Browsing by Author "Geesey, Gill G."

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Addition of copper-sequestering agents to alginate gel to enhance copper recovery from aqueous media
(1995-11) Jang, Larry K.; Nguyen, Duy V.; Kolostyak, K.; Geesey, Gill G.
A mixture of sodium alginate and sodium polystyrenesulfonate (NaPSS) was used as the absorbent for copper in this work. A viscous solution of the mixture was dispensed into a copper-containing solution circulating in a loop fluidized bed reactor to form alginate gel in situ. Batch absorption data was treated by Langmuir model to yield copper binding capacity and binding stability constant. Results were compared with those of our previous work in which no NaPSS was added to Na-alginate. Based on the Langmuir parameters, the critical copper concentration above which the addition of NaPSS can enhance the copper loading of the alginate gel was calculated. The ratio of copper loading of the alginate gel with the addition of NaPSS to that without the addition of NaPSS at any copper concentration was predicted as well. Similar calculations were made for the case of using the mixture of Na-alginate and Microcystis as the copper absorbent.
Adhesion of biofilms to inert surfaces: a molecular level approach directed at the marine environments
(1996-09) Baty, Ace M.; Frolund, B.; Geesey, Gill G.; Langille, S. E.; Quintero, Ernesto J.; Suci, Peter A.; Weiner, R. M.
Protein/ligand interactions involved in mediating adhesion between microorganisms and biological surfaces have been well‐characterized in some cases (e.g. pathogen/host interactions). The strategies microorganisms employ for attachment to inert surfaces have not been so clearly elucidated. An experimental approach is presented which addresses the issues from the point of view of molecular interactions occurring at the interface.
Adhesive extracellular polymers of hyphomonas mhs-3: interaction of polysaccharides and proteins
(1995-12) Suci, Peter A.; Frolund, B.; Quintero, Ernesto J.; Weiner, R. M.; Geesey, Gill G.
The adsorption behavior of extracellular polymeric substances (EPS) from the marine bacterium Hyphomonas MHS‐3 was investigated using attenuated total reflection Fourier transform infrared (ATR/FT‐IR) spectrometry. The protein fraction of the crude EPS (EPSC) (propanol precipitated/extracted with EDTA) dominated the adsorption onto the germanium substratum. Removal of the Protease K accessible portion of the EPSC protein, and treatment with RNase and DNase, yielded a hygroscopic substance (EPSP) which contained at least one adhesive polysaccharide component. Conditioning the substratum with EPSC diminished adsorption of the polysaccharide fractions in EPSP; pre‐adsorbed EPSC protein was not displaced. The rate of EPSC adsorption on substrata conditioned with EPSP was slower than to clean germanium; however, the projected surface coverage of protein after long times, based on an empirical datafit, was the same as that for a clean substratum; the EPSC proteins did not displace the pre‐adsorbed adhesive polysaccharide fraction. SDS‐PAGE (Coomassie blue stain) revealed an extensive homology between proteins from cell lysates and EPSC proteins. However, distinct differences in the banding pattern suggested that proteins did not originate primarily from cell lysis during the extraction procedure. The results indicate that adhesive components of EPS, with respect to a hydrophilic surface (germanium), can be either protein or polysaccharide and that they may compete for interfacial binding sites.
Adsorption of adhesive proteins from the marine mussel, mytilus edulis, on polymer films in the hydrated state using angle dependent x-ray photoelectron spectroscopy and atomic force microscopy
(1997-10) Baty, Ace M.; Leavitt, P. K.; Siedlecki, C. A.; Tyler, Bonnie J.; Suci, Peter A.; Marchant, R. E.; Geesey, Gill G.
The adsorption of mussel adhesive protein (MAP) from the marine mussel Mytilus edulis has been investigated on polystyrene (PS) and poly(octadecyl methacrylate) (POMA) surfaces using angle dependent X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). AFM images previously published in the dehydrated state using contact mode are compared with images acquired in the hydrated state using fluid Tapping Mode to assess the contribution that hydration has on the architecture of the adsorbed proteins. To further characterize the adsorbed protein layer, XPS analysis was performed at liquid nitrogen (LN2) temperature without dehydrating the samples and at room temperature after the surfaces were dehydrated. The differences observed upon dehydration can be attributed to the strength of the interactions between MAP and the two surfaces. The AFM and XPS data indicate that adsorbed MAP is stabilized on the surface of the PS through interactions that prevent the protein layer from being disrupted upon dehydration. The adsorbed MAP on the POMA surface is representative of a loosely bound protein layer that becomes highly perturbed upon dehydration.
Application of epifluorescence microscopy to the enumeration of aquatic bacterial concentrated on membrane filters
(1981) Geesey, Gill G.; Costerton, J. William
Applications of Fourier Transform Infrared Spectrometry to Studies of Copper Corrosion under Bacterial Biofilms
(1990) Geesey, Gill G.; Bremer, Philip J.
