PHYLOGENETIC HETEROGENEITY WITHIN THE GENUS HERPETOSIPHON - TRANSFER OF THE MARINE SPECIES HERPETOSIPHON COHAERENS, HERPETOSIPHON NIGRICANSAND HERPETOSIPHON PERSICUS TO THE GENUS LEWINELLA GEN, NOV. IN THE FLEXIBACTER-BACTEROIDES-CYTOPHAGA PHYLUM

Analysis of the 16S rDNA sequences of species currently assigned to th e genus Herpetosiphon revealed intrageneric phylogenetic heterogeneity . The thermotolerant freshwater species Herpetosiphon geysericola is m ost closely related to the type species Herpetosiphon aurantiacus in t he Chloroflexus Subdivision of the green non-sulfur bacteria, The mari ne species Herpetosiphon cohaerens, Herpetosiphon nigricans and Herpet osiphon persicus, on the other hand, were found to form a cluster with the sheathed bacterium Haliscomenobacter hydrossis in the Saprospira group of the Flexibacter-Bacteroides-Cytophaga (FBC) phylum. A proposa l is made to transfer these marine species to the genus Lewinella gen. nov. as Lewinella cohaerens comb, nov., Lewinella nigricans comb. nov , and Lewinella persica comb. nov. The marine sheathed gliding bacteri um Flexithrix dorotheae was also found to be a member of the FBC phylu m but on a separate phylogenetic line to the marine herpetosiphons now assigned to the genus Lewinella.