Characterization of a 29-kDa beta-1,3-glucanase from Trichoderma harzianum

A beta-1,3-glucanase, from culture filtrates of Trichoderma harzianum, was purified in sequential steps by gel filtration, hydrophobic interaction and ion exchange chromatography. A typical procedure provided 69-fold purifica tion with 0.32% yield. The molecular mass of the protein was found to be ap proximately 29 kDa, as estimated by SDS-PAGE on a 10% slab gel. The K-M and V-max values for beta-1,3-glucanase, using laminarin as substrate, were 1. 72 mg ml(-1) and 3.10 U ml(-1), respectively. The pH optimum for the enzyme was pH 4.4 and maximum activity was obtained at 50 degrees C. The enzyme w as strongly inhibited by HgCl2 and SDS. These results suggest that each bet a-1,3-glucanase produced by T. harzianum is different and is probably encod ed by different genes. (C) 2000 Federation of European Microbiological Soci eties. Published by Elsevier Science B.V. All rights reserved.