Aurearenophyceae classis nova, a new class of Heterokontophyta based on a new marine unicellular alga Aurearena cruciata gen. et sp. nov. inhabiting sandy beaches

A new heterokontophyte alga, Aurearena cruciata gen. et sp. nov., was isolated from sandy beaches in Japan. Isolates were characterized by light and electron microscopy, spectroscopy of pigment composition, and molecular phylogenetic analyses using 18S rDNA and rbcL. The alga usually possessed a cell wall but also retained two heterokont flagella beneath the cell wall. Each walled cell first produced only a single flagellate cell that subsequently divided into two flagellate cells. Electron-opaque vesicles, possibly associated with cell wall formation, were observed beneath the cell membrane. The chloroplast consisted of two compartments, each enclosed by a chloroplast envelope and the inner membrane of the chloroplast endoplasmic reticulum; these two compartments were surrounded by a common outer membrane of chloroplast endoplasmic reticulum. Molecular phylogenetic trees suggested that this alga was a new and independent member of the clade that included the Phaeophyceae and Xanthophyceae (PX clade). A new class, Aurearenophyceae classis nova was proposed for A. cruciata.     

Halocafeteria seosinensis gen. et sp. nov. (Bicosoecida), a halophilic bacterivorous nanoflagellate isolated from a solar saltern

Recently, heterotrophic nanoflagellates (HNF) have been reported to actively ingest prokaryotes in high salinity waters. We report the isolation and culture of an HNF from a Korean saltern pond of 300‰ salinity. The organism is biflagellated with an acronematic anterior flagellum and never glides on surfaces. The mitochondria have tubular cristae. Neither transitional helix nor spiral fiber were observed in the transition zones of the flagella. The cell has a cytostome supported by an arc of eight microtubules, suggesting that our isolate is a bicosoecid. Our isolate had neither mastigonemes, lorica, body scales, nor cytopharynx and thus could not be placed in any of the presently described bicosoecid genera. Phylogenetic analysis of 18S rRNA gene sequences from stramenopiles confirmed the bicosoecid affinities of our isolate, but did not place it within any established genus or family. Its closest relatives include Caecitellus and Cafeteria. The optimal range of growth temperature was 30–35°C. The isolated HNF grew optimally at 150‰ salinity and tolerated up to 363‰ salinity, but it failed to grow below 75‰ salinity, indicating that it could be a borderline extreme halophile. On the basis of its morphological features and position in 18S rRNA trees we propose a novel genus for our isolate; Halocafeteria, n. gen. The species name Halocafeteria seosinensis sp. nov. is proposed.     

Ultrastructure and 18S rDNA sequence analysis of Wobblia lunata gen. et sp. nov., a new heterotrophic flagellate (Stramenopiles, Incertae sedis)

A new heterotrophic flagellate Wobblia lunata gen. et sp. nov. is described. This organism usually attaches to the substratum showing a wobbling motion, and sometimes glides on the substratum or swims freely in the medium. W. lunata has various features characteristic of the stramenopiles. These include a hairy flagellum with tripartite tubular hairs, a mitochondrion with tubular cristae, arrangement of flagellar apparatus components and a double helix in the flagellar transition zone. W. lunata shares a double helix with heterotrophic stramenopiles, including Developayella elegans, oomycetes, hyphochytrids, opalinids and proteromonads, and could be placed in the phylum Bigyra Cavalier-Smith. However, from 18S rDNA tree analysis, these organisms form two distantly-related clades in the stramenopiles, and Wobblia appears at the base of the stramenopiles. Evaluation of morphological features and comparison of 18S rDNA sequences indicate that W. lunata is a member of the stramenopiles, but it is distinct from any other stramenopiles so far described. Its phylogenetic position within the stramenopiles is uncertain and therefore W. lunata is described as a stramenopile incertae sedis.     

Sulcochrysis biplastida gen. et sp. nov.: Cell structure and absolute configuration of the flagellar apparatus of an enigmatic chromophyte alga

Sulcochrysis biplastida gen. et sp. nov., a golden, marine, mixotrophic flagellate is described. Cells resemble Ochromonas in light microscopic features, but they are distinct at the electron microscopic level from Ochromonas or any other typical chrysophyte. Ultrastructural features that discriminate Sulcochrysis from the Chrysophyceae are: (i) a proximal helix in the flagellar transition region; (ii) basal bodies situated in the anterior depression of the nucleus; (iii) the lack of the rhizoplast; and (iv) simple flagellar hairs lacking lateral filaments. These features suggest that Sulcochrysis is a relative of the Pedinellophyceae, Dictyochophyceae and Pelagophyceae. However, Sulcochrysis has a flagellar root system similar to that of the Ochromonas-type cell and it may use the R3 root for prey capture, as do ochromonadalean algae. The R3 root and the phagotrophic mechanism using the R3 root are interpreted as a plesiomorphy, because these are also distributed in primitive heterokonts such as the bicosoecids. Sulcochrysis has one microtubule probably homologous with the x-fibre of Bicosoeca maris Picken. Based on these features it is suggested that Sulcochrysis is an organism that links bicosoecids (Bicosoeco-phyceae), Pedinellophyceae, Dictyochophyceae and Pelagophyceae.     

