Production, Purification, and Properties of an Endoglucanase Produced by the HyphomyceteChalara(Syn.Thielaviopsis)paradoxaCH32

Abstract

The hyphomycete Chalara (syn. Thielaviopsis) paradoxa produces endoglucanase activity during the late trophophase. The low molecular mass (35 kDa) endoglucanase purified from cultured broths works optimally at 37 degrees C and pH 5.0. The enzyme inactivates at pH below 3.0 and also at temperatures of 50 degrees C or higher, but it is stable at lower temperatures, including refrigeration temperature and freezing. The enzyme is inhibited by detergents, by EDTA, and by the divalent cations Hg(2+) and Ag(2+). It is also inhibited to some extent by 10 mM Zn(2+), Fe(2+), and Mg(2+), but it is stimulated by Mn(2+). Enzyme activity is not affected by reducing agents. In the presence of low concentrations of water miscible organic solvents (20%) endoglucanase activity is inhibited by 7% (for methanol) to 50% (for acetonitrile), and it is totally inhibited at higher solvent concentrations (50%). Enzyme activity is not affected by the water immiscible solvent ethyl acetate. Carboxymethylcellulose is the preferred substrate (K(m(app)) = 8.3 g/L; V(max(app)) = 1.1 microM/min). Hydrolysis of crystalline cellulosic substrates is very limited, but it is greatly enhanced by phosphoric acid swelling. The purified enzyme shows no activity toward disaccharides or aryl-glucosides. Its activity is inhibited by cellobiose.

Detergent-Compatible Purified Endoglucanase from the Agro-Industrial Residue by Trichoderma harzianum under Solid State Fermentation

“…Our results have high similarity to those found for Catharanthus roseus (Sanwal 1999). Saha (2004) and Lucas et al (2001) reported that the activities of enzymes produced by Mucor circinelloides and Chalara paradoxa were greatly enhanced when incubated with Co 2+ and Mn 2+ .…”

Isolation and screening of cellulolytic bacteria from soil and optimization of cellulase production and activity

“…As the temperature increased cas et al [41] for Chalara paradoxa. This is possibly due to binding of Hg 2+ with thiol groups and interaction with carboxyl or imidazol groups of amino acids [41]. Activation by Co 2+ and Mn 2+ is similar to results of Saha [37] from M. circineloides.…”

Purification and characterization of the kinetic parameters of cellulase produced from wheat straw by Trichoderma viride under SSF and its detergent compatibility

“…Bakare et al [38] reported an inhibitory effect of EDTA to the activities of cellulase from wild type of Pseudomonas fluorescens. According to Saha, [36] and Lucas et al [40] Co 2+ and Mn 2+ activate the enzyme that from Mucor circinelloides and Chalara paradoxa respectively.…”