- Volume 34, Issue 4, 1984

Centraalbureau voor Schimmelcultures List of Cultures, 30th ed. Centraalbureau voor Schimmelcultures, Baarn, The Netherlands, 1983, xiii + 423 pp. Hfl. 35 (current U.S., $10.97); microfiche form, Hfl. 10 (current U.S., $3.13)

Vibrios in the Environment, ed. by Rita R. Colwell. John Wiley & Sons, New York, 1984, 621 pp., $45.00.

A total of 112 Neisseria gonorrhoeae strains representing protein I serogroups WI, WII, and Will and six auxotypes were tested for their ability to reduce nitrite. All strains reduced 0.001% (wt/vol) potassium nitrite (KNO2) within 24 h and 0.01% (wt/vol) KNO2 within 48 h. None of the strains reduced 0.1% (wt/vol) KNO2 even after incubation at 37°C for 5 days, and the strains could not be cultured from these tests after incubation for 24 h. Thus, all of the N. gonorrhoeae strains tested were nitrite sensitive but were able to reduce subtoxic concentrations of KNO2. Nitrite reduction is a species characteristic for N. gonorrhoeae.

A collection of 30 clones derived from 20 luminous and nonluminous Xenorhabdus strains was studied by using deoxyribonucleic acid (DNA) relatedness and electron microscopy, as well as growth factor requirement, nutritional ability, and other biochemical tests. Nonluminous Xenorhabdus cells each contained a crystal-like structure, whereas the cells of luminous strains each contained an accumulation of amorphous material associated with mesosomes and microtubules of unknown function. Two DNA relatedness groups of nonluminous strains were delineated, one of which corresponded to Xenorhabdus nematophilus, a species associated with the nematode Steinernema feltiae (= Neoplectana carpocapsae). The other group contained yellow-pigmented bacteria associated with Steinernema bibionis and new Steinernema species. No definite phenotypic characteristic (except pigmentation) separated the two DNA relatedness groups of nonluminous Xenorhabdus strains. Four DNA relatedness groups were delineated among the luminous clones studied. These four groups could be separated by biochemical tests. Unfortunately, different clones derived from the same strain belonged to different DNA relatedness groups. This happened with the type strain of Xenorhabdus luminescens.

A mycoplasma designated strain 383T(T = type strain) was isolated from the cloaca of a turkey poult. After examination of its morphological, physical, and cultural properties this organism was assigned to the class Mollicutes, order Mycoplasmatales. The base composition of its deoxyribonucleic acid was 26.0 mol% guanine plus cytosine. Strain 383T was dependent on sterol for growth and was inhibited by digitonin. Since it gave no evidence of helical forms or of urea hydrolysis, it was assigned to the family Mycoplasmataceae, genus Mycoplasma. This organism hydrolyzed arginine and reduced triphenyltetrazolium chloride under anaerobic conditions, but other biochemical tests were negative. Strain 383T could not be identified as any of 83 currently accepted Mycoplasma. species or serovars by growth inhibition, immunofluorescence, immunodiffusion, or metabolism inhibition tests. Thus, this mycoplasma appears to be a new species, for which we propose the name Mycoplasma cloacale; the type strain is strain 383 (= NCTC 10199 = ATCC 35276).

The name Lactobacillus piscicola sp. nov. is proposed for a group of 17 bacterial strains that were isolated from diseased rainbow trout (Salmo gairdneri), cutthroat trout (Salmo clarki), and chinook salmon (Oncorhynchus tshawytscha). This bacterium was found most frequently in infected fish which had suffered some form of stress, such as that which occurs at spawning. Occasionally, pathological signs in the internal organs or skin were observed. Phenotypically, L. piscicola belongs to the family Lactobacillaceae and can be distinguished from other species of Lactobacillus by its morphology and physiological characteristics. dl-Lactic acid was produced homofermentatively from glucose. Diaminopimelic acid was present in the cell wall peptidoglycan. The 17 isolates were closely related genetically, as demonstrated by similar percent guanine-plus-cytosine contents (35 mol%) and high deoxyribonucleic acid reassociation values, both characteristics of a single species. The isolates exhibited less than 10% deoxyribonucleic acid reassociation with other reference Lactobacillus strains with similar guanine-plus-cytosine contents. Strain B270 (= ATCC 35586), which was isolated in 1970 from diseased cutthroat brood trout at Bandon Hatchery in Oregon, is designated the type strain of this new species of Lactobacillus.

