Tobacco, a vital economic crop, had its quality post-curing significantly influenced by starch content. Nonetheless, the existing process parameters during curing were inadequate to satisfy the starch degradation requirements. Microorganisms exhibit inherent advantages in starch degradation, offering significant potential in the tobacco curing process. Our study concentrated on the microbial populations on the surface of tobacco leaves and in the rhizosphere soil. A strain capable of starch degradation, designated as BS3, was successfully isolated and identified as Bacillus subtilis by phylogenetic tree analysis based on 16SrDNA sequence. The application of BS3 on tobacco significantly enhanced enzyme activity and accelerated starch degradation during the curing process. Furthermore, analyses of the metagenome, transcriptome, and metabolome indicated that the BS3 strain facilitated starch degradation by regulating surface microbiota composition and affecting genes related to starch hydrolyzed protein and key metabolites in tobacco leaves. This study offered new strategies for efficiently improving the quality of tobacco leaves.

中文翻译：

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烟叶烘烤过程中淀粉降解菌的筛选、鉴定及机理分析

烟草作为重要的经济作物，其烘烤后的品质受淀粉含量的影响显着。然而，现有的固化过程参数不足以满足淀粉降解要求。微生物在淀粉降解方面表现出固有的优势，为烟草烘烤过程提供了巨大的潜力。我们的研究集中在烟叶表面和根际土壤中的微生物种群。成功分离并鉴定出一株具有淀粉降解能力的菌株，命名为BS3枯草芽孢杆菌基于16SrDNA序列的系统发育树分析。 BS3在烟草上的应用显着增强了酶活性并加速了烘烤过程中淀粉的降解。此外，宏基因组、转录组和代谢组的分析表明，BS3菌株通过调节表面微生物群组成并影响与烟叶淀粉水解蛋白和关键代谢物相关的基因来促进淀粉降解。该研究为有效提高烟叶质量提供了新策略。