Genetic Analysis of Methylotrophic Methanogenesis in Methanosarcina Species

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Intellectual MeritThe long-term goal of this project is to understand the physiology, metabolism and ecology of methanogenic archaea through the study of experimentally tractable Methanosarcina species. The primary emphasis of these experiments will be the identification and characterization of genes that affect the use of one-carbon (C-1) compounds such as methanogenic substrates, including those that indirectly affect the process by regulating expression of the required genes. In particular, the sensing and signal transduction mechanisms involved in regulating the expression of genes needed for methanol catabolism will be examined; the genetic basis for production and consumption of methylsulfides, compounds that play a critical role in the global climate will also be investigated. To achieve these goals the following specific questions will be addressed: (1) What are the molecular mechanisms of environmental sensing and signal transduction in Methanosarcina; (2) Which Methanosarcina genes are regulated as members of the archaeal-specific Msr family of regulatory proteins; (3) What other genes are required for use of C-1 compounds in Methanosarcina; and (4) What is the extent and mechanism of post-transcriptional gene regulation in Methanosarcina? The experiments will utilize recently developed methods for genetic analysis of Methanosarcina; however, physiological, biochemical and molecular approaches will complement the genetic approach. This strategy is expected to generate data that are both novel and complementary to the results of preceding studies. The intellectual merit of the proposed research relates to the central role of methanogenic microorganisms in a number of societal problems including the production of alternative fuels from biological materials, the role of methane-producing organisms in agriculture and waste treatment, and global warming (methane is a potent greenhouse gas). The results of the proposed studies are expected to have broad implications with respect to the role of methanogens in the biosphere by revealing novel aspects of the methylotrophic pathway and by lending insight into the mechanisms for linking environmental conditions to appropriate gene expression. Moreover, a clearer understanding of the molecular mechanisms involved in archaeal transcriptional and translational control should result from examination of the highly regulated methylotrophic genes. Broader ImpactThe broader impacts of the proposed research include the training of future scientists and academics. Two graduate students will be directly supported by the requested funds; several additional students will also work on the project. The lab commonly hosts students from other universities to provide hands-on training in the labs methods. Based on past results, this study is also likely to produce new genetic tools and methods that will be useful, and freely available, to the wider microbial research community. Genetic tools and mutant strains are routinely provided to other research groups, regardless of whether they have been published. Finally, the laboratory routinely provides facilities, resources and advice to local elementary and secondary school teachers who wish to expose their students to the excitement of the microbial world.