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A strain of a hitherto undescribed coryneform bacterium from human clinical material was characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequence analysis demonstrated the strain represents a novel and deep lineage within the genus Corynebacterium sensu stricto. Chemical analyses revealed the unidentified strain was unusual in that it lacked mycolic acids. Based on the phylogenetic and phenotypic distinctiveness of the unknown isolate, it is proposed that the bacterium be classified as a new Corynebacterium species, for which the name Corynebacterium kroppenstedtii sp. nov. is proposed. The type strain is CCUG 35717T.

Whole-organism protein electrophoresis was used to compare and group unidentified coryneform bacteria resembling Gardnerella vaginalis and various Actinomyces and Arcanobacterium species. The obtained clusters of strains were further characterized by whole-cell fatty acid analysis and a variety of biochemical tests. Species-specific oligonucleotide probes based on 16S rRNA gene sequences were designed. The results demonstrate that the majority of the isolates belonged to Actinomyces turicensis; the other strains belonged to Actinomyces radingae. The descriptions of both species are emended.

Four strains of a previously unknown, catalase-negative, facultatively anaerobic, gram-positive, rod-shaped organism originating from humans were characterized by biochemical, chemical, and molecular taxonomic methods. The four strains phenotypically closely resembled one another, and although they possessed characteristics consistent with membership in the genus Actinomyces, they differed from all previously recognized species of this genus. The results of comparative 16S rRNA gene sequencing studies demonstrated that the unknown human bacterium was phylogenetically a member of the genus Actinomyces. Within the genus Actinomyces, the unidentified bacterium formed a loose, but statistically significant, association with a subgroup which included Actinomyces bovis, the type species of the genus. 16S rRNA sequence divergence values of >6%, however, unequivocally demonstrated that the unidentified bacterium represents a new subline of the genus Actinomyces. A new species, Actinomyces graevenitzii, is proposed for the four new isolates. The type strain of A. graevenitzii is CCUG 27294.

Ten strains of a hitherto undescribed catalase-negative, facultatively anaerobic, coryneform bacterium were isolated or collected by workers at three European clinical bacteriology laboratories or reference centers. These strains were isolated from humans, and most came from abscess material. Biochemical and chemotaxonomic characterization revealed that the strains belonged to the genus Actinomyces. The phenotypic features of the 10 strains were incompatible with the descriptions of the previously established Actinomyces species. A comparative 16S rRNA gene sequence analysis demonstrated that the previously undescribed strains constitute a new line in the genus Actinomyces. The name Actinomyces europaeus sp. nov. is proposed for these clinical isolates. The type strain is CCUG 32789A.

Five strains of a hitherto unknown Actinomyces-like bacterium were isolated from human clinical sources, including blood cultures. Biochemical and chemotaxonomic characterization indicated that the strains were distinct from previously described Actinomyces and Arcanobacterium species. A comparative 16S rRNA gene sequence analysis demonstrated that the undescribed strains constitute a new subline within the Actinomyces-Arcanobacterium species complex. The closest known relative of the isolates was found to be Actinomyces suis, although a 16S rRNA sequence divergence value of approximately 6% clearly demonstrated that the unknown bacterium represents a distinct species. Based on the results of the present and earlier phylogenetic investigations, it is proposed that Actinomyces suis should be reclassified in a new genus, the genus Actinobaculum, as Actinobaculum suis comb. nov. In addition, a new species, Actinobaculum schaalii, is proposed for the Actinomyces-like bacterium from human sources. The type strain of Actinobaculum schaalii is CCUG 27420.

Ten strains recognized on the basis of a computer-assisted numerical comparison of whole-cell protein patterns as members of a novel species belonging to the family Alcaligenaceae were examined by using an integrated phenotypic and genotypic approach. This species, for which we propose the name Bordetella trematum sp. nov., was more closely related to the type species of the genus Bordetella (Bordetella pertussis) than to the type species of the genus Alcaligenes (Alcaligenes faecalis) and had the general characteristics of members of this family (i.e., a DNA base ratio in the range from 57 to 70 mol%, a fatty acid profile characterized by high percentages of 16:0, 17:0 cyclo, and 14:0 3OH, nonsaccharolytic metabolism, and several classical biochemical characteristics, including aerobic and microaerobic growth, catalase activity, assimilation of citrate, an absence of anaerobic growth, and an absence of acetylmethylcarbinol and indole production, gelatin liquefaction, and esculin hydrolysis). A reevaluation of the criteria used to classify Alcaligenes denitrificans Rüger and Tan 1983 and Achromobacter xylosoxidans Yabuuchi and Ohyama 1971 as subspecies of Alcaligenes xylosoxidans and additional evidence provided in recent studies revealed that, consistent with present standards, it is appropriate to consider these two taxa distinct species of the genus Alcaligenes.

