E.C. Giles, J. Kamke, L. Moitinho-Silva, M.W. Taylor, U. Hentschel, T. Ravasi, S. Schmitt
Genet, 3:100, (2012)
16S rRNA gene, Bacteria, Marine sponges, Microbial abundance, Phylogenetic diversity
It has long been recognized that sponges differ in the abundance of
associated microorganisms, and they are therefore termed either ‘low
microbial abundance’ (LMA) or ‘high microbial abundance’ (HMA) sponges.
Many previous studies concentrated on the dense microbial communities in
HMA sponges, whereas little is known about microorganisms in LMA
sponges. Here, two LMA sponges from the Red Sea, two from the Caribbean
and one from the South Pacific were investigated. With up to only five
bacterial phyla per sponge, all LMA sponges showed lower phylum-level
diversity than typical HMA sponges. Interestingly, each LMA sponge was
dominated by a large clade within either Cyanobacteria or different classes of Proteobacteria.
The overall similarity of bacterial communities among LMA sponges
determined by operational taxonomic unit and UniFrac analysis was low.
Also the number of sponge-specific clusters, which indicate bacteria
specifically associated with sponges and which are numerous in HMA
sponges, was low. A biogeographical or host-dependent distribution
pattern was not observed. In conclusion, bacterial community profiles of
LMA sponges are clearly different from profiles of HMA sponges and,
remarkably, each LMA sponge seems to harbour its own unique bacterial