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For the utilization of natural cellulosic materials by microorganisms, a potent cellulase-producing microorganism was isolated and identified as Trichoderma spp. Rice straw used as a substrate in this study was preliminarily treated with chemical solvents and/or additionally treated with acids and by heat, and then examined with the cellulase produced by the organism. Better results in sugar production by decomposing the straw cellulose were obtained, when the cellulase was produced by cultivating the organism in the selection medium, pH 5.0, for 5 days, and when the pretreated straw substrate was additionally treated with 0.1% H₂SO₄ sulfuric acid at 120℃ for 1 hour. The enzyme production was increased by about 20%, when 0.5% urea 0.5% phosphate, 0.1% meat extract, or 5% orange peel was added into the culture medium. For the practical purposes, the sugar production from the rice straw by the cellulase-producing microorganism can be improved by extending the reaction time of the enzyme up to 24 hr or longer.
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