title: Spatial distribution of bacteria associated with the marine spongeTethya californiana.
abstract: Microbial diversity and spatial distribution of the diversity within tissue of the marine spongeTethya californianawas analyzed based on 16S rRNA gene sequences. One candidate division and nine bacterial phyla were detected, including members of all five subdivisions ofProteobacteria. Moreover, chloroplast-derivedStramenopiles- andRhodophyta-affiliated 16S rRNA gene sequences were found andStramenopilesrepresented the most abundant clones (30%) in the clone library. On the phylum-level, the microbial fingerprint ofT. californianashowed a similar pattern as its Mediterranean relativeT. aurantium.An interesting difference was thatCyanobacteriathat were abundantly present inT. aurantiumwere not found inT. californiana, but that the latter sponges harbored phototrophicStramenopilesinstead. Surprisingly, the phototrophic microorganisms were evenly distributed over the inner and outer parts of the sponge tissue, which implies that they also reside in regions without direct light exposure. The other phyla were also present in both the outer cortex and the mesohyl of the sponges. These results were confirmed by analysis on the operational taxonomic unit level. This leads to the conclusion that from a qualitative point of view, spatial distribution of microorganisms inT. californianatissue is quite homogeneous. Thirty-two percent of the operational taxonomic units shared less than 95% similarity with any other known sequence. This indicates that marine sponges are a rich source of previously undetected microbial life.
authors.affiliation: Department of Chemical Engineering, University of California Berkeley, 201 Gilman Hall, Berkeley, CA 94720 USA.
authors.forename: Detmer
authors.initials: D
authors.lastname: Sipkema
authors.affiliation: Department of Chemical Engineering, University of California Berkeley, 201 Gilman Hall, Berkeley, CA 94720 USA.
authors.forename: Harvey W
authors.initials: HW
authors.lastname: Blanch