蜡样芽孢杆菌(Bacillus cereus)筛选鉴定及在雪茄烟叶发酵中的应用研究

摘要

采用酪蛋白水解实验和蛋白酶活力测定对烟草表面微生物进行分离筛选,对所筛选菌株进行形态学观察、理化试验及16SrRNA基因测序的鉴定.将筛选所得菌株x-2添加到雪茄烟叶表面进行人工发酵,对发酵后烟叶进行常规氮化合物测定和感官质量评吸,结果表明:筛选所得菌株x-2在45℃时其产酸、中、碱性蛋白酶最高酶活力分别为91.63 U/mL、163.34 U/mL、43.82 U/mL,经过鉴定为蜡样芽孢杆菌(Bacillus cereus).在雪茄烟叶堆积发酵过程中添加x-2可明显降低烟叶含氮化合物含量,发酵结束时烟叶总氮降低21.64％、蛋白质降低13.53％、总植物碱降低36.38％,挥发碱降低24.05％;感官评吸结果显示烟叶劲头、刺激性改善最为明显,同时杂气减轻、香气增加.%One bacterial strain named x-2 was isolated from tobacco leaves and was identified belonging to Bacillus cereus on the basis of 16S rRNA gene sequencing and biochemical properties. X-2 pure culture was applied in artificial fermentation of cigar leaf, and thereafter determination of general nitrogen compound and sensory quality evaluation were carried out. Results showed that after fermentation total nitrogen, protein, total alkaloid, and volatile were decreased by 21.64% , 13.53% , 36.38% and 24.05% , respectively. Smoking tests implied that x-2 pure culture may cause more pleasing aroma while less undesirable tastes and bitterness.