一株降解木聚糖真菌的筛选及其发酵条件优化  

Screening of a Strain of Xylan-degrading Fungi and Optimization of Its Fermentation Conditions

作　　者：张健[1] 汪桐[1] 徐争辉[1] 郭莹莹[1] 李峰[1] 

机构地区：[1]淮北师范大学生命科学学院资源植物生物学安徽省重点实验室,安徽淮北235000

出　　处：《安徽农业科学》2012年第26期12773-12777,共5页Journal of Anhui Agricultural Sciences

基　　金：安徽高校省级科学研究项目(KJ2010B193)资助

摘　　要：[目的]从自然界中筛选出具有木聚糖酶活力的菌株,为今后降解农作物秸秆提供材料。[方法]以木聚糖为唯一碳源,从土壤中筛选能够降解木聚糖的菌株,并对其进行鉴定和发酵条件优化。[结果]从土壤中筛选出一株能够降解木聚糖的菌株,综合菌落、菌体形态特征和18S rRNA序列分析,初步鉴定该菌株为土曲霉(Aspergillus terreus thom.)GY-1。单因素试验研究表明,菌株GY-1最佳碳源为蔗糖,Mg2+能提高其木聚糖酶活力,最佳氮源为硝酸铵,最适温度为30℃,最适pH为6.0,该菌在培养52 h时木聚糖酶活力最高,为880.11 U/ml。L16(45)正交试验结果表明,GY-1的接种量以及培养基中蔗糖、Mg2+和硝酸铵的添加量对其木聚糖酶活力均有显著影响,GY-1菌株的最优发酵条件为:50 ml基础发酵培养基中,接种量2%,蔗糖1 g,硝酸铵0.03 g,Mg2+0.004 mol。[结论]该研究首次报道了土曲霉具有木聚糖酶活力,为研究土曲霉降解木聚糖提供了一定的试验依据。[ Objective ] To screen some xylan-degrading strains from nature and also provide material for degrading straw. [ Method] The xylan was used as sole carbon source to screen some strain capable of degrading xylan cellulolytie from the soil,the strain was then identified, and its fermentation conditions were optimized. [Result] A xylan-degrading strain was screened out from the soil. According its colony,morphological characteristics and the 18S rRNA sequence analysis ,the strain was identified to be Aspergillus terreus ,GY-1. The single factor experiments showed that the best carbon source was sucrose,Mg2＋ could improve xylanase activity, the best nitrogen source was ammonium nitrate, the most suitable temperature was 30 ℃, the most suitable pH was 6.0, xylanase activity of GY-1 was the highest for 880. 11 U/ml in 52 h. And L15 （45 ） orthogonal test showed that the quantity of GY-1 ＇s inoculatlon,sucrose,Mg and ammonium nitrate dosage had a significant effect on xylanase activity ,the optimal conditions were 50 ml fermentation medium,2% inoculation quantity, l g sucrose ,0.03g ammonium nitrate, and 0. 004 tool Mg2＋ [ Conclusion] The experiment reports that Aspergillus terreus has xylanase activity for the first time and provides a test basis for Aspergillus terreus degrading xylan.

关 键 词：木聚糖 土曲霉 单因素试验 正交试验 

分 类 号：S188[农业科学—农业基础科学] Q369[生物学—遗传学]