proteins to growth/survive in different ecological niches. In addition to the general regulation and stress response, specific metabolic pathways can be switched on and off, modifying the behavior of the strains. PMID:27001126

  12. Mycorrhizal status of the genus Carex (Cyperaceae).

    Energy Technology Data Exchange (ETDEWEB)

    Miller, R. M.; Smith, C. I.; Jastrow, J. D.; Bever, J. D.; Environmental Research; Univ. of Chicago

    1999-01-01

    The Cyperaccae have generally been considered nonmycorrhizal, although recent evidence suggests that mycotrophy may be considerably more widespread among sedges than was previously realized. This study surveyed 23 species of Carex occurring in upland and wetland habitats in northeastern Illinois. Mycorrhizal infection by arbuscular fungi was found in the roots of 16 species of Carex and appears to occur in response to many factors, both environmental and phylogenetic. While some species appear to be obligately nonmycorrhizal, edaphic influences may be responsible for infection in others. In five of the seven Carex species that were nonmycorrrhizal, a novel root character, the presence of bulbous-based root hairs, was identified. The taxonomically patchy distribution of the distinctive root hair trait suggests that these structures may have evolved several times within the genus. Evidence of multiple independent origins of the root hair trait lends support to the hypothesis that root hairs represent an adaptation to nonmycotrophy. Although taxonomic position does seem to be of importance in determining the mycorrhizal dependence of sedges, the pattern may be a patchwork of both mycorrhizal clades and clades that have adapted to the nonmycorrhizal state.

  13. Validation of hierarchical cluster analysis for identification of bacterial species using 42 bacterial isolates

    Science.gov (United States)

    Ghebremedhin, Meron; Yesupriya, Shubha; Luka, Janos; Crane, Nicole J.

    2015-03-01

    Recent studies have demonstrated the potential advantages of the use of Raman spectroscopy in the biomedical field due to its rapidity and noninvasive nature. In this study, Raman spectroscopy is applied as a method for differentiating between bacteria isolates for Gram status and Genus species. We created models for identifying 28 bacterial isolates using spectra collected with a 785 nm laser excitation Raman spectroscopic system. In order to investigate the groupings of these samples, partial least squares discriminant analysis (PLSDA) and hierarchical cluster analysis (HCA) was implemented. In addition, cluster analyses of the isolates were performed using various data types consisting of, biochemical tests, gene sequence alignment, high resolution melt (HRM) analysis and antimicrobial susceptibility tests of minimum inhibitory concentration (MIC) and degree of antimicrobial resistance (SIR). In order to evaluate the ability of these models to correctly classify bacterial isolates using solely Raman spectroscopic data, a set of 14 validation samples were tested using the PLSDA models and consequently the HCA models. External cluster evaluation criteria of purity and Rand index were calculated at different taxonomic levels to compare the performance of clustering using Raman spectra as well as the other datasets. Results showed that Raman spectra performed comparably, and in some cases better than, the other data types with Rand index and purity values up to 0.933 and 0.947, respectively. This study clearly demonstrates that the discrimination of bacterial species using Raman spectroscopic data and hierarchical cluster analysis is possible and has the potential to be a powerful point-of-care tool in clinical settings.

  14. Bacterial Community Diversity Harboured by Interacting Species.

    Directory of Open Access Journals (Sweden)

    Mikaël Bili

    Full Text Available All animals are infected by microbial partners that can be passengers or residents and influence many biological traits of their hosts. Even if important factors that structure the composition and abundance of microbial communities within and among host individuals have been recently described, such as diet, developmental stage or phylogeny, few studies have conducted cross-taxonomic comparisons, especially on host species related by trophic relationships. Here, we describe and compare the microbial communities associated with the cabbage root fly Delia radicum and its three major parasitoids: the two staphylinid beetles Aleochara bilineata and A. bipustulata and the hymenopteran parasitoid Trybliographa rapae. For each species, two populations from Western France were sampled and microbial communities were described through culture independent methods (454 pyrosequencing. Each sample harbored at least 59 to 261 different bacterial phylotypes but was strongly dominated by one or two. Microbial communities differed markedly in terms of composition and abundance, being mainly influenced by phylogenetic proximity but also geography to a minor extent. Surprisingly, despite their strong trophic interaction, parasitoids shared a very low proportion of microbial partners with their insect host. Three vertically transmitted symbionts from the genus Wolbachia, Rickettsia, and Spiroplasma were found in this study. Among them, Wolbachia and Spiroplasma were found in both the cabbage fly and at least one of its parasitoids, which could result from horizontal transfers through trophic interactions. Phylogenetic analysis showed that this hypothesis may explain some but not all cases. More work is needed to understand the dynamics of symbiotic associations within trophic network and the effect of these bacterial communities on the fitness of their hosts.

  15. Phylogenetic analysis of bacterial community in deep-sea sediment from the western Pacific "warm pool"

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A depth profile of bacterial community structure in one deep-sea sediment core of the western Pacific "warm pool" (WP) was investigated and compared with that in a sediment sample from the eastern Pacific (EP) by phylogenetic analysis of 16S rDNA fragments.Five bacterial 16S rDNA clone libraries were constructed, and t33 clones with different restriction fragment length polymorphism(RFLP) patterns were sequenced. A phylogenetic analysis of these sequences revealed that the bacterial diversity in a sample from the WP was more abundant than that in the EP sample. The bacterial population in the sediment core of WP was composed of eight major lineages of the domain bacteria. Among them the γ-Proteobacteria was the predominant and most diverse group in each section of WP sediment core, followed by the α-Proteobacteria. The genus Colwellia belonging to γ-Proteobacteria was predominant in this sample.The shift of bacterial communities among different sections of the WP sediment core was δ-, ε-Proteobacteria, and Cytopahga-Flexibacteria-Bacteroides (CFB) group. The ratios between them in the bacterial communities all showed inversely proportional to the depth of sediment. The sequences related to sulphate reducing bacteria (SRB) were detected in every section. The bacterial community structure in this sediment core might be related to the environmental characteristics of the surface seawater of the western Pacific WP.

  16. ENDOPARASITIC NEMATODES OF THE GENUS PRATYLENCHUS ON SOYBEAN

    Directory of Open Access Journals (Sweden)

    Ivana Majić

    2010-12-01

    Full Text Available The aims of the study were to determine susceptibility of soybean cultivars to root lesion nematodes (genus Pratylenchus, effect of intensity of arbuscular mycorrhizal fungi (AMF colonization on penetration of endoparasitic nematodes in soybean roots, and trophic biodiversity of nematode community in soybean. In the period 2005 - 2007, investigations were conducted at experimental sites of Agricultural Institute Osijek. Seven soybean cultivars were included (Korana, Kuna, Anica, Una, Ika, Podravka 95 i Tisa. Soil and roots were sampled during four soybean growth stages. Nematode populations from soil and root samples were determined as well as reproductive index (RI of root lesion nematode population, and intensity of AMF root colonization. Ten ecological indexes were calculated in order to determine trophic biodiversity of nematode community: H’, λ, N1, N2, E1, E2, PPI, NCR, F/B, B+F/BP. Two Pratylenchus species were determined from the soil samples: P. thornei Sher & Allen 1953 and P. scribneri Steiner 1943. The results indicate negative effect of Pratylenchus spp. (extracted from soil samples on soybean yields for all but one cultivar (Una. However, increase in root lesion nematode population did not lead to linear decrease in plant biomass. Cultivars Ika, Podravka 95, Tisa and Una proved to be the best hosts to root lesion nematodes since these cultivars statistically differed among cultivars for the highest density of root lesion nematodes. Cultivar Una showed the least susceptibility to root lesion nematodes since it had the lowest RI and negative effects on yields were not determined. Due to high RI values and negative effect on soybean yields. Population densities of root lesion nematodes from soil samples, (compared to nematodes detected in roots are more reliable indicator of root lesion nematodes damaging potential. Since values of RI for Pratylenchus spp. in soil samples were determined as very high and soybean yields were

  17. Diterpenoids from Roots and Aerial Parts of the Genus Stachys

    OpenAIRE

    Franco Piozzi; Maurizio Bruno

    2011-01-01

    The occurrence of diterpenoids from roots and aerial parts of the species of the genus Stachys (Lamiaceae, Labiatae) is reviewed. The presence of these diterpenoids in other taxa and their biological properties have been also reviewed.

  18. A new genus of Smiliini (Hemiptera: Membracidae) from Costa Rica

    Science.gov (United States)

    A new genus and species, Smilirhexia naranja, is described from Costa Rica, the southern limit of the tribe Smiliini, and represents a strong divergence from the morphology of the oak-feeding genera prevalent in North America....

  19. A review on phytochemistry and ethnopharmacological aspects of genus Calendula

    Directory of Open Access Journals (Sweden)

    Disha Arora

    2013-01-01

    Full Text Available This review includes 84 references on the genus Calendula (Asteraceae and comprises ethnopharmacology, morphology and microscopy, phytoconstituents, pharmacological reports, clinical studies and toxicology of the prominent species of Calendula. Triterpene alcohols, triterpene saponins, flavonoids, carotenoids and polysaccharides constitute major classes of phytoconstituents of the genus. A few species of this genus have medicinal value, among these Calendula officinalis Linn., has been traditionally used in the treatment of various skin tumors, dermatological lesions, ulcers, swellings and nervous disorders as well as almost 200 cosmetic formulations, i.e., creams, lotions, shampoos. Despite a long tradition of use of some species, the genus has not been explored properly. In the concluding part, the future scope of Calendula species has been emphasized with a view to establish their multifarious biological activities and mode of action.

  20. A review on phytochemistry and ethnopharmacological aspects of genus Calendula.

    Science.gov (United States)

    Arora, Disha; Rani, Anita; Sharma, Anupam

    2013-07-01

    This review includes 84 references on the genus Calendula (Asteraceae) and comprises ethnopharmacology, morphology and microscopy, phytoconstituents, pharmacological reports, clinical studies and toxicology of the prominent species of Calendula. Triterpene alcohols, triterpene saponins, flavonoids, carotenoids and polysaccharides constitute major classes of phytoconstituents of the genus. A few species of this genus have medicinal value, among these Calendula officinalis Linn., has been traditionally used in the treatment of various skin tumors, dermatological lesions, ulcers, swellings and nervous disorders as well as almost 200 cosmetic formulations, i.e., creams, lotions, shampoos. Despite a long tradition of use of some species, the genus has not been explored properly. In the concluding part, the future scope of Calendula species has been emphasized with a view to establish their multifarious biological activities and mode of action. PMID:24347926

  1. The Genus Austroleptis from South Chile and Patagonia (Diptera, Rhagionidae)

    OpenAIRE

    NAGATOMI, Akira; NAGATOMI, Hisako; ナガトミ, アキラ; ナガトミ, ヒサコ; 永冨, 昭; 永冨, 尚子

    1988-01-01

    The genus Austroleptis from South Chile and Patagonia is revised and three new species are added. So, there are eight known species, five of which are from South Chile and Patagonia and three from Australia and Tasmania.

  2. Higher genus correlators from the hermitian one-matrix model

    International Nuclear Information System (INIS)

    We develop an iterative algorithm for the genus expansion of the hermitian NxN one-matrix model (is the Penner model in an external field). By introducing moments of the external field, we prove that the genus g contribution to the m-loop correlator depends only on 3g-2+m lower moments (3g-2 for the partition function). We present the explicit results for the partition function and the one-loop correlator in genus one. We compare the correlators for the hermitian one-matrix model with those at zero momenta for c=1 CFT and show an agreement of the one-loop correlators for genus zero. (orig.)

  3. Spectral Theory and Mirror Curves of Higher Genus

    CERN Document Server

    Codesido, Santiago; Marino, Marcos

    2015-01-01

    Recently, a correspondence has been proposed between spectral theory and topological strings on toric Calabi-Yau manifolds. In this paper we develop in detail this correspondence for mirror curves of higher genus, which display many new features as compared to the genus one case studied so far. Given a curve of genus g, our quantization scheme leads to g different trace class operators. Their spectral properties are encoded in a generalized spectral determinant, which is an entire function on the Calabi-Yau moduli space. We conjecture an exact expression for this spectral determinant in terms of the standard and refined topological string amplitudes. This conjecture provides a non-perturbative definition of the topological string on these geometries, in which the genus expansion emerges in a suitable 't Hooft limit of the spectral traces of the operators. In contrast to what happens in quantum integrable systems, our quantization scheme leads to a single quantization condition, which is elegantly encoded by t...

  4. BRST quantization of superconformal theories on higher genus Riemann surfaces

    International Nuclear Information System (INIS)

    A complex contour integral method is constructed and applied to the Becchi-Rouet-Stora-Tyutin (BRST) quantization procedure of string theories on higher genus Riemann surfaces with N=0 and 1 Krichever-Novikov (KN) algebras. This method makes calculations very simple. It is shown that the critical spacetime dimension of the string theories on a genus-g Riemann surface equals that of the string theories on a genus-zero Riemann surface, and that the 'Regge intercepts' in the genus-g case are α(g)=1-3/4g-9/8g2 and 1/2-3/4g-17/16g2 for bosonic strings and superstrings, respectively. (orig.)

  5. Some adaptational peculiarities of introduced species of the genus Hydrangea

    Directory of Open Access Journals (Sweden)

    V. N. Kuchma

    2006-03-01

    Full Text Available Among studied the Hydrangea L. genus the species, which most adapted to the environment of steppe conditions, were developed. H. cinerea Stall. and H. bretschneider Dipp. are recommended for use in laying out of parks, etc.

  6. Separating Curve Complex of the Genus Two Surface is Hyperbolic

    OpenAIRE

    Sultan, Harold Mark

    2011-01-01

    A proof that the separating curve complex of the closed genus two surface has a quasi-distance formula and is delta hyperbolic using tools of Masur and Schleimer. This answers in the affirmative a Conjecture of Schleimer.

  7. Notes on genus Eurydoxa Filipjev (Lepidoptera: Tortricidae) in China

    Institute of Scientific and Technical Information of China (English)

    BYUN Bong-Kyu; YAN Shan-chun; LI Cheng-de

    2003-01-01

    Genus Eurydoxa Filipjev in China is reviewed and noted for the first time. Based on the present study, two species are recognized, including rhodopa Diakonoff and advena Filipjev. All available information for the species is reviewed and provided.

  8. Phylogeny and systematics of the anamorphic, entomopathogenic genus Beauveria

    Science.gov (United States)

    Beauveria is a cosmopolitan anamorph genus of arthropod pathogens that includes the agronomically important species B. bassiana and B. brongniartii, which are used as mycoinsecticides for the biological control of pest insects. Recent phylogenetic evidence demonstrates that Beauveria is monophyletic...

  9. Seidenforchis - a new genus of Malaxidinae (Orchidaceae) from Thailand

    OpenAIRE

    Hanna B. Margońska

    2011-01-01

    A new genus Seidenforchis of the subtribe Malaxidinae (Orchidaceae) from Southeast Asia is proposed. Three species are transferred from Crepidium to Seidenforchis. Keys for determination of Seidenforchis species and related genera of subtribe Malaxidinae from Asia, are proposed.

  10. NOMENCLATURAL NOTE ON A GENUS OF ORIENTAL RHAMPHINI (Coleoptera, Curculionidae)

    OpenAIRE

    Enzo Colonnelli

    2013-01-01

    The name Megorchestes Kojima, 2011 is here selected as the correct original spelling over Magorchestes (alternative original spelling, here rejected) and Megorchsetes (alternative original spelling, here rejected) of a recently described genus of Oriental Rhamphini.

  11. Complete Genome Sequences of Six Strains of the Genus Methylobacterium

    Energy Technology Data Exchange (ETDEWEB)

    Marx, Christopher J [Harvard University; Bringel, Francoise O. [University of Strasbourg; Christoserdova, Ludmila [University of Washington, Seattle; Moulin, Lionel [UMR, France; UI Hague, Muhammad Farhan [University of Strasbourg; Fleischman, Darrell E. [Wright State University, Dayton, OH; Gruffaz, Christelle [CNRS, Strasbourg, France; Jourand, Philippe [UMR, France; Knief, Claudia [ETH Zurich, Switzerland; Lee, Ming-Chun [Harvard University; Muller, Emilie E. L. [CNRS, Strasbourg, France; Nadalig, Thierry [CNRS, Strasbourg, France; Peyraud, Remi [ETH Zurich, Switzerland; Roselli, Sandro [CNRS, Strasbourg, France; Russ, Lina [ETH Zurich, Switzerland; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Ivanov, Pavel S. [University of Wyoming, Laramie; Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Lajus, Aurelie [Genoscope/Centre National de la Recherche Scientifique-Unite Mixte de Recherche; Land, Miriam L [ORNL; Medigue, Claudine [Genoscope/Centre National de la Recherche Scientifique-Unite Mixte de Recherche; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Stolyar, Sergey [University of Washington; Vorholt, Julia A. [ETH Zurich, Switzerland; Vuilleumier, Stephane [University of Strasbourg

    2012-01-01

    The complete and assembled genome sequences were determined for six strains of the alphaproteobacterial genus Methylobacterium, chosen for their key adaptations to different plant-associated niches and environmental constraints.

