Publikationen

2012

• Phylogenetic relationships among bacteria described from algae: Algae are a distinct source of new taxa

  Goecke, F. R., Wiese, J. ., Labes, A. ., & Imhoff, J. F. (2012). Phylogenetic relationships among bacteria described from algae: Algae are a distinct source of new taxa. In 3. Latin-American Congress of Algal Biotechnology. Abgerufen von http://oceanrep.geomar.de/19547/

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  • 2012
  • Conference Paper
  • • Franz Goecke
    • Jutta Wiese
    • Antje Labes
    • Johannes Imhoff

• Dual effect of macroalgal extracts on growth of bacteria in Western Baltic Sea

  Goecke, F. R., Labes, A. ., Wiese, J. ., & Imhoff, J. F. (2012). Dual effect of macroalgal extracts on growth of bacteria in Western Baltic Sea. Revista De Biologia Marina Y Oceanografia, 47, 75–86. Abgerufen von http://oceanrep.geomar.de/14347/

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  It is assumed that the biological characteristics of the bacterial strains used in bioactivity tests have strong influences on their susceptibility against antibacterial compounds. Therefore, the selection of bacterial test strains may rush conclusions on the effect of macroalgal extracts and metabolites on bacteria. To proof this assumption, we have analysed the biological activities of crude extracts of 16 macroalgae from the coastal waters of Kiel Fjord (Germany), and tested their effect against a panel of 10 microorganisms comprising 5 standard test strains of bacteria and 5 macroalga-associated bacteria. Fourteen macroalgae (88\%) displayed antibacterial activity against at least one of the test strains. Despite the high proportion of extracts exhibiting antimicrobial activity, only 3 strains of the standard set were susceptible to macroalgal extracts and the overall activities were low (less than 80\% of inhibition). Most of active extracts inhibited Bacillus subtilis, while no inhibition effects were found against Erwinia amylovora, Escherichia coli, and the macroalga-associated bacteria. In contrast, all extracts produced stimulatory growth effects of at least two of the tested bacteria. While growth stimulation of standard set of bacteria was rare (22.5\% of total tests) with exception of plant pathogen Erwinia amylovora and two cases of Staphylococcus lentus, it was common among bacteria associated with macroalgae (77.5\%), especially Bacillus algicola, Pseudomonas marincola and both algal-pathogenic bacteria. This study demonstrates that macroalgal extracts can display different effects, i.e., inhibition or stimulation of bacterial growth depending on the origin of the test strains, which are derived from a standard panel or from the marine environment, respectively.

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  • 2012
  • Journal Article
  • • Franz Goecke
    • Antje Labes
    • Jutta Wiese
    • Johannes Imhoff
  • • Microbiology
    • Marine algae
    • antibacterial activities
    • stimulation of bacterial growth
    • Kiel fjord

• A Novel Phytomyxean Parasite Associated with Galls on the Bull-Kelp Durvillaea antarctica (Chamisso) Hariot

  Goecke, F. R., Wiese, J. ., Nunez, A. ., Labes, A. ., Imhoff, J. F., & Neuhauser, S. . (2012). A Novel Phytomyxean Parasite Associated with Galls on the Bull-Kelp Durvillaea antarctica (Chamisso) Hariot. PLoS ONE, 7, e45358. Abgerufen von http://oceanrep.geomar.de/19148/

