Bacterial Communities on Macroalgae - Seaweed Biology - page 184

Chapter 10
Bacterial Communities on Macroalgae

Michael W. Friedrich

10.1 Introduction

Macroalgae are important primary producers in the marine environment, alter the
ecosystem by influencing sediment structure and water flow, and provide a habitat
for many marine organisms. The surface of macroalgae is an important habitat for
microorganisms, and healthy macroalgae are consistently colonized by microbial
communities (Bolinches et al. 1988 ; Jensen et al. 1996 ). Interactions of epiphytic
microorganisms with its algal host range from beneficial (Goecke et al. 2010 ; Wahl
2008 ) to disease and decomposition (Largo et al. 1995 , 1997 , 1999 ; Vairappan et al.
2001 ; Wang et al. 2008 ). Algae-associated bacteria have been shown to enhance
algal growth and provide nutrients (Croft et al. 2005 , 2006 ; Keshtacherliebson et al.
1995 ; Goecke et al. 2010 ), influence release and settlement of algal spores (Joint
et al. 2002 , 2007 ; Weinberger et al. 2007 ; see also Chap. 9 by Amsler and Chap. 11
by Potin), and either enhance or deter the settlement of invertebrate larvae
(Dobretsov and Qian 2002 ; Huggett et al. 2008 ; Patel et al. 2003 ; Steinberg and
de Nys 2002 ). Specific bacteria play an important role in the development of normal
morphology in several green algae (Marshall et al. 2006 ; Matsuo et al. 2003 ;
Nakanishi et al. 1996 ; Provasoli and Pintner 1980 ). Moreover, algal-associated
bacteria produce toxins, signaling compounds, and secondary metabolites, which
represent an interesting reservoir for the discovery of bioactive compounds (Egan
et al. 2008 ). Such intriguing microbial interactions are based on cultured bacteria.
The analysis of microbial communities associated with macroalgae, however, is
still in its infancy. Recent comprehensive reviews have examined the body of
literature available on microbial communities associated with macroalgae, which
is, however,

largely built on cultivation-based studies (Goecke et al. 2010 ;

M.W. Friedrich ( * )
BreMarE - Bremen Marine Ecology, Faculty of Biology/Chemistry University of Bremen,
28334 Bremen, Germany
e-mail: [e-mail]