Gill Geesey - Academia.edu (original) (raw)

Papers by Gill Geesey

Interactions of bacteria with metals in the aquatic environment

Applications of Fourier Transform Infrared Spectrometry to Studies of Copper Corrosion under Bacterial Biofilms

Marine Technology Society Journal, 1990

Applied and Environmental Microbiology, Sep 1, 1981

Cells of a psychrophilic marine bacterium were found to take up a variety of amino acids from sea... more Cells of a psychrophilic marine bacterium were found to take up a variety of amino acids from seawater. Some of the amino acids that were taken up were released when the cells were exposed to a hypotonic salt solution. The proportion that was released varied according t-, the amino acid. A pool of the amino acid arginine that was formed during very short periods of exposure of cells to the exogenously supplied amino acid was particularly sensitive to reductions in salinity. In general, exposure to hypotonic salt solutions also resulted in reduced amino acid uptake by the cells. Complete removal of seawater salts (SE treatment) produced obvious structural alterations in the cell envelope, resulting in an even greater reduction in amino acid uptake. Under these conditions, amino acidbinding components were released by the cells. Differential centrifugation and fluorescent antibody studies indicated that arginine-binding components are located on or near the surface of intact cells. The data suggest that substrate receptors were sensitive to reductions in seawater salt concentrations and that lesions at this level affected the organism's substrate uptake and retention capabilities.

Extracellular polymers for metal binding

Interactions between metal ions and capsular polymers

Applied and Environmental Microbiology, Nov 1, 1997

Reflected differential interference contrast microscopy and attenuated total reflection Fourier t... more Reflected differential interference contrast microscopy and attenuated total reflection Fourier transform infrared spectroscopy were used to obtain complementary data on the structural and chemical properties of a biofilm. This information was obtained nondestructively, quasisimultaneously, and in real time, thereby permitting the verification of time-dependent relationships between the biofilm's population structure, distribution, and interfacial chemistry. The approach offers opportunities to examine these relationships on a variety of substrata in the presence of a bulk aqueous phase under controlled hydrodynamic conditions.

HAL (Le Centre pour la Communication Scientifique Directe), 1987

BACTÊRIE drothermal côtier de White-Point, (Californie, USA) met en évidence la grande variété HY... more BACTÊRIE drothermal côtier de White-Point, (Californie, USA) met en évidence la grande variété HYDROTHERMALISME des types bactériens filamenteux qui le composent. Certains de ces filaments sont à MIXOTROPHIE rapprocher de ceux observés sur les sites hydrothermaux profonds, dont ils se distinguent toutefois par de plus grandes dimensions. Ainsi les filaments les plus larges, 76-100 Ltm, présentent des caractéristiques proches de celles de Beggiatoa, si ce n'est qu'ils semblent fixés à un substrat. Les Bactéries isolées à partir de ce tapis filamenteux sont mixotrophes, se développant aussi bien à partir d'un composé soufré, le thiosulfate, que de composés organiques. Les conditions classiques de culture n'ont pas permis un développement des formes filamenteuses et il apparaît que les peuplements mixtes se développent mieux en milieu inorganique que les souches isolées. FILAMENT ABSTRACT. ^=_Microscopic examination of the filamentous mats that occur around BACTERIA the coastal hydrothermal vent at White-Point (Southern California, USA) reveals the HYDROTHERMALISM high complexity of the filamentous bacterial communities. Some filaments are like MIXOTROPHY those described from the deep hydrothermal vents, except their biggest size. Indeed, the largest filaments, 76-100 um, are resembling Beggiatoa but they are not fixed on a substratum. The bacterial strains isolated from this site are mixotrophie, and grow on thiosulfate as well as on organic compounds. Common plate and liquid média did not allow cultivation of filamentous bacterial forms. Mixed cultures seemed to grow on inorganic substrates better than did the pure cultures.

Chemical characterization of deposits associated with microbiologically influenced copper corrosion in potable water systems

Application of epifluorescence microscopy to the enumeration of aquatic bacterial concentrated on membrane filters

Microbially influenced corrosion of materials used in the storage of spent nuclear fuels

International Biodeterioration & Biodegradation, 1996

Influence of surface features on microbial colonization and susceptibility to corrosion of stainless steels used in the food processing industry

Journal of Hydrologic Engineering, 2008

Reactive transport models contain terms describing microbiological and hydrological processes tha... more Reactive transport models contain terms describing microbiological and hydrological processes that control fate and transport of contaminants in porous media. Most models assume that microbial reaction rate is independent of microbial biomass distribution or that biomass is uniformly distributed across media surfaces in a manner that mass transport does not limit reaction rate. Experimental data, as well as some computational models, however, suggest otherwise, indicating a need to experimentally establish how the coupling of microbial biomass and flow distribution influence microbial reaction rates. Nuclear magnetic resonance techniques offer the opportunity to quantify in three dimensions the coupling of microbial biomass and flow velocity distribution in opaque porous media at multiple scales in a noninvasive manner. Experimental data obtained with these techniques can be used to improve the accuracy of boundary conditions used by reactive transport models to predict contaminant fate and transport at the pore and core scales. Further improvements in surface and subsurface magnetic resonance techniques may allow future detection and measurement of microbial biomass distribution in the subsurface at the field scale.

