关键词: 雪茄, 发酵, 微生物多样性, 酶活, pH

Abstract: Fermentation of tobacco leaves plays a key role in cigar quality and special favor. This paper studied the microbial diversity of tobacco leaves of two cultivars at different fermentation stages and the variation of three hydrolytic enzymes (protease, amylase and pectinase). It was found that the microbial floras were dynamic during the fermentation process. The microbial community of sample 1 was dominated by Staphylococcus at the early stage and changed to Enterobacter, Pseudomonas, and Brevibacterium at the end, while sample 2 had Staphylococcus and Tetragenococcus as the predominant species over the whole process. The enzyme activities changed a lot between cultivars and during the fermentation. For sample 1, the protease and amylase activities were maximal (165.95 U·g-1 and 0.34 U·g-1, respectively) at the end of fermentation, while the highest pectinase activity (1.30 U·g-1) was detected at the beginning. The protease activity (121.57 U·g-1) of sample 2 was the highest at the end, but lower than that of sample 1; and the pectinase and amylase activities in the middle reached to the peak,1.60 and 0.38 U·g-1, respectively, which were more than that of sample 1. Moreover, the pH of sample 1 changed significantly over the whole fermentation process, and changed to alkaline (pH 7.6) in the middle stage; and the pH of sample 2 changed little and kept acidic in three fermentation stages.

Key words: cigar, fermentation, microbial diversity, enzyme activity, pH