Catalysis by bacteria; opportunists at work
Scott, B. (2004) Catalysis by bacteria; opportunists at work. In: Iron & Sulphur Bacteria Workshop, 11 - 14 February, Murdoch University, Perth, Australia.
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Looks at the ways catalysis can occur through the action of bacteria. With billions of years of evolution, bacteria have taken every opportunity to direct and optimise the reaction coordinate. One model is a staircase with step sizes, shapes, and direction such that there is piecewise control over the whole reaction. Steps of a single size are appropriate; the effect of a series of reactions of smaller activation energies is explored; an optimal number of steps is found, with an individual step being RT.
Specific data on Fe(II) oxidation and inoculation with ochre sludge were mined (from Stevenson, 1991); the data are for a controlled pH of 5.8, oxygen at 0.023atms and without nutrient limitations. It seems that 3 to 5 steps are involved in increasing the oxidation rate 3.3 to 7.6 times.
A catalytic kinetic model involving protein as a surrogate for cells is used to fit the data. Two simultaneous differential equations evolve and are fitted to the initial and final concentrations of Fe(II) and protein. The observed trends are incompletely fit by the model but the parametric values give some insight into bacterial catalysis. The fractional mass increase in oxidation
|Publication Type:||Conference Paper|
|Murdoch Affiliation:||School of Biological Sciences and Biotechnology|
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