Analysis with anti-Mycobacterium bovis BCG and anti-M. bovis Ravenel sera, absorption tests with anti-η antibody, and the failure to detect any factor that affected η antigenic activity in M. bovis BCG or strain H37Ra confirmed the absence of η precipitinogen in M. bovis BCG and Ravenel. No η-positive strains were found among 7 strains of M. bovis, 19 representative strains of 15 mycobacterial species other than Mycobacterium tuberculosis and M. bovis, or 13 niacin-negative strains of mycobacteria isolated from patients. However, η activity was detected in all 9 laboratory strains of M. tuberculosis tested, including virulent and avirulent strains, and in 29 of 30 niacin-positive strains isolated from patients, including 15 strains with single or multiple resistance to seven drugs.

Alkalophilic actinomycete strains were examined to determine their taxonomic position. These organisms, which were isolated from Japanese soils, are capable of growing in synthetic and organic media between pH 7.0 and 11.0, but not at pH 6.5. Best growth is obtained between pH 9.0 and 10.0. Aerial mycelium is abundantly formed, and this mycelium fragments into long chains of smooth walled ectospores of varying lengths. Whole cells contain raeso-diaminopimelic acid and phosphatidylcholine, but not diagnostically important sugars. Glycine is not detected in cell walls. The major menaquinones are MK-10; they contain iso, anteiso, and unsaturated odd-numbered fatty acids. The results of biochemical, cultural, and physiological tests suggest that the strains which we examined are closely related to Nocardiopsis dassonvillei Meyer. However, these strains consistently differ from other strains of N. dassonvillei (utilize maltose and rhamnose; grow at high pH), so we propose that they are a new subspecies of Nocardiopsis dassonvillei. The type strain of Nocardiopsis dassonvillei subsp. prasina subsp. nov. is strain 208 (= JCM 3336).

Because the name Bacillus pulvifaciens Katznelson 1950 was excluded from the Approved Lists of Bacterial Names, it has lost standing in bacteriological nomenclature. Based on deoxyribonucleic acid relatedness analyses, 24 weakly catalase-positive strains of “B. pulvifaciens” could be separated into two genotypically distinct groups. Because the larger group of 17 isolates included strains with high levels of deoxyribonucleic acid relatedness (80 to 100%) to a reference strain originally isolated and studied by Katznelson, this group was considered to represent the species as first described. This group was phenotypically homogeneous. Moreover, it was not genetically or phenotypically related to members of the smaller deoxyribonucleic acid relatedness group or to the type strains of Bacillus alvei, Bacillus larvae, and Bacillus laterosporus, species that are frequently associated with diseased honeybee larvae. Based on the results of this study, the revival of the name Bacillus pulvifaciens is proposed. The type strain is strain NRRL B-3685.

Like all members of the genus Thioploca, two new marine thioplocas from the benthos of the Chilean continental shelf were found to be colonial, multicellular, gliding trichomes of uniform diameter enclosed by a common sheath. However, the cellular sulfur inclusions were located in the thin peripheral cytoplasm surrounding a large, central vacuole. Gliding motility of these organisms did not persist in diluted seawater, under fully aerobic conditions, or in anaerobic atmospheres. Low concentrations of sulfide (100 μM) were beneficial. The trichome diameters of Thioploca araucae ranged from 30 to 43 μm, and those of Thioploca chileae ranged from 12 to 20 μm. Neither species has been isolated in pure culture.

