关键词: 双倒卵形红酵母, 红枣, 烟用香原料, 微生物发酵, 卷烟加香, 全基因组测序

Abstract: To screen and identify aroma‐producing yeasts suitable for jujube fermentation with excellent aroma‐enhancing performance，and to provide strain resources for the development of high‐quality tobacco flavoring materials，the following procedures were carried out.Yeast strains were screened by preliminary olfactory evaluation and cigarette flavoring assessment of fermentation broths，and identified using matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry（MALDI‐TOF‐MS）combined with molecular biological methods.Whole‐genome sequencing was performed to analyze genomic sequences and predict gene functions.Response surface methodology was employed to optimize fermentation conditions，gas chromatography‐mass spectrometry（GC‐MS）was applied to analyze changes in aroma components，and the aroma‐enhancing effects were further validated through cigarette flavoring evaluation. The results showed that 17 aroma‐producing yeast strains were obtained by preliminary olfactory screening. Sensory evaluation indicated that strain H61 exhibited the most significant aroma‐enhancing effect and was identified as Rhodotorula diobovata. Its genome sequence length was 23 217 526 bp，with a GC content of 66.6%，and 8 114 coding genes were predicted.A total of 3 103 coding genes were annotated in the KEGG database，among which genes involved in carbohydrate and amino acid metabolism were relatively abundant in metabolic pathways. The optimum fermentation conditions were obtained by response surface methodology as follows：fermentation time 30 h，inoculum size 5%，fermentation temperature 29 ℃. GC‐MS analysis showed that the total aroma content of the jujube extract fermented by H61 was increased by 2.35 times compared with the CK1 group（jujube liquid inoculated with an equal volume of sterile water and fermented under the same conditions），and the contents of five aroma substances such as γ‐undecalactone，phenethyl acetate and hydroxyacetone were obviously increased.The sensory evaluation score was 59.1 points，which was significantly increased by 47.75% compared with the CK2 group（jujube extract prepared by fermentation with an equal volume of sterile water under the same conditions）.The eight indicators such as aroma volume，fineness and cleanliness were significantly improved. In conclusion，Rhodotorula diobovata H61 exhibits excellent aroma‐producing characteristics and promising application potential in fermentation，showing good prospects in the development of tobacco flavor ingredients derived from jujube and the improvement of cigarette sensory quality.

Key words: Rhodotorula diobovata, Jujube, Tobacco flavor raw material, Microbial fermentation, Cigarette flavoring, Whole‐genome sequencing