From Symbiosis to Methanotrophy: Diverse Functions in Rhizobiales

自1995年以来，我们的NSERC发现项目一直围绕着紫花苜蓿的固氮共生体Sinorhizobium meliloti展开。这是我们实验室所有其他工作的基础。根据这一建议，我们将继续在S. meliloti中开展工作，研究根瘤感染的遗传控制，以及PHB代谢（主要的细胞内碳储存）与氮代谢之间的调节联系。我们还将把我们的研究扩展到根瘤菌目的另一个成员，Methylosinus trichosporium菌株OB3b，这是我们几年前开始研究的。该菌株是一种甲烷营养菌，它的碳利用能力有限，仅限于C1化合物，如甲烷和甲醇。我们将研究PHB在甲烷营养生长中的作用，并启动定义最小甲烷营养基因组的研究。对毛孢霉的研究将促进这一重要甲烷化菌基因组工程方法的发展和完善，为开发将甲烷转化为高价值生物产品的专门菌株铺平道路，并为甲烷化的遗传和代谢需求提供见解。

Our NSERC Discovery program has revolved around Sinorhizobium meliloti, the nitrogen fixing symbiont of alfalfa, since 1995. This has served as the foundation for all other work in our lab. With this proposal, we are continuing to work in S. meliloti, investigating genetic control of root nodule infection, and also regulatory links between metabolism of PHB, which is the major intracellular carbon store, and nitrogen metabolism. We will also extend our research to another member of the order Rhizobiales, Methylosinus trichosporium strain OB3b, which we started working on a few years ago. This strain is a methanotroph, which has a restricted carbon utilization capability, limited to C1 compounds such as methane and methanol. We will investigate the role of PHB in methanotrophic growth, and initiate research towards defining the minimal methanotrophic genome. The work in M. trichosporium will result in the development and refinement of genome engineering methods for this important methanotroph, pave the way for development of specialized strains for the conversion of methane to high value bioproducts, and provide insight into the genetic and metabolic requirements for methanotrophy.