PHYLOGENETIC ANALYSIS OF THE GENERA ALTEROMONAS, SHEWANELLA, AND MORITELLA USING GENES-CODING FOR SMALL-SUBUNIT RIBOSOMAL-RNA SEQUENCES ANDDIVISION OF THE GENUS ALTEROMONAS INTO 2 GENERA, ALTEROMONAS (EMENDED) AND PSEUDOALTEROMONAS GEN-NOV, AND PROPOSAL OF 12 NEW SPECIES COMBINATIONS

Small-subunit ribosomal DNA sequences were determined for 17 strains b elonging to the genera Alteromonas, Shewanella, Vibrio, and Pseudomona s, and these sequences were analyzed by phylogenetic methods. The resu lting data confirmed the existence of the genera Shewanella and Morite lla, but suggested that the genus Alteromonas should be split into two genera, We propose that a new genus, the genus Pseudoalteromonas, sho uld be created to accommodate 11 species that were previously Alteromo nas species, including Pseudoalteromonas atlantica comb. nov., Pseudoa lteromonas aurantia comb. nov., Pseudoalteromonas carrageenovora comb. nov., Pseudoalteromonas citrea comb, nov., Pseudoalteromonas denitrif icans comb, nov., Pseudoalteromonas espejiana comb. nov., Pseudoaltero monas haloplanktis comb, nov. (with two subspecies, Pseudoalteromonas haloplanktis subsp, haloplanktis comb. nov, and Pseudoalteromonas halo planktis subsp. tetraodonis comb, nov.), Pseudoalteromonas luteoviolac ea comb. nov., Pseudoalteromonas nigrifaciens comb, nov., Pseudoaltero monas rubra comb. nov., and Pseudoalteromonas undina comb. nov., and o ne species that previously was placed in the genus Pseudomonas, Pseudo alteromonas piscicida comb. nov, We propose that P. haloplanktis (type strain, ATCC 14393) should be the type species of the genus Pseudoalt eromonas, At this time the emended genus Alteromonas is restricted to a single species, Alteromonas macleodii.