Organisms Commons^™

A Study Of Water-Soluble Inhibitory Compounds (Algicides) Produced By Fresh-Water Algae, Denny O. Harris, Manhar C. Parekh

KWRRI Research Reports

A complex system of growth inhibitors was observed in the green algae (Volvocaceae). Inhibitors were found in the culture filtrates of some genera which limit their own growth (autoinhibitors) while others in the family produce substances which check the growth of other genera (heteroinhibitors). These inhibitors were destroyed by autoclaving. It was decided that Pandorina morum, which produced the strongest inhibitor and Volvox tertius, the most sensitive to the inhibitor would make an excellent model system for a study of the chemical and physical properties of these naturally occurring algicides. The algicide could be removed from actively growing cultures about …

Phytoplankton Succession In The Lafayette River, Estuary, Norfolk, Virginia, Thomas W. Purcell Lll

Biological Sciences Theses & Dissertations

Abstract unavailable.

Experimentation To Develop Procedures To Be Used In The Investigation Of The Effects Of Restriction On The Unmodified Dna Of The Bacteriophage Lamda, John Haynes

Honors Theses

The results of experimentation approximately twenty years ago with variuos bacteriophages by Ralston and Krueger¹⁶, Anderson and Felix¹, Luria and Human¹², and by Bertani and Weigle² have shown that the host range of a given phage depends directly on the bacterial strain on which the phage has last propagated. This event came to be known as host-induced modification or host-controlled variation. As this phage host range is controlled by the host environment and can be altered from one generation to another it has, according to Luria, made microbiology "the last stronghold of Lamarckism" …

Factors Regulating The Growth Of Algae In Continuous Culture In Diluted Secondary Sewage Treatment Plant Effluent And Subsequent Biodegradability, Edward G. Foree, Caroline P. Wade

KWRRI Research Reports

Heterogeneous algal cultures were grown in laboratory continuous culture in continuous flow, completely mixed chemostats in secondary sewage treatment plant effluent diluted to give an ammonia nitrogen concentration of 10 mg/1. Variables were lighting, pH, carbon dioxide availability, and hydraulic residence time.

Optimum growth occurred under pH 7.0, excess CO₂, and continuous lighting conditions. The availability of artificially supplied excess CO₂ greatly increased the mass (standing crop) at steady-state over that produced under otherwise identical conditions for all residence times studied. For the case of excess CO₂ availability, the nitrogen concentration in the algal cells regulated …

Range And Optimum Growth Concentrations Of Phosphate And Nitrate For Chlamydomonas Reinhardtii, Thomas E. Hill

Masters Theses

A study was conducted on the alga Chlamydomonas reinhardtii to determine the range and optimum growth concentrations of phosphate and nitrate. There are only a few species of algae for which this type of data is known. Inorganic nutritional data is basic to the understanding of the complexities of phytoplankton ecology and eutrophication.

The "plus" strain of this heterothallic alga was cultured in a TRIS-buffered inorganic medium with various concentrations of sodium phosphate and potassium nitrate and adjusted to a pH of 7.4. The axenic cultures were evaluated at the end of 6 days with a spectrophotometer, at a wavelength …

The Role Of D-Gluconic Acid In The Regulation Of The Synthesis Of The Enzymes Of The Entner-Doudoroff Pathway In Pseudomonas Fluorescens, Steven C. Quay

Honors Theses

Induction of Entner-Duodoroff pathway enzymes in Pseudomonas fluorescens was investigated to study the role of gluconate as a possible inducer. Glucose oxidase-deficient mutants were isolated and characterized. One of these mutants, gox-7, was deficient in particulate glucose oxidase; another mutant, gox-17, was deficient in particulate glucose and gluconate oxidase activities. Gluconate, but not glucose, induced synthesis of gluconokinase and 6-phosphogluconate dehydratase in both mutants. High constitute levels of 2-keto-3-deoxy-6-phosphogluconate aldolase were found when both mutants were grown on glucose. Growth of parent and both mutant strains on glycerol also resulted in high levels of Entner-Doudoroff pathway enzymes. It was concluded …

The Duration Of The Effect Of Different Carbohydrates On Neutrophilic Phagocytosis, Judy L. Reeser

