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Effects of Methanol, Atrazine, and Copper on the Ultrastructure of Pseudokirchneriella Subcapitata (Selenastrum Capricornutum).

Description: The toxicity of methanol, atrazine, and copper to Pseudokirchneriella subcapitata (Korshikov) Hindák historically referred to as Selenastrum capricornutum Printz were determined following 96 hrs growth in a modified Goram's growth media. Methanol and atrazine inhibited fluorescence readings in the cultures by 50% (IC50) at concentrations of 2% and 82 µg/l respectively. These toxicity values compared favorably to other published reports. The IC50 for copper was 160 µg/l which is substantially higher than reported values. This is understandable because of the high chelating capacity of Goram's media. The use of stereologically derived relative volume in the chloroplasts, mitochondria, lipid bodies, phosphate bodies, and nucleus was investigated to determine if it could be used as a sensitive endpoint in toxicity tests. The volume fractions for the chloroplasts and mitochondria were normally distributed in control cells while the nuclei, phosphate bodies, and lipid bodies were not. The chloroplasts were the most dominate organelle occupying a mean relative volume of 46% and mitochondria occupied a mean relative volume of 3%. The nucleus and phosphate bodies occupied a median relative volume of 7% and 2% respectively. The lipid bodies were rare in section profile and no meaningful median relative volume could be calculated. Up to the 82nd percentile of sectioned profiles contained no recognizable lipid bodies. The use of relative volume was not a sensitive endpoint for use in toxicity tests. No significant differences in relative volume could be detected in the nucleus or phosphate bodies following any treatment. Limited differences were detected in the mitochondria, chloroplasts, and lipid bodies. The only significant differences that appear to be biologically significant occurred in methanol treated cells where an increase in the lipid bodies' relative volume was apparently concentration dependent. Significant differences in the relative volume of mitochondria and chloroplasts do not appear to be biologically significant.
Date: May 2004
Creator: Garrett, David C.
Partner: UNT Libraries

An Investigation of Algae and Common Tastes and Odors in Fresh Water

Description: The purpose of this investigation was to isolate and grow algae common to the southwest in unialgal culture; to either sustain or grow one of the principal bloom-causing organisms, with emphasis on Microcystis aeruginosa; to isolate and culture actinomycetes from the same waters from which the algae were obtained; and to inoculate these algae with actinomycetes and determine their effects through development and deterioration.
Date: 1956
Creator: Harmon, John C.
Partner: UNT Libraries

A Screening of Fungi for Metabolites Inhibitory to the Growth of Bloom-Forming Blue-Green Algae

Description: Since many approaches to dealing with algal blooms are inefficient, expensive, or harmful, it was concluded that a biologically-synthesized chemical agent, specifically inhibitory to pre-bloom algal cells, might prove helpful in controlling algal blooms. Fungi were chosen as the biological entities to investigate for such a chemical.
Date: December 1970
Creator: Hardcastle, Ronald V.
Partner: UNT Libraries

Ecological Studies of the Hudson River Near Indian Point

Description: "The general purpose of [this study is] to determine the ecological responses of the [Hudson] River to various classes of potential pollutants, so that the discharge of waste heat and radionuclides from the Indian Point Power Plant can be evaluated in context with these" (p. 1).
Date: April 1971
Creator: New York University. Medical Center. Institute of Environmental Medicine.
Partner: UNT Libraries

Effect of Indole-3-Acetic Acid on the Nucleic Acids of Synchronous Cultures of Chlorella Pyrenoidosa

Description: It was the purpose of this study to investigate the effect of various concentrations of IAA on the nucleic acids of Chlorella pyrenoidosa TX 7-11-05. The time during the life cycle when the greatest effect occurred was investigated by the use of synchronous cultures.
Date: May 1972
Creator: Peterson, James Arthur
Partner: UNT Libraries

A Qualitative Survey of the Airborne Algae, Protozoa, and Bacteria at the Denton Sewage Treatment Plant

Description: This study had a three-fold purpose. First, it was decided to determine if algae and protozoa were emitted to the air at the Denton sewage treatment plant. The information obtained could be of future importance in the fields of algal and protozoan ecology and public health. Second, it was decided to make a survey of the airborne bacteria at this plant. Some researchers have described bacterial air contamination at similar sewage treatment plants, but the one in Denton has not been studied. Third, it was hoped that in this research some relationships could be found between the bacteria and the algae and protozoa in the air in the vicinity of the sewage aeration basin. It was hypothesized that pathogenic bacteria were carried in the air with these other organisms.
Date: May 1968
Creator: Mahoney, Joseph L.
Partner: UNT Libraries

Evaluation of the Chlorophyll/Fluorescence Sensor of the YSI Multiprobe: Comparison to an Acetone Extraction Procedure

Description: The purpose of this study was to examine the suitability of the YSI model 6600 Environmental Monitoring System (multiprobe) for long term deployment at a site in Lewisville Lake, Texas. Specifically, agreement between a laboratory extraction procedure and the multiprobe chlorophyll/fluorescence readings was examined. Preliminary studies involved determining the best method for disrupting algal cells prior to analysis and examining the precision and linearity of the acetone extraction procedure. Cell disruption by mortar and pestle grinding was preferable to bath sonication. Comparison of the chlorophyll/fluorescence readings from the multiprobe and the extraction procedure indicated that they were significantly correlated but temperature dependent.
Date: May 2001
Creator: Lambert, Patricia
Partner: UNT Libraries

Integrated Assessment of Hypoxia in the Northern Gulf of Mexico

Description: This document details the ecological and economic effects of low oxygen (hypoxic) conditions in the Gulf of Mexico. This condition is caused by deforestation, river channelization, and the overuse of nitrogen in agricultural fertilizer. This document summarizes scientific evidence for the causes of hypoxia, the negative impact on Gulf of Mexico fisheries, and long-term national strategies for managing and mitigating the problem.
Date: May 2000
Creator: National Science and Technology Council (U.S.). Committee on Environment and Natural Resources.
Partner: UNT Libraries

Harmful Algal Blooms in US Waters

Description: This document discusses the causes of harmful algae blooms and their impact on the environment, public health, and the economy. The document also discusses options for managing algal blooms and current federal efforts to address the problem.
Date: October 2000
Creator: National Science and Technology Council (U.S.). Committee on Environment and Natural Resources.
Partner: UNT Libraries

Interaction of Legionella Pneumophila and selected algae and response to disinfectants

Description: Two species of cyanobacteria (Fischeralla sp. 29161 and Phormidium autumnale) and one species of green algae (Fritschiella tuberosa) were found to promote survival of Legionella pneumophila in mineral salts medium cocultures. During the early stage of incubation Fischerella sp. supported growth of Legionella pneumophila even though the bacteria would not grow in the algae-free basal medium.
Date: December 1985
Creator: Ko, Chi-mei
Partner: UNT Libraries