STARTER GRANT: Characterization of Catabolic Pathways for the Degradation of Plant-related Aromatics in the Marine Bacterium Silicibacter Pomeroyi

芳香族聚合物木质素及其相关化合物的生物降解对全球碳循环至关重要，但对天然群落及其相关过程知之甚少。美国东南部的沿海盐沼受到当地和异地来源的木质素相关化合物的严重影响，是调查分解者社区内的分解代谢途径的理想场所。海洋细菌的一个谱系的成员，Rosebrumclade，是特别适合这样的研究，因为它们是丰富的，在这些沿海盐沼，并假设是负责在这些系统中的芳香族化合物降解的一个显着的部分。该项目的重点是Roseberry分离物Silicibacter pomeroyi，并使用基因组数据，生理生长研究和基因表达水平，以更好地了解该组成员介导木质素单体成分转化的分解代谢过程和调控网络。pomeroyi揭示了三种潜在竞争的植物相关芳香族化合物降解途径的存在。其目的是：（i）确定木质素相关的化合物，可以利用的S。pomeroyi作为初级生长底物，（ii）鉴定三种途径pca、龙胆酸或boxA中的哪一种将是可分解代谢的底物，和iii.利用分子生物学方法监测这三条途径中关键酶的基因表达水平。详细描述了S. pomeroyi将提供所需的关键基础，以了解如何天然存在的芳香族化合物是由Roseoprotein血统的成员在环境中处理。该项目将通过其对代谢网络的贡献，治理过程的核心碳的地球化学循环的阐明产生广泛的影响。此外，它将为一名研究生和两名本科生提供培训机会。

The remineralization of the aromatic polymer lignin and its related compounds is critical to the global carbon cycle, yet little is known of the natural communities and the processes involved. The coastal salt marshes of the southeastern U.S. are heavily influenced by lignin-related compounds of local and allochthonous origins, and are ideal sites for investigations of catabolic pathways that are harbored within decomposer communities. Members of one lineage of marine bacteria, the Roseobacter clade, are particularly well-suited for such studies as they are abundant in these coastal salt marshes and are hypothesized to be responsible for a significant fraction of aromatic compound degradation in these systems. This project focuses on Roseobacter isolate Silicibacter pomeroyi and uses genome data, physiological growth studies, and gene expression levels to better understand the catabolic processes and regulatory networks mediating the transformation of the monomeric constituents of lignin by members of this group.The genome sequence of S. pomeroyi reveals the presence of three, potentially competing, pathways for the degradation of plant-related aromatic compounds. The aims are to: (i) Identify lignin-related compounds that can be utilized by S. pomeroyi as primary growth substrates, (ii) identify which of the three pathways, pca, gentisate, or boxA, will catabolizable substrates, and iii. utitlize molecular approaches to monitor gene expression levels of key enzymes of the three pathways. Detailed characterizations of the catabolic properties of S. pomeroyi will provide the critical foundation needed to understand how naturally-occurring aromatic compounds are processed by members of the Roseobacter lineage in the environment.This project will have broad impact through its contribution toward the elucidation of metabolic networks that govern processes central to the biogeochemical cycling of carbon. Moreover, it will support training opportunities for one graduate student and two undergraduate students.