Reclassification of Bacteroides putredinis (Weinberg et al., 1937) in a new genus Alistipes gen. nov., as Alistipes putredinis comb. nov., and description of Alistipes finegoldii sp. nov., from human sources

During studies on the bacteriology of appendicitis in children, we often isolated from inflamed and non-inflamed tissue samples, an unusual bile-resistant pigment-producing strictly anaerobic gram-negative rod. Phenotypically this organism resembles members of Bacteroides fragilis group of species, as it is resistant to bile and exhibits a special-potency-disk pattern (resistance to vancomycin, kanamycin and colistin) typical for the B. fragilis group. However, the production of brown pigment on media containing haemolysed blood and a cellular fatty acid composition dominated by iso-C15:0, suggests that the organism most closely resembles species of the genus Porphyromonas. However, the unidentified organism differs from porphyromonads by being bile-resistant and by not producing butyrate as a metabolic end-product. Comparative 16S ribosomal RNA gene sequencing studies show the unidentified organism represents a distinct sub-line, associated with but distinct from, the miss-classified species Bacteroides putredinis. The clustering of the unidentified bacterium with Bacteroides putredinis was statistically significant, but they displayed > 4% sequence divergence with each other. Chromosomal DNA-DNA pairing studies further confirmed the separateness of the unidentified bacterium and Bacteroides putredinis. Based on phenotypic and phylogenetic considerations, it is proposed that Bacteroides putredinis and the unidentified bacterium from human sources be classified in a new genus Alistipes, as Alistipes putredinis comb. nov. and Alistipes finegoldii sp. nov., respectively. The type strain of Alistipes finegoldii is CCUG 46020(T) (= AHN243(T)).     

A new fungus,Aureomyces mirabilis gen. et sp. nov., from pine-timber

Aureomyces gen. nov. with the type speciesAureomyces mirabilis sp. nov. isolated from a pine-timber,Pinus silvestris, in Finland is described and illustrated.

---

Zusammenfassung Aureomyces gen. nov. wurde mit dem ArttypeAureomyces mirabilis sp. nov. vom Kiefernholz,Pinus sylvestris, in Finnland isoliert. Der Pilz ist beschrieben und illustriert.

     

Seminibacterium arietis gen. nov., sp. nov., isolated from the semen of rams

Two gram-negative, catalase- and oxidase-positive, bacillus-shaped bacterial strains were isolated from the semen of two rams. 16S rRNA gene sequencing demonstrated that both isolates represented a distinct subline within the family Pasteurellaceae with <95% sequence similarity to any recognized member of this family. Sequencing of rpoB and infB genes confirmed this finding with the semen isolates representing a new sub-line within the family Pasteurellaceae. The main cell fatty acids of strain DICM-00342^T were C_14:0, C_16:0, C_18:1ω7c and summed feature 3 (C_16:1ω7c/iso-C_15:0 2OH). Ubiquinone Q-8 was the major quinone and 1,3-diaminopropane was the predominat polyamine. Major polar lipids were phosphatidylglycerol and phosphatidylethanolamine. The new genus can be phenotypically distinguished from currently described genera of this family based on physiological traits and a combination of signature amino acids in the RpoB protein sequence. On the basis of these results we describe a new genus and species for which we propose the name of Seminibacterium arietis gen. nov., sp. nov. (DICM11-00342^T = CCUG 61707^T = CECT 8033^T).     

Holophaga foetida gen. nov., sp. nov., a new,homoacetogenic bacterium degrading methoxylated aromatic compounds

A polyphasic approach was used in which genotypic and phenotypic properties of a gram-negative, obligately anaerobic, rod-shaped bacterium isolated from a black anoxic freshwater mud sample were determined. Based on these results, the name Holophaga foetida gen. nov., sp. nov. is proposed. This microorganism produced dimethylsulfide and methanethiol during growth on trimethoxybenzoate or syringate. The only other compounds utilized were pyruvate and trihydroxybenzenes such as gallate, phloroglucinol, or pyrogallol. The aromatic compounds were degraded to acetate. Although comparison of the signature nucleotide pattern of the five established subclasses of Proteobacteria with the 16S rDNA sequence of Holophaga foetida revealed a relationship to members of the -subclass, the phylogenetic position within the radiation of this class is so deep and dependent upon the number and selection of reference sequences that its affiliation to the Proteobacteria must be considered tentative. The type strain is H. foetida strain TMBS4 (DSM 6591).F. Bak died on 27 December 1992. A very promising and productive career thus ended much too early     

Neoscardovia arbecensis gen. nov., sp. nov., isolated from porcine slurries

Three Gram-positive, anaerobic, pleomorphic strains (PG10(T), PG18 and PG22), were selected among five strains isolated from pig slurries while searching for host specific bifidobacteria to track the source of fecal pollution in water. Analysis of the 16S rRNA gene sequence showed a maximum identity of 94% to various species of the family Bifidobacteriaceae. However, phylogenetic analyses of 16S rRNA and HSP60 gene sequences revealed a closer relationship of these strains to members of the recently described Aeriscardovia, Parascardovia and Scardovia genera, than to other Bifidobacterium species. The names Neoscardovia gen. nov. and Neoscardovia arbecensis sp. nov. are proposed for a new genus and for the first species belonging to this genus, respectively, and for which PG10(T) (CECT 8111(T), DSM 25737(T)) was designated as the type strain. This new species should be placed in the Bifidobacteriaceae family within the class Actinobacteria, with Aeriscardovia aeriphila being the closest relative. The prevailing cellular fatty acids were C(16:0) and C(18:1)ω9c, and the major polar lipids consisted of a variety of glycolipids, diphosphatidyl glycerol, two unidentified phospholipids, and phosphatidyl glycerol. The peptidoglycan structure was A1γmeso-Dpm-direct. The GenBank accession numbers for the 16S rRNA gene and HSP60 gene sequences of strains PG10(T), PG18 and PG22 are JF519691, JF519693, JQ767128 and JQ767130, JQ767131, JQ767133, respectively.     

Imantonia rotunda gen. et sp. nov., a new member of the Haptophyceae

Imantonia rotunda, a new member of the Haptophyceae, is described and records of its distribution are given. It is characterised by a distinctive “bicycle-wheel” type of scale and does not bear a haptonema.