野菜軟腐病原菌によるペクチン物質の酸化的分解について(第2報)

Abstract

A strain, of Erw. carotovora which showed a lag-period on pectic oxidation was confirmed to act in a similar manner to Erw. aroideae No. 199; though the oxygen consumption of this carotovora strain on the primarily added pectin required a lag-period before its vigorous performance; it was greatly accelerated without a lag-period at the second addition of pectin. Previously, it was assumed that a certain soluble factor contained in the oxidation medium might be responsible for the facile effect of the latter. Subsequently several properties of this soluble factor were examined by means of dialysis, heat treatment, and others. The results indicated that the effective substance might be contributed to a heat-labile, non-dialisable one, and indeed a pectic enzyme excreted from the cell during its incubation, since such a soluble factor caused the decomposition of pectin when added anaerobically to its solution, and the decomposed product thus obtained was well served to the oxidation by the organism. And it has been well mentioned, that the vigorous oxygen consumption after a lag-period or on the second addition of pectin, would be induced by the excreted enzyme during a lag-period or throughout the cell incubation. The action of the pectic enzyme which had been excreted at 30°, for 5 hrs in the course of pectic oxidation by the organism, caused remarkable decrease in the viscosity of the added pectin and increase of a small amount of the reducing group, the galacturonide of the lower molecule.