Lee Jae-Won, Gwak Ki-Seob, Kim Su-Il, Kim Mihyang, Choi Don-Ha, Choi In-Gyu
Department of Forest Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea.
J Microbiol Biotechnol. 2007 Nov;17(11):1811-7.
Extracellular enzymes from Lentinus edodes M290 on normal woods (Quercus mongolica) and waste logs from oak mushroom production were comparatively investigated. Endoglucanase, cellobiohydrolase, beta-glucosidase, and xylanase activities were higher on waste mushroom logs than on normal woods after L. edodes M290 inoculation. Xylanase activity was especially different, with a three times higher activity on waste mushroom logs. When the waste mushroom logs were used as a carbon source, a new 35 kDa protein appeared. After the purification, the optimal pH and temperature for xylanase activity were determined to be 4.0 and 50 degrees C, respectively. More than 50% of the optimal xylanase activity was retained when the temperature was increased from 20 to 60 degrees C, after a 240 min reaction. At 40 degrees C, the xylanase maintained 93% of the optimal activity, after a 240 min reaction. The purified xylanase showed a very high homology to the xylanase family 10 from Aspergillus terreus by LC/MS-MS analysis. The highest Xcorr (1.737) was obtained from the peptide KWI SQGIPIDGIG SQTHLGSGGS WTVK originated from Aspergillus terreus, indicating that the 35 kDa protein was xylanase. This protein showed low homology to a previously reported L. edodes xylanase sequence.
对香菇M290在正常木材（蒙古栎）和香菇生产废菌棒上产生的胞外酶进行了比较研究。接种香菇M290后，废菌棒上的内切葡聚糖酶、纤维二糖水解酶、β-葡萄糖苷酶和木聚糖酶活性高于正常木材。木聚糖酶活性差异尤为明显，在废菌棒上的活性高出三倍。当以废菌棒作为碳源时，出现了一种新的35 kDa蛋白质。纯化后，测定木聚糖酶活性的最适pH和温度分别为4.0和50℃。在240分钟反应后，温度从20℃升高到60℃时，木聚糖酶仍保留超过50%的最适活性。在40℃下，反应240分钟后，木聚糖酶保持93%的最适活性。通过液相色谱-串联质谱分析，纯化的木聚糖酶与土曲霉的木聚糖酶家族10具有很高的同源性。从土曲霉来源的肽KWI SQGIPIDGIG SQTHLGSGGS WTVK获得了最高的Xcorr（1.737），表明35 kDa蛋白质是木聚糖酶。该蛋白质与先前报道的香菇木聚糖酶序列同源性较低。
