Cellulase from Pea Epicotyls

Abstract

SEEDLINGS of Pisum sativum L. var. ‘Alaska’ were grown in darkness for 8 days and extracts of the apical 6 cm of epicotyl were examined for ability to catalyse the degradation of cellulose derivatives. After the tissue was washed in hypochlorite and weighed, 0.5 vol. of cold 0.1 M phosphate pH. 7.0–0.01 per cent cysteine was added and a brei was prepared by blending at top speed with a ‘VirTis’ homogenizer. The brei was centrifuged at 37,000g for 20 min at 0° C and the precipitate was homogenized and extracted again. The combined supernatants were saturated with toluene and re-centrifuged just before use as crude extract. In order to remove contaminating reducing substances, 2 vol. of cold acetone were added and the precipitate was washed with 70 per cent acetone, dissolved in water, re-precipitated with ammonium sulphate at 60 per cent saturation, suspended in water and re-centrifuged. The final supernatant was used as purified extract.