  12. Complete genome sequences of six strains of the genus methylobacterium

    Energy Technology Data Exchange (ETDEWEB)

    Marx, Christopher J [Harvard University; Bringel, Francoise O. [University of Strasbourg; Christoserdova, Ludmila [University of Washington, Seattle; Moulin, Lionel [UMR, France; Farhan Ul Haque, Muhammad [CNRS, Strasbourg, France; Fleischman, Darrell E. [Wright State University, Dayton, OH; Gruffaz, Christelle [CNRS, Strasbourg, France; Jourand, Philippe [UMR, France; Knief, Claudia [ETH Zurich, Switzerland; Lee, Ming-Chun [Harvard University; Muller, Emilie E. L. [CNRS, Strasbourg, France; Nadalig, Thierry [CNRS, Strasbourg, France; Peyraud, Remi [ETH Zurich, Switzerland; Roselli, Sandro [CNRS, Strasbourg, France; Russ, Lina [ETH Zurich, Switzerland; Aguero, Fernan [Universidad Nacional de General San Martin; Goodwin, Lynne A. [Los Alamos National Laboratory (LANL); Ivanova, N [U.S. Department of Energy, Joint Genome Institute; Kyrpides, Nikos C [U.S. Department of Energy, Joint Genome Institute; Lajus, Aurelie [Genoscope/Centre National de la Recherche Scientifique-Unite Mixte de Recherche; Land, Miriam L [ORNL; Medigue, Claudine [Genoscope/Centre National de la Recherche Scientifique-Unite Mixte de Recherche; Mikhailova, Natalia [U.S. Department of Energy, Joint Genome Institute; Nolan, Matt [U.S. Department of Energy, Joint Genome Institute; Woyke, Tanja [U.S. Department of Energy, Joint Genome Institute; Stolyar, Sergey [University of Washington; Vorholt, Julia A. [ETH Zurich, Switzerland; Vuilleumier, Stephane [University of Strasbourg

    2012-01-01

    The complete and assembled genome sequences were determined for six strains of the alphaproteobacterial genus Methylobacterium, chosen for their key adaptations to different plant-associated niches and environmental constraints.

  13. Primary description, new combinations and synonyms in the genus Laccaria

    OpenAIRE

    Denes PAZMANY

    1994-01-01

    This paper is a comprehensive enumeration of the primary descriptions and new combinations of the species, varieties, forms and supraspecific taxons of the genus Laccaria and their synonyms, on the base of the published literature.

  14. Quaternion Algebras over Curves of Genus One Without Rational Points

    Institute of Scientific and Technical Information of China (English)

    Susanne Pumpl(u)n

    2005-01-01

    Quaternion algebras over curves of genus one without rational points over perfect fields of characteristic not two are classified. As a consequence, all quaternion algebras over the function field of such a curve, which are unramified everywhere, are classified.

  15. Warionia (Asteraceae: a relict genus of Cichorieae?

    Directory of Open Access Journals (Sweden)

    Katinas, Liliana

    2008-12-01

    Full Text Available The genus Warionia, with its only species W. saharae, is endemic to the northwestern edge of the African Sahara desert. This is a somewhat thistle-like aromatic plant, with white latex, and fleshy, pinnately- partite leaves. Warionia is in many respects so different from any other genus of Asteraceae, that it has been tentatively placed in the tribes Cardueae, Cichorieae, Gundelieae, and Mutisieae. Until now, a comprehensive study of Warionia to have a complete context for discussing its taxonomic position is lacking. The general morphology, anatomy, palynology and chromosome number of W. saharae are investigated here, and the species is described and illustrated. Laticifers in leaves and stems indicate a relationship with Cichorieae, and are associated with the phloem, in contact with it or with the surrounding sclerenchyma sheath. The pollen features indicate a strong relation with Cardueae, namely the structure with Anthemoid pattern where the columellae are joined to the foot layer, the ectosexine with thin columellae, the endosexine with stout and ramified columellae, the conspicuous spines with globose bases and conspicuous apical channels, and the tectum surface very perforate. Chromosomal counts resulted in 2n = 34. The morphological and palynological evidence positions Warionia between the tribes Cardueae and Cichorieae suggesting that it could be a remnant of the ancestral stock that gave rise to both tribes.El género Warionia, y su única especie, W. saharae, es endémico del noroeste del desierto africano del Sahara. Es una planta semejante a un cardo, aromática, con látex blanco y hojas carnosas, pinnatipartidas. Warionia es tan diferente de otros géneros de Asteraceae que fue ubicada en las tribus Cardueae, Cichorieae, Gundelieae y Mutisieae. Hasta ahora, no existía un estudio global de Warionia como contexto para discutir su posición taxonómica. Se ha investigado aquí su morfología, anatomía, palinología y n

  16. Ecua, a new genus op Apocynaceae from Malesia

    OpenAIRE

    Middleton, David J.

    1996-01-01

    Whilst examining the specimens of Apocynaceae in Herbarium Bogoriense I came upon two unknown specimens which appeared to be species of Parsonsia. On further examination they turned out to belong to a new genus related to Parsonsia but differing from it in the stamens which are included within the corolla tube and the shape of the corolla, filaments and anthers. This is the second new genus recently discovered in Malesia, the first being Baharuia D.J. Middleton described from plants collected...

  17. Molecular signatures and phylogenomic analysis of the genus Burkholderia: proposal for division of this genus into the emended genus Burkholderia containing pathogenic organisms and a new genus Paraburkholderia gen. nov. harboring environmental species

    OpenAIRE

    Sawana, Amandeep; Adeolu, Mobolaji; Gupta, Radhey S.

    2014-01-01

    The genus Burkholderia contains large number of diverse species which include many clinically important organisms, phytopathogens, as well as environmental species. However, currently, there is a paucity of biochemical or molecular characteristics which can reliably distinguish different groups of Burkholderia species. We report here the results of detailed phylogenetic and comparative genomic analyses of 45 sequenced species of the genus Burkholderia. In phylogenetic trees based upon concate...

  18. The set of numerical semigroups of a given genus

    CERN Document Server

    Blanco, V

    2011-01-01

    In this paper we present a new approach to construct the set of numerical semigroups with a fixed genus. Our methodology is based on the construction of the set of numerical semigroups with fixed Frobenius number and genus. An equivalence relation is given over this set and a tree structure is defined for each equivalence class. We also provide a more efficient algorithm based in the translation of a numerical semigroup to its so-called Kunz-coordinates vector.

  19. Genus Two Stable Maps, Local Equations and Modular Resolutions

    OpenAIRE

    Hu, Yi; Li, Jun

    2012-01-01

    We describe a canonical sequence of modular blowups of the Artin stack of stable weighted genus-two curves that diagonalize certain canonical derived objects of the original Artin stack. This provides a resolution of the primary component of the moduli space of genus two stable maps to projective space, and a partial desingularization of the same moduli space. Our approach should extend to higher genera.

  20. Debatten om begreppen : genus i Kvinnovetenskaplig tidskrift 1980-1998

    OpenAIRE

    Åsberg, Cecilia

    1998-01-01

      "Concepts up for discussion: On the concept of genus in Swedish Gender Studies" This article concerns a lively conceptual debatethat took place in Kvinnovetenskaplig tidskrift (Swedish Journal of Women's Studies) between 1980-1998. When Yvonne Hirdman, a Swedish historian, in 1988 introduced the concepts of gender and gender system in KVT (in Swedish: genus and genussystem), this sparked off intense discussions and caused theoretical divisions within Swedish feminism. Opinions were divided ...

  1. A MONOGRAPH OF THE GENUS NEOCINNAMOMUM LIOU HO

    Directory of Open Access Journals (Sweden)

    A. J. G. H. KOSTERMANS

    1974-12-01

    Full Text Available ABSTRACTThe Asiatic Genus Neocinamomum comprises 6 species, of whichN. atjehense is described here for the first time. cinnamomum fargesiiLee. is moved to Neocinnamomum, N. willsonii Allen is consideredto be conspeeific with it. N. delavayi var.Mekongense hand.Mazz israised to specific rank. N. hainanianum  Allen  is reduced to N. lecomtei.Excluded from the genus is N. confertiflorum, which is moved toLitsea.

  2. The effect of storage on quality of herbs genus Origanum

    OpenAIRE

    Lenka Kouřimská; Kateřina Ešlerová; Ynus Khatri

    2016-01-01

    Herbs of Origanum genus are rich in essential oils and contain large amounts of phenols, lipids, fatty acids, flavonoids and anthocyanins. Antioxidant activity of these herbs depends on many factors, including the type herbs, post-harvest processing and subsequent processing. The aim of this study was therefore to confirm the hypothesis that the composition of oils of these two herbs of the Origanum genus depends on the post-harvest treatment of herbs and that the dried herb antioxidant activ...

  3. Shifted genus expanded W ∞ algebra and shifted Hurwitz numbers

    Science.gov (United States)

    Zheng, Quan

    2016-05-01

    We construct the shifted genus expanded W ∞ algebra, which is isomorphic to the central subalgebra A ∞ of infinite symmetric group algebra and to the shifted Schur symmetrical function algebra Λ* defined by Okounkov and Olshanskii. As an application, we get some differential equations for the generating functions of the shifted Hurwitz numbers; thus, we can express the generating functions in terms of the shifted genus expanded cut-and-join operators.

  4. Torsionfree Sheaves over a Nodal Curve of Arithmetic Genus One

    Indian Academy of Sciences (India)

    Usha N Bhosle; Indranil Biswas

    2008-02-01

    We classify all isomorphism classes of stable torsionfree sheaves on an irreducible nodal curve of arithmetic genus one defined over $\\mathbb{C}$. Let be a nodal curve of arithmetic genus one defined over $\\mathbb{R}$, with exactly one node, such that does not have any real points apart from the node. We classify all isomorphism classes of stable real algebraic torsionfree sheaves over of even rank. We also classify all isomorphism classes of real algebraic torsionfree sheaves over of rank one.

  5. Notes on the Lichen Genus Hypotrachyna (Parmeliaceae) from South Korea

    OpenAIRE

    Jayala, Udenil; Joshi, Santosh; Oh, Soon-Ok; Park, Jung-Shin; Koh, Young Jin; Hur, Jae-Seoun

    2013-01-01

    Hypotrachyna (Vainio) Hale is a somewhat rare lichen genus found on the Korean Peninsula. Since it was first recorded more than two decades ago, no detailed taxonomic or revisionary study of the genus has been conducted. Thus, the present study was conducted to carry out a detailed taxonomic and revisionary study of Hypotrachyna in South Korea. This study was based on specimens deposited in the Korean Lichen Research Institute (KoLRI). Detailed taxonomic studies and a literature review confir...

  6. A Taxonomic Study of the Genus Myelochroa in South Korea

    OpenAIRE

    Jayalal, Udeni; Joshi, Santosh; Oh, Soon-Ok; Koh, Young Jin; Hur, Jae-Seoun

    2012-01-01

    Myelochroa (Asahina) Elix & Hale is a common foliose lichen genus found on the Korean Peninsula. Since it was first recorded nearly two decades ago, no detailed taxonomic or revisionary study of the genus has been conducted. Thus, the current study was conducted to carry out a detailed taxonomic and revisionary study of Myelochroa in South Korea. This study was based on specimens deposited in the Korean Lichen Research Institute (KoLRI). Detailed taxonomic studies and a literature review conf...

  7. Revision of the genus Caelospermum Blume (Rubiaceae, Rubioideae, Morindeae)

    OpenAIRE

    Johansson, J.T.

    1988-01-01

    The genus Caelospermum Blume is revised, and a key to the 7 species recognized is presented. Caelospermum consists of lianas and, sometimes, shrubs. The genus is distributed in SE. Asia, Indonesia, the Philippines, the Caroline Islands, Papua New Guinea, the Solomon Islands, E. Australia and New Caledonia. Caelospermum is closely related to Morinda, Pogonolobus and Gynochthodes, from which it differs by inflorescence and pollen morphology, etc. Caelospermum paniculatum F. Muell. var. syncarpu...

  8. Higher Genus Abelian Functions Associated with Cyclic Trigonal Curves

    Directory of Open Access Journals (Sweden)

    Matthew England

    2010-03-01

    Full Text Available We develop the theory of Abelian functions associated with cyclic trigonal curves by considering two new cases. We investigate curves of genus six and seven and consider whether it is the trigonal nature or the genus which dictates certain areas of the theory. We present solutions to the Jacobi inversion problem, sets of relations between the Abelian function, links to the Boussinesq equation and a new addition formula.

  9. A new genus of Rhytirrhinini from Colombia (Coleoptera: Curculionidae)

    OpenAIRE

    Morrone Juan J.

    1995-01-01

    Rupanius, new genus, comprises the single species R. carinatus, new species, endemic to the Paramo biogeographic province of Colombia. It is diagnosed based on the elytra subquadrate and with a conspicuous declivital carina, and is considered similar to Puranlus Germain and Acrorius Kirsch. The genus and species are described, illustrated, and compared with the other Colombian Rhytirrhinini.Rupanius, gen. n., comprende la única especie R. carinatus, sp. n., endémica de la provincia biogeográf...

  10. An atlas of reproductive development in rockfishes, genus Sebastes

    OpenAIRE

    Shaw, Franklin R.; Morado, J. Frank; Lowe, Vanessa C.; McDermott, Susanne F.

    2012-01-01

    The genus Sebastes consists of over 100 fish species, all of which are viviparous and long-lived. Previous studies have presented schemes on the reproductive biology of a single targeted species of the genus Sebastes, but all appear to possess a similar reproductive biology as evidenced by this and other studies. This atlas stages major events during spermatogenesis, oogenesis, and embryogenesis, including atresia, in six species of Sebastes (S. alutus, S. elongatus, S. helvomaculatus, S. ...

  11. The Exiguobacterium genus: biodiversity and biogeography

    Energy Technology Data Exchange (ETDEWEB)

    Vishnivetskaya, Tatiana A [ORNL; Kathariou, Sophia [North Carolina State University; Tiedje, James M. [Michigan State University, East Lansing

    2009-01-01

    Abstract. Bacteria of the genus Exiguobacterium are low G + C, Gram-positive facultative anaerobes that have been repeatedly isolated from ancient Siberian permafrost. In addition, Exiguobacterium spp. have been isolated from markedly diverse sources, including Greenland Glacial ice, hot springs at Yellowstone National Park, the rhizosphere of plants, and the environment of food processing plants. Strains of this hereto little known bacterium that have been retrieved from such different (and often extreme) environments are worthy of attention as they are likely to be specifically adapted to such environments and to carry variations in the genome which may correspond to psychrophilic and thermophilic adaptations. However, comparative genomic investigations of Exiguobacterium spp. from different sources have been limited. In this study, we employed different molecular approaches for the comparative analysis of 24 isolates from markedly diverse environments including ancient Siberian permafrost and hot springs at Yellowstone National Park. Pulsed-field gel electrophoresis (PFGE) with I-CeuI (an intron-encoded endonuclease), AscI and NotI were optimized for the determination of genomic fingerprints of nuclease-producing isolates. The application of a DNA macroarray for 82 putative stress-response genes yielded strain-specific hybridization profiles. Cluster analyses of 16S rRNA gene sequence data, PFGE I-CeuI restriction patterns and hybridization profiles suggested that Exiguobacterium strains formed two distinct divisions that generally agreed with temperature ranges for growth. With few exceptions (e.g., Greenland ice isolate GIC31), psychrotrophic and thermophilic isolates belonged to different divisions.

  12. The Genus Asparagus in Southern Africa*

    Directory of Open Access Journals (Sweden)

    J. P. Jessop

    1966-12-01

    Full Text Available A revision of the genus Asparagus in South Africa, South West Africa, Bechuanaland, Basutoland, and Swaziland has been undertaken. Notes are given on the value of most o f the characters which have been used in the separation of species, recent literature on the nature of  Asparagus assimilatory organs, and a technique for the examination of chromosomes. Chromosome counts are listed for ten taxa. There is a key to the forty species and four varieties. In the main part of the work these taxa are described, and their synonymy, taxonomy, distribution and habitats dealt with. Six species and one variety are new. The following are the new species and combinations:  A. setaceus (Kunth (Asparagopsis setacea Kunth, A. mueronatus, A. macowanii Bak. var. zuluensis (N. E. Br.  (A. zuluensis N. E. Br., A. rigidus, A. densiflorus (Kunth  {Asparagopsis densiflora Kunth,  A. aethiopicus L. var. angusticladus, A. falcatus L. var. ternifolius (Bak.  (A. aethiopicus L. var.  ternifolius Bak.,  A. aspergillus,  A. obermeyerae,  A. krebsianus (Kunth (Asparagopsis krebsiana Kunth,  A. acocksii.  A. crassicladus. Several plants o f horticultural importance occur in South Africa. The three best known are A. plumosus, which is reduced here to synonymy under  A. setaceus (Kunth Jessop, and  A. sprengeri and  A. myersii. A. sprengeri is being reduced to synonymy under  A. densiflorus (Kunth Jessop,.  A. myersii, which is a  nomen nudum, is also regarded as belonging to  A. densiflorus.

