Although the biomass of microbes dwarfs that of plants and animals, it was only recently that science became aware of the two microscopic biological domains. But from the moment the first optical instruments revealed the curious and numerous forms taken by microbes, a new discipline was born dedicated to the study of life beyond the naked eye.
The early microscopists were struck by the extraordinary range of organisms in a sample as prosaic as a drop of pond water, but deep diversity remains the predominant feature of the microbial world. In March 2004, more than 300 years after the first observations of bacterial communities, Dr Craig Venter, pioneer of the human genome project, found over 1,800 new species and 1.2 million genes during a sequence-based inventory of microbes in a sea water filtrate. Other than in the pathogenesis of infectious disease, there are few circumstances where pure cultures occur in nature.
The definition of the modern biosphere itself reflects the astounding ability of microbes to thrive under extreme physico-chemical conditions. And beyond merely surviving, microbial metabolism wrought from a cooling volcanic wasteland an environment from which blossomed the beauty and diversity of modern life on Earth.
We will review the history of microbiology, then survey the structures, energetics, biochemistry, and genetics that lie at the mechanistic heart of microbial diversity, adaptability and ecology. Stable microbiological relations with other species will be investigated and the interactions that microbes have with humans will be explored through their roles in pollution, disease, agriculture and biotechnology: from the Alpine Iceman’s hipflask to modern expression technology.
The class will conclude with a study of life under the extreme conditions to be found on Earth, followed by a discussion of the potential for life on other planets, and the approaches being taken to find it.