Raymond D. Stapleton

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The bacterial community structure of the activated sludge from a 25 million-gal-per-day industrial wastewater treatment plant was investigated using rRNA analysis. 16S ribosomal DNA (rDNA) libraries were created from three sludge samples taken on different dates. Partial rRNA gene sequences were obtained for 46 rDNA clones, and nearly complete 16S rRNA(More)
The phenotypic and genotypic adaptation of a freshwater sedimentary microbial community to elevated (22 to 217 microgram [dry weight] of sediment-1) levels of polycyclic aromatic hydrocarbons (PAHs) was determined by using an integrated biomolecular approach. Central to the approach was the use of phospholipid fatty acid (PLFA) profiles to characterize the(More)
A multidisciplinary field study investigating the fate and transport of petroleum hydrocarbons commonly associated with jet-fuel contamination is currently underway at Columbus Air Force Base (AFB), Mississippi. Sixty sediment cores from 12 boreholes were recovered from the study aquifer. The goal of this initial sampling was to characterize the potential(More)
Subsurface sediments were recovered from two aquifers contaminated with petroleum hydrocarbons in order to isolate and characterize indigenous microorganisms capable of biodegrading fuel-related compounds. These sediments had been previously studied using catabolic gene probes providing putative demonstration of significant biodegradation potential. Based(More)
Polycyclic aromatic hydrocarbons (PAH) are widespread environmental contaminants that can, under proper conditions, be degraded by microorganisms. The responses of a riverine sedimentary microbial community to PAH contamination were examined using an integrated biochemical assay that yielded data on PAH concentration, total microbial biomass, and microbial(More)
Psychrotrophic (6 203C) enrichment cultures from deep Pacific marine sediments and Alaskan tundra permafrost reduced ferric iron when using organic acids or H2 as electron donors. The representative culture W3-7 from the Pacific sediments grew fastest at 103C, which was 5-fold faster than at 253C and more than 40-fold faster than at 43C. Fe(III) reduction(More)
Members of the genus Shewanella capable of reducing metals and forming minerals under cold-temperature conditions were isolated from 3 distinct marine habitats (the coast of Washington State, the Puget Sound, and an iron-rich microbial mat off Hawaii). Cultures of microorganisms were isolated at 8°C on nutrient agar medium prepared in artificial seawater.(More)
A marine psychrotolerant, dissimilatory Fe(III)-reducing bacterium, Shewanella sp. strain PV-4, from the microbial mat at a hydrothermal vent of Loihi Seamount in the Pacific Ocean has been further characterized, with emphases on metal reduction and iron biomineralization. The strain is able to reduce metals such as Fe(III), Co(III), Cr(VI), Mn(IV), and(More)
Evidence has shown that frequency and quantity of drug usage are reduced after treatment but the effect of opioid addiction treatment on alcohol consumption remains unclear. As part of the national Research Outcome Study in Ireland Evaluating drug treatment effectiveness (ROSIE, see www.nuim.ie/rosie) comprehensive drug and alcohol data on 404 opiate users(More)
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