  13. Role of Bacterial Exopolysaccharides (EPS in the Fate of the Oil Released during the Deepwater Horizon Oil Spill.

    Directory of Open Access Journals (Sweden)

    Tony Gutierrez

    Full Text Available Halomonas species are recognized for producing exopolysaccharides (EPS exhibiting amphiphilic properties that allow these macromolecules to interface with hydrophobic substrates, such as hydrocarbons. There remains a paucity of knowledge, however, on the potential of Halomonas EPS to influence the biodegradation of hydrocarbons. In this study, the well-characterized amphiphilic EPS produced by Halomonas species strain TG39 was shown to effectively increase the solubilization of aromatic hydrocarbons and enhance their biodegradation by an indigenous microbial community from oil-contaminated surface waters collected during the active phase of the Deepwater Horizon oil spill. Three Halomonas strains were isolated from the Deepwater Horizon site, all of which produced EPS with excellent emulsifying qualities and shared high (97-100% 16S rRNA sequence identity with strain TG39 and other EPS-producing Halomonas strains. Analysis of pyrosequence data from surface water samples collected during the spill revealed several distinct Halomonas phylotypes, of which some shared a high sequence identity (≥97% to strain TG39 and the Gulf spill isolates. Other bacterial groups comprising members with well-characterized EPS-producing qualities, such as Alteromonas, Colwellia and Pseudoalteromonas, were also found enriched in surface waters, suggesting that the total pool of EPS in the Gulf during the spill may have been supplemented by these organisms. Roller bottle incubations with one of the Halomonas isolates from the Deepwater Horizon spill site demonstrated its ability to effectively produce oil aggregates and emulsify the oil. The enrichment of EPS-producing bacteria during the spill coupled with their capacity to produce amphiphilic EPS is likely to have contributed to the ultimate removal of the oil and to the formation of oil aggregates, which were a dominant feature observed in contaminated surface waters.

  14. In Situ Confocal Raman Microscopy of Hydrated Early Stages of Bacterial Biofilm Formation on Various Surfaces in a Flow Cell.

    Science.gov (United States)

    Smith-Palmer, Truis; Lin, Sicheng; Oguejiofor, Ikenna; Leng, Tianyang; Pustam, Amanda; Yang, Jin; Graham, Lori L; Wyeth, Russell C; Bishop, Cory D; DeMont, M Edwin; Pink, David

    2016-02-01

    Bacterial biofilms are precursors to biofouling by other microorganisms. Understanding their initiation may allow us to design better ways to inhibit them, and thus to inhibit subsequent biofouling. In this study, the ability of confocal Raman microscopy to follow the initiation of biofouling by a marine bacterium, Pseudoalteromonas sp. NCIMB 2021 (NCIMB 2021), in a flow cell, using optical and confocal Raman microscopy, was investigated. The base of the flow cell comprised a cover glass. The cell was inoculated and the bacteria attached to, and grew on, the cover glass. Bright field images and Raman spectra were collected directly from the hydrated biofilms over several days. Although macroscopically the laser had no effect on the biofilm, within the first 24 h cells migrated away from the position of the laser beam. In the absence of flow, a buildup of extracellular substances occurred at the base of the biofilm. When different coatings were applied to cover glasses before they were assembled into the flow cells, the growth rate, structure, and composition of the resulting biofilm was affected. In particular, the ratio of Resonance Raman peaks from cytochrome c (CC) in the extracellular polymeric substances, to the Raman phenylalanine (Phe) peak from protein in the bacteria, depended on both the nature of the surface and the age of the biofilm. The ratios were highest for 24 h colonies on a hydrophobic surface. Absorption of a surfactant with an ethyleneoxy chain into the hydrophobic coating created a surface similar to that given with a simple PEG coating, where bacteria grew in colonies away from the surface rather than along the surface, and CC:Phe ratios were initially low but increased at least fivefold in the first 48 h. PMID:26903564

  15. Bacteria of the genus Endozoicomonas dominate the microbiome of the Mediterranean gorgonian coral Eunicella cavolini

    KAUST Repository

    Bayer, T

    2013-04-08

    Forming dense beds that provide the structural basis of a distinct ecosystem, the gorgonian Eunicella cavolini (Octocorallia) is an important species in the Mediterranean Sea. Despite the importance and prevalence of this temperate gorgonian, little is known about its microbial assemblage, although bacteria are well known to be important to hard and soft coral functioning. Here, we used massively parallel pyrosequencing of 16S rRNA genes to determine the composition and relative abundances of bacteria associated with E. cavolini collected from different depths at a site on the French Mediterranean coast. We found that whereas the bacterial assemblages of E. cavolini were distinct and less diverse than those of the surrounding water column, the water depth did not affect the bacterial assemblages of this gorgonian. Our data show that E. cavolini?s microbiome contains only a few shared species and that it is highly dominated by bacteria from the genus Endozoicomonas, a Gammaproteobacteria that is frequently found to associate with marine invertebrates.

  16. The Representatives of Amelanchier Medik. Genus in Ukraine

    Directory of Open Access Journals (Sweden)

    Opalko Anatoliy Ivanovich

    2015-04-01

    Full Text Available The information on fruit and decorative value, honey and medicinal properties of the genus Amelanchier Medik. is generalized. Their biological characteristics, chemical composition and palatability traits of the fruit, the ways of consumption and processing, including drying, preparing juices, syrups, jams, candied fruit jellies, confiture, and fruit wine are specified. The environmental adaptability and effectiveness of using juneberry for phytomelioration are mentioned. Several versions of the origin of the genus Amelanchier name and interpretation of its specific epithets are described. The controversial issues of the genus Amelanchier system were discussed from the classical and molecular genetic approaches. The attention is focused on two main aspects of views on the place of the genus Amelanchier representatives of the family Rosaceae Juss. within the particular subfamily, namely the subfamily Pyroideae Burnett (Maloideae S. Weber or the subfamily Amygdaloideae Arn., which indicates the necessity for further comparative morphological and molecular genetic studies of the family Rosaceae. The directions of evolution, habitat and invasive ability of some species of the genus Amelanchier are characterised. The list of the genus Amelanchier representatives cultivated in Ukraine is given.

  17. Bacterial Degradation of Pesticides

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær

    This PhD project was carried out as part of the Microbial Remediation of Contaminated Soil and Water Resources (MIRESOWA) project, funded by the Danish Council for Strategic Research (grant number 2104-08-0012). The environment is contaminated with various xenobiotic compounds e.g. pesticides......D student, to construct fungal-bacterial consortia in order to potentially stimulate pesticide degradation thereby increasing the chance of successful bioaugmentation. The results of the project are reported in three article manuscripts, included in this thesis. In manuscript I, the mineralization of 2...

  18. Bacterial mitotic machineries

    DEFF Research Database (Denmark)

    Gerdes, Kenn; Møller-Jensen, Jakob; Ebersbach, Gitte; Kruse, Torben; Nordström, Kurt

    2004-01-01

    Here, we review recent progress that yields fundamental new insight into the molecular mechanisms behind plasmid and chromosome segregation in prokaryotic cells. In particular, we describe how prokaryotic actin homologs form mitotic machineries that segregate DNA before cell division. Thus, the P......M protein of plasmid R1 forms F actin-like filaments that separate and move plasmid DNA from mid-cell to the cell poles. Evidence from three different laboratories indicate that the morphogenetic MreB protein may be involved in segregation of the bacterial chromosome....

  19. Bacterial terpene cyclases.

    Science.gov (United States)

    Dickschat, Jeroen S

    2016-01-01

    Covering: up to 2015. This review summarises the accumulated knowledge about characterised bacterial terpene cyclases. The structures of identified products and of crystallised enzymes are included, and the obtained insights into enzyme mechanisms are discussed. After a summary of mono-, sesqui- and diterpene cyclases the special cases of the geosmin and 2-methylisoborneol synthases that are both particularly widespread in bacteria will be presented. A total number of 63 enzymes that have been characterised so far is presented, with 132 cited references. PMID:26563452

  20. Bacterial Diversity and Community Structure in Two Bornean Nepenthes Species with Differences in Nitrogen Acquisition Strategies.

    Science.gov (United States)

    Sickel, Wiebke; Grafe, T Ulmar; Meuche, Ivonne; Steffan-Dewenter, Ingolf; Keller, Alexander

    2016-05-01

    Carnivorous plants of the genus Nepenthes have been studied for over a century, but surprisingly little is known about associations with microorganisms. The two species Nepenthes rafflesiana and Nepenthes hemsleyana differ in their pitcher-mediated nutrient sources, sequestering nitrogen from arthropod prey and arthropods as well as bat faeces, respectively. We expected bacterial communities living in the pitchers to resemble this diet difference. Samples were taken from different parts of the pitchers (leaf, peristome, inside, outside, digestive fluid) of both species. Bacterial communities were determined using culture-independent high-throughput amplicon sequencing. Bacterial richness and community structure were similar in leaves, peristomes, inside and outside walls of both plant species. Regarding digestive fluids, bacterial richness was higher in N. hemsleyana than in N. rafflesiana. Additionally, digestive fluid communities were highly variable in structure, with strain-specific differences in community composition between replicates. Acidophilic taxa were mostly of low abundance, except the genus Acidocella, which strikingly reached extremely high levels in two N. rafflesiana fluids. In N. hemsleyana fluid, some taxa classified as vertebrate gut symbionts as well as saprophytes were enriched compared to N. rafflesiana, with saprophytes constituting potential competitors for nutrients. The high variation in community structure might be caused by a number of biotic and abiotic factors. Nitrogen-fixing bacteria were present in both study species, which might provide essential nutrients to the plant at times of low prey capture and/or rare encounters with bats. PMID:26790863

  1. A Taxonomic Study on the Burrowing Cricket Genus Velarifictorus with Morphologically Resembled Genus Lepidogryllus (Orthoptera: Gryllidae: Gryllinae in Korea

    Directory of Open Access Journals (Sweden)

    Tae-Woo Kim

    2013-10-01

    Full Text Available The burrowing-cricket genus Velarifictorus Randell, 1964 is reviewed in Korea, comparing with morphologically resembled genus Lepidogryllus Otte and Alexander, 1983 for the first time. First, Velarifictorus aspersus borealis Gorochov, 1985 is confirmed from only restricted area of southern regions in Gyeongsangnam- do and Jeollanam-do. Second, Velarifictorus micado (Saussure, 1877 is confirmed from nearly all around the Korean peninsula including North Korea. Third, the previously not recorded Velarifictorus ornatus (Shiraki, 1911 is newly recognized from South Korea. Relating to the genus Velarifictorus, the resembled genus Lepidogryllus Otte and Alexander, 1983 and its species Lepidogryllus siamensis (Chopard, 1961 com. & stat. nov. is studied and compared with Velarifictorus members. A key, descriptions, tables, photographs, figures, oscillograms and spectrograms of calling sounds are provided to aid identification between the four similar species.

  2. 仿刺参体表微生物的菌相分析%Analysis of bacterial flora on Apostichopus Japonicus surface

    Institute of Scientific and Technical Information of China (English)

    成功; 裴赢莹; 张公亮; 侯红漫

    2012-01-01

    The microorganisms on the surface of Dalian Apostichopus japonicas were isolated with three kinds of media. The isolated and purified microorganisms were identified based on bacterial morphs, physiological-biochemical characteristic and 16S rDNA molecular biology to find out the bacterial composition of microflora on the surface of Dalian sea-cucumber. The result showed that 105 bacteria were identified and purified from the surface of sea cucumber. Among them 10 different kinds of genera were identified as Pseudoalteromonas, Shewanella, Pseudomonas, Vibrio, Bacillus subtilis, Proteobacterium , Alteromonadaceas , Acinetobacter , Bacillus am yloique f aciens , Staphylococcus saprophyticus, of which Pseudoalterornonas and Vibrio accounted for 23.8 % and 22.9 % respectively.%采用3种培养基对大连仿刺参体表微生物进行分离,并通过细菌形态、生理生化特性和16S rDNA分子生物学相结合的方法对分离纯化的细菌进行鉴定,从而了解大连仿刺参体表的菌群组成.结果表明,从仿刺参体表分离纯化了105株细菌,鉴定出10种不同的菌属分别为交替假单胞菌属(Pseudoalteromonas)、希瓦氏菌属(Shewanella)、假单胞菌属(Pseudomonas)、弧菌属(Vibrio)、枯草芽孢杆菌(Bacillus subtilis),变形菌属(Proteobacterium)、Alteromonadacea、不动杆菌属(Acinetobacter)、解淀粉芽孢杆菌(Bacillus amyloique aciens),腐生葡萄球菌(Staphylococcus saprophyticus),其中交替假单胞菌属和弧菌属分别占分离菌株的23.8%和22.9%.

  3. A closed orientable 3-manifold with distinct distance three genus two Heegaard splittings

    CERN Document Server

    Berge, John

    2009-01-01

    We describe an example of a closed orientable 3-manifold with distinct distance three genus two Heegaard splittings. This demonstrates that the constructions of alternate genus two Heegaard splittings of closed orientable 3-manifolds described by Rubinstein and Scharlemann in their 1998 paper Genus Two Heegaard Splittings of Orientable 3-Manifolds, does not yield all alternate genus two splittings and must be augmented.

  4. Bacterial contamination of enteral diets.

    OpenAIRE

    de Leeuw, I H; Vandewoude, M F

    1986-01-01

    Enteral feeding solutions can be contaminated by bacterial micro-organisms already present in the ingredients, or introduced during preparation or transport, or in the hospital ward. During jejunostomy feeding without pump or filter, ascending bacterial invasion of the feeding bag is possible. In patients with lowered immune response contaminated feedings can cause serious septic clinical problems. The progressive loss of the nutritional value of the enteral feeding solution by bacterial cont...

  5. Transport powered by bacterial turbulence

    OpenAIRE

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S.

    2014-01-01

    We demonstrate that collective turbulent-like motion in a bacterial bath can power and steer directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedge-like "bulldozer" draws energy from a bacterial bath of varied density. We obtain that a maximal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp regi...

  6. Spontaneous bacterial peritonitis

    Institute of Scientific and Technical Information of China (English)

    Anastasios Koulaouzidis; Shivaram Bhat; Athar A Saeed

    2009-01-01

    Since its initial description in 1964, research has transformed spontaneous bacterial peritonitis (SBP) from a feared disease (with reported mortality of 90%) to a treatable complication of decompensated cirrhosis,albeit with steady prevalence and a high recurrence rate. Bacterial translocation, the key mechanism in the pathogenesis of SBP, is only possible because of the concurrent failure of defensive mechanisms in cirrhosis.Variants of SBP should be treated. Leucocyte esterase reagent strips have managed to shorten the 'tap-toshot' time, while future studies should look into their combined use with ascitic fluid pH. Third generation cephalosporins are the antibiotic of choice because they have a number of advantages. Renal dysfunction has been shown to be an independent predictor of mortality in patients with SBP. Albumin is felt to reduce the risk of renal impairment by improving effective intravascular volume, and by helping to bind proinflammatory molecules. Following a single episode of SBP, patients should have long-term antibiotic prophylaxis and be considered for liver transplantation.

  7. Adult bacterial meningitis

    DEFF Research Database (Denmark)

    Meyer, C N; Samuelsson, I S; Galle, M;

    2004-01-01

    Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin susceptibi......Episodes of adult bacterial meningitis (ABM) at a Danish hospital in 1991-2000 were identified from the databases of the Department of Clinical Microbiology, and compared with data from the Danish National Patient Register and the Danish National Notification System. Reduced penicillin...... susceptibility occurred in 21 (23%) of 92 cases of known aetiology, compared to an estimated 6% in nationally notified cases (p <0.001). Ceftriaxone plus penicillin as empirical treatment was appropriate in 97% of ABM cases in the study population, and in 99.6% of nationally notified cases. The notification rate...... was 75% for penicillin-susceptible episodes, and 24% for penicillin-non-susceptible episodes (p <0.001). Cases involving staphylococci, Pseudomonas spp. and Enterobacteriaceae were under-reported. Among 51 ABM cases with no identified risk factors, nine of 11 cases with penicillin...

  8. [Endogenous bacterial endophthalmitis].

