Cellulase in Tomato Fruits

THERE are only a few reports of enzymes from higher plants which can hydrolyse cellulose or water-soluble cellulose derivatives. Several reports show that malt extracts are capable of hydrolysing water-soluble cellulose derivatives 1,3,11 and dispersed cellulose fibres 1,7 . A malt extract was found to hydrolyse reprecipitated cellulose more rapidly than a similar extract from barley seeds 1 . There is a single report that potato sprouts hydrolysed the cellulose in cardboard 8 . Another report 10 showed that sap from tobacco leaves and roots hydrolysed carbpxy-methylcellulose and reprecipitated cellulose. In addition to tobacco, cellulase was found on single occasions in bean leaves, roots of beet and woody nightshade, asparagus stems, and the flesh of vegetable marrow fruit. The enzyme was not detected in tomato fruits or rhubarb petioles which had p H. values of 4.3 and 3.4 respectively. The author mentioned that the p H. was greater than 5 in all the saps in which activity was found.