酸性木聚糖酶产生菌的筛选及产酶条件

SCREENING OF ACIDIC XYLANASE PRODUCING STRAIN AND STUDIES ON ITS ENZYME PRODUCTION CONDITIONS 

从１５０株真菌中筛选到８株产木聚糖酶活力在１００Ｕ／ｍＬ以上的菌株，其中活力最高的为黑曲霉（编号１４９）（Ａｓｐｅｒｇｉｌｕｓｎｉｇｅｒ）。该菌株产酶较适培养基为：麸皮半纤维素４％，ＮａＮＯ３１％，麸皮１％，用不加（ＮＨ４）２ＳＯ４和尿素的Ｍａｎｄｅｌｓ氏营养盐液配制。２８℃～３０℃振荡培养６０ｈ，酶活力最高可达３７５．２Ｕ／ｍＬ。该酶最适作用ｐＨ为４６，在ｐＨ３～１１之间基本稳定。该菌株发酵液中含有木聚糖酶（相对活力１００）外还有淀粉酶（１８），甘露聚糖酶（０９８），β木糖苷酶（０９４）和纤维素酶（０１７）。

From 150 fungal strains, the authors found 8 strain s contained mainly of xylanase activity over 100 U/mL in which the No.149 strain was the highest xylanase producer. Which tentatively identified as Aspergillas niger. The appropriate medium composition was as follows: wheat bran hemicellulose 4%; NaNO 3 1%; wheat bran 1% prepared in Mandels nutritional solution without (NH 4) 2SO 4 and urea. After cultivated in shake flask at 28℃～32℃ for 60h, the activity reached the highest value of 357.2 U/mL. The optimum pH of xylanase was 4.6 and it was stable at pH3～11. The fermented broth of strain 149 contained in addition to xylanase (relative activity 100) also included amylase(1.8), mannanase(0.98), β xylosidase(0.94) and cellulase(0.17).