M. C. Gutiérrez

Volcaniella eurihalina gen. nov., sp. nov., a moderately halophilic nonmotile gram-negative rod

A comparison of 16 gram-negative moderately halophilic aerobic rod-shaped bacteria with other halophilic and nonhalophilic gram-negative bacteria supported the establishment of Volcaniella eurihalina gen. nov., sp. nov. This comparison included phenotypic properties, salt requirements, and guanine-plus-cytosine contents of the DNAs, as well as DNA-DNA homology studies. The distinguishing features of this new bacterial genus are as follows: The organisms are nonmotile short rods that are oxidase negative; they are aerobic with a strictly respiratory type of metabolism; they are moderate halophiles, optimal growth occurs at a total salt concentration of 7.5% (wt/vol), and they exhibit a strongly euryhaline character; and they have a specific requirement for Na+ ions (sodium can be supplied as NaCl, Na2SO4, or NaBr). The minimum NaCl concentration required is 1.5% (wt/vol). The guanine-plus-cytosine content of the DNA is 59.1 to 65.7 mol%. This organism was isolated from hypersaline habitats, including saline soils and salt ponds, and from seawater. The type strain is strain F9-6 (= ATCC 49336).

Classification of “Chromobacterium marismortui” in a New Genus, Chromohalobacter gen. nov., as Chromohalobacter marismortui comb. nov., nom. rev.

Phenotypic and chemotaxonomic characteristics of seven moderately halophilic isolates from a mediterranean saltern showed that they were very closely related to “Chromobacterium marismortui.” This species, which was originally described on the basis of strains isolated from the Dead Sea, was not included on the Approved Lists of Bacterial Names and is not accepted as a member of the genus Chromobacterium since it produces a pigment that is not violacein, does not possess the characteristic flagellar arrangement, and is not genotypically related to this genus as determined by deoxyribonucleic acid-ribosomal ribonucleic acid hybridization experiments. On the basis of the special features of these strains, we propose that they should be placed in a new genus, Chromohalobacter, which includes a single species, Chromohalobacter marismortui comb. nov., nom. rev. The deoxyribonucleic acid base composition is 62.1 to 64.9 mol% guanine plus cytosine. The type strain is strain ATCC 17056 (= CCM 3518).

Proposal to transfer Halococcus turkmenicus, Halobacterium trapanicum JCM 9743 and strain GSL-11 to Haloterrigena turkmenica gen. nov., comb. nov.

The 16S rRNA gene sequences of Halococcus saccharolyticus and Halococcus salifodinae were closely related (94.5-94.7% similarity) to that of Halococcus morrhuae, the type species of the genus Halococcus. However, Halococcus turkmenicus was distinct from the other members of this genus, with low 16S rRNA similarities when compared to Halococcus morrhuae (88.7%). On the basis of phylogenetic tree reconstruction, detection of signature bases and DNA-DNA hybridization data, it is proposed to transfer Halococcus turkmenicus to a novel genus, Haloterrigena, as Haloterrigena turkmenica gen. nov., comb. nov., and to accommodate Halobacterium trapanicum JCM 9743 and strain GSL-11 in the same species. On the basis of morphological, cultural and 16S rRNA sequence data, it is also proposed that the culture collection strains of Halobacterium trapanicum NCIMB 767, ATCC 43102 and JCM 8979 should be renamed as Halococcus sp.

Aeromonas encheleia sp. nov., isolated from European eels

Four strains isolated from European eels in Valencia, Spain, were found to constitute a DNA relatedness group which is 0 to 50% related to the 13 species and DNA group 11 of the genus Aeromonas. Phenotypically, these strains have all of the properties that define the genus Aeromonas. However, they differ from the previously described Aeromonas species by three or more properties. The strains are positive for motility, growth at 37 degrees C, indole production, and arginine dihydrolase activity. They exhibit negative reactions in tests for growth at 42 degrees C and in thiosulfate-citrate-bile salts-sucrose medium (Oxoid), Simmons citrate tests, and tests for lysine and ornithine decarboxylase activities. They produce acid from salicin but not from L-arabinose, D-cellobiose, or lactose. All four strains hydrolyze esculin and arbutin but not elastin. They use L-serine as a sole carbon and energy source but cannot utilize L-arabinose, L-arginine, D-gluconate, or L-glutamine. The strains are resistant to ampicillin. The guanine-plus-cytosine content of the DNA is 59.4 to 60.8 mol%. The name Aeromonas encheleia sp. nov. is proposed for these strains; strain S181 (= CECT 4342) is the type strain. This new species is generally not pathogenic for eels or mice.

