Cellulose-degrading enzyme production by Clonostachys byssicola: Partial purification and characterization of an endoglucanase

Abstract

Agro-industrial wastes offer potential as renewable carbon sources for microbial growth and industrial enzyme production, with potential applications in textile and biofuel industries, among others. The filamentous fungus Clonostachys byssicola was cultivated for seven days in liquid medium containing 1% (w/v) soybean hulls as unique carbon source. Hemicellulase, cellulase and pectinase activities were observed in the crude extract after seven days growth. A CMCase, denominated Cb-Cel, was partially purified using ultrafiltration and chromatographic methods. With a molecular weight of 48 kDa, the enzyme was most active at 70°C and pH 5.0, and thermostable at 40 and 50°C. Cb-Cel showed K m and V max values of 15.81 ± 1.65 mg/mL and 0.59 ± 0.03 IU/mL, respectively. Phenolic compounds (tannic, 4-hydroxybenzoic, ferulic, ρ-coumaric, cinnamic acids and vanillin) had no inhibitory or deactivator effects on enzymatic activity when tested on the concentrated fraction or Cb-Cel. Enzymatic hydrolysis of CMC and filter paper hydrolysis resulted in the release of glucose, cellopentaose and cellohexaose. Enzymatic hydrolysis of soybean hulls released mostly cellohexaose, cellopentase, mannose and xylobiose. In comparison to hydrolysis of sugarcane bagasse, the hydrolysis of soybean hulls yielded higher amounts of reducing sugars, suggesting that the enzymes secreted during growth of C. byssicola are more active on this substrate as carbon source.

An update on enzymatic cocktails for lignocellulose breakdown

“…; Sciuto et al . ). This is an essential aspect to the design of an enzymatic cocktail targeting a specific substrate.…”