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Full-Text Articles in Organisms

A Study Of Naturally Occurring Algicides Produced By Freshwater Algae, Denny O. Harris, Harry D. Caldwell Dec 1974

A Study Of Naturally Occurring Algicides Produced By Freshwater Algae, Denny O. Harris, Harry D. Caldwell

KWRRI Research Reports

The mode of action of the algicide produced by Pandorina morum was examined by exposing Volvox globator and isolates spinach chloroplasts to a partially purified algicide preparation. Oxygen evolution of Volvox, whole chloroplasts and broken chloroplasts (minus the Calvin cycle),was reduced indicating that the algicide inhibits the light reactions of photosynthesis. Oxygen evolution studies of other Volvocaceae confirmed the observation that Pandorina morum is not significantly influenced by its own inhibitor. Molecular weight approximation by gel filtration established that the inhibitor has a low molecular weight (probably below 100 mw). Field studies indicate that this algicide has tremendous potential as …


Carbon And Nitrogen As Regulators Of Algal Growth In Treated Sewage, Edward G. Foree, Charles Reece Scroggin Mar 1972

Carbon And Nitrogen As Regulators Of Algal Growth In Treated Sewage, Edward G. Foree, Charles Reece Scroggin

KWRRI Research Reports

Continuous flow algal cultures were grown under three different growth conditions using secondary sewage treatment plant effluent as the growth medium. The only variable within each run was the hydraulic residence time. The concentrations of growth regulating nutrients were varied between the runs so comparisons of the algal mass, composition, nutrient uptake, and genera could be made. The importance of CO2 availability for algal growth was also studied. A kinetic theory which based algal growth on cellular nutrient concentration was verified. The second phase of the study was a batch culture study in which the same growth medium was …


Algal Growth And Decomposition: Effects On Water Quality, Phase Ii, Edward G. Foree, Ronald L. Barrow Oct 1970

Algal Growth And Decomposition: Effects On Water Quality, Phase Ii, Edward G. Foree, Ronald L. Barrow

KWRRI Research Reports

The decomposition and associated nutrient regeneration of three unialgal cultures and one mixed culture containing an indigenous population of bacteria and microscopic animals were studied under dark, constant temperature laboratory conditions. After periods of nutrient-deficient growth ranging from O to 30 days, these cultures were inoculated with decomposer populations and subjected to anaerobic and aerobic environments for the decomposition studies. The extend of decomposition was determined from the percentage volatile suspended solids and percentage particulate COD remaining after 200 days of decomposition. The average extent of decomposition was greater for aerobic than for anaerobic conditions. However, significant portions of the …


Algal Growth And Decomposition: Effects On Water Quality, Edward G. Foree, John S. Tapp Jr. Mar 1970

Algal Growth And Decomposition: Effects On Water Quality, Edward G. Foree, John S. Tapp Jr.

KWRRI Research Reports

The chemical composition of algae grown in batch culture depends mainly on environmental conditions, nutrient availability, presence of predators, cell age, and species. The effects of nutrient availability and cell age on the composition of three unialgal cultures (algae + bacteria) and one hetergeneous culture (algae + bacteria + microscopic animals) were evaluated. The cultures were grown in batch culture under both nutrient-abundant and nutrient deficient conditions and the changes in compositions were observed. Luxurious uptake where nutrients are incorporated into cellular protoplasm at levels greater than those necessary for growth, and super-luxurious uptake, where some nutrients are stored rather …