一株产木聚糖酶菌株的鉴定及产酶条件研究  

Identification of a xylanase-producing fungi strain and xylanase production condition

作　　者：吴小建[1] 吴圣进[1] 汪茜[1] 韦仕岩[1] 王灿琴[1] 

机构地区：[1]广西农业科学院微生物研究所,南宁530007

出　　处：《南方农业学报》2016年第9期1522-1527,共6页Journal of Southern Agriculture

基　　金：广西自然科学基金项目(2010GXNSFD003);广西农业科学院科技发展基金重点项目(2010Z003)

摘　　要：【目的】对一株从木薯渣堆中分离得到的产木聚糖酶嗜热真菌JG-50菌株进行分类鉴定,并研究其利用木薯渣固态发酵产酶的最佳条件,为该菌株在农业有机废弃物发酵利用中的应用提供理论依据。【方法】采用真菌形态学观察和26S rDNA基因D1/D2区序列同源性分析方法对JG-50菌株进行分类鉴定,并以单因素试验方法对JG-50菌株产木聚糖酶的最佳碳源、氮源、培养时间、培养温度和培养基初始pH等发酵条件进行优化。【结果】菌株JG-50与嗜热子囊菌(Thermoascus aurantiacus isolate MTCC 4890)的26S rDNA序列相似性为99%,结合形态学特征初步鉴定为嗜热子囊菌属的一种。该菌株能以木薯渣为碳源固态发酵产木聚糖酶,其产酶的最佳条件为:以木薯渣为碳源,添加60%麦麸,0.3%蛋白胨和0.2%酵母粉,pH6.0,以此培养基50℃培养8 d,木聚糖酶活可达4625.4U/g(干培养基)。【结论】嗜热真菌JG-50具有较强的产木聚糖酶能力,在农业有机废弃物发酵利用领域具有良好的应用前景。[Objective]A xylanase-producing thermophilic fungi strain JG-50 isolated from cassava residue was classi-fied and identified, and its fermentation conditions for enzyme production was optimized, in order to provide technical support for its application in agricultural organic waste fermentation utilization. [Method]Strain JG-50 was identified based on morphologic observation and sequence homology analysis of D1/D2 domain of 26S rDNA gene. The fermentation conditions including carbon source, nitrogen source, culture time, culture temperature and initial pH were optimized by single factor test, for producing xylanase by strain JG-50. [Result]26S rDNA sequences similarity was as high as 99%between strain JG-50 and Thermoascus aurantiacus isolate MTCC 4890. Based on morphological observation and data of 26S rDNA sequences alignment, the strain JG-50 was identified as T. aurantiacus. Strain JG-50 was able to produce xy-lanase during solid state fermentation using cassava residue as carbon resource, and the optimal fermentation substrate were, 60% of wheat bran, 0.3% of peptone and 0.2% yeast powder, with pH of 6.0. In the above substrate, the enzyme activity of xylanase reached 4625. 4 U/g after fermenting for 8 days at 50 ℃. [Conclusion]Strain JG-50 has a consider-able ability of producing xylanase, and shows good application prospect on fermentation utilization of agricultural or-ganic waste.

关 键 词：嗜热子囊菌 分类鉴定 木聚糖酶 木薯渣 

分 类 号：Q939.96[生物学—微生物学]