Purification and characterization of a new Xylanase from Humicola grisea var. Thermoidea

Abstract

The thermophilic fungus Humicola grisea var. thermoidea secretes extracellular xylanase when grown on solid and in liquid media containing wheat bran and banana plant residue as substrates, respectively. At 55ºC, xylanase from the culture filtrate of H. grisea var. thermoidea grown on banana stalk retained 50% of its activity after 28 h of incubation. A xylanase (X2) was isolated from solid state cultures with wheat bran as the carbon source. It was purified to apparent homogeneity by ultrafiltration followed by ion-exchange and hydrophobic interaction chromatography on DEAE-Sepharose and Phenyl-Sepharose resins, respectively. The enzyme had an apparent molecular weight of 29 kDa, as determined by SDS-PAGE. The purified enzyme was most active at pH and temperature ranges of 4.5-6.5 and 55-60ºC, respectively. In addition, X2 showed thermostability at 60ºC with a half-life of approx. 5.5 h. The apparent Km values, using soluble and insoluble arabinoxylans as substrates, were 10.87 and 11.20 mg/ml, respectively.

Optimization of β-Glucosidase, β-Xylosidase and Xylanase Production by Colletotrichum graminicola under Solid-State Fermentation and Application in Raw Sugarcane Trash Saccharification

“…The β-xylosidase also showed higher thermal stability than reported for enzymes from different thermophilic species [51–56], but somewhat more thermostable enzymes were produced by a few Aspergillus genera [17] and Humicola lanuginosa [40]. Similarly, C. graminicola xylanase was more thermostable than several enzymes from different thermophiles, with half-lives in the range of 4–115 min at 60 °C [57–60]. Some highly thermostable xylanases are, however, produced by Thermomyces lanuginosus THKU-49 [61] and Talaromyces thermophilus [62], with half-lives of 336 min at 70 °C and 1.0 h at 100 °C, respectively.…”

Comparative study for the kinetics of extracellular xylanases from Trichoderma harzianum and Chaetomium thermophilum

“…The optimal temperature of 60ºC for xylanase activity from T. harzianum found in this study was similar to the xylanases from Trichoderma koningii G-39 (Huang et al 1991), Humicola grisea Var. Thermoidea (Lucena-Neto and Ferreira-Filho, 2004) and A. fischeri (Chandra Raj and Chandra, 1996). The xylanase from T. harzianum exhibited higher optimal temperature that may have attractive industrial applications.…”

Characteristics of Aspergillus niger xylanases produced on rice husk and wheat bran in submerged culture and solid‐state fermentation for an applicability proposal

“…Depending of culture methods and conditions, diverse forms of these enzymes are produced, displaying varying folds, mechanisms of action, substrate specificities, hydrolytic activities and physicochemical characteristics. This multiplicity may be the result of genetic redundancy and in some cases, differential post‐translational processing have also been reported (Lucena‐Neto & Ferreira‐Filho, ; Collins et al ., ). In some cases, this multiplicity can be observed simply in a SDS‐PAGE gel (Brijwani et al ., ; Kiddinamoorthy et al ., ).…”