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Project Progress

If the central tenant of microbial bio-geography holds true, that “everything is everywhere, the environment selects” then strain level variability in microbial species must be due to local selection and hence adaptation to local environmental conditions. Samples were obtained from three depths (10m, 800m and 4500m) at the Station ALOHA, the site of the Hawaiian Ocean Time Series. ~100 sequences of high resolution Intergenic transcribed Spacer (ITS) regions linked to the more conserved but phylogenetically informative 16S rDNA were obtained for each depth. This data has been incorporated into one manuscript in submission (Brown 2006) describing the phylogeny of a deeply branching delta proteobacterial marine clade, the SAR324/Marine group A, which has previously been described as “ubiquitous”. This manuscript identifies three distinct clusters within the clade (using 16S rRNA gene sequence fragments and ITS sequence data) and highlights clearly restricted distributions of the clusters, with two occurring only in near surface tropical waters and the third in cold, deep waters in temperate and tropical regions as well as polar regions. This is the first report of a “tropical only” distribution for a “species level” marine bacterial cluster.