烟叶发酵过程中产木聚糖酶菌株的分离及鉴定

本文研究了微生物对烟叶增香的作用，研究结果对烟叶发酵有着重要意的义。在研究中用于筛选的烟叶样品选自三个年份（2007年、2008年、2009年）的五个产地（毕节、楚雄、昆明、曲靖、襄县），即有15组样品。对烟叶样品依次进行微生物的富集、分离纯化实验，然后进行产木聚糖酶菌株的筛选，筛选培养基经刚果红染液染色之后，以菌落周围出现透明圈作为产木聚糖酶菌株的筛选标准。然后对筛选出的73株产酶菌株采用3,5-二硝基水杨酸比色法（DNS法）进行木聚糖酶酶活力的测定，从中选择一株产酶活性较高的菌株-Qb4号菌株，进行形态学分析实验、生理生化实验、碳源利用分析实验以及16SrRNA保守序列分析，最终将该菌鉴定为甲基营养型芽孢杆菌。将该菌应用于烟叶増香工艺流程中，是未来本课题研究的主要方向。

Screening and Identification of a Xylanase-producing Strain during Tobacco Fermentation

Microorganisms play an important role in tobacco aroma improving. The tobacco samples were selected from five areas (Bijie, Chuxiong, Kunming, Qujing, and Xiangxian) of three years (2007, 2008 and 2009), using nutrient agar for purification, and then cultured in the screening xylanase base for rescreening. The xylanase-producing strains was screened by determining the appear transparent circles among the colonies after Congo red staining. The xylanase activities of these strains were measured by 3,5-Dinitrosalicylicacid (DNS). Qb4 strain, which had higher xylanase activity, were identified as Bacillus methylotrophilus by analysis of its morphological, physiological and biochemical characteristics, carbon source utilization and the 16S rRNA conserved sequence.