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Full-Text Articles in Medicine and Health Sciences

Metal-Resistance Genetically Engineered Bacteria, Sylvia Daunert, Donna Scott, Sridhar Ramanathan Jun 1996

Metal-Resistance Genetically Engineered Bacteria, Sylvia Daunert, Donna Scott, Sridhar Ramanathan

KWRRI Research Reports

Bacterial-based electrochemical and optical sensing systems that respond in a highly selective and sensitive manner to antimonite and arsenite have been developed. This was accomplished by using genetically engineered bacteria bearing one of two plasmids constructed for our studies. The first plasmid, pBGD23, contains the operator/promoter region (O/P) and the gene of the ArsR protein from the ars operon upstream from the β-galactosidase gene. In the absence of antimonite/arsenite, ArsR binds to the 0/P site and prevents the transcription of the genes for ArsR and β-galactosidase, thus blocking expression of these proteins. When antimonite or arsenite is present in the …


Movement Of Bacteria Through Macropores To Ground Water, M. Scott Smith, Grant W. Thomas, Robert E. White Jun 1983

Movement Of Bacteria Through Macropores To Ground Water, M. Scott Smith, Grant W. Thomas, Robert E. White

KWRRI Research Reports

Effects of soil type, flow rate, antecedent soil moisture and other factors on transport of E. coli through soils was measured on disturbed and intact columns 20 cm in diameter by 25 to 30 cm in depth. Added E. coli were distinguished from indigenous microbes using an antibiotic resistance marker. Transport of Cl- and 3H2O was also measured. Up to 96 percent of the bacteria irrigated onto the surface of intact columns were recovered in the effluent. Soil structure appeared to be related to the extent of transport. Columns prepared from mixed, repacked soil were much …


The Aquatic Toxicity Of Organic Compounds To Embryo-Larval Stages Of Fish And Amphibians, Jeffrey A. Black, Wesley J. Birge, Willaim E. Mcdonnell, Albert G. Westerman, Barbara A. Ramey, Donald M. Bruser Mar 1982

The Aquatic Toxicity Of Organic Compounds To Embryo-Larval Stages Of Fish And Amphibians, Jeffrey A. Black, Wesley J. Birge, Willaim E. Mcdonnell, Albert G. Westerman, Barbara A. Ramey, Donald M. Bruser

KWRRI Research Reports

Aquatic toxicity tests were conducted on 11 organic compounds considered hazardous to water resources. The toxicity of each compound was evaluated using embryo-larval stages of two to eight fish and amphibian species. Exposure was initiated at fertilization and maintained through 4 days posthatching. The animal test species exhibited varying degrees of sensitivity to the selected toxicants. Combined frequencies for mortality and teratogenesis at 4 days posthatching gave LC50 ranges of 3.66 to 8.25 mg/L for benzene, 1.16 to 22.42 mg/L for carbon tetrachloride, 0.11 to 1.20 mg/L for chlorobenzene, 2.03 to > 68 mg/L for chloroform, 3.01 to 5.56 mg/L …


Low Pressure Membrane Separation Process To Remove Heavy Metal Complexes, Dibakar Bhattacharyya, Chin-Shun Cheng Sep 1981

Low Pressure Membrane Separation Process To Remove Heavy Metal Complexes, Dibakar Bhattacharyya, Chin-Shun Cheng

KWRRI Research Reports

The overall objective of this investigation is to establish the rejection behavior of heavy metals in the presence of complexing agents, utilizing negatively charged ultrafiltration membranes. An extensive experimental investigation is conducted with Zn2+, Cd2+, Cu2+, and Cu1+ in the presence of cyanide, ethylenediamine tetraacetic acid, and oxalates, under insignificant concentration polarization condition. The rejection dependence of the heavy metals is found to be a function of feed metal concentration, metal types, complexing agent to metal feed molar ratio, pH and ionic strength. The dependence of rejection behavior of heavy metals and complexing …


An Avoidance Response Bioassay For Aquatic Pollutants, Jeffrey A. Black, Wesley J. Birge Apr 1980

An Avoidance Response Bioassay For Aquatic Pollutants, Jeffrey A. Black, Wesley J. Birge

KWRRI Research Reports

Avoidance response bioassays were conducted with eight aquatic contaminants, including cadmium, copper, mercury, zinc, chloroform, dioctyl phthalate (DOP), trisodium nitrilotriacetic acid (NTA), and phenol. Tests were performed in a dual-channel fluviarium system, and the toxicant injection procedure used provided good regulation of exposure concentrations. Juvenile stages of largemouth bass (Micropterus salmoides), bluegill sunfish (Lepomis macrochirus), and rainbow trout (Salmo gairdneri), and tadpoles of the American toad (Bufo americanus) proved to be suitable animals for evaluating avoidance or attraction responses. The trout was the most sensitive species tested.

