RESULTS:
1 - 4 of 4 for "Roger Y. Stanier"
Genome Size of Cyanobacteria
Summary: The genome sizes of 128 strains of cyanobacteria representative of all major taxonomic groups lie in the range 1.6 × 109 to 8.6 × 109 daltons. The majority of unicellular cyanobacteria contain genomes of 1.6 × 109 to 2.7 × 109 daltons comparable in size to those of other bacteria whereas most pleurocapsalean and filamentous strains possess larger genomes. The genome sizes are discontinuously distributed into four distinct groups which have means of 2.2 × 109 3.6 × 109 5.0 × 109 and 7.4 × 109 daltons. The data suggest that genome evolution in cyanobacteria occurred by a series of duplications of a small ancestral genome and that the complex morphological organization characteristic of many cyanobacteria may have arisen as a result of this process.
Generic Assignments, Strain Histories and Properties of Pure Cultures of Cyanobacteria
Summary: On the basis of a comparative study of 178 strains of cyanobacteria representative of this group of prokaryotes revised definitions of many genera are proposed. Revisions are designed to permit the generic identification of cultures often difficult through use of the field-based system of phycological classification. The differential characters proposed are both constant and readily determinable in cultured material. The 22 genera recognized are placed in five sections each distinguished by a particular pattern of structure and development. Generic descriptions are accompanied by strain histories brief accounts of strain properties and illustrations; one or more reference strains are proposed for each genus. The collection on which this analysis was based has been deposited in the American Type Culture Collection where strains will be listed under the generic designations proposed here.
Deoxyribonucleic Acid Base Composition of Cyanobacteria
Summary: The DNA base compositions of 176 strains of cyanobacteria were determined by thermal denaturation or by CsCl density gradient centrifugation. A summary of all data now available for this prokaryotic group is presented and the taxonomic and evolutionary implications are discussed.
Proposal to reject the genus Hydrogenomonas: Taxonomic implications
Fifty-six strains of “hydrogen bacteria” and related nonautotrophic bacteria including nearly all existing named Hydrogenomonas spp. have been compared. It is proposed that the genus Hydrogenomonas should be rejected since its type species H. pantotropha appears to be a nomen dubium; and that the various species of “hydrogen bacteria” should be assigned to other genera not specifically characterized by the ability to grow autotrophically with H2.
The two species of hydrogen bacteria most frequently isolated by enrichment show a peritrichous or degenerate peritrichous flagellar arrangement; one is nonpigmented the other produces yellow (carotenoid) cellular pigments. Of the various possible generic assignments for these two species assignment to the genus Alcaligenes is proposed. The nonpigmented species previously named Hydrogenomonas eutropha but never legitimately described is here described as A. eutrophus. The yellow species which includes both facultatively autotrophic and nonautotrophic strains is described as a new species A. paradoxus. The Gram-negative coccoid hydrogen bacterium formerly known as Micrococcus denitrificans is placed in a new genus Paracoccus. The polarly flagellated species of hydrogen bacteria including the previously named species Hydrogenomonas facilis H. flava H. ruhlandii and Pseudomonassa saccharophila are all assigned to the genus Pseudomonas.