Numerical Taxonomy of Nitrogen-Fixing "Decarboxylase-Negative" Vibrio Species Isolated from Aquatic Environments

Abstract

A total of 95 strains of the genus Vibrio were studied by using numerical taxonomic techniques to determine phenotypic relationships among “decarboxylase-negative” strains, nitrogen-fixing (¹⁵N method) strains, and other members of the Vibrionaceae. Taxonomic resemblance was estimated on the basis of 129 tests by using Euclidean distance. Most strains clustered in phena, enabling identification with existing type strains. Nitrogen-fixing strains of Vibrio natriegens were identified, but other nitrogen-fixing isolates could not be assigned to any specific species or biovar.