Characterization of the xylanolytic activity of Cellulomonas

Maximum production of xylanolytic enzymes by Cellulomonas CSI-17 required aerobic conditions, a temperature of 30⁰C and a pH between 6.2 and 7.2. Under these conditions, maximum levels of xylanolytic activity were reached within 48 hr; addition of further mineral salts and yeast extract to the growth medium decreased the time to 24 hr.

At pH values between 5.4 and 8.4 the xylanase was stable up to a temperature of 30⁰C, for at least 48 hr after harvest; over the same temperature range, theb-xylosidase was stable only at the higher end of this pH range.

The culture filtrate was similar to the growing cells in its ability to hydrolyse xylan whilst the growing cells metabolized the bulk of the hydrolysis products, the latter accumulated as soluble reducing sugars when the culture filtrate was used as the enzyme source.