AME 33:239-245 (2003)  -  doi:10.3354/ame033239

Isolation of planctomycetes from Aplysina sponges

Sheila Pimentel-Elardo1,2, Markus Wehrl1, Anja B. Friedrich1, Paul R. Jensen3, Ute Hentschel1,*

1Institut für Molekulare Infektionsbiologie, Universität Würzburg, Röntgenring 11, 97070 Würzburg, Germany
2College of Pharmacy, University of San Carlos, Cebu City 6000, Philippines
3Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92093, USA
*Corresponding author. Email:

ABSTRACT: There is mounting molecular evidence that bacteria belonging to the phylum Planctomycetes are abundant in marine sponges including members of the genus Aplysina. In an attempt to culture planctomycete bacteria from Aplysina sponges, 116 bacterial strains were isolated on selective oligotrophic media. Screening of the strain collection by fluorescence in situ hybridization with the planctomycete-specific probe Pla46 yielded 3 positive candidates. Nearly complete sequencing of the respective 16S rRNA genes revealed that the isolates were affiliated with 2 distinct clusters of the genus Pirellula: 1 isolate was obtained from a Mediterranean sponge, 1 from a Caribbean sponge and a third from Caribbean seawater. To our knowledge this is the first report of cultured Planctomycetes from marine sponges. The isolates grew slowly on oligotrophic media and failed to grow on nutrient-rich media. Pirellula sp. Strain 797 was pink-pigmented while the other 2 isolates, 16 and 81, were non-pigmented. Transmission electron microscopy revealed a pear- or droplet-shaped cell morphology that is characteristic of the genus Pirellula. The application of strain-specific oligonucleotide probes to sponge tissue cryosections showed that the isolates contribute only a minor fraction to the total microbial community that is associated with Aplysina spp. sponges.


KEY WORDS: Pirellula · Planctomycete · Aplysina · Sponge · Porifera · Sponge-associated microorganism · 16S rDNA


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