Abstract: It is difficult to be utilized at high-value for corn straw,because of its heterogeneity in constitution. This paper aims to find a fungus which can selectively degrade parenchyma cell of corn straw, and the residual fiber can be used in pulping and papermaking. In this paper, seven pathogenic fungi separated from sugarcane with pineapple disease, and Trichoderma viride were used to degrade fiber and parenchyma cell carded and sifted from steam-exploded corn straw respectively. It was shown that the degradabilities of these 8 fungi to parenchyma cell were more than those to fiber. The reason of above difference was concerned with the fungi enzyme activity and structure of material by determination of enzyme activity and study of scanning electron micrograph. Among these 8 fungi, fungus C-2 had the best selective degradation to parenchyma cell, and the difference of weight loss rate of parenchyma cell with fiber was 17.88%.

Key words: steam-exploded corn straw, fungus, Trichoderma viride, selective degradation