Environmental Microbiology and Microbial Ecology Commons^™

Survival Of Escherichia-Coli And Salmonella Spp In Estuarine Environments, Mw Rhodes, Hi Kator

VIMS Articles

Survival of Escherichia coli and Salmonella spp. in estuarine waters was compared over a variety of seasonal temperatures during in situ exposure in diffusion chambers. Sublethal stress was measured by both selective-versus-resuscitative enumeration procedures and an electrochemical detection method. E. coli and Salmonella spp. test suspensions, prepared to minimize sublethal injury, were exposed in a shallow tidal creek and at a site 7.1 km further downriver. Bacterial die-off and sublethal stress in filtered estuarine water were inversely related to water temperature. Salmonella spp. populations exhibited significantly less die-off and stress than did E. coli at water temperatures of <10°C. Although the most pronounced reductions (ca. 3 log units) in test bacteria occurred during seasonally warm temperatures in the presence of the autochthonous microbiota, 102 to 104 test cells per ml remained after 2 weeks of exposure to temperatures of >15°C. Reductions …

Characterization Of The Aquatic Environment In Lake Mead Near The Proposed Spring Canyon Pumped-Storage Project, And Assessment Of Potential Aquatic Impacts, Charles R. Liston, Stephen J. Grabowski, Bureau Of Reclamation

Publications (WR)

A pumped storage system consists of an upper reservoir and lower reservoir separated by an elevation difference. During low demand energy periods such as nights and weekends water is pumped from the lower to the upper reservoir using available energy from conventional steam electric power plants. During high energy demand periods, such as mornings and afternoons of weekdays, upper reservoir water is allowed to drop back down through the same system of water conduits and turbines, generating electricity to conveniently meet abrupt electrical energy requirements. The same water turbines thus act both as pumps and as conventional hydroelectric turbines.

Because …

Can We Guarantee The Safety Of Genetically Engineered Organisms In The Environment?, Kathleen H. Keeler, Frances E. Sharples

School of Biological Sciences: Faculty Publications

Can we guarantee the safety of genetically engineered organisms in the environment? To anticipate my remarks, the answer to the title question is “No, we cannot guarantee the safety of genetically engineered organisms released into the environment.” Indeed, it is a tenet of the scientific method that nothing can be proved, only disproved. Thus, we can never show that a release will be safe. We could only show that it would be unsafe, if that were the case. However, if the question is posed differently, for example, can we safely release genetically engineered organisms into the environment?, the answer is …

Propagation Of Adherent Bacteria On The Brittlestar Ophionereis Annulata (Le Conte) After Enrichment Of Seawater With Amino Acids, Michael A. Rice

Michael A Rice

Epidermal surfaces of the ophiouroid Ophionereis annulata (Le Conte) were examined by scanning electron microscopy. Microvilli, which are characteristic of many transport epithelia, are present on the epidermal surfaces. Epidermal surfaces of freshly-collected brittlestars were compared with brittlestars that were maintained in the laboratory for 48 hours in fresh seawater and in seawater enriched with 20uM glycine. Very few bacteria were observed on the surface of the freshly-collected animals or on animals maintained in the laboratory in fresh seawater. The epidermal surfaces of animals maintained in seawater enriched with 20 uM glycine showed extensive mats of coccoid and bacilloid bacteria. …