scholarly journals Chromosomal transformation in the cyanobacterium Agmenellum quadruplicatum.

1990 ◽  
Vol 172 (4) ◽  
pp. 1916-1922 ◽  
Author(s):  
E Essich ◽  
S E Stevens ◽  
R D Porter
Keyword(s):  
Agmenellum Quadruplicatum

Effect of Iron Limitation on the Ultrastructure of Agmenellum Quadruplicatum

1981 ◽  
Vol 39 ◽  
pp. 410-411
Author(s):  
L. P. Hardie ◽  
D. L. Balkwill ◽  
S. E. Stevens
Keyword(s):  
Growth Medium ◽  
Green Alga ◽  
Natural Habitat ◽  
Iron Limitation ◽  
Natural Environments ◽  
Blue Green Alga ◽  
Marine Cyanobacterium ◽  
Natural Systems ◽  
Thin Sectioning ◽  
Agmenellum Quadruplicatum

Agmenellum quadruplicatum is a unicellular, non-nitrogen-fixing, marine cyanobacterium (blue-green alga). The ultrastructure of this organism, when grown in the laboratory with all necessary nutrients, has been characterized thoroughly. In contrast, little is known of its ultrastructure in the specific nutrient-limiting conditions typical of its natural habitat. Iron is one of the nutrients likely to limit this organism in such natural environments. It is also of great importance metabolically, being required for both photosynthesis and assimilation of nitrate. The purpose of this study was to assess the effects (if any) of iron limitation on the ultrastructure of A. quadruplicatum. It was part of a broader endeavor to elucidate the ultrastructure of cyanobacteria in natural systemsActively growing cells were placed in a growth medium containing 1% of its usual iron. The cultures were then sampled periodically for 10 days and prepared for thin sectioning TEM to assess the effects of iron limitation.

scholarly journals The glnA gene of the cyanobacterium Agmenellum quadruplicatum PR-6 is nonessential for ammonium assimilation.

1993 ◽  
Vol 175 (3) ◽  
pp. 604-612 ◽  
Author(s):  
S J Wagner ◽  
S P Thomas ◽  
R I Kaufman ◽  
B T Nixon ◽  
S E Stevens
Keyword(s):  
Ammonium Assimilation ◽  
Agmenellum Quadruplicatum

scholarly journals Carbon-13 NMR Studies of Salt Shock-Induced Carbohydrate Turnover in the Marine Cyanobacterium Agmenellum quadruplicatum

1986 ◽  
Vol 82 (3) ◽  
pp. 646-652 ◽  
Author(s):  
Elisha Tel-Or ◽  
Susan Spath ◽  
Lester Packer ◽  
Rolf J. Mehlhorn
Keyword(s):  
Nmr Studies ◽  
Marine Cyanobacterium ◽  
Salt Shock ◽  
Agmenellum Quadruplicatum

Cyanobacterial evolution: results of 16S ribosomal ribonucleic acid sequence analyses

1979 ◽  
Vol 57 (6) ◽  
pp. 879-888 ◽  
Author(s):  
L. Bonen ◽  
W. F. Doolittle ◽  
G. E. Fox
Keyword(s):  
Ribonucleic Acid ◽  
Phylogenetic Diversity ◽  
Filamentous Cyanobacteria ◽  
Sequence Analyses ◽  
Group Iii ◽  
Computer Aided ◽  
Agmenellum Quadruplicatum ◽  
Ribosomal Ribonucleic Acid ◽  
Red Algal

We report here the sequences of oligonucleotides released by T1-ribonuclease digestion of the 16S ribosomal RNA's (rRNA's) of the unicellular cyanobacteria Agmenellum quadruplicatum (strain BG-1) and Synechococcus 7502. We compare them with sequences previously obtained for the 16S rRNA's of six other cyanobacteria and two chloroplasts, and conclude that: (i) Synechocystis-like unicells form a discrete cluster which also (and surprisingly) includes Agmenellum quadruplicatum, usually considered to be a Synechococcus; (ii) filamentous cyanobacteria of the genera Nostoc and Fischerella arose from within the Synechocystis group; (iii) phylogenetic diversity (and hence presumably evolutionary antiquity) within the Synechococcus group is very great; and (iv) red algal chloroplasts are of definite cyanobacterial origin, while Euglena chloroplasts are of separate and quite possibly noncyanobacterial origin. We also present the results of a computer-aided search among the 10 oligonucleotide 'catalogues' for families of related but nonidentical sequences. Examination of these families reinforces the above conclusions.

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