木聚糖酶高产菌株的鉴定及产酶条件的优化  

Identification of A Xylanase-Producing Fungi and Its Orthogonal Experiment of Fermentation Conditions

作　　者：徐燕[1] 田宝玉[1] 江贤章[1] 黄钦耿[1] 王春香[1] 黄建忠[1] 

机构地区：[1]福建师范大学教育部工业微生物工程研究中心,福建福州350108

出　　处：《生物技术》2009年第1期51-55,共5页Biotechnology

基　　金：福建省科技攻关重大项目(2005Q007);福建省发改委重大项目(No.[2004]477)资助

摘　　要：目的:通过了解木聚糖酶高产菌株A79的遗传背景,并优化其产木聚糖酶的液体发酵条件,为下一步工业化生产和木聚糖酶制剂的研制奠定基础。方法:通过形态观察和18S rDNA基因的分子系统进化分析,对菌株A79进行鉴定;通过单因素和均匀设计试验,优化其产胞外木聚糖酶的液体发酵条件。结果:通过对18S rDNA基因的分子系统进化分析,菌株A79被鉴定为黑曲霉(Aspergillus nigerA79)。其最佳产酶培养基为:玉米芯5.0%,麸皮0.5%,纤维物质1.0%,玉米浆1.1%,(NH4)2SO40.8%,蛋白胨0.8%,CaCO30.5%,KH2PO40.23%,MgSO4.7H2O 0.08%,微量元素(Mandels)0.08%,pH自然。最佳发酵条件为:接种量5%(2.0×107),28℃2、50r/min振荡培养96h。结论:经优化培养,酶活力由前期的50 000u/ml提高到90 000u/ml,增加了近50%。Objective：To understand basic information and optimize submerged fermentation conditions for a high xylanase- producing strain A79 for developing available industrial technologies and commercial enzyme products. Method： Strain A79 was identified by molecular phyloganatic analysis of 18S rDNA sequences and improved to produce extracellular xylanase by orthogonal experiment design. Result：High xylanase- producing strain A79 was identified as Aspergillus niger by using molecular phylogenetic analysis of 18S rDNA sequences and morphological observation. Through orthogonal experiment, the optimal submerge fermentation condition was obtained for producing extracellular xylanases of Aspergillus niger A79. The suitable medium contained （W/V）：5.0% corncob, 0.5% wheat bran, 1.1% corn steep liquor, 0.8% （NH4）2SO4, 0.8% peptone, 0.5% CaCO3, 0.23% KH2PO4, 0.08% MgSO4·7H2O, 0.08% mandels, nature pH.Fermentation process was studied, and the result showed the optimum conditions for xylanase secretion was about 96 horns at 28℃ and 250rpm. Conclusion： The optimum xylanase activity of A79 was increased by 50% compared to that of previous 50 000μg/（ml·min）.

关 键 词：木聚糖酶 18SrRNA基因 系统进化分析 产酶条件 单因素和均匀设计实验 

分 类 号：Q946.5[生物学—植物学] Q93-331