Assessment of lead toxicity to desulfovibrio desulfuricans g20: influence of components of lactate c medium
(2001-08) Sani, Rajesh K.; Geesey, Gill G.; Peyton, Brent M.
The bioavailability and toxicity of lead (Pb) to Desulfovibrio desulfuricans G20 is greatly influenced by aqueous phase chemical composition. Apparent Pb toxicity is reduced by precipitation and complexation with chemicals found in standard growth media for sulfate-reducing bacteria (SRB). To determine the influence of medium composition on observed Pb toxicity, a new medium was developed to more accurately assess the toxicity of Pb to Desulfovibrio desulfuricans. The new medium, metal toxicity medium (MTM), eliminates abiotic Pb precipitation and minimizes formation of Pb complexes in solution. Significant growth of Desulfovibrio desulfuricans was observed on MTM in the absence of Pb, while no measurable growth was observed at 3 mg/1 Pb as PbCl2. For comparison, in Lactate C medium (Burlage et al., 1998) abiotic Pb precipitation was apparent, and the specific growth rate at 100 mg/1 Pb was only reduced by 8.1% compared to the Pb-free control. Toxicity was measured in terms of longer lag times and slower growth rates (including no growth) as compared to Pb-free controls. This report describes the effects of specific medium components on Pb toxicity to Desulfovibrio desulfuricans and provides a better baseline for comparison of natural and industrial waters for observing heavy metal toxicity on SRB.
Atomic force microscopy examination of the topography of a hydrated bacterial biofilm on a copper surface
(1992-04) Bremer, Philip J.; Geesey, Gill G.; Drake, B.
A bacterium, designated CCI#8, that was isolated from a corroded copper coupon colonized both polished and unpolished copper surfaces under batch culture conditions. Atomic Force Microscopy (AFM) images revealed that the biofilm was heterogeneous in nature, both in depth and in cell distribution. Bacterial cells were shown to be associated with pits on the surface of the unpolished copper coupons. These observations support previous studies that CCI#8 is associated with the pitting corrosion of copper.
Auger electron and x-ray photoelectron spectroscopic study of the biocorrosion of copper by alginic acid polysaccharide
(1989-08) Jolley, John G.; Geesey, Gill G.; Hankins, Michael R.; Wright, Randy B.; Wichlacz, Paul L.
Thin films (3.4 nm) of copper on germanium substrates were exposed to 2% alginic acid polysaccharide aqueous solution. Pre- and post-exposure characterization were done by Auger electron spectroscopy and X-ray photoelectron spectroscopy. Ancillary graphite furnace atomic absorption spectroscopy was used to monitor the removal process of the copper thin film from the germanium substrate. Results indicate that some of the copper was oxidized by the alginic acid solution. Some of the copper was removed from the Cu/Ge interface and incorporated into the polymer matrix. Thus, biocorrosion of copper was exhibited by the alginic acid polysaccharide.
Auger electron spectroscopy and x-ray photoelectron spectroscopy of the biocorrosion of copper by gum arabic, bacterial culture supernatant and Pseudomonas atlantica expolymer
(1988-04) Jolley, John G.; Geesey, Gill G.; Hankins, Michael R.; Wright, Randy B.; Wichlacz, Paul L.
Thin films (3.4 nm) of copper on germanium substrates were exposed to 10% gum arabic aqueous solution, 1% bacterial culture supernatant (BCS) (aqueous and simulated sea water solutions) and 0.5% Pseudomonas atlantica exopolymer (aqueous and simulated sea water solutions). Pre- and post-exposure characterization were done by Auger electron spectroscopy and x-ray photoelectron spectroscopy. Ancillary graphite furnace atomic absorption spectroscopy was used to monitor the removal process of the copper thin film from the germanium substrate. Results indicate that the copper was oxidized by the gum arabic and BCS, and some was removed from the Cu/Ge interface by all three polymers and incorporated into the polymer matrix. Thus, biocorrosion of copper was exhibited by the gum arabic, BCS and Pseudomonas atlantica exopolymer.
Bacterial behavior at surfaces
(2001-06) Geesey, Gill G.
Population level studies demonstrate that bacterial colonization of surfaces and subsequent biofilm architecture are controlled by a variety of factors that include the hydrodynamics, surface chemistry and genotype of the cell. New molecular tools now extend our ability to investigate among bacterial cells within a surface-associated population subtle phenotypic differences that do not involve changes in genotype. Such resolution has led to new discoveries in relationships between bacterial cells and their environment.
Bacterial biofilms in nature and disease
(1987-01) Costerton, J. William; Cheng, K. -J.; Geesey, Gill G.; Ladd, Timothy I.; Nickel, J. Curtis; Dasgupta, Mrinal; Marrie, Thomas J.