Clays and Clay Minerals, Oct 1, 2012

Mineralization of microbial biomass is a common phenomenon in geothermal habitats, but knowledge ... more Mineralization of microbial biomass is a common phenomenon in geothermal habitats, but knowledge of the structure of the minerals formed in these environments is limited. A combination of spectroscopic, microscopic, and stable isotopic methods, as well as the chemical analysis of spring water, were employed in the present study to characterize calcium carbonate minerals deposited in filamentous cyanobacterial mats in different locations of La Duke hot spring, a circumneutral thermal feature near the north entrance of Yellowstone National Park, Montana, USA. Calcite was the primary crystalline mineral phase associated with biofilm-containing deposits closest to the source of the spring and the suspended microbial biomass in a pool further from the source. The carbonate minerals at all sites occurred as aggregated granules, ~2 mm in diameter, in close association with the microbial biomass. Only in the deposits closest to the source were the granules organized as laminated structures interspersed with microbial biomass. The calcium carbonate grains contained two distinct regions: a dense monolithic calcite core and a porous dendritic periphery containing organic matter (OM). Electron energy loss spectroscopy (EELS) indicated that the voids were infilled with OM and carbonates. The EELS technique was employed to distinguish the source of carbon in the organic matter and carbonate mixture. The studies of carbon isotope compositions of the calcium carbonates and the saturation indices for calcite in the spring waters suggest that processes (abiotic vs. biotic) controlling the carbonate formation may vary among the sampling sites.

In Situ, Real-Time FT-IR/CIR/ATR Study of the Biocorrosion of Copper by Gum Arabic, Alginic Acid, Bacterial Culture Supernatant and Pseudomonas atlantica Exopolymer

Applied Spectroscopy, Aug 1, 1989

Thin films (2.0 nm) of copper on germanium internal reflection elements (IREs) were exposed to 10... more Thin films (2.0 nm) of copper on germanium internal reflection elements (IREs) were exposed to 10% gum arabic (aqueous solution), 2% alginic acid (aqueous solution), 1% bacterial culture supernatant (BCS, simulated seawater solution), and 0.5% Pseudomonas atlantica exopolymer (simulated seawater solution) and monitored in situ, real time, with the use of Fourier transform infrared/cylindrical internal reflection/attenuated total reflection spectroscopy as a function of time at ambient conditions. Ancillary graphite furnace atomic absorption spectroscopy was used to monitor the removal process of the copper thin film from the germanium IREs. Results indicate that some of the copper was removed from the Cu/Ge interface by all four polymers and incorporated into the polymer matrix. Thus, biocorrosion of copper was exhibited by the four polymers in the order of alginic acid < gum arabic < BCS > Pseudomonas atlantica exopolymer. The FT-IR/CIR/ATR technique can be successfully used to monitor biocorrosion systems in in situ, real-time settings.

Gene Expression of Cells Attached to Surfaces

Biofilms, 2000

Water pollution/marine and estuarine pollution

ABSTRACT

How Bacteria Stick

Scientific American, 1978

Adhesive Produced by Microorganisms

ACS Symposium Series, 2004

A water-based adhesive from non-petrochemical feedstock was produced by an efficient microbial fe... more A water-based adhesive from non-petrochemical feedstock was produced by an efficient microbial fermentation process. The adhesive was susceptible to water but very resistant to solvents such as jet fuel. After curing, theadhesive could be re-moistened and used again to bond surfaces together. Shear strength on anodized aluminum averaged 819 psi and tensile strength ranged from 500 to 1500 psi depending on the substrate and production method. The parent adhesive was modified to several water resistant forms which maintained good adhesive strength.

A sensitive chromatographic method for the detection of pyruvyl groups in microbial polymers from sediments

Microbial Ecology, 1990

A method was developed for the quantitation of pyruvyl groups in microbial polymers using mild ac... more A method was developed for the quantitation of pyruvyl groups in microbial polymers using mild acid hydrolysis, o-phenylenediamine labeling, reversed-phase high-performance liquid chromatography (RP-HPLC), and fluorescence detection. The method was used to determine the pyruvate content of various microbial exopolysaccharides and to estimate the abundance of polymeric pyruvate in freshwater sediments. The results of this method were compared with those of several other pyruvate assays. The detection limit of the method was 1.6 nmol pyruvate. As little as 3.7μg of the bacterial polysaccharide xanthan gum, or from 5 to 22 mg of sediment (depending on polymeric pyruvate content), were needed for detection and quantitation of polymeric pyruvate. The results should be useful in determining the contribution of polymeric pyruvate to total metal-binding ligands in sediments.