Haloarcula quadrata sp. nov., a square, motile archaeon isolated from a brine pool in Sinai (Egypt)

The motile, predominantly square-shaped, red archaeon strain 801030/1T, isolated from a brine pool in the Sinai peninsula (Egypt), was characterized taxonomically. On the basis of its polar lipid composition, the nucleotide sequences of its two 16S rRNA genes, the DNA G+C content (60.1 mol%) and its growth characteristics, the isolate could be assigned to the genus Haloarcula. However, phylogenetic analysis of the two 16S rRNA genes detected in this organism and low DNA-DNA hybridization values with related Haloarcula species showed that strain 801030/1T is sufficiently different from the recognized Haloarcula species to warrant its designation as a new species. A new species, Haloarcula quadrata, is therefore proposed, with strain 801030/1T (= DSM 11927T) as the type strain.

Deleya salina sp. nov., a Moderately Halophilic Gram-Negative Bacterium

Deleya salina sp. nov., which was isolated from hypersaline habitats, is described. Our description is based on 26 strains that exhibit high levels of phenotypic similarity (simple matching coefficient, >74%) and DNA-DNA homology (<71%). The organisms are moderately halophilic gram-negative rods; growth occurs at salt concentrations between 2.5 and 20% (wt/vol) (optimal growth occurs at a salt concentration of 5% [wt/vol]). D. salina is aerobic, nonmotile, and catalase and oxidase positive. The cells accumulate poly-β-hydroxybutyrate, and the G+C contents of the DNAs range from 60.4 to 64.2 mol%. The type strain is strain F8-11 (= ATCC 49509).

Haloterrigena salina sp. nov., an extremely halophilic archaeon isolated from a salt lake

A novel extremely halophilic strain, designated XH-65(T), isolated from the salt lake Xilinhot in Inner Mongolia, PR China, was subjected to a polyphasic taxonomic characterization. Strain XH-65(T) is neutrophilic, non-motile and requires at least 2.5 M NaCl for growth, with an optimum at 3.4 M NaCl, and grows at pH 6.0-9.0, with optimum growth at pH 7.5. Strain XH-65(T) grows at 25-50 degrees C, with optimal growth at 37 degrees C. Magnesium is not required for growth. On the basis of 16S rRNA gene sequence analysis, strain XH-65(T) was shown to belong to the genus Haloterrigena and was related to Haloterrigena turkmenica VKM B-1734(T) (98.1 % sequence similarity), Haloterrigena saccharevitans AB14(T) (96.9 %), Haloterrigena thermotolerans PR5(T) (96.3 %), Haloterrigena limicola AX-7(T) (95.8 %) and Haloterrigena hispanica FP1(T) (95.7 %). DNA-DNA hybridization revealed 37 % relatedness between strain XH-65(T) and Htg. turkmenica VKM B-1734(T). The polar lipid composition revealed the presence of phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester and mannose-2,6-disulfate (1-->2)-glucose glycerol diether (S(2)-DGD). The results of the DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain XH-65(T) from the six Haloterrigena species with validly published names. Therefore, strain XH-65(T) represents a novel species, for which the name Haloterrigena salina sp. nov. is proposed, with the type strain XH-65(T) (=CGMCC 1.6203(T) =JCM 13891(T)).

