Alteromonas atlantica sp. nov. and Alteromonas carrageenovora sp. nov., Bacteria That Decompose Algal Polysaccharides

Abstract

We studied seven strains of aerobic, marine, polarly flagellated bacteria which decompose alginate, agar, and carrageenan. The major respiratory quinone of these strains was ubiquinone-8. The G+C content of their DNA was 39.5 to 41.7 mol%. “Pseudomonas atlantica” IAM 12927 and the conspecific five isolates were concluded to constitute a single species distinguished from the other nonpigmented Alteromonas species by DNA-DNA hybridization (homology values of more than 82%) and phenotypic similarity (similarity coefficients, based on assimilation of 145 carbon compounds, were 79 to 96%). “Pseudomonas carrageenovora” IAM 12662, the sole extant strain, was distinct from “P. atlantica” and other Alteromonas species in DNA-DNA hybridization and phenotypic features. Taxonomic affinity to Alteromonas espejiana was indicated by DNA-DNA hybridization with “P. atlantica” IAM 12927 and the five conspecific isolates (39 to 55%) and with “P. carrageenovora” IAM 12662 (43 to 45%). Phenotypically, higher similarity values (79 to 89%) for assimilation of 145 carbon compounds were shared between A. espejiana IAM 12927T and the six conspecific strains, including “P. atlantica” IAM 12927. Alteromonas atlantica sp. nov. (type strain, IAM 12927, =ATCC 19262, =NCIMB 301) and Alteromonas carrageenovora (type strain, IAM 12662, =IFO 12985, =ATCC 43555, =NCIMB 302) are proposed for “P. atlantica” IAM 12927 and the conspecific five isolates and “P. carrageenovora” IAM 12662, respectively. A set of phenotypic features which differentiate the two Alteromonas species is described.