College of Engineering
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The College of Engineering at Montana State University will serve the State of Montana and the nation by fostering lifelong learning, integrating learning and discovery, developing and sharing technical expertise, and empowering students to be tomorrow's leaders.
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Item Surfactant-enhanced bioremediation: a review of the effects of surfactants on the bioavailability of hydrophobic organic chemicals in soils(1999) Jordan, Ryan N.; Cunningham, Alfred B.Item 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.Item An observation of microbial cell accumulation in a finned tube(1983-12) Turakhia, Mukesh Harilal; Characklis, William G.Biofouling in heat exchange equipment results in significant energy loss by increasing heat transfer resistance and fluid frictional resistance. This paper compares the deposition and distribution of attached microbial cells on a smooth tube and a tube with inner fins after 100 hours exposure. Preliminary results suggest a significantly different distribution of attached microbial cells on the finned tube.Item Role of biofilms in neurosurgical device-related infections(2005-10) Baxton Jr, Ernest E.; Ehrlich, Garth D.; Hall-Stoodley, Luanne; Stoodley, Paul; Veeh, Rick; Fux, C. A.; Hu, Fen Z.; Quigley, Matthew; Post, J. C.Bacterial biofilms have recently been shown to be important in neurosurgical device-related infections. Because the concept of biofilms is novel to most practitioners, it is important to understand that both traditional pharmaceutical therapies and host defense mechanisms that are aimed at treating or overcoming free-swimming bacteria are largely ineffective against the sessile bacteria in a biofilm. Bacterial biofilms are complex surface-attached structures that are composed of an extruded extracellular matrix in which the individual bacteria are embedded. Superimposed on this physical architecture is a complex system of intercellular signaling, termed quorum sensing. These complex organizational features endow biofilms with numerous microenvironments and a concomitant number of distinct bacterial phenotypes. Each of the bacterial phenotypes within the biofilm displays a unique gene expression pattern tied to nutrient availability and waste transport. Such diversity provides the biofilm as a whole with an enormous survival advantage when compared to the individual component bacterial cells. Thus, it is appropriate to view the biofilm as a multicellular organism, akin to metazoan eukaryotic life. Bacterial biofilms are much hardier than free floating or planktonic bacteria and are primarily responsible for device-related infections. Now that basic research has demonstrated that the vast majority of bacteria exist in biofilms, the paradigm of biofilm-associated chronic infections is spreading to the clinical world. Understanding how these biofilm infections affect patients with neurosurgical devices is a prerequisite to developing strategies for their treatment and prevention.Item Effects of cell condition, pH, and temperature on lead, zinc, and copper sorption to Acidithiobacillus caldus strain BC13(2010-12) Aston, John E.; Apel, William A.; Lee, Brady D.; Peyton, Brent M.This study describes the effects of cell condition, pH, and temperature on lead, zinc, and copper sorption to Acidithiobacillus caldus strain BC13 with a Langmuir model. Copper exhibited the highest loading capacity, 4.76±0.28mmolg−1, to viable cells at pH 5.5. The highest kL(binding-site affinity) observed was 61.2±3.0 Lmmol−1 to dehydrated cells at pH 4.0. The pHs that maximized loading capacities and binding-site affinities were generally between 4.0 and 5.5, where the sum of free-proton and complexedmetal concentrations was near a minimum. Of additional importance, lead, zinc, and copper sorbed to viable cells at pH values as low as 1.5. Previous studies with other acidithiobacilli did not measure viablecell sorption below pH 4.0. In separate experiments, desorption studies showed that far less copper was recovered from viable cells than any other metal or cell condition, suggesting that uptake may play an important role in copper sorption by At. caldus strain BC13. To reflect an applied system, the sorption of metal mixtures was also studied. In these experiments, lead, zinc, and copper sorption from a tertiary mixture were 40.2±4.3%, 28.7±3.8%, and 91.3±3.0%, respectively, of that sorbed in single-metal systems.