貝萊斯芽孢桿菌在改善雪茄煙葉品質中的應用?

摘 要：以CX-014雪茄茄衣晾制結束后的煙葉為材料，對其進行微生物分離純化，從中篩選出了一株產酶豐富且酶活均處于中高水平的菌株H1，通過形態學和分子生物學方法對該菌株進行了鑒定，并探究了在雪茄煙葉發酵過程中添加外源苯丙氨酸和葡萄糖對該菌株降解煙葉中大分子物質、增加雪茄煙葉香氣成分的促進作用。結果表明：H1菌株被鑒定為貝萊斯芽孢桿菌（Bacillus velezensis）；在添加外源營養物的條件下經菌株H1發酵后的雪茄煙葉中果膠降解率達到34.93%，淀粉、木質素、蛋白質和纖維素等大分子物質的含量也明顯降低；當接菌量為2.4×107 CFU/g，并添加0.25%苯丙氨酸和0.5%葡萄糖的外源物質的情況下，雪茄煙葉在37℃下發酵6 d后，煙葉中新增了異佛爾酮和2，5-十八碳二炔酸甲酯等香氣物質，且β-大馬酮、2-仲-丁基環戊酮等的含量明顯增多，香氣得到明顯改善。同時，菌株H1的產香發酵成本低，操作工藝簡單，可以在工業生產中推廣，以提高煙葉品質。

關鍵詞：貝萊斯芽孢桿菌；雪茄煙葉；降解酶；品質；增香

中圖分類號：TS444 文獻標識碼：A 文章編號：1006-060X（2023）04-0082-08

Abstract：With the cured wrapper of a cigar tobacco CX-014 as material， a strain H1 producing abundant hydrolases of good activities was" selectively obtained through microbial isolation and purification. Then the morphologic observation and molecular biology method were used for its identification. Whether it could facilitate the hydrolysis of macromolecules and the formation of aroma substances in cigar tobacco during the fermentation process in the presence of exogenous phenylalanine and glucose was further explored. The identification results showed that strain H1 was Bacillus velezensis. Relying on fermentation by strain H1 along with adding exogenous nutrients， the degradation rate of pectin in cigar leaves reached 34.93%， and the contents of macromolecules such as amylum， lignins， proteins and cellulose also decreased significantly. After 6-day fermentation at 37℃ under the conditions of an inoculation amount being 2.4×107 CFU/g and adding 0.25% phenylalanine and 0.5% glucose，" some new aromatic substances like isophorone and 2， 5-octadecadiynoic acid methyl ester appeared， meanwhile the contents of β-damascenone and 2-sec-butylcyclopentanone significantly increased， so that the aroma note of the cigar tobaccos was improved markedly. In conclusion， the flavoring fermentation cost of strain H1 is low and the operation process is simple， so it can be popularized in industrial production to improve the quality of tobacco leaves.

Key words： Bacillus velezensis; cigar tobacco leave; hydrolases; quality; flavoring

未經醇化的雪茄煙葉雜氣較重，因此提高雪茄煙葉品質必需進行醇化，而在煙葉醇化過程中微生物的作用非常關鍵，雪茄煙葉經微生物發酵后其香氣變得豐富、柔和[1]。目前研究人員認為對雪茄煙葉進行發酵和醇化是改善煙葉品質的一個重要生化過程，其機理主要分為酶作用、微生物作用和化學作用3大類[2-3]。雪茄煙葉表面微生物能夠合成分泌多種胞外水解酶，這些酶可以加快淀粉、果膠、纖維素、蛋白質和木質素等大分子物質的降解，將其轉化為一些小分子化合物，使化學成分協調，減輕辛辣和雜氣，增加香氣化合物含量，最終改善煙草品質[4-6]。……