    Science.gov (United States)

    Cornut, P-L; Chiquet, C

    2011-01-01

    Endogenous bacterial endophthalmitis, also called metastatic bacterial endophthalmitis, remains a diagnostic and therapeutic challenge. It is a rare and potentially sight-threatening ocular infection that occurs when bacteria reach the eye via the bloodstream, cross the blood-ocular barrier, and multiply within the eye. It usually affects immunocompromised patients and those suffering from diabetes mellitus, malignancy, or cardiac disease, but has also been reported after invasive procedures or in previously healthy people. In most cases, the ocular symptoms occur after the diagnosis of septicemia or systemic infection. Ocular symptoms include decreased vision, redness, discharge, pain, and floaters. The ocular inflammatory signs may be anterior and/or posterior. Bilateral involvement occurs in nearly 25% of cases. A wide range of microorganisms are involved, with differences in their frequency according to geography as well as the patient's age and past medical history, because of variations in the predisposing conditions and the source of the sepsis. The majority of patients are initially misdiagnosed, and ophthalmologists should be aware of this because prompt local and general management is required to save the eye and/or the patient's life. PMID:21145128

  9. Topographic diversity of fungal and bacterial communities in human skin.

    Science.gov (United States)

    Findley, Keisha; Oh, Julia; Yang, Joy; Conlan, Sean; Deming, Clayton; Meyer, Jennifer A; Schoenfeld, Deborah; Nomicos, Effie; Park, Morgan; Kong, Heidi H; Segre, Julia A

    2013-06-20

    Traditional culture-based methods have incompletely defined the microbial landscape of common recalcitrant human fungal skin diseases, including athlete's foot and toenail infections. Skin protects humans from invasion by pathogenic microorganisms and provides a home for diverse commensal microbiota. Bacterial genomic sequence data have generated novel hypotheses about species and community structures underlying human disorders. However, microbial diversity is not limited to bacteria; microorganisms such as fungi also have major roles in microbial community stability, human health and disease. Genomic methodologies to identify fungal species and communities have been limited compared with those that are available for bacteria. Fungal evolution can be reconstructed with phylogenetic markers, including ribosomal RNA gene regions and other highly conserved genes. Here we sequenced and analysed fungal communities of 14 skin sites in 10 healthy adults. Eleven core-body and arm sites were dominated by fungi of the genus Malassezia, with only species-level classifications revealing fungal-community composition differences between sites. By contrast, three foot sites--plantar heel, toenail and toe web--showed high fungal diversity. Concurrent analysis of bacterial and fungal communities demonstrated that physiologic attributes and topography of skin differentially shape these two microbial communities. These results provide a framework for future investigation of the contribution of interactions between pathogenic and commensal fungal and bacterial communities to the maintainenace of human health and to disease pathogenesis. PMID:23698366

  10. Comparative genomic analysis reveals a diverse repertoire of genes involved in prokaryote-eukaryote interactions within the Pseudovibrio genus.

    Directory of Open Access Journals (Sweden)

    Stefano eRomano

    2016-03-01

    Full Text Available Strains of the Pseudovibrio genus have been detected worldwide, mainly as part of bacterial communities associated with marine invertebrates, particularly sponges. This recurrent association has been considered as an indication of a symbiotic relationship between these microbes and their host. Until recently, the availability of only two genomes, belonging to closely related strains, has limited the knowledge on the genomic and physiological features of the genus to a single phylogenetic lineage.Here we present 10 newly sequenced genomes of Pseudovibrio strains isolated from marine sponges from the west coast of Ireland, and including the other two publicly available genomes we performed an extensive comparative genomic analysis. Homogeneity was apparent in terms of both the orthologous genes and the metabolic features shared amongst the 12 strains. At the genomic level, a key physiological difference observed amongst the isolates was the presence only in strain P. axinellae AD2 of genes encoding proteins involved in assimilatory nitrate reduction, which was then proved experimentally. We then focused on studying those systems known to be involved in the interactions with eukaryotic and prokaryotic cells. This analysis revealed that the genus harbors a large diversity of toxin-like proteins, secretion systems and their potential effectors. Their distribution in the genus was not always consistent with the phylogenetic relationship of the strains. Finally, our analyses identified new genomic islands encoding potential toxin-immunity systems, previously unknown in the genus.Our analyses shed new light on the Pseudovibrio genus, indicating a large diversity of both metabolic features and systems for interacting with the host. The diversity in both distribution and abundance of these systems amongst the strains underlines how metabolically and phylogenetically similar bacteria may use different strategies to interact with the host and find a niche

  11. Comparative Genomic Analysis Reveals a Diverse Repertoire of Genes Involved in Prokaryote-Eukaryote Interactions within the Pseudovibrio Genus

    Science.gov (United States)

    Romano, Stefano; Fernàndez-Guerra, Antonio; Reen, F. Jerry; Glöckner, Frank O.; Crowley, Susan P.; O'Sullivan, Orla; Cotter, Paul D.; Adams, Claire; Dobson, Alan D. W.; O'Gara, Fergal

    2016-01-01

    Strains of the Pseudovibrio genus have been detected worldwide, mainly as part of bacterial communities associated with marine invertebrates, particularly sponges. This recurrent association has been considered as an indication of a symbiotic relationship between these microbes and their host. Until recently, the availability of only two genomes, belonging to closely related strains, has limited the knowledge on the genomic and physiological features of the genus to a single phylogenetic lineage. Here we present 10 newly sequenced genomes of Pseudovibrio strains isolated from marine sponges from the west coast of Ireland, and including the other two publicly available genomes we performed an extensive comparative genomic analysis. Homogeneity was apparent in terms of both the orthologous genes and the metabolic features shared amongst the 12 strains. At the genomic level, a key physiological difference observed amongst the isolates was the presence only in strain P. axinellae AD2 of genes encoding proteins involved in assimilatory nitrate reduction, which was then proved experimentally. We then focused on studying those systems known to be involved in the interactions with eukaryotic and prokaryotic cells. This analysis revealed that the genus harbors a large diversity of toxin-like proteins, secretion systems and their potential effectors. Their distribution in the genus was not always consistent with the phylogenetic relationship of the strains. Finally, our analyses identified new genomic islands encoding potential toxin-immunity systems, previously unknown in the genus. Our analyses shed new light on the Pseudovibrio genus, indicating a large diversity of both metabolic features and systems for interacting with the host. The diversity in both distribution and abundance of these systems amongst the strains underlines how metabolically and phylogenetically similar bacteria may use different strategies to interact with the host and find a niche within its

  12. Periodic growth of bacterial colonies

    Science.gov (United States)

    Yamazaki, Yoshihiro; Ikeda, Takemasa; Shimada, Hirotoshi; Hiramatsu, Fumiko; Kobayashi, Naoki; Wakita, Jun-ichi; Itoh, Hiroto; Kurosu, Sayuri; Nakatsuchi, Michio; Matsuyama, Tohey; Matsushita, Mitsugu

    2005-06-01

    The formation of concentric ring colonies by bacterial species Bacillus subtilis and Proteus mirabilis has been investigated experimentally, focusing our attention on the dependence of local cell density upon the bacterial motility. It has been confirmed that these concentric ring colonies reflect the periodic change of the bacterial motility between motile cell state and immotile cell state. We conclude that this periodic change is macroscopically determined neither by biological factors (i.e., biological clock) nor by chemical factors (chemotaxis as inhibitor). And our experimental results strongly suggest that the essential factor for the change of the bacterial motility during concentric ring formation is the local cell density.

  13. The genus Rhaponticum in East Asia

    Directory of Open Access Journals (Sweden)

    Gorovoy, P.

    2010-12-01

    Full Text Available The genus Rhaponticum in East Asia has always been a taxon for discussion. Rhaponticum carthamoides from East Siberia comprises three subspecies: carthamoides, chamarensis and orientale. Even though they differ in morphology, they do not have isolated areas. Rhaponticum satzyperovii was recently described and its author pointed out its affinity with Rh. uniflorum. Plant height, stem indumentum, and radical and stem leaf dissection were signaled as the diagnostic characters. Our present study on living and herbarium specimens of Rh. satzyperovii shows that the diagnostic characters are not consistent. The species area was also claimed to be an argument for considering Rh. satzyperovii a distinct species. This area covers the south of the Primorye Province in the Far East of Russia with some locations in the adjacent Jewish Autonomous Region and in China. In our study, the area of Rh. satzyperovii is found to be within the area of Rh. uniflorum and thereafter they turned out to have no disjunction. In East Asia, Rh. uniflorum is characterized by a wide range of morphological variability. We suggest that Rh. satzyperovii should be included within Rh. uniflorum without any taxonomic rank.El género Rhaponticum en el Este de Asia ha sido siempre un taxón discutido. Rhaponticum carthamoides del Este de Siberia incluye tres subespecies: carthamoides, chamarensis y orientale. Aunque difieren en su morfología, sus áreas no están aisladas. Rhaponticum satzyperovii fue descrito recientemente y su autor señaló su afinidad con Rh. uniflorum. Los caracteres diagnósticos fueron la altura de la planta, el indumento del tallo y las divisiones de las hojas basales y caulinares. Nuestro estudio de plantas vivas y muestras de herbario de Rh. satzyperovii muestra que los caracteres diagnósticos no son consistentes. El área de distribución también se argumentó para considerar Rh. satzyperovii una especie diferente. El área cubre el sur de la provincia de

  14. Humpback whale populations share a core skin bacterial community: towards a health index for marine mammals?

    Science.gov (United States)

    Apprill, Amy; Robbins, Jooke; Eren, A Murat; Pack, Adam A; Reveillaud, Julie; Mattila, David; Moore, Michael; Niemeyer, Misty; Moore, Kathleen M T; Mincer, Tracy J

    2014-01-01

    Microbes are now well regarded for their important role in mammalian health. The microbiology of skin--a unique interface between the host and environment--is a major research focus in human health and skin disorders, but is less explored in other mammals. Here, we report on a cross-population study of the skin-associated bacterial community of humpback whales (Megaptera novaeangliae), and examine the potential for a core bacterial community and its variability with host (endogenous) or geographic/environmental (exogenous) specific factors. Skin biopsies or freshly sloughed skin from 56 individuals were sampled from populations in the North Atlantic, North Pacific and South Pacific oceans and bacteria were characterized using 454 pyrosequencing of SSU rRNA genes. Phylogenetic and statistical analyses revealed the ubiquity and abundance of bacteria belonging to the Flavobacteria genus Tenacibaculum and the Gammaproteobacteria genus Psychrobacter across the whale populations. Scanning electron microscopy of skin indicated that microbial cells colonize the skin surface. Despite the ubiquity of Tenacibaculum and Psychrobater spp., the relative composition of the skin-bacterial community differed significantly by geographic area as well as metabolic state of the animals (feeding versus starving during migration and breeding), suggesting that both exogenous and endogenous factors may play a role in influencing the skin-bacteria. Further, characteristics of the skin bacterial community from these free-swimming individuals were assembled and compared to two entangled and three dead individuals, revealing a decrease in the central or core bacterial community members (Tenacibaculum and Psychrobater spp.), as well as the emergence of potential pathogens in the latter cases. This is the first discovery of a cross-population, shared skin bacterial community. This research suggests that the skin bacteria may be connected to humpback health and immunity and could possibly serve

  15. Humpback whale populations share a core skin bacterial community: towards a health index for marine mammals?

    Directory of Open Access Journals (Sweden)

    Amy Apprill

    Full Text Available Microbes are now well regarded for their important role in mammalian health. The microbiology of skin--a unique interface between the host and environment--is a major research focus in human health and skin disorders, but is less explored in other mammals. Here, we report on a cross-population study of the skin-associated bacterial community of humpback whales (Megaptera novaeangliae, and examine the potential for a core bacterial community and its variability with host (endogenous or geographic/environmental (exogenous specific factors. Skin biopsies or freshly sloughed skin from 56 individuals were sampled from populations in the North Atlantic, North Pacific and South Pacific oceans and bacteria were characterized using 454 pyrosequencing of SSU rRNA genes. Phylogenetic and statistical analyses revealed the ubiquity and abundance of bacteria belonging to the Flavobacteria genus Tenacibaculum and the Gammaproteobacteria genus Psychrobacter across the whale populations. Scanning electron microscopy of skin indicated that microbial cells colonize the skin surface. Despite the ubiquity of Tenacibaculum and Psychrobater spp., the relative composition of the skin-bacterial community differed significantly by geographic area as well as metabolic state of the animals (feeding versus starving during migration and breeding, suggesting that both exogenous and endogenous factors may play a role in influencing the skin-bacteria. Further, characteristics of the skin bacterial community from these free-swimming individuals were assembled and compared to two entangled and three dead individuals, revealing a decrease in the central or core bacterial community members (Tenacibaculum and Psychrobater spp., as well as the emergence of potential pathogens in the latter cases. This is the first discovery of a cross-population, shared skin bacterial community. This research suggests that the skin bacteria may be connected to humpback health and immunity and could

  16. [Small intestine bacterial overgrowth].

    Science.gov (United States)

    Leung Ki, E L; Roduit, J; Delarive, J; Guyot, J; Michetti, P; Dorta, G

    2010-01-27

    Small intestine bacterial overgrowth (SIBO) is a condition characterised by nutrient malabsorption and excessive bacteria in the small intestine. It typically presents with diarrhea, flatulence and a syndrome of malabsorption (steatorrhea, macrocytic anemia). However, it may be asymptomatic in the eldery. A high index of suspicion is necessary in order to differentiate SIBO from other similar presenting disorders such as coeliac disease, lactose intolerance or the irritable bowel syndrome. A search for predisposing factor is thus necessary. These factors may be anatomical (stenosis, blind loop), or functional (intestinal hypomotility, achlorydria). The hydrogen breath test is the most frequently used diagnostic test although it lacks standardisation. The treatment of SIBO consists of eliminating predisposing factors and broad-spectrum antibiotic therapy. PMID:20214190

  17. Studying bacterial multispecies biofilms

    DEFF Research Database (Denmark)

    Røder, Henriette Lyng; Sørensen, Søren Johannes; Burmølle, Mette

    2016-01-01

    The high prevalence and significance of multispecies biofilms have now been demonstrated in various bacterial habitats with medical, industrial, and ecological relevance. It is highly evident that several species of bacteria coexist and interact in biofilms, which highlights the need for evaluating...... the approaches used to study these complex communities. This review focuses on the establishment of multispecies biofilms in vitro, interspecies interactions in microhabitats, and how to select communities for evaluation. Studies have used different experimental approaches; here we evaluate the...... benefits and drawbacks of varying the degree of complexity. This review aims to facilitate multispecies biofilm research in order to expand the current limited knowledge on interspecies interactions. Recent technological advances have enabled total diversity analysis of highly complex and diverse microbial...

  18. Bacterial communities associated with the ctenophores Mnemiopsis leidyi and Beroe ovata.

    Science.gov (United States)

    Daniels, Camille; Breitbart, Mya

    2012-10-01

    Residing in a phylum of their own, ctenophores are gelatinous zooplankton that drift through the ocean's water column. Although ctenophores are known to be parasitized by a variety of eukaryotes, no studies have examined their bacterial associates. This study describes the bacterial communities associated with the lobate ctenophore Mnemiopsis leidyi and its natural predator Beroe ovata in Tampa Bay, Florida, USA. Investigations using terminal restriction fragment length polymorphism (T-RFLP) and cloning and sequencing of 16S rRNA genes demonstrated that ctenophore bacterial communities were distinct from the surrounding water. In addition, each ctenophore genus contained a unique microbiota. Ctenophore samples contained fewer bacterial operational taxonomic units (OTUs) by T-RFLP and lower diversity communities by 16S rRNA gene sequencing than the water column. Both ctenophore genera contained sequences related to bacteria previously described in marine invertebrates, and sequences similar to a sea anemone pathogen were abundant in B. ovata. Temporal sampling revealed that the ctenophore-associated bacterial communities varied over time, with no single OTU detected at all time points. This is the first report of distinct and dynamic bacterial communities associated with ctenophores, suggesting that these microbial consortia may play important roles in ctenophore ecology. Future work needs to elucidate the functional roles and mode of acquisition of these bacteria. PMID:22571334

  19. A Meta-Analysis of the Bacterial and Archaeal Diversity Observed in Wetland Soils

    Directory of Open Access Journals (Sweden)

    Xiaofei Lv

    2014-01-01

    Full Text Available This study examined the bacterial and archaeal diversity from a worldwide range of wetlands soils and sediments using a meta-analysis approach. All available 16S rRNA gene sequences recovered from wetlands in public databases were retrieved. In November 2012, a total of 12677 bacterial and 1747 archaeal sequences were collected in GenBank. All the bacterial sequences were assigned into 6383 operational taxonomic units (OTUs 0.03, representing 31 known bacterial phyla, predominant with Proteobacteria (2791 OTUs, Bacteroidetes (868 OTUs, Acidobacteria (731 OTUs, Firmicutes (540 OTUs, and Actinobacteria (418 OTUs. The genus Flavobacterium (11.6% of bacterial sequences was the dominate bacteria in wetlands, followed by Gp1, Nitrosospira, and Nitrosomonas. Archaeal sequences were assigned to 521 OTUs from phyla Euryarchaeota and Crenarchaeota. The dominating archaeal genera were Fervidicoccus and Methanosaeta. Rarefaction analysis indicated that approximately 40% of bacterial and 83% of archaeal diversity in wetland soils and sediments have been presented. Our results should be significant for well-understanding the microbial diversity involved in worldwide wetlands.

