Abstract:In order to understand antioxidant enzymes activities in response to temperature increment and the active oxygen free radical clearing function of antioxidant enzymes in antarctic ice mircoralgae Chlorophyceae L4, the free radical generation rate, the malonaldehyde (MDA) content changes and the corresponding antioxidant enzymes activities changes in Chlorophyceae L4 at different temperatures were determined. The results showed that the free radical generation rate and MDA content in Chlorophyceae L4 increased rapidly in early time (24 to 72 hours) of temperature increment, then decreased rapidly, and could return to tolerable leve1 at the end of time. Under the stress of high temperature, the superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities in Chlorophyceae L4 slowed down sharply in early time, then increased obviously, which were much higher than those in the control，and their activities became higher at higher temperatures. In a word, the antioxidant enzymes system plays an important role in the adaptation of antarctic ice microalgae to high temperature environment.
