Enhanced stability of laccase in the presence of phenolic compounds

The storage stability of laccase (EC 1.10.3.2) from the white-rot basidomyc ete Trametes versicolor in potassium-citrate buffer was enhanced by various phenolic compounds as well as by lignin sulfonate. The highest storage sta bility was obtained with phenolics, e.g. phloroglucin and 3,5-dihydroxybenz oic acid; these represent substrates of laccase which an oxidized slowly be cause of their relatively high redox potential and which did not precipitat e from the solution within the tested period of time. Sterilization enhance d the stability of laccase but additional stabilization by phenolics was ob served both under sterile and non-sterile conditions. We thus concluded tha t stabilization occurred not only through prevention of microbial degradati on.