Compounds associated with algal surfaces mediate epiphytic colonization of the marine macroalga Fucus vesiculosus. Issue 2 (5th February 2013)

• Record Type: Journal Article
• Authors: Lachnit, Tim; Fischer, Matthias; Künzel, Sven; Baines, John F.; Harder, Tilmann
• Is Part Of: FEMS microbiology ecology. Volume 84:Issue 2(2013)
• Page Start: 411
• Page End: 420
• Publication Date: 2013-02-05
• Subjects: Microbial ecology -- Periodicals; Microbiology -- Periodicals; 579.17
• DOI: 10.1111/1574-6941.12071
• Languages: English
• ISSNs: 0168-6496

Abstract

<abstract abstract-type="main" id="fem12071-abs-0001"> <title>Abstract</title> <p>The macroalga <italic>Fucus vesiculosus</italic> carries a specific community of surface bacteria. To identify chemical compounds that possibly mediate abundance and community composition of algae‐associated bacteria, we tested the effect of surface‐available algal compounds on bacterial settlement and community composition under field conditions. Compounds on algal thalli were separated from the surface by extraction with organic solvents and investigated on growth inhibition and settlement of bacterial isolates. Based on <italic>in vitro</italic> data, partially purified extract fractions were then exposed to bacterial colonizers <italic>in vivo</italic> followed by bacterial enumeration and community analysis. The polar fraction of the algal surface extract revealed a significant profouling effect for Vibrionales, whereas the nonpolar fraction – containing the xanthophyll pigment fucoxanthin and other unidentified nonpolar surface compounds – revealed a significant 80% reduction of surface colonizing bacteria. The analysis of bacterial surface communities by 454 pyrosequencing demonstrated that the antifouling activity of nonpolar algal surface compounds was targeting the abundance of natural bacterial colonizers rather than the relative composition of bacterial members within the community. Moreover, the bacterial community composition on <italic>F. vesiculosus</italic> was markedly different from artificial control substrates and chemically manipulated experimental treatments, suggesting that other, nonextractable surface features and/or physical properties render algal‐specific epiphytic bacterial communities.</p> </abstract>