Kinetics of utilisation of a highly polymerised carbon source (starch) in a chemostat culture of <i>klebsiella aerogenes</i>: Pullulanase and α‐amylase activities

Abstract

Abstract Starch and amylose utilisation by K. aerogenes under chemostat conditions were studied as models of polymer degradation in the chemostat. The effects of growth rate on the process and upon cellular concentrations of α‐amylase and pullulanase were determined. The debranching enzyme (pullulanase) activity was greatest when the highly branched polymer (starch) limited growth. The pullulanase activity varied inversely with the dilution rate when starch limited growth but increased with dilution rate when nitrogen limited growth. Pullulanase seems to be the enzyme controlling growth rate. The polymer substrate affinities ( K s values) expressed on a molar basis were about the same as the values observed for monomers.