Abstract: The amylase‑producing strain Bacillus velezensis A8‑1 preserved in the early stage of the experiment was used as the test strain，and its metabolic capacity and sensitivity to different carbon sources and chemical substances were analyzed by Biolog technology.The enzyme production process was optimized through single‑factor experiments，Placket‑Burman experiments and Box‑Behnken experiments.The amplification effect of the process was verified by fermentation in a 1 000 L tank，and the change characteristics of chemical composition and sensory quality of tobacco leaves after the application of amylase produced by this amylase‑producing strain in tobacco leaf fermentation were explored.The results indicated that among the 70 different carbon sources，Bacillus velezensis A8‑1 had metabolic capacity for 65 of them and was intolerant to most of the bacteriostatic agents.The optimal shaking flask fermentation conditions after fermentation optimization were as follows：corn flour 20 g/L，soybean cake flour 80 g/L，K₂HPO₄ 1 g/L，fermentation time 36 h，temperature 37 ℃ ，pH value 7，inoculation amount 3%，and liquid loading volume 50 mL. Under these conditions，the enzyme activity could reach up to 133.3 U/mL at most.In a 1 000 L fermenter，the enzyme activity was 161.0 U/mL.After applying this amylase to the fermentation of tobacco leaves，the starch content of the tobacco leaves decreased by 15.4%，while the contents of reducing sugar and total sugar increased by 5.6% and 8.5% respectively.The contents of polyphenolic compounds，amino acids and Amadori compounds all increased to varying degrees，indicating that it had certain improvement effects on the chemical composition of tobacco leaves. The sensory evaluation results showed that the fermented tobacco leaves improved to varying degrees in terms of comfort，smoke characteristics and aroma style，with the total sensory evaluation score increasing by 0.64 points.In conclusion，the industrial fermentation production of the amylase‑producing strain Bacillus velezensis A8‑1 is feasible，and the application of the produced amylase in tobacco leaf fermentation can effectively improve the quality of tobacco leaves and has good practical application prospects and promotion value.

Key words: Bacillus velezensis, Amylase, Fermentation, Optimization, Process amplification, Tobacco

摘要： 以前期保存的产淀粉酶菌株贝莱斯芽孢杆菌（Bacillus velezensis）A8-1为供试菌株，利用Biolog技术分析其对不同碳源及化学物质的代谢能力与敏感度；通过单因素试验、Plackett-Burman试验及Box-Behnken试验优化其产酶工艺，经1 000 L罐发酵验证工艺放大效果，并探究该产淀粉酶菌株所产淀粉酶应用于烟叶发酵后，烟叶化学成分与感官品质的变化特征。结果表明，70 种不同碳源中，Bacillu svelezensis A8-1对其中的65种有代谢能力，且对大部分抑菌剂无耐受能力。经发酵优化后的最优摇瓶发酵条件为玉米粉20 g/L、黄豆饼粉80 g/L、K₂HPO₄ 1 g/L、发酵时间36 h、温度37 ℃、pH值7、接种量3%、装液量50 mL，在此条件下，酶活力最高可达133.3 U/mL；在1 000 L发酵罐中，酶活力为161.0 U/mL。将该淀粉酶应用于烟叶发酵后，烟叶的淀粉含量降低15.4%，还原糖和总糖含量分别增加5.6%和8.5%，多酚类化合物、氨基酸和Amadori化合物含量均有不同程度提升，表明其对烟叶化学成分有一定的改善作用。感官评价结果显示，发酵后的烟叶在舒适感、烟气特征和香气风格等各方面有不同程度改善，感官评价总分提高0.64分。综上，产淀粉酶菌株Bacillus velezensis A8-1工业化发酵生产具有可行性，所产淀粉酶应用于烟叶发酵可有效改善烟叶品质，具有较好的实际应用前景与推广价值。

关键词: 贝莱斯芽孢杆菌, 淀粉酶, 发酵, 优化, 工艺放大, 烟草