一株哈茨木霉的鉴定及固态发酵产木聚糖酶条件研究

Identification of Trichoderma harzianum strain and xylanase production condition under solid state fermentation

以分离自平菇栽培污染菌包的菌株ZJ-01为研究对象,结合形态学以及核糖体蛋白18S序列同源性分析对菌株进行鉴定,并对菌株的产木聚糖酶条件进行优化。结果表明,菌株ZJ-01的形态与哈茨木霉(Trichoderma harzianum)形态相似,系统进化树分析发现ZJ-01与哈茨木霉亲缘关系较近,聚为一类,将该菌株归属为哈茨木霉。哈茨木霉ZJ-01固态发酵产木聚糖酶的最适碳源原料为玉米皮,最适氮源原料为玉米酒精酒糟,最适氮源和碳源原料质量比为8∶2,最适发酵时间为72 h。在此优化条件下,木聚糖酶活力可达3574 U/g。该结果可为进一步研究哈茨木霉产木聚糖酶用于生产低聚木糖的可行性奠定基础。

ZJ-01 strain isolated from contaminated fruiting body of oyster mushroom was used as the material,which was identified by morphological observation and homological analysis of ribosome 18S protein sequences,and the xylanase production conditions were optimized.The results showed that the morphology of ZJ-01 was similar to that of Trichoderma harzianum,and the phylogenetic tree analysis indicated that ZJ-01 strain had the closest genetic relation with T.harzianum BCS8A,then ZJ-01 strain was identified belonging to T.harzianum.The best carbon material and nitrogen material for xylanase production under solid-state fermentation of ZJ-01 were corn husk and corn alcohol distillate,respectively,and the most favorable mass ratio of nitrogen material and carbon material was 8∶2,the optimum fermentation time was 72 h.The xylanase activity was above 3574 U/g under the optimum conditions.The results could lay foundation for further study of feasibility for producing xylo-oligosaccharide with xylanase.