Lipid Analysis in Microbial Ecology

n nature, microorganisms rarely exist as monocultures, but live in communities with other microbes. These communities play an important role in the biosphere, primarily in recycling biologically important elements. All the essential biochemical cycles of carbon, hydrogen, nitrogen, oxygen, and sulfur are mediated by communities of microorganisms. Consequently, understanding what microbes in a natural environment are doing, rather than simply which microbes are present, is important to understanding their role within ecosystems. Analytical techniques developed in the last decade offer insights into the nature of these important ecosytem components. Microbial communities include viruses, eubacteria, archaebacteria, fungi, protozoa, micrometazoa, and algae (Margulis et al. 1986). The communities exist throughout the biosphere and even occupy such extreme environments as boiling-hot springs (Brock 1978); the deep sea at high hydrostatic pressure (ca. 1200 atmospheres; Jannasch and Taylor 1984); the cold deserts of Antarctica in the pore spaces of sandstone (Friedmann 1982); deep subsurface Analytical techniques developed in the last decade offer insights into these important