Halopiger aswanensis sp. nov., a polymer- producing and extremely halophilic archaeon isolated from hypersaline soil

Strain 56(T) was isolated from a hypersaline soil in Aswan (Egypt). Cells were pleomorphic rods. The organism was neutrophilic, motile and required at least 1.7 M (10 % w/v) NaCl, but not MgCl(2), for growth; optimal growth occurred at > or =3.8 M (> or =22.5 %) NaCl. The strain was thermotolerant with an optimum temperature for growth of 40 degrees C, although growth was possible up to 55 degrees C. The G+C content of the DNA of the novel strain was 67.1 mol%. 16S rRNA gene sequence analysis revealed that strain 56(T) was a member of the phyletic group defined by the family Halobacteriaceae, showing the highest similarity to Halopiger xanaduensis SH-6(T) (99 %) and the next highest similarity of 94 % to other members of the family Halobacteriaceae. DNA-DNA hybridization revealed 27 % relatedness between strain 56(T) and Hpg. xanaduensis SH-6(T). Polar lipid analysis revealed the presence of the bis-sulfated glycolipid S(2)-DGD-1 as the sole glycolipid and the absence of the glycerol diether analogue phosphatidylglycerosulfate. Both C(20 x 20) and C(20 x 25) core lipids were present. Strain 56(T) accumulated large amounts of polyhydroxybutyrate and also secreted an exopolymer. Physiological and biochemical differences suggested that Hpg. xanaduanesis and strain 56(T) were sufficiently different to be separated into two distinct species. It is suggested that strain 56(T) represents a novel species of the genus Halopiger , for which the name Halopiger aswanensis sp. nov. is proposed. The type strain is strain 56(T) (=DSM 13151(T)=JCM 11628(T)).

DNA Relatedness among Aeromonas allosaccharophila Strains and DNA Hybridization Groups of the Genus Aeromonas

The genomic relatedness among three Aeromonas allosaccharophila strains, including the type strain, and other Aeromonas type and reference strains that were assigned to DNA hybridization groups was estimated by DNA-DNA hybridization (competition procedure using a membrane method). All A. allosaccharophila strains were highly related (70 to 100%) to strains 289T (= CECT 4199T) and ATCC 35942. Type strains of other validated Aeromonas species, reference strains of DNA groups 8 and 11, and the Aeromonas sp. strain ATCC 43946 (enteric group 501) were 0 to 41% related to A. allosaccharophila 289T and ATCC 35942. The G+Cs content of A. allosaccharophila strains were in the range 55.9 to 57.3 mol%. The G+C content of the type strain of this species was 56.9 mol%, a value somewhat lower than that reported in the original description.

Halorubrum kocurii sp nov., an archaeon isolated from a saline lake

A Gram-negative, non-motile, neutrophilic, rod-shaped, extremely halophilic archaeon, designated strain BG-1(T), was isolated from a salt lake, Lake Bagaejinnor, in Inner Mongolia, China. Strain BG-1(T) was able to grow at 25-55 degrees C, required at least 2.5 M NaCl for growth (with an optimum at 3.4 M NaCl) and grew at pH 6.0-9.0 (with an optimum at pH 7.5). Hypotonic treatment with less than 2.0 M NaCl caused cell lysis. Phylogenetic analysis of the almost-complete 16S rRNA gene sequence positioned the isolate within the genus Halorubrum in the family Halobacteriaceae. Strain BG-1(T) was most closely related to Halorubrum aidingense 31-hong(T) (98.8% sequence similarity), Halorubrum saccharovorum NCIMB 2081(T) (98.6%), Halorubrum lacusprofundi ACAM 34(T) (98.6%) and Halorubrum lipolyticum 9-3(T) (98.4%). However, values for DNA-DNA hybridization between strain BG-1(T) and the most closely related members of the genus Halorubrum were below 40%. Analysis of the polar lipids of strain BG-1(T) revealed the presence of mannosyl-2-sulfate-(1-4)-glycosyl-archaeol, the main glycolipid found in neutrophilic species of the genus Halorubrum. The G+C content of the genomic DNA was 69.4 mol% (T(m)). Comparison of the phenotypic characteristics of the strain with those of Halorubrum species supported the conclusion that BG-1(T) represents a novel species within this genus, for which the name Halorubrum kocurii sp. nov. is proposed. The type strain is BG-1(T) (=CECT 7322(T) =CGMCC 1.7018(T) =JCM 14978(T)).