Deoxyribonucleic acid relationships among marine vibrios pathogenic to fish

Michael H. Schiewe; Jorge H. Crosa; Erling J. Ordal

doi:10.1139/m77-142

Deoxyribonucleic acid relationships among marine vibrios pathogenic to fish

Canadian Journal of Microbiology ◽

10.1139/m77-142 ◽

1977 ◽

Vol 23 (8) ◽

pp. 954-958 ◽

Cited By ~ 26

Author(s):

Michael H. Schiewe ◽

Jorge H. Crosa ◽

Erling J. Ordal

Keyword(s):

Pacific Northwest ◽

Vibrio Anguillarum ◽

Significant Degree ◽

Dna Homology ◽

Homology Groups ◽

Dna Base ◽

The Pacific ◽

Related Group ◽

Marine Vibrios ◽

Sequence Relationships

Polynucleotide sequence relationships among 19 strains of marine vibrios, 15 of which were pathogenic to fish, were assessed by analysis of DNA–DNA homo- and hetero-duplexes with the endonuclease S1. DNA base compositions (mole% guanine–cytosine (GC) of selected vibrio strains were determined by thermal denaturation. Pathogenic strains from the Pacific Northwest had identical mole % GC but could be divided into two discrete, yet related, DNA-homology groups. One highly related group was typical of Vibrio anguillarum and showed greater than 70% within-group polynucleotide sequence homology. Second group (designated V1669) showed greater than 83% within-group homology but only about 60% relatedness to V. anguillarum. Neither group showed a significant degree of relatedness to V. parahaemolyticus (biotypes parahaemolyticus or alginolyticus) or to representative strains of any of the other previously described homology groups which we tested.

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A taxonomic study of the Spirillum lipoferum group, with descriptions of a new genus, Azospirillum gen. nov. and two species, Azospirillum lipoferum (Beijerinck) comb. nov. and Azospirillum brasilense sp. nov.

Canadian Journal of Microbiology ◽

10.1139/m78-160 ◽

1978 ◽

Vol 24 (8) ◽

pp. 967-980 ◽

Cited By ~ 498

Author(s):

Jeffrey J. Tarrand ◽

Noel R. Krieg ◽

Johanna Döbereiner

Keyword(s):

Thermal Denaturation ◽

New Genus ◽

Free Medium ◽

Dna Homology ◽

Azospirillum Lipoferum ◽

Dna Base Composition ◽

Homology Groups ◽

Group I ◽

Dna Base ◽

Group Ii

Sixty-one strains of the root-associated nitrogen fixer Spirillum lipoferum exhibited a similar morphology in peptone–succinate salts medium: vibrioid cells having a diameter of 1.0 μm. When grown in broth the cells had a single polar flagellum, but when grown on agar at 30 °C lateral flagella of shorter wavelength were also formed. The DNA base composition was 69–71 mol % guanine + cytosine when determined by thermal denaturation. DNA homology experiments indicated the occurrence of two distinct but related homology groups: 46 strains were in group I and 15 strains were in group II. Group II strains were distinguished by their ability to use glucose as a sole carbon source for growth in nitrogen-free medium, by their production of an acidic reaction in a peptone-based glucose medium, by their requirement for biotin, and by their formation of wider, longer, S-shaped or helical cells in semisolid nitrogen-free malate medium. The results indicate that two species exist, and on the basis of their characteristics it is proposed that they be assigned to a new genus, Azospirillum. Strains belonging to group II are named A.lipoferum (Beijerinck) comb, nov., while those belonging to group I are named A.brasilense sp. nov. Strain Sp 59b (ATCC 29707) is proposed as the neotype strain for A. lipoferum, and strain Sp 7 (ATCC 29145) is proposed as the type strain for A. brasilense.

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