  20. Characterisation of the bacterial community structures in the intestine of Lampetra morii.

    Science.gov (United States)

    Li, Yingying; Xie, Wenfang; Li, Qingwei

    2016-07-01

    The metagenomic analysis and 16S rDNA sequencing method were used to investigate the bacterial community in the intestines of Lampetra morii. The bacterial community structure in L. morii intestine was relatively simple. Eight different operational taxonomic units were observed. Chitinophagaceae_unclassified (26.5 %) and Aeromonas spp. (69.6 %) were detected as dominant members at the genus level. The non-dominant genera were as follows: Acinetobacter spp. (1.4 %), Candidatus Bacilloplasma (2.5 %), Enterobacteria spp. (1.5 %), Shewanella spp. (0.04 %), Vibrio spp. (0.09 %), and Yersinia spp. (1.8 %). The Shannon-Wiener (H) and Simpson (1-D) indexes were 0.782339 and 0.5546, respectively. The rarefaction curve representing the bacterial community richness and Shannon-Wiener curve representing the bacterial community diversity reached asymptote, which indicated that the sequence depth were sufficient to represent the majority of species richness and bacterial community diversity. The number of Aeromonas in lamprey intestine was two times higher after stimulation by lipopolysaccharide than PBS. This study provides data for understanding the bacterial community harboured in lamprey intestines and exploring potential key intestinal symbiotic bacteria essential for the L. morii immune response. PMID:27180095

  1. Bacterial community in sclerotia of Cenococcum species and soil in sub-alpine forest, central Japan

    Science.gov (United States)

    Nonoyama, Y.; Narisawa, K.; Ohta, H.; Watanabe, M.

    2009-04-01

    Species of Cenococcum, ectomycorrhizal fungi, may be particularly abundant in cold- or nutrient-stressed habitats. The fungus is easily recognized by its jet-black hyphae, and distinct compact masses of fungal mycelium called sclerotia. They are hard, black, comparatively smooth and mostly spherical. Sclerotia are formed in rhizosphere and can provide sufficient inoculums for several years. The purpose of this study is to investigate bacterial community inside sclerotia, with an interest on contribution of sclerotia to microbial diversity in rhizosphere. To investigate bacterial community inside of the fungal sclerotia by 16S rDNA gene clone library, several hundred of sclerotia (ca. 1g) were collected from sub-alpine forest soil in central Japan. Furthermore, three sclerotium grains were applied to investigate internal bacteria community by culture method. The isolated bacterial strains were then proceeded to determine their 16S rDNA partial sequences. The predominant group determined by clone library analysis of 16S ribosomal RNA genes with DNA from the sclerotia was Acidobacteria in both sclerotia and soil. Bacterial community of sclerotia showed higher diversity compared to soil. On the contrary, bacterial flora isolated from single sclerotium differed each other. Additionally, the bacterial community was composed by limited species of related genus.

  2. Conjunctival sac bacterial flora isolated prior to cataract surgery

    Directory of Open Access Journals (Sweden)

    Suto C

    2012-01-01

    Full Text Available Chikako Suto1,2, Masahiro Morinaga1,2, Tomoko Yagi1,2, Chieko Tsuji3, Hiroshi Toshida41Department of Ophthalmology, Saiseikai Kurihashi Hospital, Saitama; 2Department of Ophthalmology, Tokyo Women's Medical University, Tokyo; 3Department of Clinical Laboratory, Saiseikai Kurihashi Hospital, Saitama; 4Department of Ophthalmology, Juntendo University Shizuoka Hospital, Izunokuni, Shizuoka, JapanObjective: To determine the trends of conjunctival sac bacterial flora isolated from patients prior to cataract surgery.Subjects and methods: The study comprised 579 patients (579 eyes who underwent cataract surgery. Specimens were collected by lightly rubbing the inferior palpebral conjunctival sac with a sterile cotton swab 2 weeks before surgery, and then cultured for isolation of bacteria and antimicrobial sensitivity testing. The bacterial isolates and percentage of drug-resistant isolates were compared among age groups and according to whether or not patients had diabetes mellitus, hyperlipidemia, dialysis therapy, oral steroid use, dry eye syndrome, or allergic conjunctivitis.Results: The bacterial isolation rate was 39.2%. There were 191 strains of Gram-positive cocci, accounting for the majority of all isolates (67.0%, among which methicillin-sensitive coagulase-negative staphylococci was the most frequent (127 strains, 44.5%, followed by methicillin-resistant coagulase-negative staphylococci (37 strains, 12.7%. All 76 Gram-positive bacillary isolates (26.7% were from the genus Corynebacterium. Among the 16 Gram-negative bacillary isolates (5.9%, the most frequent was Escherichia coli (1.0%. The bacterial isolation rate was higher in patients >60 years old, and was lower in patients with dry eye syndrome, patients under topical treatment for other ocular disorders, and patients with hyperlipidemia. There was no significant difference in bacterial isolation rate with respect to the presence/absence of diabetes mellitus, steroid therapy, dialysis, or

  3. F-theory on Genus-One Fibrations

    CERN Document Server

    Braun, Volker

    2014-01-01

    We argue that M-theory compactified on an arbitrary genus-one fibration, that is, an elliptic fibration which need not have a section, always has an F-theory limit when the area of the genus-one fiber approaches zero. Such genus-one fibrations can be easily constructed as toric hypersurfaces, and various $SU(5)\\times U(1)^n$ and $E_6$ models are presented as examples. To each genus-one fibration one can associate a $\\tau$-function on the base as well as an $SL(2,\\mathbb{Z})$ representation which together define the IIB axio-dilaton and 7-brane content of the theory. The set of genus-one fibrations with the same $\\tau$-function and $SL(2,\\mathbb{Z})$ representation, known as the Tate-Shafarevich group, supplies an important degree of freedom in the corresponding F-theory model which has not been studied carefully until now. Six-dimensional anomaly cancellation as well as Witten's zero-mode count on wrapped branes both imply corrections to the usual F-theory dictionary for some of these models. In particular, n...

  4. Molecular approaches for bacterial azoreductases

    Directory of Open Access Journals (Sweden)

    Montira Leelakriangsak

    2013-12-01

    Full Text Available Azo dyes are the dominant types of synthetic dyes, widely used in textiles, foods, leather, printing, tattooing, cosmetics, and pharmaceutical industries. Many microorganisms are able to decolorize azo dyes, and there is increasing interest in biological waste treatment methods. Bacterial azoreductases can cleave azo linkages (-N=N- in azo dyes, forming aromatic amines. This review mainly focuses on employing molecular approaches, including gene manipulation and recombinant strains, to study bacterial azoreductases. The construction of the recombinant protein by cloning and the overexpression of azoreductase is described. The mechanisms and function of bacterial azoreductases can be studied by other molecular techniques discussed in this review, such as RT-PCR, southern blot analysis, western blot analysis, zymography, and muta-genesis in order to understand bacterial azoreductase properties, function and application. In addition, understanding the regulation of azoreductase gene expression will lead to the systematic use of gene manipulation in bacterial strains for new strategies in future waste remediation technologies.

  5. Environmental context shapes the bacterial community structure associated to Peltigera cyanolichens growing in Tierra del Fuego, Chile.

    Science.gov (United States)

    Ramírez-Fernández, Lía; Zúñiga, Catalina; Carú, Margarita; Orlando, Julieta

    2014-03-01

    The structure of the associated bacterial community of bipartite cyanolichens of the genus Peltigera from three different environmental contexts in the Karukinka Natural Park, Tierra del Fuego, Chile, was assessed. The sampling sites represent different habitat contexts: mature native forest, young native forest and grassland. Recently it has been determined that the bacterial community associated to lichens could be highly structured according to the mycobiont or photobiont identities, to the environmental context and/or to the geographic scale. However, there are some inconsistencies in defining which of these factors would be the most significant on determining the structure of the microbial communities associated with lichens, mainly because most studies compare the bacterial communities between different lichen species and/or with different photobiont types (algae vs. cyanobacteria). In this work bipartite lichens belonging to the same genus (Peltigera) symbiotically associated with cyanobacteria (Nostoc) were analyzed by TRFLP to determine the structure of the bacterial community intimately associated with the lichen thalli and the one present in the substrate where they grow. The results indicate that the bacterial community intimately associated differs from the one of the substrate, being the former more influenced by the environmental context where the lichen grows. PMID:24165746

  6. The gut bacterial communities associated with lab-raised and field-collected ants of Camponotus fragilis (Formicidae: Formicinae).

    Science.gov (United States)

    He, Hong; Wei, Cong; Wheeler, Diana E

    2014-09-01

    Camponotus is the second largest ant genus and known to harbor the primary endosymbiotic bacteria of the genus Blochmannia. However, little is known about the effect of diet and environment changes on the gut bacterial communities of these ants. We investigated the intestinal bacterial communities in the lab-raised and field-collected ants of Camponotus fragilis which is found in the southwestern United States and northern reaches of Mexico. We determined the difference of gut bacterial composition and distribution among the crop, midgut, and hindgut of the two types of colonies. Number of bacterial species varied with the methods of detection and the source of the ants. Lab-raised ants yielded 12 and 11 species using classical microbial culture methods and small-subunit rRNA genes (16S rRNAs) polymerase chain reaction-restriction fragment-length polymorphism analysis, respectively. Field-collected ants yielded just 4 and 1-3 species using the same methods. Most gut bacterial species from the lab-raised ants were unevenly distributed among the crop, midgut, and hindgut, and each section had its own dominant bacterial species. Acetobacter was the prominent bacteria group in crop, accounting for about 55 % of the crop clone library. Blochmannia was the dominant species in midgut, nearly reaching 90 % of the midgut clone library. Pseudomonas aeruginosa dominated the hindgut, accounting for over 98 % of the hindgut clone library. P. aeruginosa was the only species common to all three sections. A comparison between lab-raised and field-collected ants, and comparison with other species, shows that gut bacterial communities vary with local environment and diet. The bacterial species identified here were most likely commensals with little effect on their hosts or mild pathogens deleterious to colony health. PMID:24748441

  7. History Leaves Its Mark on Soil Bacterial Diversity.

    Science.gov (United States)

    Martiny, Jennifer B H

    2016-01-01

    Dispersal is closely tied to the origin and maintenance of microbial diversity. With its focus on a narrow group of soil bacteria, recent work by Andam and colleagues on Streptomyces has provided perhaps the strongest support so far that some bacterial diversity in soils can be attributed to regional endemism (C. P. Andam et al., mBio 7:e02200-15, 2016, http://dx.doi.org/10.1128/mBio.02200-15). This means that dispersal is limited enough to allow for evolutionary diversification. Further analyses suggest that signatures of climate conditions more than 10,000 years ago can be detected in contemporary populations of this genus. These legacies have implications for how future climate change might alter soil microbial diversity. PMID:27273826

  8. Enterobacter spp.: A new evidence causing bacterial wilt on mulberry

    Institute of Scientific and Technical Information of China (English)

    PRAPHAT; Kawicha

    2010-01-01

    Thirty-six pathogenetic bacterial strains were isolated from wilted mulberry plants in Hangzhou,Zhejiang province of China.The six representative strains were confirmed to be involved in more than one Enterobacter species by common bacteriological test,electron microscope observation,hypersensitive reaction,Koch’s postulates,physiological and biochemical test,biolog,fatty acid methyl esters analysis (FAMEs),enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR),16s rRNA sequences analysis,and comparative analysis with 7 type strains and 3 reference strains.This is the first report on mulberry disease caused by Enterobacter spp.in the world providing new evidence on induction of the plant disease in this genus.The results are not only important in the mulberry disease management but also have significant scientific value for further studies of opportunistic human pathogens and environmental strains in Enterobacter.

  9. Progress in bacterial cellulose matrices for biotechnological applications.

    Science.gov (United States)

    Cacicedo, Maximiliano L; Castro, M Cristina; Servetas, Ioannis; Bosnea, Loulouda; Boura, Konstantina; Tsafrakidou, Panagiota; Dima, Agapi; Terpou, Antonia; Koutinas, Athanasios; Castro, Guillermo R

    2016-08-01

    Bacterial cellulose (BC) is an extracellular polymer produced by many microorganisms. The Komagataeibacter genus is the best producer using semi-synthetic media and agricultural wastes. The main advantages of BC are the nanoporous structure, high water content and free hydroxyl groups. Modification of BC can be made by two strategies: in-situ, during the BC production, and ex-situ after BC purification. In bioprocesses, multilayer BC nanocomposites can contain biocatalysts designed to be suitable for outside to inside cell activities. These nanocomposites biocatalysts can (i) increase productivity in bioreactors and bioprocessing, (ii) provide cell activities does not possess without DNA cloning and (iii) provide novel nano-carriers for cell inside activity and bioprocessing. In nanomedicine, BC matrices containing therapeutic molecules can be used for pathologies like skin burns, and implantable therapeutic devices. In nanoelectronics, semiconductors BC-based using salts and synthetic polymers brings novel films showing excellent optical and photochemical properties. PMID:26927233

  10. A Review on the Terpenes from Genus Vitex.

    Science.gov (United States)

    Yao, Jin-Long; Fang, Shi-Ming; Liu, Rui; Oppong, Mahmood Brobbey; Liu, Er-Wei; Fan, Guan-Wei; Zhang, Han

    2016-01-01

    The genus Vitex, which belongs to the Verbenaceae family, includes approximately 250 species. Some species of the genus Vitex have traditionally been used for the treatment of headaches, ophthalmodynia, coughs, asthma, premenopausal syndrome, etc. Chemical investigations indicate that the characteristic constituents of the genus Vitex are terpenes, and 210 of these compounds, including monoterpenoids, sesquiterpenoids, diterpenoids and triterpenoids, have been obtained from 12 species. Pharmacological studies had shown that these terpenes possess anti-inflammatory, antitumor, antibacterial, antioxidant activities, and so on. In this paper, the identity of these terpenes and their pharmacological effects are reviewed, which can provide references for further research regarding the chemistry and utilization of the Vitex species. PMID:27608002

  11. Phylogeny of ambrosia beetle symbionts in the genus Raffaelea.

    Science.gov (United States)

    Dreaden, Tyler J; Davis, John M; de Beer, Z Wilhelm; Ploetz, Randy C; Soltis, Pamela S; Wingfield, Michael J; Smith, Jason A

    2014-12-01

    The genus Raffaelea was established in 1965 when the type species, Raffaelea ambrosia, a symbiont of Platypus ambrosia beetles was described. Since then, many additional ambrosia beetle symbionts have been added to the genus, including the important tree pathogens Raffaelea quercivora, Raffaelea quercus-mongolicae, and Raffaelea lauricola, causal agents of Japanese and Korean oak wilt and laurel wilt, respectively. The discovery of new and the dispersal of described species of Raffaelea to new areas, where they can become invasive, presents challenges for diagnosticians as well as plant protection and quarantine efforts. In this paper, we present the first comprehensive multigene phylogenetic analysis of Raffaelea. As it is currently defined, the genus was found to not be monophyletic. On the basis of this work, Raffaelea sensu stricto is defined and the affinities of undescribed isolates are considered. PMID:25457944

  12. Phytochemistry and pharmacological activities of the genus Prunella.

    Science.gov (United States)

    Bai, Yubing; Xia, Bohou; Xie, Wenjian; Zhou, Yamin; Xie, Jiachi; Li, Hongquan; Liao, Duanfang; Lin, Limei; Li, Chun

    2016-08-01

    Prunella is a genus of perennial herbaceous plants in the Labiatae family. There are approximately 15 species worldwide, distributed widely in the temperate regions and tropical mountains of Europe and Asia. In the genus Prunella, P. vulgaris is the most studied, following a several thousand-year history as a traditional antipyretic and antidotal Chinese herb. Furthermore, since ancient times, P. vulgaris has been widely used as a cool tea ingredient and consumed as a vegetable. The genus Prunella contains triterpenoids and their saponins, phenolic acids, sterols and associated glycosides, flavonoids, organic acids, volatile oil and saccharides. Modern pharmacological studies have revealed that Prunella possess antiviral, antibacterial, anti-inflammatory, immunoregulatory, anti-oxidative, anti-tumor, antihypertensive and hypoglycemic functions. The active components related to these functions are mainly triterpenoids, phenolic acids, flavonoids and polysaccharides. This review mainly summarizes recent advances in traditional usage, chemical components and pharmacological functions. PMID:26988527

  13. Evolution of the leukotoxin operon in genus Mannheimia

    DEFF Research Database (Denmark)

    Larsen, J.; Pedersen, A. G.; Christensen, H.; Bisgaard, M.; Angen, Øystein; Ahrens, Peter; Olsen, J. E.

