Secretion of Amylase by the Marine Bacterium, Alteromonas rubra

Abstract

A. rubra possesses a constitutive IX-amylase which is secreted during the stationary phase of growth when glucose (at concentrations below 5 mM) is the carbon source. The activity of the enzyme was increased about eightfold over the control level when the organism was grown on O· 2 % (wjv) starch or maltose, with secretion starting in the late logarithmic phase of growth and continuing into the stationary phase. IX-Amylase secretion was repressed by the addition of glucose, at concentrations in excess of 5 mM, when the organism was grown on a medium containing starch or maltose as carbon source.