The genus Acetivibrio is emended to include nonmotile, gram-negative, obligately anaerobic rods that produce acetic acid and ethanol from fermentation of carbohydrates. A new species, Acetivibrio cellulosolvens, which was isolated from a cellulose-enriched culture of sludge, is described. The colonies on agar are entire, raised, and cream colored. The cells are straight rods, gram-negative, nonsporeforming, and nonmotile. The isolate which we studied ferments cellobiose, cellulose, esculin, and salicin and does not require yeast extract or rumen fluid for growth. The major end products produced from cellobiose or cellulose are acetic acid, ethanol, CO2, and H2. Lactic acid and glucose also are produced in small amounts. The type strain of A. cellulosolvens is strains BAS (= NRC 2936).

Deoxyribonucleic acid (DNA) was extracted from mycobacterial cells by gentle lysis (sodium dodecyl sulfate and pronase treatment) of wall-deficient forms obtained after d-cycloserine and glycine treatment. DNA from Mycobacterium fallax CIP 8139T (= ATCC 352191) (T = type strain) was 3H-labeled by nick-translation. DNA relatedness studies (S1 nuclease method) showed that the seven M. fallax strains studied form a single DNA hybridization group which is less than 25% related to 16 other species of the genus Mycobacterium. The guanine-plus-cytosine content of M. fallax DNA was 68 mol%, and the guanine-plus-cytosine contents of Mycobacterium aurum, Mycobacterium chitae, Mycobacterium duvalii, Mycobacterium flavescens, Mycobacterium gilvum, Mycobacterium neoaurum, Mycobacterium parafortuitum, Mycobacterium thermoresistibile, and Mycobacterium vaccae DNAs were 64 to 65 mol%.

A species of the new genus Saccharothrix is described under the name Saccharothrix australiensis sp. nov. This aerobic genus is characterized by fragmentation of both the vegetative and aerial mycelia into ovoid elements and the following novel cell chemistry: type III cell wall (meso-diaminopimelic acid present); galactose and rhamnose present as characteristic whole-cell sugars; absence of nocardomycolic acids; and type PII phospholipid pattern. The guanine-plus-cytosine content of the deoxyribonucleic acid is 73 mol%. The type strain of Saccharothrix australiensis is strain LL-BM782Ce82 (= ATCC 31947 = NRRL 11239).

The effects of pH, temperature, the presence or absence of glucose and cellobiose, and culture medium on cellulase synthesis or activity or both by 12 strains of Cellulomonas were compared. The liquefaction of carboxymethyl cellulose (CMC) gels by eight of the strains was examined. The optimum temperature for hydrolysis of CMC during growth was 40°C, and the optimum pH was 7 to 7.5. The eight strains broke into two distinct groups with a fourfold difference in rates of CMC or filter paper hydrolysis during growth. The presence of either glucose or cellobiose in the culture medium stimulated growth but repressed either the synthesis or the activity of CMC and filter paper cellulases. This effect is the opposite of that reported previously for Bacillus CMC cellulase. The greatest rate of filter paper hydrolysis occurred in a synthetic medium. The cell-free carboxymethylcellulase of Cellulomonas flavigena ATCC 482T was partially purified by molecular exclusion chromatography on Bio-Gel P-100 and Sephadex G-75. The partially purified enzyme had a molecular weight of 40,000 and optimum activity at pH 7.0. Cellobiose was a competitive inhibitor of the enzyme activity. The results obtained with the partially purified enzyme indicated that the results obtained by using CMC gels were valid.

Of 30 Actinomyces strains isolated from infections in dogs, 15 were found to have galactose, glucose, and rhamnose in their cell wall carbohydrates, whereas the remainder had only galactose and glucose. No 6-deoxytalose was detected in any of our analyses. The biochemical characteristics of the rhamnose-positive strains deficient in 6-deoxytalose were similar to those of Actinomyces viscosus ATCC 19246 and ATCC 27045, a reference dog strain. In contrast, the 15 strains having only galactose and glucose in their wall carbohydrates had biochemical and serological characteristics unlike those of any previously accepted species of Actinomyces. The name Actinomyces hordeovulneris sp. nov. is proposed for this organism which is associated with thoracic, abdominal, or recurrent localized infections that sometimes are associated with awns of foxtails (Hordeum spp). The type strain of A. hordeovulneris is strain ATCC 35275 (= UCD 81-332-9).

