Microbial Genomics
at the U.S. Department of Energy

Fun Facts About Microbes

• Microbes first appeared on earth about 3.5 billion years ago. They are critically important in sustaining life on our planet.
• Microbes outnumber all other species and make up most living matter.
• Less than .5% of the estimated 2 to 3 billion microbial species have been identified.
• Microbes comprise ~60% of the earths biomass.
• Microbes drive the chemistry of life and affect the global climate.
• Microbial cycling of such critical chemical elements as carbon and nitrogen helps keep the world inhabitable for all life forms.
• Microbes generate at least half the oxygen we breathe.
• Microbes thrive in an amazing diversity of habitats in extremes of heat, cold, radiation, pressure, salinity, acidity, and darkness, and often where no other life forms could exist and where nutrients come only from inorganic matter.
• Microbes offer unusual capabilities reflecting the diversity of their environmental niches. These may prove useful as a source of new genes and organisms of value in addressing bioremediation, global change, biotechnology, and energy production.
• Microbial studies will help us define the entire repertoire of organisms in specialized niches and, ultimately, the mechanisms by which they interact in the biosphere.
• Diversity patterns of microorganisms can be used for monitoring and predicting environmental change.
• Microbes are roots of life's family tree. An understanding of their genomes will help us understand how more complex genomes developed.
• Microbial genomes are modest in size and relatively easy to study (usually no more than 10 million DNA bases, compared with some 3 billion in the human and mouse genomes).
• Microbial communities are excellent models for understanding biological interactions and evolution.
• Most microbes do not cause disease.