Monitoring Bacterial Diversity of the Marine Sponge Ircinia strobilina upon Transfer into Aquaculture

Abstract

Marine sponges in the genus Ircinia are known to be good sources of secondary metabolites with biological activities. A major obstacle in the development of sponge-derived metabolites is the difficulty in ensuring an economic, sustainable supply of the metabolites. A promising strategy is the ex situ culture of sponges in closed or semiclosed aquaculture systems. In this study, the marine sponge Ircinia strobilina (order Dictyoceratida: family Irciniidae) was collected from the wild and maintained for a year in a recirculating aquaculture system. Microbiological and molecular community analyses were performed on freshly collected sponges and sponges maintained in aquaculture for 3 months and 9 months. Chemical analyses were performed on wild collected sponges and individuals maintained in aquaculture for 3 months and 1 year. Denaturing gradient gel electrophoresis was used to assess the complexity of and to monitor changes in the microbial communities associated with I. strobilina. Culture-based and molecular techniques showed an increase in the Bacteroidetes and Alpha-and Gammaproteobacteria components of the bacterial community in aquaculture. Populations affiliated with Beta-and Deltaproteobacteria, Clostridia, and Planctomycetes emerged in sponges maintained in aquaculture. The diversity of bacterial communities increased upon transfer into aquaculture.

Diversity and functional analysis of luxS genes in Vibrios from marine sponges Mycale laxissima and Ircinia strobilina

“…ml À1 . Total bacterial counts obtained by microscopic enumeration of 4,6-diamidino-2-phenylindole-stained cells was 1.1 ± 4.4 Â 10 9 cells cm À3 and 2.8±0.4 Â 10 9 cells cm À3 for M. laxissima and I. strobilina, respectively (Mohamed, 2007;Mohamed et al, 2008d).…”

“…Total genomic DNA was extracted by a published method (Pitcher et al, 1989), modified for sponge tissues (Enticknap et al, 2006;Mohamed et al, 2008d). DNA was extracted from the filters obtained from surrounding seawater samples as described by Somerville et al (1989).…”

“…Serial dilutions of water samples were processed similarly for bacterial isolation. Total bacterial counts were determined using methods described by Mohamed et al (2008d).…”

“…Symbiotic relationships between sponges and microorganisms are considered to contribute to the health and nutrition of sponges (Mohamed et al, 2010). Many studies have shown the metabolic phenotypes of sponge-associated microbes (Taylor et al, 2007;Mohamed et al, 2008dMohamed et al, , 2010, although little evidence exists confirming the contribution of symbiotic microbes to sponge well-being or survival (Webster and Blackall, 2009). Exceptions are the translocation of photosynthate from cyanobacteria to the host sponge (Wilkinson, 1979) and a decrease in health status of sponges associated with loss of cyanobacteria (Thacker, 2005).…”

Activity profiles for marine sponge-associated bacteria obtained by 16S rRNA vs 16S rRNA gene comparisons

“…The analysis of 16S rRNA genes through clone libraries and fingerprinting approaches such as denaturing gradient gel electrophoresis (DGGE) has greatly extended our knowledge about the phylogenetic richness of sponge-associated bacteria and archaea (Webster et al, 2001(Webster et al, , 2004Hentschel et al, 2002;Taylor et al, 2004Taylor et al, , 2007bHolmes and Blanch, 2006;Longford et al, 2007;Schmitt et al, 2007Schmitt et al, , 2008Thiel et al, 2007;Mohamed et al, 2008b;Zhu et al, 2008). Researchers in other systems have taken this approach one step further, yielding insights into both richness and activity by comparing 16S rRNA gene-and 16S rRNA-derived sequences, respectively (Moeseneder et al, , 2005Winter et al, 2001;Troussellier et al, 2002;Mills et al, 2005;Gentile et al, 2006;Martinez et al, 2006;Brinkmann et al, 2008;McIlroy et al, 2008;West et al, 2008;Rodriguez-Blanco et al, 2009).…”