Characterization of Alkali-tollerant Thermostable Compound Enzyme from Saccharomonospora Viridis and its Synergistic Bleaching Mechanism on Pulp

The biotechnological approach in pulp and paper industry has attracted considerable interest as a potential way to overcome some ecological and economical problems related to conventional industrial technologies. According to the foregoing research, compound enzyme produced by Saccharomonospora viridis contained both xylanase and lignin peroxidase, and had both thermostable and alkali tolerance. This paper mainly reports the characteristics of compound enzyme and its reaction mechanism in synergistic bleaching pulp. Results showed that the alkali-tolerant thermostable compound enzyme was maximally active at pH 7 and retained 63.55 % activity at 90 degrees C for 3 h. Compound enzyme treatment on pulp removed 7.1 % of xylan, 11% of lignin (both Klason Lignin and Acid-soluble fignin) and 39.2 % of LCC, which resulted in a brightness increment of 3.2 %ISO. Compoud enzyme treatment degraded xylan and poly-arabinose evidently, dissolved small molecular lignin and LCC, strengthened the infiltration of chemicals by loosing the fibre structure. Crystallinity of enzymatic treatment pulp was also enhanced.