西柏三烯-4,6-二醇降解菌的筛选鉴定及其在再造烟叶中的应用

Screening and Identification of a Cembratriene-4,6-diol Degradating Strain and Its Application in Reconstituted Tobacco

为明确西柏三烯-4,6-二醇(CBT)的生物降解机制,探究CBT降解菌在再造烟叶中的应用,以CBT(0. 3 g/L)为唯一碳源,采用稀释涂布平板法从初烤后烟叶中分离得到1株高效降解CBT产香的菌株H3-1,该菌株发酵30 h后CBT的降解率达到85. 85%,降解产物为金合欢醛,在培养基中加入麦芽糖(2 g/L)时,发酵液中有茄酮检出;根据形态特征和系统进化树分析,初步鉴定菌株H3-1为新鞘氨醇杆菌(Novosphingobium sp)。将H3-1菌制剂按5%接种到再造烟叶浓缩液中,发酵24 h后检测发现,苯甲醇、2-乙酰基吡咯、甲基麦芽酚、苯乙醇、2-乙基-3-甲基马来酰亚胺、甲基环戊酮、茄酮、二氢猕猴桃内酯、4-羟基-β-二氢大马酮、9-羟基-4,7-巨豆三烯酮、4-(3-羟基丁基)-3,5,5-三甲基-2-环己烯-1-酮、叶绿醇、棕榈酸含量升高;评吸结果显示,发酵后再造烟叶较发酵前相比香气浓度和香气量均有所改善。综上,新鞘氨醇杆菌H3-1可降解CBT生成金合欢醛和茄酮,且该菌株具有增加再造烟叶浓缩液香气量、提高香气质的作用。

To study the biodegrading mechanism and application of cembratriene-4,6-diol(CBT)degrading bacteria in reconstituted tobacco,a high efficient CBT degrading strain H3-1 was isolated from tobacco leaf by spread plate method.As the sole carbon and energy source,85.85%CBT can be degraded with this bacterium strain in 30 h,and the main degradation product is farnesal.In addition,when the maltose(2 g/L)was added to the medium,the degradation product contained solanone.The strain H3-1 was identified preliminarily as Novosphingobium sp through the analysis of classical morphology and ITS sequence of phylogenetic tree.Adding strain H3-1(5%)in reconstituted tobacco concentrate solution,The results showed that the concentration of benzyl alcohol,2-acetylpyrrole,3-hydroxy-2-methyl-4H-pyran-4-one,benzyl alcohol,2-ethyl-3-methyl-maleimide,methyl-cyclopentanone,solanone,dihydroactinidiolide,4-hydroxy-β-damascone,9-hydroxy-4,7-giant bean three ketene,4-(3-hydroxybutyl)-3,5,5-trimethyl 2-cyclohexene-1-ketone,phytol and palmitic acid were increased after 24 h,and smoking results showed that the concentration of aroma and aroma quantity were improved.In conclusion,Novosphingobium sp H3-1 can improve the smoking quality of reconstituted tobacco through degrading CBT into farnesal and solanone.