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  Durvillaea antarctica (Fucales, Phaeophyceae) is a large kelp of high ecological and economic significance in the Southern Hemisphere. In natural beds along the central coast of Chile (Pacific Ocean), abnormal growth characterized by evident gall development and discolorations of the fronds/thallus was observed. Analysing these galls by light microscopy and scanning electron microscopy revealed the presence of endophytic eukaryotes showing typical characteristics for phytomyxean parasites. The parasite developed within enlarged cells of the subcortical tissue of the host. Multinucleate plasmodia developed into many, single resting spores. The affiliation of this parasite to the Phytomyxea (Rhizaria) was supported by 18S rDNA data, placing it within the Phagomyxida. Similar microorganisms were already reported once 23 years ago, indicating that these parasites are persistent and widespread in D. antarctica beds for long times. The symptoms caused by this parasite are discussed along with the ecological and economic consequences. Phytomyxean parasites may play an important role in the marine ecosystem, but they remain understudied in this environment. Our results demonstrate for the first time the presence of resting spores in Phagomyxida, an order in which resting spores were thought to be absent making this the first record of a phagomyxean parasite with a complete life cycle so far, challenging the existing taxonomic concepts within the Phytomyxea. The importance of the here described resting spores for the survival and ecology of the phagomyxid parasite will be discussed together with the impact this parasite may have on the strongest seaweed of the world , which is an important habitat forming and economic resource from the Southern Hemisphere.

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  • 2012
  • Journal Article
  • • Franz Goecke
    • Jutta Wiese
    • Alejandra Nunez
    • Antje Labes
    • Johannes Imhoff
    • Sigrid Neuhauser
  • • SP-NOV
    • LESSONIA-NIGRESCENS
    • MARINE MACROALGAE
    • CENTRAL CHILE
    • NEW-ZEALAND
    • PHAEOPHYTA
    • RHODOPHYTA
    • ALGAE
    • DURVILLEALES
    • INFECTIONS

• Phylogenetic relationships among bacteria described from algae: Distinct source of new taxa

  Goecke, F. R., Thiel, V. ., Wiese, J. ., Labes, A. ., & Imhoff, J. F. (2012). Phylogenetic relationships among bacteria described from algae: Distinct source of new taxa. In Jahrestagung der Vereinigung für Allgemeine und Angewandte Mikrobiologie. Abgerufen von http://oceanrep.geomar.de/19548/

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  • 2012
  • Conference Paper
  • • Franz Goecke
    • Vera Thiel
    • Jutta Wiese
    • Antje Labes
    • Johannes Imhoff

• Efficiency and material protection of a new cell disruption method for the extraction of bioactives from algae, bacteria and fungi

  Labes, A. . (2012). Efficiency and material protection of a new cell disruption method for the extraction of bioactives from algae, bacteria and fungi. In Analytica. Abgerufen von http://oceanrep.geomar.de/15362/

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  • 2012
  • Conference Paper
  • • Antje Labes

• Bacteria associations with co-occurring macroalgae: Host, epiphyte and environmental factors

  Goecke, F. R., Labes, A. ., Wiese, J. ., & Imhoff, J. F. (2012). Bacteria associations with co-occurring macroalgae: Host, epiphyte and environmental factors. European Journal of Phycology, 46, 45–50. Abgerufen von http://oceanrep.geomar.de/19586/

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  Bacteria associated with 2 macroalgae growing in the Kiel Fjord (Baltic Sea) were investigated seasonally over two years by scanning electron microscopy and cultivation methods. Seasonal variations and significant differences between both macroalgal species with respect to the associated bacteria were observed. 166 bacterial strains were isolated from the macroalgae and classified by phylogenetic analysis of 16S rRNA gene sequences. The strains formed 82 phylotypes according to sequence similarities of499.0\%. Samples from Fucus vesiculosus revealed 43 and from Delesseria sanguinea 57 bacterial phylotypes. They affiliated to Actinobacteria, Alphaproteobacteria, Bacilli, Betaproteobacteria, Flavobacteria, Gammaproteobacteria, and Sphingobacteria. Following the assumption that chemical interactions rule the bacteria-macroalga associations, we tested the biological activity of both macroalgae and isolated bacterial strains against a panel comprising standard and ecologically relevant microorganisms (Gram-positive and Gram-negative bacteria, including macroalgal pathogens and surface associated strains, and a yeast). Both macroalgae presented inhibitory activity against at least one microorganism, but overall the inhibitory activities were low. In contrast, all extracts stimulated growth of many of the tested bacteria. While growth stimulation was common concerning bacteria associated with macroalgae, no stimulation was shown for the standard set of bacteria (with exception of one case of stimulation of the plant pathogen Erwinia amylovora). Regarding the potential biological activity of microorganisms associated with macroalgae, more than 60\% of the bacterial phylotypes inhibited the growth of at least one microorganism. A higher proportion of strains showed antimicrobial activity against the set of bacteria associated with macroalgae as compared to standard set of microorganisms. Certain phylotypes are consistently found as epiphytes, suggesting their specific association with macroalgae. The presented positive and negative effects of macroalgal extracts on growth of macroalga-associated bacteria, significant bacterial activity against macroalgal pathogens and competitors, and potential degradative capabilities support the assumption that complex chemical interactions shape the bacteria-macroalga relationships.

