Biodegradation and utilization of bagasse with Trichoderma reesie

Studies were carried out on the preparation of a new chemical pulp from non woody cellulosic materials by hydrogen peroxide-alkaline pulping of depithed sugar cane bagasse. The cooking liquor was a mixture of water, sodium hydroxide las Na2O 15% on raw material), Varying amount of hydrogen peroxide from 1-4% on raw material and small quantities of auxiliary (EDTA). The liquor ratio of the mixture to cellulosic materials was 6:1 and the time of cooking was from 0.5 to 1 h at 140-160 degrees C. The treated delignified materials were dried and introduced into fermentation media as inducing carbon source for Trichoderma reesie. Cellulases of the two samples A and B gave a markedly high cellulase activity. They were partially purified from the culture filtrate with a purification of 7.6 and 5.6 fold and yield of 73.1 and 61.9%, respectively. The untreated materials and pure cellulose powder were used individually in control and reference media, respectively. The untreated bagasse gave a markedly low cellulase activity. Incubation period, temperature, initial pH value and nature of the nutritive constituents were investigated. Optimum conditions for cellulase production and activity of the two samples A and B were obtained on the 6th and 7th days of incubation at pH 6.0 and 30 degrees C and assayed at pH 5.5 to 6.0 and 40 to 45 degrees C. The stability of the cellulase produced from T. reesie was studied. The enzyme solution was stable at temperature up to 40 degrees C, above which a gradual inactivation occurred until 60 degrees C. The enzyme was stable at pH, between 5.0 and 6.0. (C) 1999 Elsevier Science Ltd. All rights reserved.