Ninety genotypically characterized Aeromonas strains, including members of all 14 currently established genospecies, were studied by performing gas-liquid chromatographic analysis of their cellular fatty acid methyl esters (FAMEs). A total of 44 fatty acids and two alcohols were found in members of the genus Aeromonas. All 90 strains contained 12:0, 13:0 iso, 14:0, 15:0 iso 3OH, 16:0, 16:1 ω7c, 17:0 iso, iso 17:1 ω9c, summed feature 3 (16:1 iso I and/or 14:0 3OH), and summed feature 7 (18:1 ω7c, 18:1 ω9t, and/or 18:1 ω12t), whereas all but one strain (99%) also contained 15:0 iso. Although the FAME profiles were very similar, minor quantitative variations could be used to differentiate phenospecies and/or hybridization groups. A cluster analysis of the mean data revealed five FAME clusters, which were compared with phenotypic and genotypic groups identified in the genus Aeromonas. Hybridization groups that constituted the Aeromonas hydrophila complex, the Aeromonas caviae complex, and the Aeromonas sobria complex were basically grouped into distinct FAME clusters. The taxonomic positions of hybridization groups 7 and 11 in these clusters, however, remained unclear. All of our results were highly reproducible. A new database of Aeromonas FAME fingerprints was generated, and this database can be used for rapid identification of unknown aeromonads. Using a large set of well-characterized aeromonads, we demonstrated for the first time that gas-liquid chromatographic FAME analysis can be used to differentiate the majority of the phenospecies and/or hybridization groups in the genus Aeromonas.

The taxonomic positions of strains previously assigned to Pseudomonas diminuta and Pseudomonas vesicularis were investigated by a polyphasic approach. The results of DNA-rRNA hybridization studies indicated that these two species belong to a separate genus in the alpha subclass (rRNA superfamily IV) of the Proteobacteria, for which the name Brevundimonas is proposed. Genus delineation and species delineation were determined by comparing the results of numerical analyses of whole-cell protein patterns, fatty acid compositions, and phenotypic characteristics and by measuring DNA base ratios and degrees of DNA relatedness. Taxonomic characteristics of Brevundimonas diminuta and Brevundimonas vesicularis strains were compared with characteristics of reference strains belonging to the following phylogenetically related taxa: a group of organisms gathered in Enevold Falsen group 21, the genera Sphingomonas and Rhizomonas, and the generically misclassified organisms [Pseudomonas] echinoides and "[Pseudomonas] riboflavina."

The taxonomic relationships of strains belonging to Centers for Disease Control group M-5 were examined. Previous studies of rRNA cistron similarities placed this organism on the Neisseriaceae rRNA branch of rRNA superfamily III; the closest neighbors included the genus Neisseria and groups EF-4a and EF-4b. The group M-5 strains were characterized by a range of phenotypic tests, and their G+C contents and DNA-DNA relatedness levels were determined. In addition, a numerical taxonomic analysis of the whole-cell protein patterns (obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) of group M-5 and related taxa was performed. The strains studied included 45 group M-5 strains, the type strains of six Neisseria species or subspecies, three group EF-4a reference strains, and three group EF-4b reference strains plus the type strain of the phenotypically similar organism Oligella urethralis. Our results showed that the group M-5 strains were members of a homogeneous taxon distinct from phylogenetically closely related taxa. The genomic divergence as revealed by levels of rRNA cistron similarity and phenotypic characteristics indicate that group M-5 can be considered a new species of the genus Neisseria. We therefore propose the new species Neisseria weaveri, with NCTC 12742 (= CCUG 4007 = ISL775/91 = LMG 5135) as the type strain. N. weaveri strains are strictly aerobic, gram-negative, nonmotile, rod-shaped organisms which are catalase and oxidase positive, nonsaccha-rolytic, and able to grow on MacConkey agar and do not reduce nitrate but generally reduce nitrite. The guanine-plus-cytosine contents of the DNAs of six representative strains were in the range from 50 to 51 mol%. Almost all 45 group M-5 strains were originally isolated from human wounds following dog bites.

