The microbial community of Vetiver root and its involvement into essential oil biogenesis
The microbial community of Vetiver root and its involvement into essential oil biogenesis
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DOI：
10.1111/j.1462-2920.2008.01703.x
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发表时间：
2008-10-01
影响因子：
5.1
通讯作者：
Alifano, Pietro
中科院分区：
文献类型：
--
作者：
Del Giudice, Luigi;Massardo, Domenica Rita;Alifano, Pietro
香根草是世界上唯一种植的植物，其根精油是倍半萜醇和烃的混合物，广泛用于香料和化妆品。光和透射电子显微镜表明，细菌的存在下，在皮层薄壁精油生产细胞和溶菌陷窝密切相关的精油。这一发现和证据表明，纯香根草在体外产生的只有微量的油与一个显着不同的组成相比，在体内香根草植物的油刺激的假设，这些细菌参与油代谢。我们使用基于培养和培养独立的方法来分析香根草根的微生物群落。结果表明，细菌的系统发育谱很广，包括α-，β-和γ-变形菌，高G + C含量的革兰氏阳性细菌，和属于纤维杆菌/酸杆菌组的微生物。我们分离了根相关细菌，并表明它们中的大多数能够通过使用油倍半萜作为碳源生长，并将它们代谢，将大量通常在商业香根草油中发现的化合物释放到培养基中。几种细菌也能够诱导香根草倍半萜合酶的基因表达。这些结果支持了一个有趣的假设，即细菌可能在精油生物合成中发挥作用，从而有可能使用它们来操纵香根草油分子结构。
Vetiver is the only grass cultivated worldwide for the root essential oil, which is a mixture of sesquiterpene alcohols and hydrocarbons, used extensively in perfumery and cosmetics. Light and transmission electron microscopy demonstrated the presence of bacteria in the cortical parenchymatous essential oil-producing cells and in the lysigen lacunae in close association with the essential oil. This finding and the evidence that axenic Vetiver produces in vitro only trace amounts of oil with a strikingly different composition compared with the oils from in vivo Vetiver plants stimulated the hypothesis of an involvement of these bacteria in the oil metabolism. We used culture-based and culture-independent approaches to analyse the microbial community of the Vetiver root. Results demonstrate a broad phylogenetic spectrum of bacteria, including alpha-, beta- and gamma-Proteobacteria, high-G+C-content Gram-positive bacteria, and microbes belonging to the Fibrobacteres/Acidobacteria group. We isolated root-associated bacteria and showed that most of them are able to grow by using oil sesquiterpenes as a carbon source and to metabolize them releasing into the medium a large number of compounds typically found in commercial Vetiver oils. Several bacteria were also able to induce gene expression of a Vetiver sesquiterpene synthase. These results support the intriguing hypothesis that bacteria may have a role in essential oil biosynthesis opening the possibility to use them to manoeuvre the Vetiver oil molecular structure.