The growth of bacteria in pure cultures has been the mainstay of microbiologicaltechnique from the time of Pasteur to the present. Solid media techniques have allowed the isolation of individual species from complex natural populations. These pure isolates are intensively studied as they grow in batch cultures in nutrient-rich media. This experimental approach has served well in providing an increasingly accurate understanding of prokaryotic genetics and metabolism and in facilitating the isolation and identification of pathogens in a wide variety of diseases. Further, vaccines and antibiotics developed on the basis of in vitro data and tested on test-tube bacteria have provided a large measure of control of these pathogenic organisms.During the last two decades microbial ecologists have developed a series of exciting new techniques for the examination of bacteria growing in vivo, and often in situ, in natural environments and in pathogenic relationships with tissues. The data suggest that these organisms differ profoundly from cells of the same species grown in vitro. Brown & Williams (12) have shown that bacteria growing in infected tissues produce cell surface components not found on cells grown in vitro and that a whole spectrum of cell wall structures may be produced in cells of the same species in response to variations in nutrient status, surface growth, and other environmental factors (67). We and others (28) have used direct ecological methods to examine bacterial cells growing in natural and pathogenic ecosystems, and we find that many important populations grow in adherent biofilms and structured consortia that are not seen in pure cultures growing in nutrient-rich media. In fact, it is difficult to imagine actual natural or pathogenic ecosystems in which the bacteria would be as well nourished and as well protected as they are in single-species batch cultures.In this review we summarize and synthesize the data generated by the new direct methods of studying mixed natural bacterial populations in situ. Generally, morphological data give us a basic concept of community structure, direct bioch emical techniques monitor metabolic processes at the whole community level, and specific probes define cell surface structures in situ. Any in vitr o techniques used in these ecological studies are sel ected to mimic the natural ecosystem as closely as possible. In our estimation, data from studies of bacter ia growing in single-species batch cultures continue to be very valuable. However, these data represent a single, and perhaps unrepresentative, point in the broad spectrum of bacterial characteristics expressed in response to altered environmental factors. In retrospect, it may become apparent that the phenotypic plasticity of bacteri a (12, 107) and their ability to form structured and cooperative consortia will prove to be their most remarkable characteristics.
Bacterial Biofilms in Relation to Internal Corrosion Monitoring and Biocide Strategies
(1988) Costerton, J. William; Geesey, Gill G.; Jones, P. A.
This paper is a review of leading research in the field of bacterial corrosion monitoring with specific emphasis on systems that transport liquids rather than gases. However, the principles of bacterial corrosion presented below are universal and independent of whatever media is transported through the pipeline. It has now been established that the primary mechanism of bacterial corrosion of metal surfaces involves the creation, within an adherent biofilm, of local physiochemical ''corrosion cells''. The practical consequence of this perception is that we now know that bacteria must be in sustained contact with a metal surface, in well-organized microbial communities before the corrosion process is initiated. Decades of research in Aquatic Microbiology have shown that numbers and types of planktonic (floating) bacteria bear little relationship to the numbers and types of sessile (adherent) bacteria in biofilms in the same system, and that planktonic bacteria are much more susceptible to antibacterial agents than are their sessile counterparts.
Bacterial colonization of artificial substrate in the vicinity of deep-sea hydrothermal vents
(1998-06) Guezennec, J.; Ortega-Morales, O.; Raguenes, G.; Geesey, Gill G.
Artificial substrata of different material composition were deployed at deep-sea hydrothermal areas on the Mid-Atlantic Ridge for exposure times ranging from 1 to 12 days. After 4 days of exposure, a very thick but loosely-bound biofilm formed on all surfaces. Two bacterial morphotypes dominated the attached microbial community: rod-shaped bacteria sometimes several cell layers thick and large filamentous forms attached to the substratum at one end of the filament. Quantitative extraction of biofilm lipids associated with the substratum surface indicated the accumulation of a large amount of bacterial biomass after 4 days of exposure for all substrata. Microbial biomass accumulated at different rates on the different substrata. The greatest biomass was associated with 316L stainless steel and titanium substrata. Polar lipid fatty acid (PLFA) analysis of lipid extracts contained signatures of sulfate reducing bacteria and fatty acids (FA) previously reported in filamentous sulfur-oxidizing bacteria. The results demonstrate rapid in situ colonization of artificial substrata by hydrothermal vent microbial populations irrespective of the nature of the substratum.
Bacterially derived biopolymers as wood adhesives
(2004-12) Haag, Anthony P.; Maier, Raina M.; Combie, Joan; Geesey, Gill G.