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  • 2012
  • Journal Article
  • • Franz Goecke
    • Antje Labes
    • Jutta Wiese
    • Johannes Imhoff

• Secondary metabolites from deep sea bacteria: an efficient route for biodiscovery from extreme habitats

  Labes, A. ., Oesterwalbesloh, J. ., & Imhoff, J. F. (2012). Secondary metabolites from deep sea bacteria: an efficient route for biodiscovery from extreme habitats. In Extremophiles. Abgerufen von http://oceanrep.geomar.de/15367/

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  • 2012
  • Conference Paper
  • • Antje Labes
    • Jan Oesterwalbesloh
    • Johannes Imhoff

• First crenarchaeal chitinase found in Sulfolobus tokodaii

  Staufenberger, T. ., Imhoff, J. F., & Labes, A. . (2012). First crenarchaeal chitinase found in Sulfolobus tokodaii. Microbiological Research, 167, 262–269. Abgerufen von http://oceanrep.geomar.de/12897/

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  This is the first description of a functional chitinase gene within the crenarchaeotes. Here we report of the heterologues expression of the ORF BAB65950 from Sulfolobus tokodaii in E. coli. The resulting protein degraded chitin and was hence classified as chitinase (EC 3.2.4.14). The protein characterization revealed a specific activity of 75 mU/mg using colloidal chitin as substrate. The optimal activity of the enzyme was measured at pH 2.5 and 70 ?C, respectively. A dimeric enzyme configuration is proposed. According to amino acid sequence similarities chitinases are attributed to the two glycoside hydrolase families 18 and 19. The derived amino acid sequence of the S. tokodaii gene differed from sequences of these two glycoside hydrolase families. However, within a phylogenetic tree of protein sequences, the crenarchaeal sequence of S. tokodaii clustered in close proximity to members of the glycoside hydrolase family 18.

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  • 2012
  • Journal Article
  • • Tim Staufenberger
    • Johannes Imhoff
    • Antje Labes
  • • Microbiology
    • Chitinase
    • Glycoside hydrolase
    • Crenarchaea
    • Protein overexpression

• Secondary metabolites of fungi from the German Wadden Sea

  Silber, J. ., Ohlendorf, B. ., Erhard, A. ., Labes, A. ., Goodfellow, M. ., & Imhoff, J. F. (2012). Secondary metabolites of fungi from the German Wadden Sea. In Jahrestagung der Vereinigung für Allgemeine und Angewandte Mikrobiologie. Abgerufen von http://oceanrep.geomar.de/19556/

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  • 2012
  • Conference Paper
  • • Johanna Silber
    • Birgit Ohlendorf
    • Arlette Erhard
    • Antje Labes
    • M. Goodfellow
    • Johannes Imhoff

• Marine fungi: a rich source for natural products

  Silber, J. ., Ohlendorf, B. ., Erhard, A. ., Labes, A. ., & Imhoff, J. F. (2012). Marine fungi: a rich source for natural products. In SUBMARINER Blue Biotechnology Cooperation Event: New Strategies and Future Perspectives. Abgerufen von http://oceanrep.geomar.de/20272/

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  • 2012
  • Conference Paper
  • • Johanna Silber
    • Birgit Ohlendorf
    • Arlette Erhard
    • Antje Labes
    • Johannes Imhoff