News & Notes: Production, Purification, and Properties of an Endo-1,3-β-Glucanase from the Basidiomycete Agaricus bisporus

Abstract

Agaricus bisporus H 25 produced extracellular endo-1, 3-beta-glucanase when grown in a static culture at 25 degrees C in a minimal synthetic medium supplemented with A. bisporus cell walls plus fructose. Endo-1,3-beta-glucanase was purified 17.85-fold from 20-day-old culture filtrates by precipitation at 80% ammonium sulfate saturation, Sephadex G-75 gel filtration, and preparative PAGE followed by electroelution. The purified enzyme yielded a single band in both native and SDS-polyacrylamide gels with a molecular mass of 32 kDa (SDS-PAGE) and 33.7 kDa (MALDI-MS), showing an isoelectric point of 3.7. The enzyme was active against beta-1,3- linkages and, to a lesser extent, against beta-1,6-, exhibiting an endohydrolytic mode of action and a glycoprotein nature. Significant activities of the endo-glucanase against laminarin and pustulan were observed between pH 4 and 5.5, and between 40 degrees and 50 degrees C for laminarin, and between 30 degrees and 50 degrees C for pustulan. The optimum pH and temperature were 4.5 and 45 degrees C for both substrates.

Senescence of the Lentinula edodes Fruiting Body After Harvesting

“…bisporus produce an endo-β-1,3-glucanase (Galán et al, 1999) and an endo--1,3-glucanase has also been reported from L. edodes (Grienier et al, 2000) that exhibits similarities to the anti-fungal thaumatin-like (TL) proteins that are highly conserved in plants. Plants accumulate a large number of pathogenesis-related (PR) proteins, which are divided into five families (PR1-PR5), and TL proteins share sequence homology with the thaumatin isoforms from arils of Thaumatococcus danielli (Dudler et al, 1994) are members of the PR5 family (van Loon and van Strien, 1999).…”

Production, purification and partial characterization of a novel endo-β-1,3-glucanase from Agaricus brasiliensis

“…However, most studies on the production and regulation of fungal endoglucanases focused on Trichoderma reesei [16][17][18] and Phanerochaete chrysosporium [19,20], and studies of endoglucanases of edible mushrooms except A. bisporus are limited [14]. Fungal glucanases were commonly responsible for the degradation of exopolysaccharides such as pullulans in the late stage of the submerged cultures [21][22][23].…”

“…Edible mushrooms such as Agaricus bisporus, Lentinula edodes and Pleurotus sajor-caju produce endo-b-1,4-glucanase (EC 3.2.1.4), cellobiohydrolase (EC 3.2.1.91), and b-glucosidase (EC 3.2.1.21) when cultivated on glucan and cellulose rich materials in either submerged culture or in solid-state systems [14,15]. However, most studies on the production and regulation of fungal endoglucanases focused on Trichoderma reesei [16][17][18] and Phanerochaete chrysosporium [19,20], and studies of endoglucanases of edible mushrooms except A. bisporus are limited [14].…”

Lentinula edodes tlg1 Encodes a Thaumatin-Like Protein That Is Involved in Lentinan Degradation and Fruiting Body Senescence

“…Previously, we reported that two exo-b-1,3-glucanase-encoding genes (exg1 and exg2) are involved in morphogenesis of L. edodes (Sakamoto et al, 2005a(Sakamoto et al, , 2005b and that the enzyme encoded by exg2 is also involved in postharvest degradation of lentinan (Sakamoto et al, 2005b). In addition, A. bisporus mushrooms produce an endo-b-1,3-glucanase (Galán et al, 1999), and an endo-glucanase has also been reported for L. edodes (Grenier et al, 2000) that exhibits similarities to the antifungal thaumatin-like (TL) proteins that are highly conserved in plants.…”