Influence of Storage Temperature on Total Peroxidase Activity in Crude Extracts from Picea abies L. Karst. Needles*

Peroxidases are enzymes with numerous functions in plant cells and are, therefore, interesting objects of current biochemical research. The purpose of this work was to investigate the effect of 30 days storage at different temperatures on the peroxidase activity in crude extracts from one-year old needles of Picea abies L. Karst. Total peroxidase activity was detected in the ex-tract reaction with guaiacol and H2O2. Colour product was quantified by absorbance measure-ment at 470 nm. Measurements were performed daily in the first 10 days, and on the 12th, 14th, 16th, 18th and 30th day of the experiment. Extracts stored for 30 days were subjected to poly-acrylamide gel electrophoresis, incubated with peroxidase substrates, and the resulting bands were quantified. Three different dependences on storage temperature were noticed. Extracts kept at –196 °C and –20 °C displayed no change in activity, samples kept at +24 °C and +37 °C de-creased the activity, while those kept at +4 °C manifested a considerable rise in activity. Elec-tropherogram analysis revealed two isoenzymes, with total activities resembling those obtained spectrophotometrically. There was no difference in isoenzyme appearance between samples. Recommendations regarding enzyme extract storage are given