2.8. Temperature effect studies
2.8.1. Pure dextran Dextran T2000
TM(500 ppm) was prepared in pH 5.4 acetate buffer. Dextranase enzymes 2–4 were first diluted (0.015 g/100 ml pH 5.4 acetate buffer). The ‘‘concentrated’’ dextranase 2 had also been previously diluted 4.6X to make it economically equivalent to the nearest priced ‘‘nonconcentrated’’ dextranase. Diluted enzyme (1 ml) was added to the dextran (2 ml) in a test-tube, coverered with aluminum foil, and thoroughly mixed. For the control, de-ionized water (1 ml) was added instead of dilute dextranase. The test-tubes were placed in a shaking water-bath (90 rpm) at different temperatures ranging from 26.6 to 65.5 8 C for 25 min. After incubation, the test-tubes were immediately placed in a boiling water-bath for 2.5 min to denature the enzyme, and cooled on ice. Preliminary experiments were undertaken to ensure that2.5 min boiling was sufficienttime tostop further dextranase action. Undiluted duplicate aliquots were analyzed on IC–IPAD.