Avoidance was significant in tests …


Some Of The Effects Of Domestic Sewage Discharged Into Hickman And Jessamine Creeks In Jessamine County, Kentucky, Henry H. Howell, Mike W. Jones, Robert A. Kuehne Feb 1976

Some Of The Effects Of Domestic Sewage Discharged Into Hickman And Jessamine Creeks In Jessamine County, Kentucky, Henry H. Howell, Mike W. Jones, Robert A. Kuehne

KWRRI Research Reports

A 6-week study was made in the summer of 1971 as an initial effort to determine the extent of pollution that the three sewage disposal plants in Jessamine County, Kentucky, are contributing to its streams. With the rapid population increase in Lexington and nearby municipalities, this study should furnish a basis of comparison for future investigations. Eighteen collecting stations were established in riffle areas of Hickman and Jessamine Creeks, and coliform bacteria, macro-invertebrate populations, fish populations and chemical water quality of each riffle area were studied.

Hickman Creek's flow was augmented by approximately 3,100,000 gallons/day (11,735 -m3/day) from …


Metabolic Capabilities Of Sulfur Oxidizing Bacteria And Their Role In Water Pollution, M. I. H. Aleem Sep 1974

Metabolic Capabilities Of Sulfur Oxidizing Bacteria And Their Role In Water Pollution, M. I. H. Aleem

KWRRI Research Reports

This report describes investigations into the physiology of microorganisms that are commonly involved in the oxidation of inorganic sulfur compounds. The metabolic activities of these bacteria play a potent role in several fields of economic importance such as strip mining operations, water pollution, corrosion, metallurgy, petroleum technology and soil fertility processes.

The oxidation of inorganic sulfur compounds was studied in the chemolithotrophs Thiobacillus denitrificans, Thiobacillus A2, Thiobacillus neapolitanus, and a photolithotroph Rhodopseudomonas palustris. Cell suspensions from all of the thiobacilli catalyzed completely the oxidation of sulfide, thiosulfate, and sulfite to sulfate. The oxidation of thiosulfate in R. palustris …


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 …


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 Jan 1972

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 …


Metabolic Role Of Sulfates And Sulfides Producing Bacteria In Pollution Of Waters, M. I. H. Aleem Dec 1971

Metabolic Role Of Sulfates And Sulfides Producing Bacteria In Pollution Of Waters, M. I. H. Aleem

KWRRI Research Reports

Cytochrome transport particles from Nitrobacter catalyzed nitrite, ascorbate as well as NADH oxidation with concomitant phosphate esterification yielding P/0 ratios of 1.0, 0.6 and 2.0 respectively. Phosphorylation coupled to nitrite oxidation was not effected by rotenone, amytal or antimycin while 50 and 70% inhibition of the NADH-linked phosphorylation was observed in the presence of HOQNO and rotenone respectively. Cell-free extracts from Nitrobacter also catalyzed an energy-dependent reduction of NAD+ by nitrite. The reduction of cytochrome c by NŌ2 was energy-dependent which involved the reversal of electrons from cytochrome a1. The subsequent energy-linked reduction of the flavoproteins …


Procedures For Trace Analysis Of Dissolved Inorganic And Organic Constituents In Water, Gary D. Christian, Charles E. Matkovich, W. Lynn Schertz Jan 1971

Procedures For Trace Analysis Of Dissolved Inorganic And Organic Constituents In Water, Gary D. Christian, Charles E. Matkovich, W. Lynn Schertz

KWRRI Research Reports

A study of different solvent systems for the atomic absorption determination of cobalt revealed that acetone results in best sensitivity. Acetone is the solvent of choice for the sensitive measurement of several metals. Hence, methods were investigated for the separation of acetone from water by salting out so that possible solvent extraction of metal chelates into this solvent could be performed. About two-thirds saturated calcium chloride proved to be the best system for salting out of the acetone. It is essentially a neutral salt and is in general a weakly complexing salt, resulting in minimum interference in solvent extractions. Solvent …


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 …