- Volume 36, Issue 4, 1986

Three new saccharolytic Bacteroides species that have DNAs with guanine-plus-cytosine contents of 40 to 46 mol%, produce major amounts of succinate, and were isolated principally from human feces are described: Bacteroides caccae, with ATCC 43185 as the type strain; B. merdae, with ATCC 43184 as the type strain; and B. stercoris, with ATCC 43183 as the type strain. These groups previously have been referred to as the “3452A,” “T4-1,” and “subsp. a” groups, respectively.

The group 1 methanol-utilizing bacteria examined in this study are gram-negative, nonsporeforming, rod-shaped organisms which use the ribulose monophosphate pathway for methanol utilization. These organisms are generally motile by means of a single polar flagellum, but a small number of strains are nonmotile, and although most are obligately methylotrophic, several strains utilize d-fructose in addition to methanol. Their deoxyribonucleic acid base composition ranges from 50.0 to 56.0 mol% guanine plus cytosine. Their cellular fatty acids consist predominantly of large amounts of straight-chain saturated C16:0 acid and unsaturated C16:1 acid. The major ubiquinone is Q-8, and Q-7 and Q-9 are present as minor components. Type strain TK 0113 (= Yordy and Weaver T-11 = ATCC 29475 = JCM 2850 = NCIB 11375) of Methylobacillus glycogenes is included in this group. The genus Methylobacillus was established based on the description of only one nonmotile strain, which does not utilize d-fructose. Therefore, we propose emendation of the genus Methylobacillus and Methylobacillus glycogenes, in which polarly flagellated organisms and d-fructose-utilizing organisms are included.

Two species of the new genus Catellatospora, belonging to the “actinoplanates” group, are described under the names Catellatospora citrea sp. nov. and Catellatospora ferruginea sp. nov. The organisms of this genus are aerobic and produce nonfragmenting vegetative hyphae and no true aerial mycelium. Short chains of nonmotile spores emerge singly or in tufts from the vegetative hyphae on the surface of agar media. The organisms have meso-diaminopimelic and 3-hydroxydiaminopimelic acids and glycine in the cell walls (a type II cell wall); xylose and arabinose (a pattern D whole-cell sugar); and phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannosides but not phosphatidylcholine (a type PII phospholipid pattern). The major menaquinones in C. citrea and C. ferruginea are MK-9 (H4) and MK-10 (H8), respectively. The guanine-plus-cytosine content of the deoxyribonucleic acids ranges from 70.9 to 71.5 mol%. The type strain of type species C. citrea is strain IFO 14495T (6183-ET), and the type strain of C. ferruginea is strain IFO 14496T (6257-CT).

A disease persisting in Norwegian salmonid cultures since the late 1970s is caused by a Vibrio-like bacterium. This bacterium belongs to the genus Vibrio, but it differs from all previously described species of this genus. The name Vibrio salmonicida sp. nov. is proposed. The type strain is strain NCMB 2262 (= HI 7751).

Strains of Vibrio salmonicida that were isolated from different localities on the Norwegian west coast and strains of Vibrio anguillarum, Vibrio ordalii, and Vibrio parahemolyticus were compared genetically. Our results showed that strains of V. salmonicida constitute a homogeneous group (82 to 100% deoxyribonucleic acid homology), which is distinct from the other species, and that V. anguillarum is a rather diverse species. This diversity seems to be related to the host specificity of the bacterial strains.

A total of 443 strains of Vibrio, many of which were isolated from estuaries in the United States, were studied with numerical taxonomy to determine relationships among those species known to be pathogenic for humans, e.g., V. cholerae, V. mimicus, V. fluvialis, V. parahaemolyticus, and V. vulnificus, as well as among strains not identifiable from the minimum diagnostic characteristics likely to be used in many clinical laboratories. Similarity coefficients were calculated on the basis of 133 characters, using Euclidean distance. Most of the strains clustered in phena along with reference strans. Several new, as yet undescribed phena containing strains isolated from diverse geographic locations were detected. Deficiencies in current schemes for identification of V. vulnificus and V. parahaemolyticus were observed, and the definitions of these species were extended by using information obtained in this study.

Thirteen strains of rod-shaped lactic acid bacteria, resistant to high concentrations of acetic acid, were isolated from the fermented broth of rice vinegar. These isolates showed homofermentation and differed from all the validly described homofermentative species of the genus Lactobacillus. Although the isolates were divided into two groups on the basis of acid production pattern from carbohydrates and nutritional requirements for growth, all showed extremely high deoxyribonucleic acid homology. The isolates were considered to represent a new species of the genus Lactobacillus. The two groups, based on their biochemical and physiological properties, were treated as biovar I and biovar II. A new species proposed for these isolates was named Lactobacillus acetotolerans. The type strain of L. acetotolerans sp. nov. is NBI3014 (=JCM 3825).

