【摘要】 中性内切-β-葡聚糖酶在纺织、食品和造纸等领域中应用广泛。研究采用一株重组里氏木霉(Trichoderma reesei)生产中性内切-β-葡聚糖酶,发酵液经SDS-PAGE检测,显示了来自特异腐质霉(Humicola insolens)内切-β-葡聚糖酶的蛋白条带(约52 kDa)。对重组里氏木霉的发酵性能进行了研究,表明碳源对内切-β-葡聚糖酶的形成有重要影响,当采用乳糖与微晶纤维素的复合碳源时,酶活力和产率都可明显提高。利用玉米浆粉作为氮源,其适宜浓度为12 g·L-1。培养基初始pH值对发酵酶活力及产率有一定影响,适宜的初始pH值为5.0。在2 m3的发酵罐进行产酶试验,发酵96 h酶活可高达8012 U·mL-1。酶学性质研究表明:该酶在50℃以下稳定,在45~55℃有明显的催化作用,其最适催化温度为50℃。在pH 5.0~7.0稳定性较好,并且有明显的催化作用,其最适催化pH值为6.0。生物整理实验结果显示重组里氏木霉所产酶液用于牛仔布水洗时反染较少,水洗效果良好。更多还原

【Abstract】 A recombinant Trichoderma reesei was used to produce neutral endo-β-glucanase and SDS-PAGE analysis reveals that Humicola insolens endo-β-glucanase(approximately 52 kDa) is detected in the fermentation broth. The fermentation properties of the recombinant T. reesei were studied and the results show that the carbon sources play an important role in the formation of endo-β-glucanase. When using lactose and microcrystalline cellulose as the composite carbon source, both enzyme activity and productivity increased. The suitable concentration of the corn steep powder as a nitrogen source is 12 g·L-1 and the optimum initial pH value of fermentation medium is 5.0. When the endo-β-glucanase production process is carried out in a 2 m3fermenter, the endo-β-glucanase activity can reach to 8012 U·mL-1 after 96 h. Study on enzymatic properties shows that the enzyme is stable when the temperature is below 50℃, and it has obvious catalysis effects in the range of 45~55℃ with the optimal temperature of 50℃. The enzyme shows high stability and catalytic effects under pH of 5.0~7.0 and the optimal pH value is 6.0. Biofinishing studies with the enzyme indicate that endo-β-glucanase obtained from the recombinant T. reesei process has good appearance for the denim garments with little backstaining on the fabrics.更多还原