FIG. 6.

Phylogenetic tree depicting relationships among partial 16S rRNA gene sequences of Bacteroidetes phylotypes detected during phytoplankton bloom experiment 1 (shown in boldface type) compared to type species of representative genera in the phylum. The approximate position of phylotype MED-S4 is indicated by the short boldface broken line; the sequence was not included in the alignment due to its shorter length. Phylotypes found in natural and experimental algal blooms in previous articles are also included. Phylotype codes are as follows: S and T (this paper), AY and BY (61), AWS (72), BB (5), and DI (J. Pinhassi, unpublished data). Phylotype and isolate names are followed by their GenBank accession number. The scale bar depicts 0.1 substitution per nucleotide position.