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为了研究桦剥管菌木材纤维素降解机制,试验分别于23℃和28℃培养桦剥管菌,用菌落直径比较生长速度;以白桦木屑、云杉木屑和麦麸为底物诱导培养,以不加木屑的马铃薯液体培养基为对照,测定12 d内桦剥管菌在纤维素外切酶和纤维素内切酶两种纤维素酶活变化;以云杉木屑、白桦木屑、玉米秸秆和麦麸为诱导物,测定15~21 d内木聚糖酶和甘露聚糖酶两种半纤维素酶活变化;检测8种不同金属离子以及金属离子抑制剂EDTA对两种半纤维素酶活性的影响;并对白桦木屑诱导桦剥管菌产半纤维素酶的酶学性质进行了初探。结果表明:桦剥管菌菌丝更适合在28℃培养;纤维素外切酶和纤维素内切酶的最适底物分别为白桦木屑和云杉木屑,木聚糖酶和甘露聚糖酶最适底物分别为麦麸和玉米秸秆;两种半纤维素酶的最适反应温度均为50℃,最适反应pH值分别为5.0和6.0;8种金属离子中,仅Co2+对两种半纤维酶活性均有促进作用,EDTA对两种酶活性均具有较强抑制作用。
In order to study the cellulose degradation mechanism of Betula platyphylla wood, the Betula platyphylla was cultured at 23 ℃ and 28 ℃ respectively, and the growth rate was compared with the colony diameter. The white birch sawdust, spruce sawdust and wheat bran were used as substrates to induce culture. As a control, the liquid culture medium without wood chips was used as a control, and the activities of cellulase and cellulose endonuclease in the 12-day-old Betula utilis were determined. The contents of spruce sawdust, birch sawdust, corn stalk and Wheat bran as an inducer, the determination of xylanase and mannanase within 15 ~ 21 d enzyme hemicellulase activity changes; detection of 8 different metal ions and metal ion inhibitor EDTA on two hemicellulase activity The effects of birch sawdust on the enzymatic properties of hemicellulase induced by Betula edulis were discussed. The results showed that the mycelium of Betula platyphylla was more suitable for culturing at 28 ℃. The optimum substrates of exo-cellulase and cellulase were birch sawdust and spruce sawdust, xylanase and mannanase The optimum substrates were wheat bran and corn stalks respectively. The optimal reaction temperature of both hemicellulases was 50 ℃, and the optimum reaction pH was 5.0 and 6.0 respectively. Of the 8 metal ions, only Co2 + Hemicellulase activity has a promoting effect, EDTA on both enzyme activity has a strong inhibitory effect.