Bacterial particles and

Potcntiomctric Biosensors Potentiometric electrodes for the analysis of molecules of biochemical importance can be constructed in a fashion similar to that used for gas-sensing electrodes. The most common class of potentiometric biosensors are the so-called enzyme electrodes, in which an enzyme is trapped or immobilized at the surface of an ion-selective electrode. Reaction of the analyte with the enzyme produces a product whose concentration is monitored by the ion-selective electrode. Potentiometric biosensors have also been designed around other biologically active species, including antibodies, bacterial particles, tissue, and hormone receptors. 

Source Compiled from Cammann, K. Working with ion-Seiective Eiectrodes. Springer-Verlag Berlin, 1977 and Lunte, C. E. Heineman, W. R. "Electrochemical Techniques in Bioanalysis." In Steckham, E., ed. Topics in Current Chemistry, Vol. 143, Springer-Verlag Berlin, 1988, p. 8. - Abbreviations E = enzyme B = bacterial particle T = tissue. 

Under most circumstances microorganisms are attached to solid soil particles and await the arrival of water, nutrients, and electron acceptors. When the biomass is above the water table, the dependence is upon migration of nutrients and diffusion of oxygen downward (or upward via capillary action). Bacterial colonies that develop below the saturated zone are dependent upon liquid phases for the delivery of necessary growth media. 

Gram-negative Bacteria. The significant data are summarized in Table IV. Cinkotai et al. (11,12) showed that the prevalence of byssinotic symptoms correlated best with gram-negative rod counts in the total airborne dust from cardrooms of cotton mills. This correlation could be Increased by multiplying the bacterial counts by the years of exposure of the worker. These bacteria also correlated with the number of 2-4 ym particles and the amount of protease in the air. 

Dust particles inhaled in tobacco smoke, together with bronchial mucus, must be removed from the airways by the ciliated epithelium. Ciliary activity, however, is depressed by tobacco smoke mucociliary transport is impaired. This depression favors bacterial infection and contributes to the chronic bronchitis associated with regular smoking. Chronic injury to the bronchial mucosa could be an important causative factor in increasing the risk in smokers of death from bronchial carcinoma. 

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