CELLULOLYTIC ENZYME-ACTIVITY IN THE MARINE PROTIST SCHIZOCHYTRIUM-AGGREGATUM

The culture medium from 4-5 day old cultures of Schizochytrium aggregatum was show to contain cellulolytic enzyme activity (beta-1,4 glucanase) demonstrated by the hydrolysis of sodium carboxymethylcellulose in agar gels. The enzyme was concentrated from the culture filtrate by ultrafiltration and dialysis and fractionated by gel filtration. Three peaks of cellulase activity were detected in the fractionated preparation suggesting the presence of isozymes. Enzyme activity was low at pH 4.15 with a steep rise in activity at pH 5.05, with a maximum activity plateau between pH values of 5.1 and 7.4. The results are discussed in the context of the biology of the organism.