Phylogenetic heterogeneity within the genus Herpetosiphon: transfer of the marine species Herpetosiphon cohaerens, Herpetosiphon nigricans and Herpetosiphon persicus to the genus Lewinella gen. nov. in the Flexibacter-Bacteroides-Cytophaga phylum

Abstract

Phylogenetic heterogeneity within the genusAnalysis of the 16s rDNA sequences of species currently assigned to the genus Herpetosiphon revealed intrageneric phylogenetic heterogeneity. The thermotolerant freshwater species Herpetosiphon geysericola is most closely related to the type species Herpetosiphon aurantiacus in the Chloroflexus subdivision of the green non-sulf ur bacteria. The marine species Herpetosiphon cohaerens, Herpetosiphon nigricans and Herpetosiphon 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-Cyfophaga (FBC) phylum. A proposal 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 bacterium Flexithrix dorotheae was also found to be a member of the FBC phylum but on a separate phylogenetic line to the marine herpetosiphons now assigned to the genus Lewinella.

Lewinella agarilytica sp. nov., a novel marine bacterium of the phylum Bacteroidetes, isolated from beach sediment

“…The genus currently contains three species, Lewinella cohaerens, Lewinella persica and Lewinella nigricans, all of which were isolated from marine environments, including beach sand and brown mud. Despite having similar morphological characteristics (Holt, 1989), the genera Lewinella and Herpetosiphon were found to belong to different phylogenetic lineages, according to data from 16S rRNA gene sequencing studies (Sly et al, 1998). The genus Herpetosiphon currently contains the thermotolerant freshwater species Herpetosiphon aurantiacus (Holt & Lewin, 1968) and Herpetosiphon geysericola (Lewin, 1970).…”

“…The genus Lewinella was proposed by Sly et al (1998) to encompass the marine species of the genus Herpetosiphon (Holt & Lewin, 1968). The genus currently contains three species, Lewinella cohaerens, Lewinella persica and Lewinella nigricans, all of which were isolated from marine environments, including beach sand and brown mud.…”

Lewinella antarctica sp. nov., a marine bacterium isolated from Antarctic seawater

“…L. cohaerens, L. nigricans and L. persica, isolated from littoral sediment samples and originally assigned to the genus Herpetosiphon by Lewin (1970), were later transferred to the new genus Lewinella on the basis of data from 16S rRNA gene sequence analyses (Sly et al, 1998). L. agarilytica (Lee, 2007) and L. lutea (Khan et al, 2007) were isolated from shallow marine sediment samples, whilst L. marina (Khan et al, 2007) was isolated from a sea snail.…”

“…The genus Lewinella (Sly et al, 1998) belongs to the family 'Saprospiraceae' within the phylum Bacteroidetes and currently contains the six species Lewinella cohaerens, L. nigricans, L. persica, L. lutea, L. marina and L. agarilytica, which were isolated from marine sources. L. cohaerens, L. nigricans and L. persica, isolated from littoral sediment samples and originally assigned to the genus Herpetosiphon by Lewin (1970), were later transferred to the new genus Lewinella on the basis of data from 16S rRNA gene sequence analyses (Sly et al, 1998).…”

Roseivirga ehrenbergii gen. nov., sp. nov., a novel marine bacterium of the phylum ‘Bacteroidetes’, isolated from the green alga Ulva fenestrata

“…In addition, Flammeovirga aprica, formerly Cytophaga aprica (Reichenbach, 1989), and Persicobacter diffluens, formerly Cytophaga diffluens (Reichenbach, 1989), were isolated from rocky sand in Hawaii and from beach mud near Mumbai, India, respectively (Lewin, 1969;Reichenbach, 1989;Nakagawa et al, 1997). A number of marine bacteria isolated from different beach-sand samples, such as [Flexibacter] aggregans, 'Microscilla arenaria', 'Microscilla furvescens' and [Flexibacter] tractuosus, remain to be reclassified within new taxa (Bernardet et al, 1996;Nakagawa et al, 1997;Sly et al, 1998). A single strain of the dark-orange-pigmented agarolytic bacterium Reichenbachia agariperforans, inhabiting coastal waters of the Sea of Japan, was described (Nedashkovskaya et al, 2003b).…”