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The primary energy source for the growth of the Acidithiobacillus ferrooxidans is derived from the anaerobic respiration, in which the iron or sulfur serves as an electron acceptor with hydrogen or sulfur serving as an electron donor. Data indicate that the respiratory process is coupled to a c-type cytochrome oxidation.

The direct electrodeposition of glucose oxidase (EC 1.1.3.4) on a platinum electrode was investigated as a means for controlled immobilization. The presence of a nonionic detergent, Triton X-100, was found essential to produce a multilayered deposit. Moreover, to work properly, the detergent must be present above its critical micelle concentration. Under these conditions, a deposit of ~50 enzyme layers (480 nm), with surface uniformity of [+ or -] 20 nm, was verified using an electrochemical quartz crystal microbalance and by atomic force microscopy. In the absence of detergent, a layer of 25 nm is formed. Contrary to most previous claims, the deposition, which is potential dependent but optimal at 1.3 V versus AgCl/ Ag electrode, is not electrophoretically driven, but is instead controlled by a lowering of the pH at the electrode surface due to concomitant oxygen evolution.

A procedure is described that provides for electrochemically mediated deposition of enzyme and a polymer layer permselective for endogenous electroactive species. Electrodeposition was first employed for the direct immobilization of glucose oxidase to produce a uniform, thin, and compact film on a Pt electrode. Electropolymerization of phenol was then employed to form an anti-interference and protective polyphenol film within the enzyme layer. In addition, a stability-reinforcing membrane derived from (3-aminopropyl)trimethoxysilane was constructed by electrochemically assisted cross-linking. This hybrid film outside the enzyme layer contributed to the improved stability and permselectivity. The resulting glucose sensor was characterized by a short response time (

Proper statistical analysis of underground water level data can help discern coseismic effects. Data first have to be smoothed to interpolate missing observations and correct outlying observations. Observations are then decomposed into nonstationary trend, barometric pressure, earth tide and precipitation components. The coseismic effect can then be explained as a function of magnitude and hypocentral distance of the earthquake., 1. INTRODUCTION Various anomalous changes of underground water level accompanied by large earthquakes have been reported since ancient times (Roeloffs 1988). But it is actually quite difficult to quantitatively evaluate [...]

Researchers describe a system that uses an electrode to function as an electron acceptor to support anaerobic iron respiration in eubacteria and archaebacteria. This would allow scientists to grow these bacteria in culture. Using such a system resulted in a 12-fold increase in yield of Thiobacillus ferrooxidans compared to the yield in the absence of the electrode.