Ref ID : 3740
William B. Baker and D.E. Buetow; Hydrolytic Enzymes of Euglena gracilis: Characterization and Activity as a Function of Culture Age and Carbon Deprivation. J.Protozool. 23(1):167-176, 1976
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Optimal assay conditions are described for 8 hydrolases of Euglena gracilis var. bacillaris, SM-L1 (streptomycin-bleached) strain, 7 of which have an acid pH-optimum. Acid phosphatase, beta-galactosidase, beta-glucosidase, beta-fucosidase, cathepsin D, RNase, DNase, and an esterase are active in cell homogenates. Amylase has very low activity, and beta-glucuronidase, arylsulfatase, beta, N-acetyl-glucosaminidase, alpha-fucosidase, and alpha- and beta-mannosidase are inactive. Hydrolase activity increases as a culture proceeds from the midexponential to the late stationary-phase of growth, being most pronounced in the case of beta-glucosidase. In cultures deprived of a utilizable carbon source, the specific activities of the hydrolases (per mg total protein or dry weight) increase. When expressed on a per cell basis, however, the activities of DNase decrease while those of beta-galactosidase, cathepsin D, and RNase increase. The hydrolases appear to be involved in the adaptation of Euglena to the metabolic demands imposed by different conditions of growth.