Key points are not available for this paper at this time.
The xyn2 gene of a filamentous mesophilic fungus, Trichoderma reesei, coding xylanase 2 (Xyn2) was previously expressed in Pichia pastoris. In the present study, the recombinant Xyn2 was prepared from a 15 litre fermenter, and subsequently characterised. It has been confirmed to have a molecular mass of 21 kDa, an optimal pH of 6.0 and an optimal temperature of 60 degrees C. When tested using oat-spelt xylan, it showed a Km and catalytic rate constant (kcat) of 1.1 mg/ml and 512.4/s, respectively. Analysis of the products from oat-spelt xylan degradation confirmed that the enzyme was an endoxylanase with xylotriose and xylobiose as the main degradation products. The unprocessed Xyn2 was supplemented to a xylan-containing diet to determine its influences on performance and nutrient digestibilities by weaned pigs. Results showed that the average body-weight gain increased 16.9 % when piglets received Xyn2 at a concentration of 500 U/kg diet. There also was a positive (0.05 < P < 0.10) effect on the digestibility values of crude protein, ash, Ca and acid-detergent fibre with Xyn2 supplementation. The potential benefits of Xyn2 in the nutrition of weaned pigs should make it an alternative applicant for industrial xylanase production.
He et al. (Tue,) studied this question.