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R P Ayala

Publications and source records attributed to R P Ayala.

10 recordsLinked to original sources
PubMed1978

Phosphate metabolism in blue-green bacteria. V. Factors affecting phosphate uptake in Plectonema boryanum.

Plectonema boryanum requires approximately 5 days of exposure to a culture medium lacking phosphorus to induce the "polyphosphate overplus" phenomenon. At pH9, phosphate uptake is greatest both from normal culture medium and from dilute salt solutions. Phosphate uptake from dilute salt solutions was greatest when Na+ or K+ are combined with Ca2+ or Ca2+ and Mg2+. Cells starved of phosphorus in the presence of a high concentration of K+ or Ca2+ in the medium, and then allowed to take up phosphorus under the same conditions, assimilate more phosphorus than with other major ions.

Cyanobacteria↗
PubMed1977

Fine structure of wall bodies in large cells of an Anabaena species.

A new type of inclusion in blue-green algae termed a wall body is described. These are elongate bodies of medium electron density, from 6 to 70 nm in thickness and at least 0.2 micrometer in depth found in large cells of Anabaena sp. B387. The bodies are up to 12 micrometer long, extending the complete length of the cell in some cases. Some of the bodies are bifurcated and the ends appeared to come in contact with the plasma membrane. The wall bodies lie at various angles in the cells. Up to six have been observed in a single thin section of a cell. The large cells are found in greater numbers in cultures grown in a medium solidified with agar. Comparison of the bodies to the mucopolymer layer (layer 2) of the cell wall is made.

Cell Membrane↗
PubMed1976

The fine structure of a microplate-microtubule array, microfilaments and polyhedral body associated microtubules in several species of Anabaena.

A microplate-microtubule array was observed in Anabaena sp. (B-378). This structure consists of an arched plate, about 8 nm thick, and various microtubules, 12 nm in diameter and 50 nm long, arranged in rows. The microtubules project at right angles from one side of the plate into the cytoplasm or towards the plasma membrane. Up to twelve microplate-microtubule arrays were observed in a single section of a cell. Microfilaments, about 2.8 nm in diameter and of undetermined length, were observed in four isolates of Anabaena. The microfilaments were always found in bundles, nwhich varied in size, up to 0.63 mum across and 0.91 mum long. Microtubules, 10 nm in diameter and about 150 nm in length, were observed associated with one facet of polyhedral bodies in 8 out of 20 isolates of Anabaena. The microtubules occurred in groups of up to 20 or more, and were always oriented with the long axis parallel to the facet of a polyhedral body. In cross section, the microtubules had an electron transparent lumen 5 nm wide and a wall 2.5 nm thick. These structures are compared to previously described microtubules and microfilaments.

Cyanobacteria↗