棒曲霉UA-2木聚糖酶的蔗渣固态发酵

Xylanase Production on Bagasse with Solid State Fermentation by Aspergillus clavatus UA 2

棒曲霉（Ａｓｐｅｒｇｉｌｕｓｃｌａｖａｔｕｓ）ＵＡ－２固态发酵蔗渣产木聚酶的培养基为每克蔗渣加营养液５ｍｌ，初始ｐＨ８．５．营养液的适宜组成为每升含：ＮＨ４ＮＯ３１０ｇ、Ｋ２ＨＰＯ４６ｇ、ＭｇＳＯ４·７Ｈ２Ｏ０．７５ｇ、ＣａＣｌ２０．７５ｇ、ＦｅＳＯ４·７Ｈ２Ｏ１１．２５ｍｇ、ＭｎＳＯ４·Ｈ２Ｏ３．７５ｍｇ、ＺｎＳＯ４３．０ｍｇ、ＣｏＣｌ２４．５ｍｇ．在上述培养基中接入其湿重１０％（Ｗ／Ｗ）的新鲜的ＵＡ－２种子曲，２８℃培养１０８ｈ，其木聚糖酶，滤纸降解酶和羧甲基纤维素酶的活力分别为２６９５．６、２８．５和４２．７ｕ／ｇ蔗渣．酶反应的最适ｐＨ５．０，最适温度５０℃；在ｐＨ４．０～１１．０内酶活性十分稳定．５０℃保温１ｈ，酶活剩余５５％，８℃下放置２３ｄ，活力几乎不变．磷酸盐，半胱氨酸对酶有激活作用。

The medium composition for the xylanase production on bagasse with solid state fermentation by Asp. clavatus UA 2 and the characteristics of crude enzyme preparation were examined. Composition of the suitabe medium was as follows: 5 ml of nuttrient solution were added for one gram bagasse with initial pH 8.5. The suitable nutrient solution consisted of ∶10 g NH 4HO 3, 6 g K 2HPO 4,0.75 g MgSO 4·7H 2 O,0.75 g CaCl 2,11.25 mg FeSO 4·7H 2 O,3.75 mg MnSO 4·H 2O,3.0 mg ZnSO 4,4.5 mg CoCl 2 and 1 000 ml of distilled water. The amount of seed cultures inoculated was 10 % of the medium moisture weight. After growing at 28 ℃ for 108 h, the activity of xylanase, filter paper degradase and carboxymethylcellulase were 2 695.6 u/g,28.5 u/g and 42.7 u/g,respectively. The optimal pH and temperature for xylanase reaction were pH 5.0 and 50 ℃, respectively, Having incubated the enzyme at 50 ℃ for 1 h, the enzyme retatined 55 % of its original activity. The xylanase activity was hardly changed upon storage at 8 ℃ for 23 days. EDTA and p chloromerouribenzoic acid inhibited xylanase activity, but phosphate and cysteine increased its activity.