    The leukotoxin protein of Mannheimia haemolytica belongs to the HlyA-like subfamily of cytotoxic RTX (repeats in toxin) proteins. To test the hypothesis that different lineages of genus Mannheimia gained the leukotoxin operon via horizontal gene transfer we used a strategy that combines compositi......The leukotoxin protein of Mannheimia haemolytica belongs to the HlyA-like subfamily of cytotoxic RTX (repeats in toxin) proteins. To test the hypothesis that different lineages of genus Mannheimia gained the leukotoxin operon via horizontal gene transfer we used a strategy that combines......RNA sequences; (iii) phylogeny of 24 leukotoxin gene sequences and 16 homologous genes retrieved from SWISS-PROT by using PSI-BLAST. Our data show no evidence for horizontal gene transfer into this clade. We propose that vertical descent from the common ancestor of genus Mannheimia, with subsequent loss of...

  14. Higher genus correlators for the complex matrix model

    International Nuclear Information System (INIS)

    In this paper, the authors describe an iterative scheme which allows us to calculate any multi-loop correlator for the complex matrix model to any genus using only the first in the chain of loop equations. The method works for a completely general potential and the results contain no explicit reference to the couplings. The genus g contribution to the m-loop correlator depends on a finite number of parameters, namely at most 4g - 2 + m. The authors find the generating functional explicitly up to genus three. The authors show as well that the model is equivalent to an external field problem for the complex matrix model with a logarithmic potential

  15. Flavonoids from the genus Astragalus: Phytochemistry and biological activity

    Directory of Open Access Journals (Sweden)

    Viktor M Bratkov

    2016-01-01

    Full Text Available Flavonoids, the most common plant polyphenols are widely distributed in every species and possess a broad range of pharmacological activities. The genus Astragalus is the largest in the Fabaceae family with more than 2,500 species spread. They are known to contain different metabolites such as flavonoids, saponins, and polysaccharides. Plants from the genus have been used in the traditional medicine of many countries for centuries. This paper is focused on the large group of flavonoid compounds. Details on structure as well as information about the pharmacological properties of flavonoids, isolated from Astragalus species have been discussed. This review is based on publications until the first half of 2014 and includes also the results from our phytochemical investigations of the genus.

  16. Flavonoids from the Genus Astragalus: Phytochemistry and Biological Activity.

    Science.gov (United States)

    Bratkov, Viktor M; Shkondrov, Aleksandar M; Zdraveva, Petranka K; Krasteva, Ilina N

    2016-01-01

    Flavonoids, the most common plant polyphenols are widely distributed in every species and possess a broad range of pharmacological activities. The genus Astragalus is the largest in the Fabaceae family with more than 2,500 species spread. They are known to contain different metabolites such as flavonoids, saponins, and polysaccharides. Plants from the genus have been used in the traditional medicine of many countries for centuries. This paper is focused on the large group of flavonoid compounds. Details on structure as well as information about the pharmacological properties of flavonoids, isolated from Astragalus species have been discussed. This review is based on publications until the first half of 2014 and includes also the results from our phytochemical investigations of the genus. PMID:27041870

  17. Obtaining genus 2 Heegaard splittings from Dehn surgery

    CERN Document Server

    Baker, Kenneth L; Luecke, John

    2012-01-01

    Let K' be a hyperbolic knot in S^3 and suppose that some Dehn surgery on K' with distance at least 3 from the meridian yields a 3-manifold M of Heegaard genus 2. We show that if M does not contain an embedded Dyck's surface (the closed non-orientable surface of Euler characteristic -1), then the knot dual to the surgery is either 0-bridge or 1-bridge with respect to a genus 2 Heegaard splitting of M. In the case M does contain an embedded Dyck's surface, we obtain similar results. As a corollary, if M does not contain an incompressible genus 2 surface, then the tunnel number of K' is at most 2.

  18. Genetic variability assessment in the genus Passiflora by SSR markers

    Directory of Open Access Journals (Sweden)

    Claudia Lougon Paiva

    2014-09-01

    Full Text Available The genus Passiflora encompasses many species that are endemic to the Brazilian territory, including some with economic value. Studies on genetic diversity in this genus are fundamental because they allow understanding genetic variability and distance. The present study aimed to determine the genetic variability and distances among 10 species of the genus Passiflora by using microsatellite markers (Simple Sequence Repeat, SSR. Twenty-eight heterologous microsatellite markers were tested, but only 12 were used in the diversity analysis because they amplified in at least 80% of the species. A clear separation was observed among the subgenuses studied, as well as wide variation among the accessions of Passiflora. This knowledge enables breeders to explore diversity and transfer favorable alleles found in wild species.

  19. Phylogenetic placement of the ectomycorrhizal genus Cenococcum in Gloniaceae (Dothideomycetes).

    Science.gov (United States)

    Spatafora, Joseph W; Owensby, C Alisha; Douhan, Greg W; Boehm, Eric W A; Schoch, Conrad L

    2012-01-01

    Cenococcum is a genus of ectomycorrhizal Ascomycota that has a broad host range and geographic distribution. It is not known to produce either meiotic or mitotic spores and is known to exist only in the form of hyphae, sclerotia and host-colonized ectomycorrhizal root tips. Due to its lack of sexual and asexual spores and reproductive structures, it has proven difficult to incorporate into traditional classification within Ascomycota. Molecular phylogenetic studies of ribosomal RNA placed Cenococcum in Dothideomycetes, but the definitive identification of closely related taxa remained elusive. Here we report a phylogenetic analysis of five nuclear loci (SSU, LSU, TEF1, RPB1, RPB2) of Dothideomycetes that placed Cenococcum as a close relative of the genus Glonium of Gloniaceae (Pleosporomycetidae incertae sedis) with strong statistical support. Glonium is a genus of saprobic Dothideomycetes that produces darkly pigmented, carbonaceous, hysteriate apothecia and is not known to be biotrophic. Evolution of ectomycorhizae, Cenococcum and Dothideomycetes is discussed. PMID:22453119

  20. The versatility and adaptation of bacteria from the genus Stenotrophomonas

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, R.P.; van der Lelie, D.; Monchy, S.; Cardinale, M.; Taghavi, S.; Crossman, L.; Avison, M. B.; Berg, G.; Dow, J. M.

    2009-07-01

    The genus Stenotrophomonas comprises at least eight species. These bacteria are found throughout the environment, particularly in close association with plants. Strains of the most predominant species, Stenotrophomonas maltophilia, have an extraordinary range of activities that include beneficial effects for plant growth and health, the breakdown of natural and man-made pollutants that are central to bioremediation and phytoremediation strategies and the production of biomolecules of economic value, as well as detrimental effects, such as multidrug resistance, in human pathogenic strains. Here, we discuss the versatility of the bacteria in the genus Stenotrophomonas and the insight that comparative genomic analysis of clinical and endophytic isolates of S. maltophilia has brought to our understanding of the adaptation of this genus to various niches.

  1. [Advances in chemical constituents and bioactivity of Salvia genus].

    Science.gov (United States)

    Peng, Qing; Liu, Jian-xun

    2015-06-01

    The genus Salvia in the family Lamiaceae with nearly 1 000 species, is widespread in temperate and tropical regions around the world. Many species of genus Salvia are important medicinal plants with a long history of which Danshen (the dried roots and rhizomes of S. miltiorrhiza) is one of the most popular herbal traditional medicines in Asian countries. The chemical constituents from Salvia plants mainly contain sesquiterpenoids, diterpenoids, triterpenoids, steroids and polyphenols etc, which exhibit antibacterial, antidermatophytic, antioxidant, anti-inflammatory, antineoplastic, antiplatelet aggregation activities and so on. In this article, the development of new constituents and their biological activities of Salvia genus in the past five years were reviewed and summarized for its further development and utilization. PMID:26552163

  2. Surviving Chytridiomycosis: Differential Anti-Batrachochytrium dendrobatidis Activity in Bacterial Isolates from Three Lowland Species of Atelopus

    OpenAIRE

    Flechas, Sandra V.; Sarmiento, Carolina; Martha E Cárdenas; Edgar M Medina; Restrepo, Silvia; Amézquita, Adolfo

    2012-01-01

    In the Neotropics, almost every species of the stream-dwelling harlequin toads (genus Atelopus) have experienced catastrophic declines. The persistence of lowland species of Atelopus could be explained by the lower growth rate of Batrachochytrium dendrobatidis (Bd) at temperatures above 25°C. We tested the complementary hypothesis that the toads' skin bacterial microbiota acts as a protective barrier against the pathogen, perhaps delaying or impeding the symptomatic phase of chytridiomycosis....

  3. Three new species in the genus Wilkinsonellus (Braconidae, Microgastrinae) from the Neotropics, and the first host record for the genus.

    Science.gov (United States)

    Arias-Penna, Diana Carolina; Whitfield, James B; Janzen, Daniel H; Hallwachs, Winnie

    2013-01-01

    The genus Wilkinsonellus Mason is a poorly sampled but widely distributed tropical genus of Microgastrinae (Braconidae), parasitoid wasps that exclusively attack caterpillars (Lepidoptera). Currently, species of Wilkinsonellus have been described only from the Palaeotropics, but the genus was known to occur in the Neotropics. Here we describe the first three species from Central and South America: Wilkinsonellus alexsmithi sp. n., Wilkinsonellus kogui sp. n.,and Wilkinsonellus panamaensis sp. n. These species descriptions confirm that Wilkinsonellus is a Pantropical genus. A dichotomous key for the three new Neotropical species is given. The first recorded host for the genus, Microthyris prolongalis (Crambidae), is also reported, for Wilkinsonellus alexsmithi. PMID:23794899

  4. Three new species in the genus Wilkinsonellus (Braconidae, Microgastrinae from the Neotropics, and the first host record for the genus

    Directory of Open Access Journals (Sweden)

    Diana Arias

    2013-05-01

    Full Text Available The genus Wilkinsonellus Mason is a poorly sampled but widely distributed tropical genus of Microgastrinae (Braconidae, parasitoid wasps that exclusively attack caterpillars (Lepidoptera. Currently, species of Wilkinsonellus have been described only from the Palaeotropics, but the genus was known to occur in the Neotropics. Here we describe the first three species from Central and South America: Wilkinsonellus alexsmithi sp. n., Wilkinsonellus kogui sp. n., and Wilkinsonellus panamaensis sp. n. These species descriptions confirm that Wilkinsonellus is a Pantropical genus. A dichotomous key for the three new Neotropical species is given. The first recorded host for the genus, Microthyris prolongalis (Crambidae, is also reported, for Wilkinsonellus alexsmithi.

  5. Molecular Signatures and Phylogenomic Analysis of the Genus Burkholderia: Proposal for Division of this Genus into the Emended Genus Burkholderia Containing Pathogenic Organisms and a New Genus Paraburkholderia gen. nov. Harboring Environmental Species

    Directory of Open Access Journals (Sweden)

    Aman eSawana

    2014-12-01

    Full Text Available The genus Burkholderia contains large number of diverse species which are not reliably distinguished by the available biochemical or molecular characteristics. We report here results of detailed phylogenetic and comparative genomic analyses of 45 sequenced species of the genus Burkholderia. In phylogenetic trees based upon concatenated sequences for 21 conserved proteins as well as 16S rRNA gene sequences, Burkholderia species grouped into two major clades. Within these main clades a number of smaller clades were also clearly distinguished. Our comparative analysis of protein sequences from Burkholderia spp. has identified 42 highly specific molecular markers in the form of conserved sequence indels (CSIs that are uniquely found in different clades of Burkholderia spp. Six of these CSIs are specific for a group of Burkholderia spp. (referred to as Clade I which contains all clinically relevant members of the genus as well as the phytopathogenic Burkholderia species. The second main clade (Clade II composed of the environmental Burkholderia species, is also distinguished by 2 of the identified CSIs. Additionally, our work has also identified 3 CSIs that are specific for the Burkholderia cepacia complex, 4 CSIs that are uniquely found in the Burkholderia pseudomallei group, 5 CSIs that are specific for the phytopathogenic Burkholderia spp. and 22 other CSI that distinguish two groups within Clade II. The described molecular markers provide highly specific means for the demarcation of different groups of Burkholderia spp. and for development of novel diagnostic assays for the clinically important members of the group. Based upon the results from different lines of studies, a division of the genus Burkholderia into two genera is proposed. In this new proposal, the emended genus Burkholderia will contain only the clinically relevant and phytopathogenic Burkholderia species, whereas all other Burkholderia spp. are transferred to a new genus

  6. Fossil history and modern distribution of the genus Abies (Pinaceae)

    Institute of Scientific and Technical Information of China (English)

    XIANG Xiaoguo; CAO Ming; ZHOU Zhekun

    2007-01-01

    The plants of the genus Abies are dominant and key species in the dark coniferous forest in the Northern Hemisphere.There are 52 species,one subspecies and 12 varieties in the genus Abies in the world.The history and modern distribution of Abies were discussed.The genus has three modern distribution centers:South Europe,North America and East Asia.These areas are also rich in fossil records.The vertical distribution regions of Abies are from sea level to an elevation of 4,700 m,concentrated in 1,000-2,000 m(15 species).In China,the genus distributes in 20 provinces,especially abundant in the Hengduan Mountains.Meanwhile,endemic and relic phenomena are obvious in this genus.There are seven relic species with both limited individuals and limited distributed regions.Based on the fossil records and the latest phylogenetic data,the following hypothesis was proposed:Abies originated from the middle and high altitudes of the Northern Hemisphere in the middle Cretaceous and it was dispersed southward in the Eocene due to global climate cooling down.The distribution of Abies was deeply influenced by geological events such as the uplift of Himalaya,the Alps,the Rocky Mountains,the occurrence of the Asian Monsoon as well as the Quaternary glaciers.Finally,the current distribution pattern appeared in the Quaternary.The genus Abies has a fossil history and modern distribution pattern similar to that of Cathaya and Pseudolarix.

  7. Metagenomic Analysis of Bacterial Communities of Antarctic Surface Snow

    Directory of Open Access Journals (Sweden)

    Anna Lopatina

    2016-03-01

    Full Text Available The diversity of bacteria present in surface snow around four Russian stations in Eastern Antarctica was studied by high throughput sequencing of amplified 16S rRNA gene fragments and shotgun metagenomic sequencing. Considerable class- and genus-level variation between the samples was revealed indicating a presence of inter-site diversity of bacteria in Antarctic snow. Flavobacterium was a major genus in one sampling site and was also detected in other sites. The diversity of flavobacterial type II-C CRISPR spacers in the samples was investigated by metagenome sequencing. Thousands of unique spacers were revealed with less than 35% overlap between the sampling sites, indicating an enormous natural variety of flavobacterial CRISPR spacers and, by extension, high level of adaptive activity of the corresponding CRISPR-Cas system. None of the spacers matched known spacers of flavobacterial isolates from the Northern hemisphere. Moreover, the percentage of spacers with matches with Antarctic metagenomic sequences obtained in this work was significantly higher than with sequences from much larger publically available environmental metagenomic database. The results indicate that despite the overall very high level of diversity, Antarctic Flavobacteria comprise a separate pool that experiences pressures from mobile genetic elements different from those present in other parts of the world. The results also establish analysis of metagenomic CRISPR spacer content as a powerful tool to study bacterial populations diversity.

  8. Genus distributions of graphs under self-edge-amalgamations

    OpenAIRE

    Khan, Imran F.; Poshni, Mehvish Irfan; Gross, Jonathan L.

    2015-01-01

    We investigate the well-known problem of counting graph imbeddings on all oriented surfaces with a focus on graphs that are obtained by pasting together two root-edges of another base graph. We require that the partitioned genus distribution of the base graph with respect to these root-edges be known and that both root-edges have two 2-valent endpoints. We derive general formulas for calculating the genus distributions of graphs that can be obtained either by self-co-amalgamating or by self-c...

  9. Holographic partition functions and phases for higher genus Riemann surfaces

    Science.gov (United States)

    Maxfield, Henry; Ross, Simon F.; Way, Benson

    2016-06-01

    We describe a numerical method to compute the action of Euclidean saddle points for the partition function of a two-dimensional holographic CFT on a Riemann surface of arbitrary genus, with constant curvature metric. We explicitly evaluate the action for the saddles for genus two and map out the phase structure of dominant bulk saddles in a two-dimensional subspace of the moduli space. We discuss spontaneous breaking of discrete symmetries, and show that the handlebody bulk saddles always dominate over certain non-handlebody solutions.

  10. Note on twisted elliptic genus of K3 surface

    International Nuclear Information System (INIS)

    We discuss the possibility of Mathieu group M24 acting as symmetry group on the K3 elliptic genus as proposed recently by Ooguri, Tachikawa and one of the present authors. One way of testing this proposal is to derive the twisted elliptic genera for all conjugacy classes of M24 so that we can determine the unique decomposition of expansion coefficients of K3 elliptic genus into irreducible representations of M24. In this Letter we obtain all the hitherto unknown twisted elliptic genera and find a strong evidence of Mathieu moonshine.

  11. N=2 gauged WZW models and the elliptic genus

    International Nuclear Information System (INIS)

    Witten recently gave further evidence for the conjectured relationship between the A-series of the N = 2 minimal models and certain Landau-Ginzburg models by computing the elliptic genus for the latter. The results agree with those of the N = 2 minimal models, as can be calculated from the known characters of the discrete series representations of the N = 2 superconformal algebra. The N = 2 minimal models also have a lagrangian representation as supersymmetric gauged WZW models. We calculate the elliptic genera, interpreted as a genus one path integral with twisted boundary conditions, for such models and recover the previously known result. (orig.)