A polyphasic taxonomic study was performed to determine the relationships of 10 Moraxella-like strains isolated mainly from the human respiratory tract in Sweden. Two of the strains formed a separate subgroup on the basis of both their protein contents and their fatty acid contents. However, the overall protein and fatty acid profiles revealed that all 10 strains were highly related. Representative strains of the two subgroups exhibited high DNA binding values (98%) with each other and had an identical DNA base ratio (44 mol% G+C). DNA-rRNA hybridizations revealed that this taxon can be included in the genus Moraxella, which is only distantly related to phenotypically similar genera, such as the genera Neisseria and Kingella. The results of an extensive phenotypic analysis indicated that the general biochemical profile of the 10 strains conforms with the description of the genus Moraxella given in Bergey's Manual of Systematic Bacteriology. We therefore consider these organisms members of a new Moraxella species, for which the name Moraxella lincolnii is proposed. Furthermore, we also conclude that Moraxella osloensis belongs, genotypically as well as phenotypically, to the genus Moraxella.

We used DNA-rRNA hybridization, DNA base composition, polyacrylamide gel electrophoresis of whole-cell proteins, DNA-DNA hybridization, numerical analysis of phenotypic features, and immunotyping to study the taxonomy of the genus Comamonas. The relationships of this genus to Aquaspirillum aquaticum and a group of clinical isolates (E. Falsen group 10 [EF 10]) were studied. Our DNA and rRNA hybridization results indicate that the genus Comamonas consists of at least the following five genotypic groups: (i) Comamonas acidovorans, (ii) Comamonas testosteroni, (iii) Comamonas terrigena, (iv) A. aquaticum and a number of EF 10 strains, and (v) other EF 10 strains, several unnamed clinical isolates, and some misnamed strains of Pseudomonas alcaligenes and Pseudomonas pseudoalcaligenes subsp. pseudoalaligenes. The existence of these five groups was confirmed by the results of immunotyping and protein gel electrophoresis. A numerical analysis of morphological, auxanographic, and biochemical data for the same organisms revealed the existence of three large phena. Two of these phena (C. acidovorans and C. testosteroni) correspond to two of the genotypic groups. The third phenon contains strains belonging to the other three genotypic groups, including most EF 10 strains and the type strains of C. terrigena and A. aquaticum. The strains belonging to the third phenon were all incorporated into C. terrigena, and we propose that the use of the name Aquaspirillum aquaticum should be discontinued. Emended descriptions of the genus Comamonas and C. terrigena are presented.

Phenotypic and phylogenetic studies were performed on a hitherto undescribed Gram-positive, catalase-negative, chain-forming coccus isolated from human blood. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown organism constitutes a new phylogenetic line, close to, but distinct from. Facklamia and Globicatella. The unknown bacterium was readily distinguished from currently recognized Facklamia species and Globicatella sanguinis by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Dolosicoccus paucivorans gen. nov., sp. nov. The type strain of Dolosicoccus paucivorans is CCUG 39307T.

Four strains of a previously undescribed Actinomyces-like bacterium were isolated from canine and feline clinical specimens. Phenotypic studies indicated the strains were members of the genus Actinomyces, and most closely resembled Actinomyces viscosus serotype I and Actinomyces slackii. Comparative 16S rRNA gene sequencing studies demonstrated the unknown bacterium constitutes a new subline within a group of Actinomyces species, which includes Actinomyces bovis, the type species of the genus. Based on phylogenetic and phenotypic evidence it is proposed that the unknown bacterium be classified as Actinomyces bowdenii sp. nov. The type strain of Actinomyces bowdenii is CCUG 37421T.

Two strains of a hitherto undescribed Gram-positive, catalase-negative, facultatively anaerobic coccus isolated from sheep were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains were genealogically highly related and constitute a new line close to, but distinct from, Helcococcus kunzii. The unknown bacterium was readily distinguished from H. kunzii by biochemical tests and electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Helcococcus ovis sp. nov. The type strain of Helcococcus ovis is CCUG 37441T.

