Regulation of respiratory activity by oxygen in Arthrobacter fluorescens ammonium-limited chemostat culture

Abstract

The effect of a sudden imposition of either oxygen limitation or over oxygenation on an Arthrobacter sp. ammonium-limited chemostat culture was studied at growth rate of 0.03 h−1. Growth and respiratory activity of the cultures were examined during the transition periods and at both steady-states. Arthrobacter fluorescens responded to oxygen limitation by increasing respiratory rate and degrading polysaccharide content. In contrast, an increase in dissolved oxygen concentration caused a decrease in respiration rate and an increase in biosynthesis of endogenous polysaccharides. Under both conditions an inverse relationship seemed to occur between respiration rate and yield coefficients.