  12. The genus cicerbita wallr. (cichorieae- asteraceae) in Pakistan and Kashmir

    International Nuclear Information System (INIS)

    The genus Cicerbita Wallr. of the tribe Cichorieae-Asteraceae is revised for Pakistan and Kashmir. A broader generic concept of the genus is accepted and in all 11 species have been recognized including 3 new species viz. Cicerbita astorensis, Roohi Bano and Qaiser, C. alii, Roohi Bano and Qaiser and C. gilgitensis Roohi Bano and Qaiser. 5 new combinations, including 3 at species and 2 at varietal level have also been proposed. An artificial key to all the species is provided. Latin diagnosis, illustrations of newly described species, world wide and local distribution and ecological notes of all the species are also furnished. (author)

  13. Large N elliptic genus and AdS/CFT correspondence

    International Nuclear Information System (INIS)

    According to one of Maldacena's dualities, type IIB string theory on AdS3XS3XK3 is equivalent to a certain N=(4,4) superconformal field theory. In this note we compute the elliptic genus of the boundary theory in the supergravity approximation. A finite quantity is obtained once we introduce a particular exclusion principle. In the regime where the supergravity approximation is reliable, we find exact agreement with the elliptic genus of a σ model with target space K3N/SN. (author)

  14. Notes on the genus Punctelia in Denmark

    DEFF Research Database (Denmark)

    Christensen, Steen; Søchting, Ulrik

    2007-01-01

    establishing the genus Punctelia, did not re-combine P. ulophylla, nor include it in the accompanying key. She probably considered it as a synonym of P. subrudecta. In a study on European Punctelia species with lecanoric acid, van Herk & Aptroot (2000) accepted the taxon and made the combination Punctelia...... name at species level, proposed the combination Punctelia jeckeri, and lectotypified the name. As a preparatory work to a forthcoming revision of the Danish lichen checklist (Søchting & Alstrup 2007) it was decided to examine the Danish material of the genus Punctelia....

  15. Shape transitions of high-genus fluid vesicles

    Science.gov (United States)

    Noguchi, Hiroshi

    2015-12-01

    The morphologies of genus-2 to -8 fluid vesicles are studied by using dynamically triangulated membrane simulations with area-difference elasticity. It is revealed that the alignments of the membrane pores alter the vesicle shapes and the types of shape transitions for the genus g ≥ 3 . At a high reduced volume, a stomatocyte with a circular alignment of g + 1 pores continuously transforms into a discocyte with a line of g pores with increasing intrinsic area difference. In contrast, at a low volume, a stomatocyte transforms into a (g+1) -hedral shape and subsequently exhibits a discrete phase transition to a discocyte.

  16. Taxonomic Study of the Genus Apalacris Walker (Orthoptera: Catantopidae).

    Science.gov (United States)

    Zheng, Z M; Lin, L L; Niu, Y

    2016-02-01

    The research history of the genus Apalacris is reviewed; a key to all known species of the genus is given, and one new species, Apalacris eminifronta n. sp., and one new combination, Apalacris maculifemura (Lin & Zheng), are described. The new species is very closely related to Apalacris antennata Liang, but differs in the following characters: (1) tegmen longer, reaching apex of hind femur; (2) basal part of inner side of hind femur orange red; (3) frontal ridge more protruded, obviously depressed under median ocellus in lateral view; and (4) epiphallus bridge prominent, ancora shorter than anterior projection. PMID:26514365

  17. Large N elliptic genus and AdS/CFT Correspondence

    International Nuclear Information System (INIS)

    According to one of Maldacena's dualities, type IIB string theory on AdS3 x S3 x K3 is equivalent to a certain N = (4, 4) superconformal field theory. In this note we compute the elliptic genus of the boundary theory in the supergravity approximation. A finite quantity is obtained once we introduce a particular exclusion principle. In the regime where the supergravity approximation is reliable, we find exact agreement with the elliptic genus of a sigma model with target space K3N/SN

  18. Holographic partition functions and phases for higher genus Riemann surfaces

    CERN Document Server

    Maxfield, Henry; Way, Benson

    2016-01-01

    We describe a numerical method to compute the action of Euclidean saddlepoints for the partition function of a two-dimensional holographic CFT on a Riemann surface of arbitrary genus, with constant curvature metric. We explicitly evaluate the action for the saddles for genus two and map out the phase structure of dominant bulk saddles in a two-dimensional subspace of the moduli space. We discuss spontaneous breaking of discrete symmetries, and show that the handlebody bulk saddles always dominate over certain non-handlebody solutions.

  19. Approximation algorithms for Euler genus and related problems

    OpenAIRE

    Chekuri, Chandra; Sidiropoulos, Anastasios

    2013-01-01

    The Euler genus of a graph is a fundamental and well-studied parameter in graph theory and topology. Computing it has been shown to be NP-hard by [Thomassen '89 & '93], and it is known to be fixed-parameter tractable. However, the approximability of the Euler genus is wide open. While the existence of an O(1)-approximation is not ruled out, only an O(sqrt(n))-approximation [Chen, Kanchi, Kanevsky '97] is known even in bounded degree graphs. In this paper we give a polynomial-time algorithm wh...

  20. Frigitilla gen. nov., a new genus of Amazonian Mutillidae (Hymenoptera).

    Science.gov (United States)

    Bartholomay, Pedro R; Williams, Kevin A; Luz, David R; Morato, Elder F

    2015-01-01

    Mutilla frigidula Cresson, 1902 was transferred to Tobantilla by Williams et al. (2011), based on morphological similarities with females of that genus. Discovery of the male of this species indicated significant morphological differences from Tobantilla. We therefore erect the genus, Frigitilla gen. nov., for Mutilla frigidula. Herein, we describe the male of F. frigidula (Cresson, 1902), comb. nov., associate it with its host (Trypoxylon spp.), and discuss its relations to other mutillid genera. The impact of collecting method and specimen age on the integumental coloration of specimens is discussed, emphasizing the need to diagnose species on consistent structural features rather than differences in color pattern. PMID:26249052

  1. Evolution of Bacterial Suicide

    Science.gov (United States)

    Tchernookov, Martin; Nemenman, Ilya

    2013-03-01

    While active, controlled cellular suicide (autolysis) in bacteria is commonly observed, it has been hard to argue that autolysis can be beneficial to an individual who commits it. We propose a theoretical model that predicts that bacterial autolysis is evolutionarily advantageous to an individualand would fixate in physically structured environments for stationary phase colonies. We perform spatially resolved agent-based simulations of the model, which predict that lower mixing in the environment results in fixation of a higher autolysis rate from a single mutated cell, regardless of the colony's genetic diversity. We argue that quorum sensing will fixate as well, even if initially rare, if it is coupled to controlling the autolysis rate. The model does not predict a strong additional competitive advantage for cells where autolysis is controlled by quorum sensing systems that distinguish self from nonself. These predictions are broadly supported by recent experimental results in B. subtilisand S. pneumoniae. Research partially supported by the James S McDonnell Foundation grant No. 220020321 and by HFSP grant No. RGY0084/2011.

  2. Electromagnetism of Bacterial Growth

    Science.gov (United States)

    Ainiwaer, Ailiyasi

    2011-10-01

    There has been increasing concern from the public about personal health due to the significant rise in the daily use of electrical devices such as cell phones, radios, computers, GPS, video games and television. All of these devices create electromagnetic (EM) fields, which are simply magnetic and electric fields surrounding the appliances that simultaneously affect the human bio-system. Although these can affect the human system, obstacles can easily shield or weaken the electrical fields; however, magnetic fields cannot be weakened and can pass through walls, human bodies and most other objects. The present study was conducted to examine the possible effects of bacteria when exposed to magnetic fields. The results indicate that a strong causal relationship is not clear, since different magnetic fields affect the bacteria differently, with some causing an increase in bacterial cells, and others causing a decrease in the same cells. This phenomenon has yet to be explained, but the current study attempts to offer a mathematical explanation for this occurrence. The researchers added cultures to the magnetic fields to examine any effects to ion transportation. Researchers discovered ions such as potassium and sodium are affected by the magnetic field. A formula is presented in the analysis section to explain this effect.

  3. The rare bacterial biosphere.

    Science.gov (United States)

    Pedrós-Alió, Carlos

    2012-01-01

    All communities are dominated by a few species that account for most of the biomass and carbon cycling. On the other hand, a large number of species are represented by only a few individuals. In the case of bacteria, these rare species were until recently invisible. Owing to their low numbers, conventional molecular techniques could not retrieve them. Isolation in pure culture was the only way to identify some of them, but current culturing techniques are unable to isolate most of the bacteria in nature. The recent development of fast and cheap high-throughput sequencing has begun to allow access to the rare species. In the case of bacteria, the exploration of this rare biosphere has several points of interest. First, it will eventually produce a reasonable estimate of the total number of bacterial taxa in the oceans; right now, we do not even know the right order of magnitude. Second, it will answer the question of whether "everything is everywhere." Third, it will require hypothesizing and testing the ecological mechanisms that allow subsistence of many species in low numbers. And fourth, it will open an avenue of research into the immense reserve of genes with potential applications hidden in the rare biosphere. PMID:22457983

  4. Transport Powered by Bacterial Turbulence

    Science.gov (United States)

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S.

    2014-04-01

    We demonstrate that collective turbulentlike motion in a bacterial bath can power and steer the directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedgelike "bulldozer" draws energy from a bacterial bath of varied density. We obtain that an optimal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp region of the carrier, which is shielded from the outside turbulent fluctuations.

  5. Transport powered by bacterial turbulence.

    Science.gov (United States)

    Kaiser, Andreas; Peshkov, Anton; Sokolov, Andrey; ten Hagen, Borge; Löwen, Hartmut; Aranson, Igor S

    2014-04-18

    We demonstrate that collective turbulentlike motion in a bacterial bath can power and steer the directed transport of mesoscopic carriers through the suspension. In our experiments and simulations, a microwedgelike "bulldozer" draws energy from a bacterial bath of varied density. We obtain that an optimal transport speed is achieved in the turbulent state of the bacterial suspension. This apparent rectification of random motion of bacteria is caused by polar ordered bacteria inside the cusp region of the carrier, which is shielded from the outside turbulent fluctuations. PMID:24785075

  6. Spontaneous bacterial peritonitis: a therapeutic update.

    Science.gov (United States)

    Strauss, Edna; Caly, Wanda Regina

    2006-04-01

    Spontaneous bacterial peritonitis (SBP) is one of the main infectious complications of cirrhosis and occurs in 8-30% of hospitalized patients with ascites. SBP is characterized by infection of the ascitic fluid (AF) in the absence of any primary focus of intra-abdominal infection. The main route by which the AF becomes infected is the hematogenous route. The pathogenic mechanism by which infection develops is bacterial translocation from the intestinal flora to the mesenteric lymph nodes and from there to the bloodstream. Contributing factors are an increased growth of Gram-negative aerobic bacilli in the jejunum, changes in the intestinal barrier and in addition factors which could reduce the local flow of blood. For clinical diagnosis, patients with SBP may present signs of peritoneal irritation and pain, together with changes in gastrointestinal motility, sometimes with nausea, vomiting, diarrhea or ileus. Many patients, however, may not present any symptoms or signs as a result of the presence of SBP. Diagnostic paracentesis of the AF must be performed for every patient with cirrhosis, hospitalized with ascites. Laboratory diagnosis of SBP is carried out by polymorphonuclear count in the AF, together with a positive culture from the AF, which is characteristically monomicrobial. Escherichia coli has been the main bacterium isolated from AF as well as other Gram-negative bacteria from the Enterobacteriaceae family and Streptococcus genus. A more rapid diagnosis of SBP can be obtained via the use of leukocyte esterase, which is present in biological fluids and reacts with a component of the dipstick, changing its color. During the acute phase of SBP, antibiotics should be initiated promptly once the clinical and laboratory diagnosis of SBP has been made, before the result of AF culture. Cefotaxime or other third-generation cephalosporins have been considered the first-choice empirical antibiotics in the treatment of cirrhotic patients with SBP, and is efficacious

  7. Nitratireductor aquimarinus sp. nov., isolated from a culture of the diatom Skeletonema costatum, and emended description of the genus Nitratireductor.

    Science.gov (United States)

    Jang, Gwang Il; Hwang, Chung Yeon; Cho, Byung Cheol

    2011-11-01

    Two Gram-negative-staining, aerobic bacterial strains, designated CL-SC21(T) and CL-SC22, were isolated from a culture of the diatom Skeletonema costatum (Korean Marine Microalgae Culture Center, KMMCC strain B-396) established from the East Sea, Korea. The two novel strains shared 99.9 % 16S rRNA gene sequence similarity. Analysis of the 16S rRNA gene sequences showed an affiliation with the genus Nitratireductor, with the strains sharing 96.5-97.5 % similarity with the type strains of recognized species of the genus Nitratireductor and being most closely related to Nitratireductor aquibiodomus NL21(T). Phylogenetic analyses of the 16S rRNA gene sequences showed that strain CL-SC21(T) together with strain CL-SC22 belonged to the genus Nitratireductor and formed a robust clade among closely related Nitratireductor species. The polar lipids comprised phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, two unidentified aminophospholipids, an unidentified aminolipid, an unidentified phospholipid and five unidentified lipids. Ubiquinone 10 was the major quinone. The major cellular fatty acids of strains CL-SC21(T) and CL-SC22 were C(18 : 1)ω7c (70.6-72.3 %) and C(19 : 0)ω8c cyclo (10.9-11.8 %). The genomic DNA G+C contents of strains CL-SC21(T) and CL-SC22 were 56.7 and 57.1 mol%, respectively. The level of DNA-DNA relatedness between strains CL-SC21(T) and CL-SC22 was 86 % (reciprocal 91 %), indicating that the two isolates represented a single species. However, levels of DNA-DNA relatedness between N. aquibiodomus NL21(T) and strains CL-SC21(T) and CL-SC22 were 28 % (reciprocal 45 %) and 25 % (reciprocal 50 %), respectively. Phylogenetic analysis and the results of biochemical tests showed that strains CL-SC21(T) and CL-SC22 were different from all recognized species of the genus Nitratireductor. Thus, strains CL-SC21(T) and CL-SC22 represent a novel species of the genus Nitratireductor

  8. Fecal bacterial microbiome diversity in chronic HIV-infected patients in China

    Science.gov (United States)

    Sun, Yang; Ma, Yingfei; Lin, Ping; Tang, Yi-Wei; Yang, Liying; Shen, Yinzhong; Zhang, Renfan; Liu, Li; Cheng, Jun; Shao, Jiashen; Qi, Tangkai; Tang, Yan; Cai, Rentian; Guan, Liqian; Luo, Bin; Sun, Meiyan; Li, Ben; Pei, Zhiheng; Lu, Hongzhou

    2016-01-01

    The purpose of this study was to identify fecal bacterial microbiome changes in patients with chronic human immunodeficiency virus (HIV) infection in China. Bacterial 16S rRNA genes were amplified, sequenced (454 pyrosequencing), and clustered into operational taxonomic units using the QIIME software. Relative abundance at the phylum and genus levels were calculated. Alpha diversity was determined by Chao 1 and observed-species indices, and beta diversity was determined by double principal component analysis using the estimated phylogeny-based unweighted Unifrac distance matrices. Fecal samples of the patients with chronic HIV-infection tended to be enriched with bacteria of the phyla Firmicutes (47.20%±0.43 relative abundance) and Proteobacteria (37.21%±0.36) compared with those of the non-HIV infected controls (17.95%±0.06 and 3.81%±0.02, respectively). Members of the genus Bilophila were exclusively detected in samples of the non-HIV infected controls. Bacteroides and arabacteroides were more abundant in the chronic HIV-infected patients. Our study indicated that chronic HIV-infected patients in China have a fecal bacterial microbiome composition that is largely different from that found in non-HIV infected controls, and further study is needed to evaluate whether microbiome changes play a role in disease complications in the distal gut, including opportunistic infections. PMID:27048741

  9. Insights into the emergent bacterial pathogen Cronobacter spp., generated by multilocus sequence typing and analysis

    Directory of Open Access Journals (Sweden)

    StephenForsythe

    2012-11-01

    Full Text Available Cronobacter spp. (previously known as Enterobacter sakazakii is a bacterial pathogen affecting all age groups, with particularly severe clinical complications in neonates and infants. One recognised route of infection being the consumption of contaminated infant formula. As a recently recognised bacterial pathogen of considerable importance and regulatory control, appropriate detection and identification schemes are required. The application of multilocus sequence typing (MLST and analysis (MLSA of the seven alleles atpD, fusA, glnS, gltB, gyrB, infB and ppsA (concatenated length 3036 base pairs has led to considerable advances in our understanding of the genus. This approach is supported by both the reliability of DNA sequencing over subjective phenotyping and the establishment of a MLST database which has open access and is also curated; http://www.pubMLST.org/cronobacter. MLST has been used to describe the diversity of the newly recognised genus, instrumental in the formal recognition of new Cronobacter species (C. universalis and C. condimenti and revealed the high clonality of strains and the association of clonal complex 4 with neonatal meningitis cases. Clearly the MLST approach has considerable benefits over the use of non-DNA sequence based methods of analysis for newly emergent bacterial pathogens. The application of MLST and MLSA has dramatically enabled us to better understand this opportunistic bacterium which can cause irreparable damage to a newborn baby’s brain, and has contributed to improved control measures to protect neonatal health.