Phenotypic and phylogenetic studies were performed on two strains of a hitherto undescribed Aerococcus-like organism isolated from the human vagina. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains constitute a new subline within the genus Aerococcus. The unknown bacterium was readily distinguished from the two currently recognized Aerococcus species, Aerococcus viridans and Aerococcus urinae, by biochemical tests and electrophoretic analysis of whole-cell proteins. On the basis of phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium be classified as Aerococcus christensenii sp. nov. The type strain of A. christensenii is CCUG 28831T.

Three strains of a previously undescribed catalase-positive non-lipophilic coryneform bacterium isolated from human clinical specimens were characterized by phenotypic and molecular taxonomic methods. Morphologically the unknown bacterium consisted of pleomorphic rods, some of which displayed bulges/knobs at their ends. All three strains were similar in that they produced acid from fructose, glucose, maltose and sucrose and were urease-positive. Chemotaxonomic investigations revealed the presence of meso-diaminopimelic acid and short-chain mycolic acids consistent with the genus Corynebacterium sensu stricto. Comparative 16S rRNA gene sequencing showed that the three strains are genealogically highly related and constitute a new subline within the genus Corynebacterium, displaying > 3% sequence divergence with recognized species. The unknown bacterium was distinguished from currently validly published Corynebacterium species by phenotypic tests, including electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, it is proposed that the unknown bacterium from clinical specimens be classified as Corynebacterium sundsvallense sp. nov. The type strain is CCUG 36622T.

A polyphasic taxonomic study that included DNA-DNA hybridizations, DNA base ratio determinations, 16S rDNA sequence analysis, whole-cell protein and fatty acid analyses, AFLP (amplified fragment length polymorphism) fingerprinting and an extensive biochemical characterization was performed on 10 strains provisionally identified as Alcaligenes faecalis-like bacteria. The six environmental and four human isolates belonged to the genus Ralstonia and were assigned to a new species for which the name Ralstonia gilardii sp, nov. is proposed. The type strain is LMG 5886(T).

Six strains of a hitherto undescribed gram-positive, catalase-negative, facultatively anaerobic coccus from human sources were characterized by phenotypic and molecular taxonomic methods. Comparative 16S rRNA gene sequencing studies demonstrated that the unknown strains were genealogically homogeneous and constitute a new line closely related to, but distinct from, the genus Globicatella. The unknown bacterium was readily distinguished from Globicatella sanguis, the type species of the genus Globicatella, by the results of biochemical tests and an electrophoretic analysis of whole-cell proteins. Based on phylogenetic and phenotypic evidence, we propose that the unknown bacterium be classified as Facklamia hominis gen. nov., sp. nov. The type strain of Facklamia hominis is CCUG 36813.

[Pseudomonas] rubrisubalbicans. a mild plant pathogen, Herbaspirillum seropedicae, and EF group 1 strains (clustered by an immunological method) were investigated by a polyphasic approach with DNA-rRNA and DNA-DNA hybridizations and auxanography on 147 substrates. Our results show that they all belong to the genus Herbaspirillum. In addition to H. seropedicae, two other species are described: Herbaspirillum rubrisubalbicans and a new unnamed species, Herbaspirillum species 3, containing mainly strains of clinical origin. The three species can be differentiated on the basis of their auxanographic features and DNA-DNA similarities. The type strain of H. rubrisubalbicans is NCPPB 1027 (=LMG 2286): Representative strains of the third Herbaspirillum species are strains CCUG 189 (=LMG 5523), CCUG 10263 (=LMG 5934), and CCUG 11060 (=LMG 5321). It has been confirmed that H. rubrisubalbicans is an endophytic diazotroph. It colonizes the roots, the stems, and predominantly the leaves of sugarcane (Saccharum spp.), while Herbaspirillum seropedicae colonizes in large numbers many different species of the Gramineae. Both diazotrophic Herbaspirillum species could be differentiated with meso-erythritol and N-acetylglucosamine. Oligonucleotide probes based on partial sequences of the 23S rRNA of H. seropedicae and H. rubrisubalbicans (HS and HR probes, respectively), were constructed and used as diagnostic probes.

