Biogeography of bacteria associated with the marine sponge Cymbastela concentrica

Abstract

Recent debate regarding microbial biogeography has focused largely on free-living microbes, yet those microbes associated with host organisms are also of interest from a biogeographical perspective. Marine eukaryotes and associated bacteria should provide ideal systems in which to consider microbial biogeography, as (i) bacteria in seawater should be able to disperse among individuals of the same host species, yet (ii) potential for adaptation to particular hosts (and thus speciation) also exists. We used 16S rDNA-DGGE (denaturing gradient gel electrophoresis) to examine geographic variability in bacterial community composition in the marine sponge Cymbastela concentrica. Denaturing gradient gel electrophoresis banding patterns (and phylogenetic analysis of excised DGGE bands) indicated different communities in Cymbastela concentrica from tropical versus temperate Australia. In contrast, communities were very similar over a 500-km portion of the sponge's temperate range. Variation in bacterial community composition was also considered with respect to ocean current patterns. We speculate that the divergent communities in different parts of the sponge's range provide evidence of endemism attributed to host association, although variation in environmental factors such as light and temperature could also explain the observed results. Interestingly, bacterial communities in seawater varied much less between tropical and temperate locations than did those in C. concentrica, supporting the concept of widespread dispersal among these free-living microbes.

Functional genomic signatures of sponge bacteria reveal unique and shared features of symbiosis

“…In contrast, the community of C. concentrica was dominated by distinct phylogenetic clusters within the g-proteobacteria, Phyllobacteriaceae, Sphingomondales, Neisseriales and Nitrospiracae, among others (Figure 1). In particular, the a-and g-proteobacterial groups are related to bacteria found in other sponges, as previously reported (Taylor et al, 2005(Taylor et al, , 2007b, whereas phyla such as Acidobacteria and Chloroflexi described to be present in some sponge species are absent in C. concentrica. A total of 34 sequences (0.95% of all sequences) were common to both the C. concentrica and the planktonic community.…”

“…The sponge Cymbastela concentrica is an abundant marine sponge found in shallow waters along the Australian east coast and has been previously studied with respect to its bacterial community composition (Taylor et al, 2004b(Taylor et al, , 2005. Fingerprinting analysis based on the 16S rRNA gene of temporal and spatial replicate samples for this sponge showed a stable bacterial community profile, which was distinct from that of the surrounding water, and showed specific phylotypes shared with the bacterial communities of other sponges.…”

Pyrosequencing reveals highly diverse and species-specific microbial communities in sponges from the Red Sea

“…The bacterial communities in sea water and sponge have been studied and compared with other studies based on molecular techniques with lower resolution, such as denaturing gradient gel electrophoresis, T-RFLP and conventional clone library construction (Taylor et al, 2005;Lee et al, 2009a, b), as well as the tag pyrosequencing technique (Webster et al, 2009). All these studies demonstrated that highly distinct bacterial communities in sea water diverged from those associated with sponges, the same observation as ours.…”

Variability and abundance of the epiphytic bacterial community associated with a green marine Ulvacean alga

“…For the analysis of temporal variation over seasons, three individual samples were randomly selected from each time point. Selected DGGE bands were excised and sequenced using a standard protocol (Taylor et al, 2005). The TOPO TA cloning kit (Invitrogen, Carlsbad, CA, USA) was used for DGGE bands for which initial sequencing indicated the presence of multiple sequences, and up to 10 clones per band were sequenced.…”