The 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 Impact The 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.

Project Report

Methane-producing microorganisms have a significant impact on a number of issues related to our well-being including the production of renewable fuels from biological materials, nutrition in ruminant animals (cattle, sheep, goats, etc.), waste treatment, and greenhouse gas production. As such, a detailed knowledge of their biology is highly desirable. The increased knowledge of how methanogens adapt and thrive in nature informs and enhances applied research efforts in each of these areas. In this project, we employed a combination of genetic, molecular biological and biochemical approaches to study the mechanisms of gene regulation and substrate catabolism used by these unusual and poorly understood organisms. The results of our studies have broad scientific implications regarding the mechanisms by which methane-producing microorganisms sense and adapt to their environment. Our experiments revealed novel sensory and signal transduction systems that control gene expression in response to substrate availability. Bioinformatic analyses suggest that genes similar to the ones we identified will play a role in the regulation of many methanogen genes. Our results have significant implications regarding the molecular mechanisms of archaeal transcriptional control, and are consistent with a new paradigm for gene regulation, distinct from that found in either bacteria or eukaryotes. Further, the datasets we created can be used as benchmarks allowing other researchers to compare their results to ours. We also identified for the first time the genes needed to catabolize various methyl-sulfides, molecules that are abundant in marine ecosystems. These pathways are likely to be widely employed by other anaerobic microbes, helping to explain and quantify this aspect of the global sulfur and carbon cycles. In addition to the intellectual and scientific merits of this research, this project also served to enhance the broader scientific community. Four graduate students and one post-doctoral researcher received hands-on training during this study. The genetic tools and mutant strains created during this work were routinely provided to other research groups. Our lab also hosted students from other universities for training in the anaerobic and genetic techniques needed to study methanogenic archaea. Finally, we provided facilities, resources and advice to local elementary and secondary school teachers who wished to expose their students to the excitement of the microbial world.

Project Start
Project End
Budget Start
2010-09-01
Budget End
2014-08-31
Support Year
Fiscal Year
2010
Total Cost
$697,263
Indirect Cost
Name
University of Illinois Urbana-Champaign
Department
Type
DUNS #
City
Champaign
State
IL
Country
United States
Zip Code
61820