The relationships between Rhizobium fredii and the rhizobia that nodulate Galega officinalis and Galega orientalis (goat’s rue) and recognized species of Rhizobium and Bradyrhizobium were investigated by using deoxyribonucleic acid (DNA)-DNA hybridization, legume nodulation tests, and phage typing. The R. fredii strains formed a distinct DNA homology group which could be divided into two subgroups. The mean levels of relative homology at 65°C of 11 strains of R. fredii with R. fredii reference strains USDA 208 and USDA 191 were 86 and 80%, respectively. These values were significantly higher (Student’s t test, P < 0.001) than the mean levels of relative homology with DNAs from other groups of rhizobia. The Galega-nodulating rhizobia also formed a distinct DNA homology group. The mean levels of relative homology at 65°C of DNAs from 11 strains with DNAs from reference strains gall and galNW3, which effectively nodulate G. officinalis, were 79 and 85%, respectively. These values were also significantly higher (Student’s t test, P < 0.001) than the values obtained with DNAs from other groups of rhizobia. These results correlated with cross-inoculation and phage-typing results and indicated that the two groups are genetically distinct. Genomic DNA was used as a probe in a modified colony hybridization autoradiographic procedure for the identification of DNAs from Rhizobium leguminosarum, R. fredii, and Rhizobium sp. (Galega) in colonies and from nodules.

A new genus, Acidianus, is characterized from studies of 26 isolates of thermoacidophilic archaebacteria from different solfatara fields and marine hydrothermal systems; these isolates grow as facultative aerobes by lithotrophic oxidation and reduction of SO, respectively, and are therefore different from the strictly aerobic Sulfolobus species. The Acidianus isolates have a deoxyribonucleic acid guanine-plus-cytosine content of 31 mol%. In contrast, two of three Sulfolobus species, including the type species, have a guanine-plus-cytosine content of 37 mol%; Sulfolobus brierleyi is the exception, with a guanine-plus-cytosine content of 31 mol%. In contrast to its earlier descriptions, S. brierleyi is able to grow strictly anaerobically by hydrogen-sulfur autotrophy. Therefore, it is described here as a member of the genus Acidianus. The following species are assigned to the genus Acidianus: Acidianus infernus sp. nov. (type strain, strain DSM 3191) and Acidianus brierleyi comb. nov. (type strain, strain DSM 1651).

Deoxyribonucleic acid hybridization studies done on 24 Providencia friedericiana strains showed that they were highly related (74 to 86% at 75°C) to the type strain of Providencia rustigianii. In addition, their biochemical reactions were the same. Therefore, the names P. rustigianii and P. friedericiana are subjective synonyms. Because P. rustigianii was described and validated first, it is the senior synonym and has priority over the junior synonym, P. friedericiana.

On the basis of phenetic and chemotaxonomic criteria a new nonmotile anaerobic gram-negative rod-shaped bacterium from dental root canals is described. The new species has characteristics in common with species of the genus Bacteroides, but there are also many differences. According to a detailed biochemical analysis the new species is closer to the genus Mitsuokella than to Bacteroides. We propose a new species, Mitsuokella dentalis. The type strain of M. dentalis is strain DSM 3688.

Of 29 strains of various Saccharomyces spp., 24 gave generally similar chromosomal band patterns (14 to 17 bands in the size range from 200 to 2,000 kilobase pairs), as determined by orthogonal field alternation gel electrophoresis. However, most of these stains showed unique band patterns due to chromosome polymorphisms. Strains of Saccharomyces kluyveri, Candida albicans, Candida utilis, Kluyveromyces lactis, Pichia canadensis, and Schwanniomyces occidentalis gave bands that were indicative of small numbers of larger chromosomes (> 1,000 kilobase pairs). These results suggest that Saccharomyces kluyveri should be included in another genus and that Saccharomyces spp. may be different from other yeasts in having a large number of chromosomes, the majority of which are smaller than 1,000 kilobase pairs.

Strain NCDO 1859 (= IFO 3884) was selected as the neotype strain of Pediococcus acidilactici by Garvie in 1974 and was confirmed as such on the Approved Lists in 1980. P. acidilactici and Pediococcus pentosaceus are difficult to separate by using only phenotypic data, and the choice of NCDO 1859 relied on such data. Subsequently, two independent deoxyribonucleic acid (DNA)-DNA homology studies have shown that the DNA of NCDO 1859 has high levels of homology with the DNAs of strains of P. pentosaceus, including the type strain (93 to 100%), but low levels of homology (20 to 34%) with authentic strains of P. acidilactici. Moreover, the guanine-plus-cytosine content of the DNA of NCDO 1859 is within the range of P. pentosaceus guanine-pluscytosine contents, which are 4 to 5 mol% below the guanine-plus-cytosine contents of strains of P. acidilactici. Clearly, at some point, NCDO 1859 was misidentified by using only phenotypic data and should be rejected as the neotype strain of P. acidilactici. In addition, I propose that Pediococcus acidilactici should be conserved, with DSM 20284 as the neotype strain. This action is not in line with strict application of the International Code of Nomenclature of Bacteria but will ensure the continuity of nomenclature and avoid the confusion which would result from the alterations necessary if the code were followed in this instance.