Open AccessPurification and characterization of an exo‐β‐1,3‐glucanase produced by Trichoderma asperellum
Author(s) -
Bara Maria Teresa F,
Lima Adilson L,
Ulhoa Cirano J
Publication year - 2003
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1016/s0378-1097(02)01191-6
Subject(s) - laminarin , glucanase , chromatography , size exclusion chromatography , chemistry , hydrolysis , rhizoctonia solani , enzyme , chitinase , ion chromatography , extracellular , gel electrophoresis , substrate (aquarium) , beta glucosidase , molecular mass , enzyme assay , biochemistry , biology , botany , ecology
Trichoderma asperellum produces at least two extracellular β‐1,3‐glucanases upon induction with cell walls from Rhizoctonia solani . A β‐1,3‐glucanase was purified by gel filtration and ion exchange chromatography. A typical procedure provided 35.7‐fold purification with 9.5% yield. The molecular mass of the purified exo‐β‐1,3‐glucanases was 83.1 kDa as estimated using a 12% (w/v) SDS–electrophoresis slab gel. The enzyme was only active toward glucans containing β‐1,3‐linkages and hydrolyzed laminarin in an exo‐like fashion to form glucose. The K m and V max values for exo‐β‐1,3‐glucanase, using laminarin as substrate, were 0.087 mg ml −1 and 0.246 U min −1 , respectively. The pH optimum for the enzyme was pH 5.1 and maximum activity was obtained at 55°C. Hg 2+ strongly inhibited the purified enzyme.