The phylogenetic relationships among seven strains of methylotrophic methane-producing bacteria were determined by ribosomal ribonucleic acid hybridization and deoxyribonucleic acid homology techniques. The strains tested had deoxyribonucleic acid guanine-plus-cytosine contents of 39 to 43 mol% and represented a diversity of phenotypic characteristics. Our results indicate that these strains should be divided into six species within the genera Methanosarcina, Methanolobus, and Methanococcoides. The genus Methanosarcina includes Methanosarcina barkeri strains MS and 227, Methanosarcina sp. strain TM-1, Methanosarcina acetivorans strain C2A, and Methanosarcina mazei strain S-6. The genus Methanolobus is represented by Methanolobus tindarius strain Tindari 3, and the genus Methanococcoides is represented by Methanococcoides methylutens strain TMA-10. Despite phenotypic similarities between Methanolobus tindarius and Methanococcoides methylutens, we propose that these species remain in separate genera based on differences in ribosomal ribonucleic acid homology and fractional differences in midpoint temperatures. The divisions indicated by deoxyribonucleic acid homology experiments complemented the ribosomal ribonucleic acid hybridization results. Phenotypic characteristics were consistent with these phylogenetic divisions; an apparent exception was cell wall composition, which is a conserved trait. Methanosarcina acetivorans had only a thin protein cell wall, but all other strans of Methanosarcina previously studied have been reported to have heteropolysaccharide cell walls. We present evidence which indicates that a protein component may be associated with the heteropolysaccharide cell wall of Methanosarcina barkeri strain 227.

A new species, Bacillus azotofixans, is described. This taxon is based upon 16 soil and root-associated strains that exhibit acetylene-reducing ability and nitrogen-fixing Bacillus sp. strain Hino. B. azotofixans is phenotypically similar to Bacillus polymyxa and Bacillus macerans. However, 13 tests (nitrate reduction; production of acid and gas from xylose, arabinose, lactose, ribose, and glycerol; resistance to lysozyme; liquefaction of gelatin; starch hydrolysis; decomposition of casein and pectin; production of dihydroxyacetone; susceptibility to B. polymyxa phages) differentiate it from B. polymyxa, and 12 characteristics (spore position; Voges-Proskauer test; nitrate reduction; production of acid and gas from xylose, arabinose, lactose, ribose, and glycerol; growth at 45°C; hydrolysis of starch; decomposition of pectin; formation of crystalline dextrins) differentiate it from B. macerans. The guanine-plus-cytosine contents of five strains ranged from 47.9 to 52.5 mol%. All strains reduced acetylene much more efficiently than B.polymyxa or B. macerans. In four strains, nitrogen fixation was confirmed by micro-Kjeldahl analysis of acetylene-reducing cultures. Acetylene reduction was not inhibited by nitrate and was not dependent on yeast extract or thiamin plus biotin. The proposed type strain of B. azotofixans is strain P3L-5 (= ATCC 35681).

A new species, Treponema socranskii, and three new subspecies, T. socranskii subsp. socranskii, T. socranskii subsp. buccale, and T. socranskii subsp. paredis, which were isolated from supragingival and subgingival samples from patients with periodontitis and from patients with experimental gingivitis, are described. These organisms are treponemes that ferment carbohydrates and require rumen fluid or shortchain volatile fatty acids for growth. Fermentable carbohydrates are required as an energy source. The major products of fermentation are acetic, lactic, and succinic acids. Trace amounts of formic acid are also produced. The level of deoxyribonucleic acid-deoxyribonucleic acid homology within each subspecies is greater than 80%, whereas the level of homology between subspecies is about 60%. The average guanineplus-cytosine content of the deoxyribonucleic acid is 51 ± 1 mol%. The type strain of T. socranskii is strain ATCC 35536 (= VPI DR56BRIII6); the type strain of T. socranskii subsp. buccale is strain ATCC 35534 (= VPI D2B8); and the type strain T. socranskii subsp. paredis is strain ATCC 35535 (= VPI D46CPE1).