- 學位論文
芽孢桿菌屬、胚芽乳酸菌與冠突散囊菌生合成之有機揮發性物質分析
Study of volatile organic compounds from Bacillus sp., Lactiplantibacillus plantarum and Eurotium cristatum
本文將於2029/08/06開放下載。若您希望在開放下載時收到通知，可將文章加入收藏。
摘要
芽孢桿菌屬 (Bacillus sp.) 的細菌經常被認為是植物根際促生菌 (plant growth promoting rhizobacteria, PGPR)，又由於其具有內孢子形成能力，該屬細菌可以製成長期穩定且能抵抗不利環境條件的粉末或是液態產品，此類微生物產品被認為是化學肥料與農藥的最佳替代品。現今研究指出芽孢桿菌屬細菌具有多種揮發性有機化合物 (volatile organic compounds, VOCs) 且已被證實分別可以抗菌、促進植物生長和控制植物病蟲害。胚芽乳酸菌 (Lactiplantibacillus plantarum) 是一類常見於天然發酵蔬果、土壤或是動物腸道中的乳酸菌，具有其作為益生菌去優化食品品質與風味的潛力，現今已有團隊針對胚芽乳酸菌之 VOCs 進行發酵食品成分分析的相關研究。冠突散囊菌 (Eurotium cristatum) 是從茯磚茶 (Fuzhuan Brick Tea, FBT) 分離出來的金黃色真菌，現今已有針對冠突散囊菌之發酵茶中 VOCs 成分分析的相關研究，冠突散囊菌可以有效提升茶的風味和品質。本研究針對前述包括 5 種不同芽孢桿菌、胚芽乳酸菌及冠突散囊菌共 7 種微生物，在有、無含糖培養基的生長環境，針對不同培養時間後所生產之 VOCs 進行分析與比較，從中得知在不同培養基和生長時間下其 VOCs 產物及菌株之間 VOCs 組成成分之差異。結果顯示，在 YPSG 培養基中，Bacillus velezensis、Bacillus subtilis K1 和 Bacillus amyloliquefaciens 都會大量生產 acetoin；Bacillus megaterium能夠大量生產 3-methyl-1-butanol；Bacillus coagulans 具有大量生產 acetic acid、3-methyl-butanoic acid 和 2-methylbutanoic acid 的能力。在 MRS 培養基中，L.plantarum 產生較多 2,3,4-trimethyloxetane、3-methyl-1-butanol 和 acetic acid。在 YPD 培養基中，E.cristatum 以 2-butanone、trans-1,2-dimethylcyclopropane 和 2,3-butanediol 為主要產物。在 LB 培養基 (不含糖) 中，B.velezensis、B.subtilis K1 和 B.amyloliquefaciens 主要 VOCs 產物為 2,5- dimethylpyrazine；而 B.megaterium 和 B.coagulans 主要 VOCs 產物為 dimethyl disulfide、2,5-dimethylpyrazine 和 dimethyl trisulfide。因此，VOCs 的種類與產量會因為有無含糖而影響其豐富度。此外，從主成分分析 (Principal Component Analysis , PCA) 中發現在含糖培養基條件下，菌株被分成 4 個群落，B.velezensis、B. subtilis K1 和 B.amyloliquefaciens 一群，B.megaterium 和 L.plantarum 一群，B.coagulans 一群，E.cristatum 一群；在 LB 培養基中，芽孢桿菌屬菌株被分成 3 個群落，B.velezensis、B.subtilis K1 和 B.amyloliquefaciens 一群，B.megaterium 一群，B.coagulans 一群。在 PCA 分析中，被分類為同一群代表其 VOCs 組成成分相似度較高。
並列摘要
Bacillus sp. contain common plant growth promoting rhizobacteria (PGPR). As a result of its ability to form endospores, powder or liquid products that are long-term stable and resistant to adverse environmental conditions can be made of this genus of bacteria. This kind of microbial products are considered to be the best alternatives to chemical fertilizers and pesticide. It has been widely reported that Bacillus sp. strains have strong production capabilities of volatile organic compounds (VOCs). Furthermore, numerous VOCs from Bacillus sp. strains have also been used to promote plant growth as well as control plant diseases and pests. Lactiplantibacillus plantarum is a type of lactic acid bacteria commonly found in spontaneously fermented fruits, vegetables, soil, and animal intestines. It has the potential to be used as a probiotic to optimize food quality and flavor. Nowadays, there are a lot of research focus on the analysis of VOCs from L.plantarum in fermented foods. Eurotium cristatum is a golden-colored fungus isolated from Fuzhuan Brick Tea (FBT). More recently, there have been several analysis of VOCs in fermented tea. This fungus can effectively enhance the flavor and quality of the tea. In this study, we analyzed and compared the VOCs produced by 5 different Bacillus species, Lactiplantibacillus plantarum and Eurotium cristatum which cultured in media with and without sugar at different culture times. The results show that Bacillus velezensis, Bacillus subtilis K1, and Bacillus amyloliquefaciens all produce large amounts of acetoin in the YPSG medium; Bacillus megaterium is capable of producing plenty of 3-methyl-1-butanol; Bacillus coagulans has the ability to produce a large quantity of acetic acid, 3-methylbutanoic acid, and 2-methylbutanoic acid. In the MRS medium, L.plantarum produces higher amounts of 2,3,4-trimethyloxetane, 3-methyl-1-butanol, and acetic acid. In the YPD medium, E.cristatum mainly produces 2-butanone, trans- 1,2-dimethylcyclopropane, and 2,3-butanediol. In the LB medium (without sugar), the major VOCs produced by B.velezensis, B.subtilis K1, and B.amyloliquefaciens are 2,5-dimethylpyrazine, while the main VOCs produced by B.megaterium and B.coagulans are dimethyl disulfide, 2,5-dimethylpyrazine, and dimethyl trisulfide. Therefore, whether the presence of sugar affects the types and yield of VOCs. Moreover, principal component analysis (PCA) revealed that the strains could be separated into four clusters in sugar-containing medium. B.velezensis, B.subtilis K1, and B.amyloliquefaciens were classified as a separate cluster, B.megaterium and L.plantarum were one cluster, B.coagulans was another cluster, and E.cristatum was the other one. In the LB medium, Bacillus species were separated into three clusters. B.velezensis, B.subtilis K1, and B.amyloliquefaciens were classified as a separate cluster, B.megaterium was one cluster, and B.coagulans was the other one. In PCA analysis, we consider groups of VOCs having similar composition in the same cluster.
參考文獻
1.Barone GD, Zhou Y, Wang H, Xu S, Ma Z, Cernava T, Chen Y. 2024. Implications of bacteria‒bacteria interactions within the plant microbiota for plant health and productivity. J Zhejiang Univ Sci B doi:10.1631/jzus.B2300914:1-16.
2.Rangel LI, Bolton MD. 2022. The unsung roles of microbial secondary metabolite effectors in the plant disease cacophony. Curr Opin Plant Biol 68:102233.
3.Finkel OM, Castrillo G, Herrera Paredes S, Salas Gonzalez I, Dangl JL. 2017. Understanding and exploiting plant beneficial microbes. Curr Opin Plant Biol 38:155-163.
4.Montero-Montoya R, Lopez-Vargas R, Arellano-Aguilar O. 2018. Volatile organic compounds in air: sources, distribution, exposure and associated illnesses in children. Ann Glob Health 84:225-238.
5.Kanchiswamy CN, Malnoy M, Maffei ME. 2015. Bioprospecting bacterial and fungal volatiles for sustainable agriculture. Trends Plant Sci 20:206-11.