Loma Linda University Electronic Theses, Dissertations & Projects

In order to determine the duration of the effect of glucose, fructose, sucrose, honey, starch, and orange juice on neutrophilic phagocytosis, 10 subjects underwent a complete series of carbohydrate tolerance tests. Blood samples were drawn at specific time periods following ingestion of 100 grams of each carbohydrate. Blood was then analyzed for glucose and phagocytic index (the mean number of bacteria engulfed per leukocyte); a red blood cell and white blood cell count and differential white cell count were done also on about 1/2 of the samples. In addition, 7 other subjects participated in a fasting study in which no …

Molecular Weight Determinations Of Some Salmonella Potsdam Bacteriophage Dna's, Winston H. Richards

Loma Linda University Electronic Theses, Dissertations & Projects

Two group A phages, P9c/2 and P4/2, were studied. Their density, sedimentation velocity, and biochemical properties were compared. Their densities were determined by density gradient centrifugation in 38.3% cesium chloride. Sedimentation velocity was used to determine their molecular weights. To accomplish this, the DNA of P9c/2 and P4/2 was labeled with tritium and T₂ DNA, labeled with ³²P, was used as a standard. The DNA of P9c/2 and P4/2 was separately mixed with T₂ DNA and centrifuged in a 0-15% sucrose gradient. The molecular weights were calculated using the formula D₂/D₁= (M_{2 …}

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 …

Mastitis : Prevention And Control. 3. Implementing The Mastitis Control Programme, F C. Wilkinson

Journal of the Department of Agriculture, Western Australia, Series 4

FARMERS who have followed the first two articles in this series should by now have established the recommended milking routine and be familiar with it.

A Study Of Puccinia Graminis And Cronartium Ribicola, Duane W. Hughes

Graduate Student Research Papers

It was the purpose of this study (1) to review the literary history of rusts in the United States and in the Northwest in particular, ( 2) to learn where rusts generally are found geographically, (3) to gain further information regarding the etiology of wheat rust (Puccinia graminis tritici), of white pine blister rust (Cronartium ribicola) and to become enlightened on other rusts, (4) to learn ways of controlling the two rusts, black stem rust of wheat and white pine blister rust, and to gain an appreciation of the economic importance of rust prevention.

A Survey Of Typical And Atypical Mycobacteria Isolated From Human Specimens, Joseph Paul Truant

Henry Ford Hospital Medical Journal

No abstract provided.

Unusual Bacterial Isolates Obtained From A Variety Of Clinical Specimens, J. P. Truant

Henry Ford Hospital Medical Journal

No abstract provided.

Development Of Pleurotus Ulmarius Fr. Grown In Pure Culture, Delbert Swartz, J. D. Collar

Journal of the Arkansas Academy of Science

No abstract provided.

Absence Of Pasteurella Pestis In The Wildlife Of Arkansas, R. Reece Corey, Leo J. Paulissen, Delbert Swartz

Journal of the Arkansas Academy of Science

No abstract provided.

Further Studies On An Antibiotic Substance Produced By Rhizopus Nigricans Ehrenberg, Kenneth D. Mace, Delbert Swartz

Journal of the Arkansas Academy of Science

No abstract provided.

List Of The Smut Fungi Of Arkansas, George E. Templeton

Journal of the Arkansas Academy of Science

No abstract provided.

A Study Of The Bacteriological Effectiveness Of Oral Thermometer Procedures In Three Selected Hospitals, Esther Mae Rose

Loma Linda University Electronic Theses, Dissertations & Projects

Because pathogens such as streptococcus and staphylococcus have been transferred in many hospitals, the source of the infections is of concern to doctors, nurses, and other medical personnel. As shown by the review of literature, good techniques are necessary to stop the spread of disease.

It was the purpose of this study to investigate one facet of patient safety by: (1) the culture of thermometers ready for use in three selected hospitals; (2) to determine the effectiveness of the Group, Individual, and Central Supply methods of disinfection currently practiced in the three selected hospitals.

The method for the experiment of …

The Staphylococci, Joseph Paul Truant

Henry Ford Hospital Medical Journal

No abstract provided.

Antibiotic Substance Produced By Rhizopus Nigricans Ehrenberg, Billy Joe Williams

Journal of the Arkansas Academy of Science

No abstract provided.

Kidney Of The Frog, Felix Taubman

Bachelors’ Theses

The frog has been used exclusively in both high school and college as the main source of experimental biological and zoological studies. Because it is so easily obtained and so finely adapted to our purposes, we chose it as the specimen upon which to do our thesis work. Much has been done experimentally on the kidneys with the frog. The purpose of this thesis is to present a general view of the external and microscopic anatomy of the frog kidney and with this as a groundwork to present the problems of secretion; whether secretion is carried on by the renal …