This microbiological research by Dr. Deming will focus on the positive interactive effects between elevated hydrostatic pressures and extremes in temperature. The work seeks to understand the limits of life on this planet (and perhaps elsewhere), both during early Archaean stages and in more contemporary settings. By focusing on the simplest of microorganisms and on environmental parameters conventionally viewed as biologically inhibitory, Dr. Deming has discovered novel types of bacteria operating in environments previously considered depauperate if not sterile of life, from hadal depths (8300m) in the Puerto Rico Trench to superheated hydrothermal vents (350 C) in the Pacific to subzero muds in the Arctic. During the period of this Presidential Young Investigator award, Dr. Deming will research bacteria from the benthic marine environment to address several issues: * What is the molecular-genetic basis for stable metabolic processes at the most extreme conditions to temperature and pressure? * Do bacteria from extreme marine environments produce extracellular enzymes of unique physical/chemical properties that alter the environments apart from living organism? * To what extent is the ecological importance of benthic bacteria tied to relationships (symbiotic, mutualistic) with other marine inhabitants? * What is the global significance of carbon cycling by benthic bacteria, especially in climatically dynamic polar regions and hydrodynamically variable temperate zones? Sea-going portions of the research plan will involve in situ measurements of the carbon-cycling activities of natural bacterial assemblages in benthic samples, using microscopic and radioisotopic tracer techniques. Laboratory research will include recovery of novel microorganisms and selected enzymes and nucleic acids, experimental tests for activity and stability of both the organism and its constituents under extreme temperatures and pressures, and molecular study of those genes most likely to open new avenues of both fundamental and applied research.
