Browsing by Author "Trulear, Michael Gerald"

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Activity of Pseudomonas aeruginosa in Biofilms: Steady State
(1984-12) Bakke, Rune; Trulear, Michael Gerald; Robinson, J. A.; Characklis, William G.
Aerobic glucose metabolism by Pseudomonas aeruginosa in steady-state biofilms at various substrate loading rates and reactor dilution rates was investigated. Variables monitored were substrate (glucose), biofilm cellular density, biofilm extracellular polymeric substance (EPS) density, and suspended cellular and EPS concentrations. A mathematical model developed to describe the system was compared to experimental data. Intrinsic yield and rate coefficients included in the model were obtained from suspended continuous culture studies of glucose metabolism by P. aeruginosa. Experimental data compared well with the mathematical model, suggesting that P. aeruginosa does not behave differently in steady-state biofilm cultures, where diffusional resistance is negligible, than in suspended cultures. This implies that kinetic and stoichiometric coefficients for P. aeruginosa derived in suspended continuous culture can be used to describe steady-state biofilm processes.
Biofouling film development and its effects on energy losses: a laboratory study
(1980) Characklis, William G.; Bryers, James D.; Trulear, Michael Gerald; Zelver, Nick
Experiments on biofouling of tubes are reported. Processes leading to fouling biological film development are identified and the procedures used in the experimental work are described. Results concerning the growth of biofouling and its effects on fluid friction and heat transfer are presented.
Cellular reproduction and extracellular polymer formation by pseudonomas aeruginosa in continuous culture
(1984-12) Robinson, J. A.; Trulear, Michael Gerald; Characklis, William G.
The kinetics of cellular reproduction and the rate and extent of synthesis of extracellular polymeric substances (EPS) were investigated for P. aeruginosa growing in glucose-limited chemostats. μmax and Ks estimates of 0.4 h−1 and 2 mg glucose C/L, respectively, at 25°C were obtained for this bacterium. The extent of EPS formation was inversely related to the growth rate of P. aeruginosa. The rate of EPS formation had both growth- and non-growth-associated components. The growth-associated polymer formation rate coefficient (k) was 0.3 mg polymer C/mg cellular C and the non-growth-associated polymer formation rate coefficient (k′) was 0.04 mg polymer C/mg cellular C/h. The values for k and k′ must be regarded as provisional since the product formation data were quite variable at low dilution rates. Estimates of the cellular (Yx/s) and polymer (Yp/s) yield coefficients were 0.3 mg cellular C/mg glucose C and 0.6 mg polymer C/mg glucose C, respectively. Most of the non-growth-associated consumption of glucose detected was due to exopolymer formation.
Cellular reproduction and extracellular polymer formation in the development of biofilms
(Montana State University - Bozeman, College of Engineering, 1983) Trulear, Michael Gerald
Dynamics of biofilm processes
(1982-09) Trulear, Michael Gerald; Characklis, William G.
Biofilms can develop on almost any surface exposed to an aqueous environment. The biofilm systems that result can be used beneficially, as exemplified by fixed-film wastewater treatment processes (for example, trickling filters and rotating biological contactors). In addition, biofilms play a major positive role in stream purification processes. However, biofilms can be quite troublesome in certain engineering systems. In water distribution systems and heat transfer equipment, for example, biofilms can cause substantial energy losses resulting from increased fluid frictional resistance and increased heat transfer resistance. The significance of biofilm development on various processes is summarized.
Dynamics of biofilm processes
(1979) Trulear, Michael Gerald; Characklis, William G.
Dynamics of Biofilm Processes: Methods
(1982-01) Characklis, William G.; Bryers, James D.; Trulear, Michael Gerald; Zelver, Nick
Methods available for measuring biofilm accumulation are presented. The methods are conveniently classified as either direct or indirect measurement techniques. The direct techniques involve measurement of biofilm thickness or biofilm mass. The indirect measurement techniques include (1) methods for measuring specific biofilm constituents (e.g. polysaccharide) and (2) methods for determining microbial activity within the biofilm. These methods are discussed in relation to their use in both laboratory studies and in the field for continuous monitoring of biofilm processe
Fundamental considerations in biofouling control
(1980) Characklis, William G.; Trulear, Michael Gerald; Stathopoulos, N.; Chang, L. C.
The term fouling refers to the formatioin of inorganic and/or organic deposits on surfaces. In cooling systems, these deposits form on condenser tube walls increasing fluid frictional resistance, accelerating corrosion and impairing heat transfer Biological fouling, or biofouling, results form the attachment and growth of microbial organisms (microfouling) or macrobial organisms (macrofouling). This paper is directed at microbial fouling.
Fundamental Considerations of Fixed Film Systems
(1985) Characklis, William G.; Bakke, Rune; Trulear, Michael Gerald
Oxidation and Destruction of Microbial Films
(1980) Characklis, William G.; Trulear, Michael Gerald; Stathopoulos, N.; Chang, L. C.