TY - JOUR KW - antimicrobial activities KW - bacterial cultures KW - chemical associations KW - Delesseria KW - epiphytic bacteria KW - Fucus KW - Kiel KW - macroalgabacteria associations AU - Franz Goecke AU - Antje Labes AU - Jutta Wiese AU - Johannes Imhoff AB - Bacteria associated with Fucus vesiculosus and Delesseria sanguinea, two macroalgae from the Kiel Fjord were investigated seasonally over two years by cultivation-based methods. A total of 166 bacterial strains were isolated from the macroalgae, affiliated to seven classes of bacteria (Actinobacteria, Bacilli, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Cytophagia and Flavobacteria). According to 16S rRNA gene sequence similarities they were arranged in 82 phylotypes of\ensuremath>99.0\% sequence identity. Assuming that chemical factors rule the bacteriamacroalga and bacteriabacteria interactions on algal surfaces, we tested the antibiotic activity of the bacterial isolates not only against a panel of four standard test organisms (Bacillus subtilis, Candida glabrata, Escherichia coli and Staphylococcus lentus) but also four macroalga-associated microorganisms: Algicola bacteriolytica and Pseudoalteromonas elyakovii (macroalgal pathogens), and Bacillus algicola and Formosa algae (strains associated with algal surfaces). Organic extracts of more than 51\% of the isolates from the two macroalgae inhibited the growth of at least one of the tested microorganisms. As much as 46\% and 45\% of the isolates derived from F. vesiculosus and D. sanguinea, respectively, showed antimicrobial activity against the set of macroalga-associated bacteria, compared with 13 and 19\% against a standard set of microorganisms. High antibacterial activity against macroalgal pathogens and bacterial competitors support the assumption that complex chemical interactions shape the relationships of bacteria associated with macroalgae and suggest that these bacteria are a rich source of antimicrobial metabolites. BT - European Journal of Phycology M1 - 1 N1 - WOS:000316444400004 N2 - Bacteria associated with Fucus vesiculosus and Delesseria sanguinea, two macroalgae from the Kiel Fjord were investigated seasonally over two years by cultivation-based methods. A total of 166 bacterial strains were isolated from the macroalgae, affiliated to seven classes of bacteria (Actinobacteria, Bacilli, Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Cytophagia and Flavobacteria). According to 16S rRNA gene sequence similarities they were arranged in 82 phylotypes of\ensuremath>99.0\% sequence identity. Assuming that chemical factors rule the bacteriamacroalga and bacteriabacteria interactions on algal surfaces, we tested the antibiotic activity of the bacterial isolates not only against a panel of four standard test organisms (Bacillus subtilis, Candida glabrata, Escherichia coli and Staphylococcus lentus) but also four macroalga-associated microorganisms: Algicola bacteriolytica and Pseudoalteromonas elyakovii (macroalgal pathogens), and Bacillus algicola and Formosa algae (strains associated with algal surfaces). Organic extracts of more than 51\% of the isolates from the two macroalgae inhibited the growth of at least one of the tested microorganisms. As much as 46\% and 45\% of the isolates derived from F. vesiculosus and D. sanguinea, respectively, showed antimicrobial activity against the set of macroalga-associated bacteria, compared with 13 and 19\% against a standard set of microorganisms. High antibacterial activity against macroalgal pathogens and bacterial competitors support the assumption that complex chemical interactions shape the relationships of bacteria associated with macroalgae and suggest that these bacteria are a rich source of antimicrobial metabolites. PY - 2013 SP - 47 EP - 60 T2 - European Journal of Phycology TI - Phylogenetic analysis and antibiotic activity of bacteria isolated from the surface of two co-occurring macroalgae from the Baltic Sea UR - http://oceanrep.geomar.de/19592/ VL - 48 ER -