The notion has been steadily gaining ground that the reducing powers of animal tissues are due to enzymic action. In March, 1910, one of us adduced evidence that this so-called “reductase” was active in the press-juice of liver and kidney of sheep, ox, horse, and frog. Soluble Prussian blue, methylene blue, and sodium indigo-disulphonate are all reduced more or less perfectly to leuco-compounds by press juice, whereas by a boiled control they are not. It seemed very desirable to conduct several lines of investigation arising out of the main contention that the tissues were capable of carrying out reduction-processes because they contained an endo-enzyme, viz., How rapidly does the press juice deteriorate in reducing activity; how does it behave in respect of such comparatively stable but reducible substances as NaNO
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; in what way, exactly, does its activity vary with temperature; in what way, if any, is the catalase of the liver related to the reductase ? It seemed, in particular, highly desirable that a method capable of following the reduction changes quantitatively should be devised in order to enable us to follow the velocity of any given reaction being studied.
The Biotransformation and Biodecolorization of Methylene Blue by Xenobiotic Bacterium Ralstonia pickettii