Hybridization experiments were carried out between DNAs from more than 70 strains of Campylobacter spp. and related taxa and either 3H-labeled 23S rRNAs from reference strains belonging to Campylobacter fetus, Campylobacter concisus, Campylobacter sputorum, Campylobacter coli, and Campylobacter nitrofigilis, an unnamed Campylobacter sp. strain, and a Wolinella succinogenes strain or 3H- or 14C-labeled 23S rRNAs from 13 gram-negative reference strains. An immunotyping analysis of 130 antigens versus 34 antisera of campylobacters and related taxa was also performed. We found that all of the named campylobacters and related taxa belong to the same phylogenetic group, which we name rRNA superfamily VI and which is far removed from the gram-negative bacteria allocated to the five rRNA superfamilies sensu De Ley. There is a high degree of heterogeneity within this rRNA superfamily. Organisms belonging to rRNA superfamily VI should be reclassified in several genera. We propose that the emended genus Campylobacter should be limited to Campylobacter fetus, Campylobacter hyointestinalis, Campylobacter concisus, Campylobacter mucosalis, Campylobacter sputorum, Campylobacter jejuni, Campylobacter coli, Campylobacter Iari, and “Campylobacter upsaliensis.” Wolinella curva and Wolinella recta are transferred to the genus Campylobacter as Campylobacter curvus comb. nov. and Campylobacter rectus comb. nov., respectively. Bacteroides gracilis and Bacteroides ureolyticus are generically misnamed and are closely related to the genus Campylobacter. Campylobacter nitrofigilis, Campylobacter cryaerophila, and an unnamed Campylobacter sp. strain constitute a new genus, for which the name Arcobacter is proposed; this genus contains two species, Arcobacter nitrofigilis comb. nov. (type species) and Arcobacter cryaerophilus comb. nov. Wolinella succinogenes so far is the only species of the genus Wolinella. The genus Helicobacter is also emended; Campylobacter cinaedi and Campylobacter fennelliae are included in this genus as Helicobacter cinaedi comb. nov. and Helicobacter fennelliae comb. nov., respectively. The genus “Flexispira,” with “Flexispira rappini” as the only species, is closely related to the genus Helicobacter. The free-living, sulfur-reducing campylobacters do not belong to any of these genera; they probably constitute a distinct genus within rRNA superfamily VI.

Streptococcus dysgalactiae consists of at least five distinct subgroups on the basis of serogroups, biotypes, and hosts. A chemotaxonomic and phenotypic examination of 80 S. dysgalactiae strains representing the known diversity within this species and 49 reference strains representing all members of the streptococcal pyogenic species group revealed two subpopulations of strains within S. dysgalactiae. The name S. dysgalactiae subsp. dysgalactiae is proposed for strains of animal origin. These strains belong to Lancefield serogroups C and L, are alpha-, beta-, or nonhemolytic, and do not exhibit streptokinase activity on human plasminogen or proteolytic activity on human fibrin. The name S. dysgalactiae subsp. equisimilis is proposed for human isolates. These strains belong to Lancefield serogroups C and G, are beta-hemolytic, and exhibit streptokinase activity on human plasminogen and proteolytic activity on human fibrin.

The taxonomic relationships of Moraxella urethralis, the Centers for Disease Control (CDC) group IVe, Taylorella equigenitalis, and other gram-negative bacteria were studied by deoxyribonucleic acid (DNA)-DNA polyacrylamide gel electrophoresis of cellular proteins, and serological, biochemical, and auxanographic analyses. A high relationship was detected between M. urethralis and the CDC group IVe strains. However, no relationship of M. urethralis and CDC group IVe with genuine Moraxella species was observed. We describe a new genus, Oligella, containing two species: Oligella urethralis (to accommodate Moraxella urethralis) and Oligella ureolytica (to accommodate CDC group IVe strains). The type species is Oligella urethralis, with type strain ATCC 17960T. The type strain of Oligella ureolytica is CDC C379 (ATCC 43534, CCUG 1465, LMG 6519). Oligella is a member of rRNA superfamily III, containing, e.g., the Pseudomonas acidovorans and Pseudomonas solanacearum complexes and Chromobacterium, Janthinobacterium, and Neisseria species. The closest relatives of Oligella species are Taylorella equigenitalis and the Alcaligenaceae family.

