中文摘要：

有 pH 抵抗和高盐忍耐的宽范围的绗维素酶在红树属植物森林里从牡蛎 Crassostrea rivularis 生活的消化的腺被孤立。作为 CrCel 说出的 27 kDa 绗维素酶被净化由从在非减少的钠 dodecylsufate-polyacrylamide 胶化电气泳动以后的胶化的阴离子交换层析和抽取的 40.6 褶层。净化的绗维素酶的特定的活动是对 carboxymethyl 纤维素 CMC 的 23.4 U/mg。CrCel 的 N 终端氨基酸顺序决心是 NQKCQANSRV。CrCel 最好水解 -1,4-glucosidic 向木聚糖在纤维素材料和显示降级活动的非结晶的部分结合。K _m 和 V _{为 CMC 的 CrCel 的最大} 价值决心是 2.1% 汵瑡潩 ? 景 ? 剄′獵湩 ? 浳污 ? 湩整晲牥湩 ? 乒 ? 楳乒 ? 灡牰慯档 ? 潢桴漠 ? 桴?散汬洠杩慲潴祲愠摮椠癮獡癩?桰湥瑯灹獥眠牥?楳湧晩捩湡汴?瑡整畮瑡摥眠敨?潣灭牡摥眠瑩?桴?潣瑮潲? 散汬s

英文摘要：

A cellulase with wide range of pH resistance and high salt tolerance was isolated from the digestive gland of the oyster Crassostrea rivularis living in mangrove forests. The 27 kDa cellulase named as CrCel was purified 40.6 folds by anion exchange chromatography and extraction from the gel after non-reducing sodium dodecylsufate-polyacrylamide gel electrophoresis. The specific activity of the purified cellulase was 23.4 U/mg against carboxymethyl cellulose （CMC）. The N-terminal amino acid sequence of CrCel was determined to be NQKCQANSRV. CrCel preferably hydrolyzes β-1,4-glucosid- ic.bonds in the amorphous parts of cellulose materials and displays degradation activity toward xylan. The Krn and Vmax values of CrCel for CMC were determined to be 2.1% ± 0.4% and 73.5 ± 3.3 U mg-1, respectively. The optimal pH value and temperature of CrCel were 5.5 and 40℃, respectively. Theenzyme was stable in a wide range of pH, retaining over 60% activity after incubation for 80 min in the pH range of 3.0-9.0. In addition, CrCel showed remarkable tolerance to salt and remained ac- tive at high NaCI concentrations, but also retained over 70% activity after incubation in 0.5-2 M NaCI for up to 24 h. On the basis of the N-terminal sequence alignment and its similar properties to other animal cellulases, CrCel was regarded as a member of glycosyl hydrolase family 45 β-1,4-gluca- nases. CrCel is the first reported cellulase isolated from mangrove invertebrates, which suggests that it may participate in the assimilation of cellulolytic materials derived from the food sources of the oyster and contribute to the consumption of mangrove primary production. The unique proper- ties of this enzyme make it a potential candidate for further industrial application.