Screening of Strain from Reconstituted Sheet Tobacco Making High-Yield Enzyme and Aroma

Reconstituted sheet tobacco (RST) is critical to the quality of cigarette. The purpose of this study was to extract and cultivate bacteria from tobacco leaf stalks, scraps, and concentrate from RST production lines. A total of 21 strains with unique morphologies were obtained. Through a series of screening tests, a Bacillus subtilis strain B-NS-7 was found for its ability to produce high levels of protease, amylase, and pectinase, as well as ferment tobacco concentrate to enhance aroma. The B-NS-7 fermented concentrate had a 48.3% increase in aroma compared to the original concentrate as determined by HS–SPME–GC–MS. The concentrate was inoculated with a 1% volume fraction of the strain and fermented at 37 °C for 24 h to achieve maximum aroma production of 116.3 μg/mL. Among these, neophytadiene was responsible for the majority of the fragrance enhancement, and B-NS-7 was identified as an aldehydic and alkene-flavored strain with superior sensory quality to the original liquid. This strain has been deposited at the China General Microbiological Culture Collection Center (CGMCC No. 23716). By way of this study, B. subtilis B-NS-7 was intended to be used in the manufacturing of RST through microbial fermentation to improve the quality, and the fermentation conditions for aroma creation were optimized, providing suggestions for the microbial development of the RST industry.