  10. ANItools web: a web tool for fast genome comparison within multiple bacterial strains

    Science.gov (United States)

    Han, Na; Qiang, Yujun; Zhang, Wen

    2016-01-01

    Background: Early classification of prokaryotes was based solely on phenotypic similarities, but modern prokaryote characterization has been strongly influenced by advances in genetic methods. With the fast development of the sequencing technology, the ever increasing number of genomic sequences per species offers the possibility for developing distance determinations based on whole-genome information. The average nucleotide identity (ANI), calculated from pair-wise comparisons of all sequences shared between two given strains, has been proposed as the new metrics for bacterial species definition and classification. Results: In this study, we developed the web version of ANItools (http://ani.mypathogen.cn/), which helps users directly get ANI values from online sources. A database covering ANI values of any two strains in a genus was also included (2773 strains, 1487 species and 668 genera). Importantly, ANItools web can automatically run genome comparison between the input genomic sequence and data sequences (Genus and Species levels), and generate a graphical report for ANI calculation results. Conclusion: ANItools web is useful for defining the relationship between bacterial strains, further contributing to the classification and identification of bacterial species using genome data. Database URL: http://ani.mypathogen.cn/ PMID:27270714

  11. Bacterial flora of sturgeon fingerling

    International Nuclear Information System (INIS)

    The study on microbial populations is a suitable tool to understand and apply control methods to improve the sanitary level of production in fish breeding and rearing centers, ensure health of sturgeon fingerlings at the time of their release into the rivers and also in the conversation and restoration of these valuable stocks in the Caspian Sea, Iran. A laboratory research based on Austin methods (Austin, B., Austin, D.A. 1993) was conducted for bacterial study on 3 sturgeon species naming A. persicus, A. stellatus and A. nudiventris during different growth stages. Bacterial flora of Acinetobacter, Moraxella, Aeromonas, Vibrio, Edwardsiella, Staphylococcus, Proteus, Yersinia, Pseudomonas and Plesiomonas were determined. The factors which may induce changes in bacterial populations during different stages of fife are the followings: quality of water in rearing ponds, different conditions for growth stages, suitable time for colonization of bacterial flora in rearing pond, water temperature increase in fingerlings size and feeding condition. (author)

  12. Bacterial Communities: Interactions to Scale

    Science.gov (United States)

    Stubbendieck, Reed M.; Vargas-Bautista, Carol; Straight, Paul D.

    2016-01-01

    In the environment, bacteria live in complex multispecies communities. These communities span in scale from small, multicellular aggregates to billions or trillions of cells within the gastrointestinal tract of animals. The dynamics of bacterial communities are determined by pairwise interactions that occur between different species in the community. Though interactions occur between a few cells at a time, the outcomes of these interchanges have ramifications that ripple through many orders of magnitude, and ultimately affect the macroscopic world including the health of host organisms. In this review we cover how bacterial competition influences the structures of bacterial communities. We also emphasize methods and insights garnered from culture-dependent pairwise interaction studies, metagenomic analyses, and modeling experiments. Finally, we argue that the integration of multiple approaches will be instrumental to future understanding of the underlying dynamics of bacterial communities. PMID:27551280

  13. On a new species of the genus Testudo

    NARCIS (Netherlands)

    Lidth de Jeude, van Th.W.

    1893-01-01

    On arranging the tortoises of the genus Testudo in the collections of the Leyden Museum I met with a mounted specimen, collected at the Cape of Good Hope by the late Kuhl and van Hasselt, which though having much in common with Testudo geometrica L., yet in other points differs from that species and

  14. Recursion Relation of Hyperelliptic Psi-Functions of Genus Two

    OpenAIRE

    MATSUTANI, Shigeki

    2001-01-01

    A recursion relation of hyperelliptic psi functions of genus two, which was derived by D.G. Cantor (J. reine angew. Math. 447 (1994) 91-145), is studied. As Cantor's approach is algebraic, another derivation is presented as a natural extension of the analytic derivation of the recursion relation of the elliptic psi function.

  15. Quantum cohomology of moduli spaces of genus zero stable curves

    OpenAIRE

    Fontanari, Claudio

    2007-01-01

    We investigate the (small) quantum cohomology ring of the moduli spaces of stable n-pointed curves of genus 0. In particular, we determine an explicit presentation in the case n=5 and we outline a computational approach to the case n=6.

  16. On the Genus of a Random Riemann Surface

    OpenAIRE

    Gamburd, Alexander; Makover, Eran

    2001-01-01

    Brooks and Makover introduced an approach to random Riemann surfaces based on associating a dense set of them - Belyi surfaces - with random cubic graphs. In this paper, using Bollobas model for random regular graphs, we examine the topological structure of these surfaces, obtaining in particular an estimate for the expected value of their genus.

  17. Termites of the Genus Odontotermes are Optionally Keratophagous

    NARCIS (Netherlands)

    Freymann, Bernd P.; Visser, Sara N. de; Mayemba, Emilian P.; Olff, Han

    2007-01-01

    In this study we tested experimentally whether the consumption of mammalian hooves by termites of the genus Odontotermes is a mere incidental, previously overlooked event, or whether higher termites frequently exploit hooves of ungulates as a supplementary food source. The experiment was conducted i

  18. FLORAE MALESIANAE PRAECURSORES XV*THE GENUS GAULTHERIA IN MALAYSIA

    Directory of Open Access Journals (Sweden)

    H. SLEUMER

    1957-09-01

    Full Text Available In this revision of the Malaysian species of the genus GaultheriaKalm ex L. 24 species and 9 varieties resp. forms are recognized. Among the new taxa described are 9 species and 1 variety. The localities of the revised material are given in detail. An index to specimens is added.

  19. Taxonomic studies of nectrioid fungi in Japan: The genus Cosmospora

    Science.gov (United States)

    Seven species of the genus Cosmospora collected in Japan are reported in this article. Among them, Cosmospora japonica is described as a new species. Cosmospora henanensis, C. rubrisetosa and C. triqua, all of which are known only from their type localities, are added to the Japanese mycoflora. Othe...

  20. A Finite Genus Solution of the Veselov's Discrete Neumann System

    International Nuclear Information System (INIS)

    The Veselov's discrete Neumann system is derived through nonlinearization of a discrete spectral problem. Based on the commutative relation between the Lax matrix and the Darboux matrix with finite genus potentials, a special solution is calculated with the help of the Baker—Akhiezer—Kriechever function.

  1. Ruwenzoria, a new genus of the Xylariaceae from Central Africa

    DEFF Research Database (Denmark)

    Stadler, M.; Læssøe, Thomas; Fournier, J.; Decock, C.; Persoh, D.; Rambold, G.

    2010-01-01

    Abstract During a foray to the mountain rainforests of the Democratic Republic of the Congo, a peculiar species of Xylariaceae was found, which could not be accommodated in any of the existing genera. It is recognised as representative of a new genus, named Ruwenzoria, owing to the presence of a...

  2. PIXE analysis of trace elements in Genus Hippophae L

    International Nuclear Information System (INIS)

    Trace elements in four kinds of the Genus Hippophae L pulps were analysed by PIXE. Optimization of the system performance was done by carefully selecting the absorbers. Analytical sensitivities of the PIXE system were obtained by means of 'external standard method'

  3. Genus Zero Graph Segmentation: Estimation of Intracranial Volume

    DEFF Research Database (Denmark)

    Jensen, Rasmus Ramsbøl; Thorup, Signe Strann; Paulsen, Rasmus Reinhold; Darvann, Tron A.; Hermann, Nuno V.; Larsen, Per; Kreiborg, Sven; Larsen, Rasmus

    present a fully automatic 3D graph-based method for segmentation of the ICV in non-contrast CT scans. We reformulate the ICV segmentation problem as an optimal genus 0 segmentation problem in a volumetric graph. The graph is the result of a volumetric spherical subsample from the data connected using...

  4. Studies in the family Thelypteridaceae V. The genus Pneumatopteris Nakai

    NARCIS (Netherlands)

    Holttum, R.E.

    1973-01-01

    I re-described this genus in Blumea 19 (1971) 42. The principal characters there enumerated are: rhizome-scales broad, thin, with marginal hairs (some bearing mucilage glands) but rarely superficial hairs; lower pinnae, usually several pairs, reduced, the transition to reduced pinnae abrupt or gradu

  5. Formulae for Arithmetic on Genus 2 Hyperelliptic Curves

    DEFF Research Database (Denmark)

    Lange, Tanja

    2005-01-01

    The ideal class group of hyperelliptic curves can be used in cryptosystems based on the discrete logarithm problem. In this article we present explicit formulae to perform the group operations for genus 2 curves. The formulae are completely general but to achieve the lowest number of operations we...

  6. Studies in the family Thelypteridaceae X. The genus Coryphopteris

    NARCIS (Netherlands)

    Holttum, R.E.

    1976-01-01

    All known species of this genus are described, with synonymy for each and a key for identification. Seventeen new species are described: C. andersonii, C. andreae, C. arthrotricha, C. atjehensis, C. athyrioides, C. borealis, C. brevipilosa, C. hubrechtensis, C. iwatsukii, C. kolombangarae, C. meioba

  7. The transfer of the genus Lytocaryum to Syagrus

    Science.gov (United States)

    Technical Abstract In this paper we formally transfer all four known species of Lytocaryum to the genus Syagrus based on recent molecular analyses, which show it as a monophyletic group either nested within Syagrus making Syagrus paraphyletic or sister to it. Because of these conflicting results bet...

  8. Evolution of the leukotoxin operon in genus Mannheimia

    DEFF Research Database (Denmark)

    Larsen, J.; Pedersen, A. G.; Christensen, H.;

    2005-01-01

    The leukotoxin protein of Mannheimia haemolytica belongs to the HlyA-like subfamily of cytotoxic RTX (repeats in toxin) proteins. To test the hypothesis that different lineages of genus Mannheimia gained the leukotoxin operon via horizontal gene transfer we used a strategy that combines...

  9. A revision of the genus Odontolejeunea (Spruce) Schiffn. (Leujeuneaceae, Hepaticae)

    NARCIS (Netherlands)

    Teeuwen, M.

    1988-01-01

    A taxonomic revision is presented for the epiphyllous liverwort genus Odontolejeunea (Lejeuneaceae subf. Ptychantoideae). Three species are accepted: O. decemdentata (Spruce) Steph.; O. lunulata (Web.) Schiffn. and O. rhomalea (Spruce) Steph. All three species occur in tropical America, and O. lunul

  10. A revision of the genus Odontolejeunea (Spruce) Schiffn. (Leujeuneaceae, Hepaticae)

    OpenAIRE

    Teeuwen, M

    1988-01-01

    A taxonomic revision is presented for the epiphyllous liverwort genus Odontolejeunea (Lejeuneaceae subf. Ptychantoideae). Three species are accepted: O. decemdentata (Spruce) Steph.; O. lunulata (Web.) Schiffn. and O. rhomalea (Spruce) Steph. All three species occur in tropical America, and O. lunulata occurs also in tropical Africa.

  11. Water-Striders of the American Genus Trochopus

    NARCIS (Netherlands)

    Drake, Carl J.; Doesburg , van P.H.

    1966-01-01

    In April 1898 the veliid genus Trochopus Carpenter was erected to hold a new halophilous water-strider from Jamaica, described as marinus. The specimens were netted in numbers on standing salt waters beneath mangrove trees in swamps near the head of Kingston Harbour. In August of the same year CHAMP

  12. The genus Nervilia (Orchidaceae) in Africa and the Arabian Peninsula

    NARCIS (Netherlands)

    Pettersson, Börge

    1991-01-01

    The orchidaceous genus Nervilia Comm. ex Gaud, is revised for Africa, including Madagascar and other islands, and the Arabian peninsula. Sixteen species are recognized, two of which are each subdivided into two varieties. Keys are presented for all taxa. Lectotypes or neotypes are given for all rele

  13. The genus Rhododendron L. in Indochina and Siam

    NARCIS (Netherlands)

    Sleumer, H.

    1958-01-01

    In the course of my recent revision of the genus Rhododendron in Malaysia it has become evident, that the subsect. Irrorata, regarded as purely South Eastern Asiatic up to now, is also represented in the Malay Peninsula and Sumatra, whilst the subsect. Euvireya, outside of its large Malaysian area,

  14. Sesquiterpene lactones. XXXIV. Guaianolides in the genus Leuzea DC.

    Directory of Open Access Journals (Sweden)

    Gerard Nowak

    2014-02-01

    Full Text Available Guaianolides were found in three species of the genus Leuzea DC. Chlorojanerin, cynaropicrin and janerin were isolated from L. rhapontica subg. helenifolia (Gren, Gordon Holub and L. rhaponticoides Graells. From L. carthamoides (Willd. DC., chlorojanerin, cynaropicrin, janerin, cebellin E and repdiolide were obtained.

  15. On a new species of the Longicorn genus Zonopterus, Hope

    NARCIS (Netherlands)

    Ritsema Cz., C.

    1889-01-01

    This species, of which I have three female specimens before me, is most nearly allied to and strongly resembles the type of the genus: Zonopterus flavitarsis Hope 1). It is of the same size and general form, but the sides of the prothorax, which are distinctly bisinuate in flavitarsis, are more regu

  16. The genus filtration in the smooth concordance group

    OpenAIRE

    Wang, Shida

    2015-01-01

    We define a filtration of the smooth concordance group based on the genus of representative knots. We use the Heegaard Floer epsilon and Upsilon invariants to prove the quotient groups with respect to this filtration are infinitely generated. Results are applied to three infinite families of topologically slice knots.

  17. New species of the stingless bee genus Schwarziana (Hymenoptera, Apidae

    Directory of Open Access Journals (Sweden)

    Gabriel A.R. Melo

    2015-12-01

    Full Text Available ABSTRACT Two new species of the stingless bee genus Schwarziana from Brazil are described and illustrated. Schwarziana bocainensis sp. nov. is described from Serra da Bocaina, in São Paulo, and S. chapadensis sp. nov. is described from Chapada dos Veadeiros, in Goiás. An identification key to workers of the known species of Schwarziana is provided.

  18. Pyrrolizidine alkaloids from Bulgarian species of the genus Senecio

    Directory of Open Access Journals (Sweden)

    NADEZHDA KOSTOVA

    2006-12-01

    Full Text Available Nine Bulgarian species from the genus Senecio were studied phytochemically and/or by GC-MS analysis. Senecivernine-N-oxide was isolated and identified by spectral data for the first time. Different types of pyrrolizidine alkaloids were tested for cytotoxicity on murine lymphocytes. At a concentration of 100 µg/ml, the alkaloid retroisosenine showed immunosuppressive effect.

  19. A new genus of Staphylinidae (Coleoptera) from the Lower Cretaceous

    DEFF Research Database (Denmark)

    Schomann, Andrea Maria; Solodovnikov, Alexey

    2012-01-01

    The fossil genus of rove beetles Apticaxgen.n. with two new species, A. volanssp.n. and A. solidussp.n., is described from the Nova Olinda Member of the Crato Formation in north-eastern Brazil (Aptian–Albian, dated as 125–99.6 Ma old). Both species belong to the clade Staphylininae + Paederinae in...

  20. Australopithecus sediba and the earliest origins of the genus Homo.

    Science.gov (United States)

    Berger, Lee

    2012-01-01

    Discovered in 2008, the site of Malapa has yielded a remarkable assemblage of early hominin remains attributed to the species Australopithecus sediba. The species shows unexpected and unpredicted mosaicism in its anatomy. Several commentators have questioned the specific status of Au. sediba arguing that it does not exceed the variation of Au. africanus. This opinion however, does not take into account that Au. sediba differs from Au. africanus in both craniodental and postcranial characters to a greater degree than Au.africanus differs from Au. afarensis in these same characters. Au. sediba has also been questioned as a potential ancestor of the genus Homo due to the perception that earlier specimens of the genus have been found than the c198 Ma date of the Malapa sample. This opinion however, does not take into account either the poor condition of these fossils, as well as the numerous problems with both the criteria used to associate them with the genus Homo, nor the questionable provenance of each of these specimens. This argument also does not acknowledge that Malapa is almost certainly not the first chronological appearance of Au. sediba, it is only the first known fossil occurrence. Au. sediba should therefore be considered a strong potential candidate ancestor of the genus Homo until better preserved specimens are discovered that would refute such a hypothesis. PMID:23011933