The wood adhesive market is very large and problems due to volatile organic compounds and toxic chemicals in many adhesives and their production are signiﬁcant. In addition, most of the adhesives are derived from depleting petrochemical resources. An environmentally friendly wood adhesive based on renewable resources and produced by microbial fermentation has been explored. Using the shear block test method, a microbially produced polysaccharide has been tested and the effects of wood type, humidity, set time, partial acetylation, and surface wetting agents were determined. Shear strength of the microbial polysaccharide adhesive was compared to that of a commercial wood adhesive and other polysaccharides. Shear strengths of up to 20MPa (3000 psi) for bonding maple have been obtained at 53% relative humidity and 22ºC.
Bacterially derived wood adhesive
(2006-06) Haag, Anthony P.; Geesey, Gill G.; Mittelman, M. W.
Wood adhesives play an essential role in industry, however, many contain significant amounts of toxic components and volatile organic compounds (VOCs) and most are produced from depleting petrochemical resources. We are currently investigating adhesives derived from microbial extracellular polysaccharides for use in the wood products market. Polysaccharides are generally non-toxic, biodegradable, and produced from renewable resources. This study focuses on a new extracellular polysaccharide-based adhesive with performance that may be useful in some wood product applications. The adhesive exhibits improved performance over a previously described bacterial polysaccharide and produces shear strengths on maple substrates of up to 20 MPa at 53% relative humidity and 22 °C. Full strength was achieved in two days with half strength in 2 h. Although shear strength was sensitive to relative humidity, moisture resistance was substantially increased by partial acetylation of the polysaccharide.
Bacterially derived wood adhesive
(2006-06) Haag, Anthony P.; Geesey, Gill G.; Mittelman, M. W.
In an effort to improve AOAC Method 966.04, the Sporicidal Activity of Disinfectants Test, selected modifications to the procedure were evaluated in a collaborative study. Method 966.04 is used to generate efficacy data to support the product registration of sporicides and sterilants. The method is a carrier-based test that provides a qualitative measure of product efficacy against spores of Bacillus subtilis and Clostridium sporogenes. The use of garden soil extract and the lack of standard procedures for the enumeration of spores and neutralization of the test chemicals have been considered problematic for many years. The proposed modifications were limited to the B. subtilis and hard surface carrier (porcelain penicylinder) components of the method. The study included the evaluation of a replacement for soil extract nutrient broth and an establishment of a minimum spore titer per carrier, both considered crucial for the improvement and utilization of the method. Additionally, an alternative hard surface material and a neutralization confirmation procedure were evaluated. To determine the equivalence of the proposed alternatives to the standard method, 3 medium/carrier combinations, (1) soil extract nutrient broth/porcelain carrier (current method), (2) nutrient agar amended with 5 µg/mL manganese sulfate/porcelain carrier, and (3) nutrient agar amended with 5 µg/mL manganese sulfate/stainless steel carrier were analyzed for carrier counts, HCl resistance, efficacy, quantitative efficacy, and spore wash-off. The test chemicals used in the study represent 3 chemical classes and are commercially available antimicrobial liquid products: sodium hypochlorite (bleach), glutaraldehyde, and a combination of peracetic acid and hydrogen peroxide. Four laboratories participated in the study. The results of the spore titer per carrier, HCl resistance, efficacy, and wash-off studies demonstrate that amended nutrient agar in conjunction with the porcelain is comparable to the current method, soil extract nutrient broth/porcelain. The nutrient agar method is simple, inexpensive, reproducible, and provides an ample supply of high quality spores. Due to the current use of porcelain carriers for testing C. sporogenes, it is advisable to retain the use of porcelain carriers until stainless steel can be evaluated as a replacement carrier material for Clostridium. The evaluation of stainless steel for Clostridium has been initiated by the Study Director. Study Director recommendations for First Action revisions are provided in a modified method.
Binding of Metal Ions by Extracellular Polymers of Biofilm Bacteria
(1988-11) Geesey, Gill G.; Jang, Larry K.; Jolley, John G.; Hankins, Michael R.; Iwaoka, Teika; Griffiths, Peter R.
Exopolymers which anchor sessile bacteria to metallic surfaces exhibit the capacity to bind copper ions with high affinity. Ionized carboxyl groups on the polymers appear to participate in cupric ion binding. Formation of complexes between the polymers and cupric ions results in the release of protons from the polymer molecule. Attenuated total reflectance Fourier transform infrared spectroscopy showed that polymers composed of acidic polysaccharides promote ionization and deterioration of metallic copper surfaces. X-ray photoelectron spectroscopy studies revealed that the ionic state of the surface-derived copper varied depending on the type of acidic polysaccharide that was in contact with the surface. The results suggest that exopolymers elaborated by adherent bacteria can enhance corrosion of the surfaces with which they are associated.
Biocorrosion
(2000) Geesey, Gill G.; Beech, Iwona; Bremer, Philip J.; Webster, Barbara J.; Wells, D. Bret
Biofouling of engineered materials and systems
(2000) Geesey, Gill G.; Bryers, James D.