Biogeography of the marine actinomycete Salinispora
Article first published online: 18 JUL 2006
Volume 8, Issue 11, pages 1881–1888, November 2006
How to Cite
Jensen, P. R. and Mafnas, C. (2006), Biogeography of the marine actinomycete Salinispora. Environmental Microbiology, 8: 1881–1888. doi: 10.1111/j.1462-2920.2006.01093.x
- Issue published online: 18 JUL 2006
- Article first published online: 18 JUL 2006
- Received 21 November, 2005; accepted 4 March, 2006.
Marine actinomycetes belonging to the genus Salinispora were cultured from marine sediments collected at six geographically distinct locations. Detailed phylogenetic analyses of both 16S rRNA and gyrB gene sequences reveal that this genus is comprised of three distinct but closely related clades corresponding to the species Salinispora tropica, Salinispora arenicola and a third species for which the name ‘Salinispora pacifica’ is proposed. Salinispora arenicola was cultured from all locations sampled and provides clear evidence for the cosmopolitan distribution of an individual bacterial species. The co-occurrence of S. arenicola with S. tropica and S. pacifica suggests that ecological differentiation as opposed to geographical isolation is driving speciation within the genus. All Salinispora strains cultured to date share greater than 99% 16S rRNA gene sequence identity and thus comprise what has been described as a microdiverse ribotype cluster. The description of this cluster as a new genus, containing multiple species, provides clear evidence that fine-scale 16S rDNA sequence analysis can be used to delineate among closely related species and that more conservative operational taxonomic unit values may significantly underestimate global species diversity.