EFFECTS OF MICROWAVES ON GREEN ALGAE.

By exposing an algal suspension to microwave power of variable density, two types of thermal effects on algae have been observed. Using 4,900 MHz and an exposure time sufficient to raise the temperature of the aqueous medium beyond 50 degree C resulted in proteolysis and complete failure of the alga to photosynthesize and grow. At 100 degree C it was observed that a rapid degradation of chlorophyll occurred which surpassed the effect of conventional heating. However, microwave irradiation at 2,450 MHz, which entailed a rise in temperature of not more than 35-40 degree C, exerted a stimulating effect on photosynthesis and subsequent algal growth as compared to conventional heating within the same temperature range. The results obtained provide evidence that microwaves may be a useful tool in studies designed to investigate some of the biological aspects of thermal pollution and productivity of green cells.