The historical and present taxonomic and nomenclatural status of the following taxa were examined: “Vibrio terrigenus” Gunther 1894, “Vibrio percolans” Mudd and Warren 1923, “Vibrio alcaligenes” Lehmann and Neumann 1927, “Lophomonas alcaligenes” Galarneault and Leifson 1956, “Comamonas percolans” Davis and Park 1962, “Comamonas terrigena” Hugh 1962, “Pseudomonas terrigena” Hugh 1965, “Vibrio cyclosites” Gray and Thornton 1928, “Vibrio neocistes” Gray and Thornton 1928, “Vibrio cuneatus” Gray and Thornton 1928, and “Comamonas compransoris” Nozhevnikova and Zavarzin 1974. Most of these organisms have been misnamed. Deoxyribonucleic acid-ribosomal ribonucleic acid hybridization experiments localized “C. terrigena” (“V. percolans”) NCIB 8193, “V. neocistes” NCIB 2582, and “V. cyclosites” NCIB 2581 on the Pseudomonas acidovorans ribosomal ribonucleic acid branch in the direct vicinity of Pseudomonas testosteroni. Deoxyribonucleic acid-deoxyribonucleic acid hybridization experiments, serological studies, gel electropherograms of soluble proteins, and a numerical analysis of phenotypic features supported placement of these strains and clinical isolate CCUG 12940 in a single taxon, for which we propose revival of the name Comamonas terrigena Hugh 1962. The type strain is strain NCIB 8193 (= ATCC 8461 = LMG 1253 = CCUG 15327). C. terrigena is the type species of the genus Comamonas Davis and Park 1962 nom. rev. An extensive phenotypic description of C. terrigena is given, and this species can be differentiated from P. acidovorans and P. testosteroni. “Achromobacter cystinovorum” NCIB 4854 is misnamed and was found to be very closely related to P. acidovorans. “V. alcaligenes” NCTC 9239 was found to be misnamed and is closely related to Pseudomonas diminuta, which is itself inappropriately retained in the genus Pseudomonas. The classification of “V. cuneatus” NCIB 8194 as Pseudomonas fluorescehs is confirmed. “C. compransoris” DSM 1231 and “V. cyclosites” ATCC 14635 (the so-called synonymous strain of “V. cyclosites” NCIB 2581) are definitely not members of C. terrigena. These two strains differ considerably from each other, as well as from all of the other strains investigated; their exact taxonomic position is unknown.

The relationships of the yellow-pigmented hydrogen-oxidizing species Pseudomonas flava, Pseudomonas pseudoflava, Pseudomonas palleronii, Pseudomonas taeniospiralis, and “Pseudomonas carboxydoflava,” which are all members of the acidovorans ribosomal ribonucleic acid (rRNA) complex in rRNA superfamily III, were studied by using deoxyribonucleic acid (DNA):rRNA hybridization, immunotyping, numerical analysis of biochemical and auxanographic features, polyacrylamide gel electrophoresis of cellular proteins, numerical analysis of fatty acid patterns, and DNA:DNA hybridization. Our results show that these five yellow-pigmented hydrogen-oxidizing Pseudomonas species are more closely related to each other than to other taxa belonging to the acidovorans rRNA complex. We propose the transfer of these species to a new genus, Hydrogenophaga, with the following four species: Hydrogenophaga flava (formerly Pseudomonas flava), Hydrogenophaga pseudoflava (to accommodate both Pseudomonas pseudoflava and “Pseudomonas carboxydoflava”), Hydrogenophaga taeniospiralis (formerly Pseudomonas taeniospiralis), and Hydrogenophaga palleronii (formerly Pseudomonas palleronii). The type species is H. flava, with monotype strain DSM 619 (= LMG 2185 = CCUG 1658). Because H. flava grows slowly and unreliably, but is genotypically and protein electrophoretically very similar to H. pseudoflava, the latter species can be used as an alternative reference taxon for the new genus. The type strains of H. pseudoflava, H. taeniospiralis, and H. palleronii are strains GA3 (= LMG 5945 = CCUG 13799). DSM 2082 (= LMG 7170 = CCUG 15921), and Stanier 362t1 (= LMG 2366t1 = CCUG 20334), respectively.