Biomass photochemistry XIV: Photosensitized pre-treatment of cellulose and its role on cellulase efficiency

Abstract

α-Cellulose, methylcellulose and filter paper (Whatman No. 1) were irradiated with UV light at λ > 254 nm and λ > 300 nm in the presence of sodium nitrite as sensitizer. The degradation of cellulose derivatives was monitored by viscosity, weight loss and thermogravimetric measurements. For the samples irradiated at λ > 254 nm and λ > 300 nm in the presence of the sensitizer, the intrinsic viscosities were similar for fluences in the range 0 – 64 kJ m −2. The sensitizer, which generates OH radicals through photochemical activation, improves tenfold the efficiency of the enzymatic hydrolysis of a-cellulose by cellulase. The results clearly indicate that irradiation at λ > 300 nm is a good pre-treatment for the enzymatic hydrolysis of α-cellulose.