|Agar plate with microorganisms. Public domain image. SOURCE.|
The field began when Antonie van Leeuwenhoek (1632-1723), a Dutch draper who ground lenses and created microscopes as a hobby, described and drew many microorganisms, which he called "animalcules". Microbiology was further developed when in 1864 Louis Pasteur disproved spontaneous generation (or abiogenesis; that living things could come from nonliving matter) and Ferdinand Cohn classified bacteria in 1872.
There are eight important characteristics of microorganisms: morphology (size, shape, and arrangement of cells), nutrition, physiology, reproduction and growth, metabolism, pathogenesis (whether the microorganism is disease-causing), antigenicity (whether the microorganisms causes antibodies to be released when introduced into an animal), and genetic characterization (the chemical composition, synthesis, and replication of genetic material).
These characteristics are studied using a range of technology. Microscopy includes light microscopy (light microscopes have magnifications up to 2000x), electron microscopy (with magnifications that enable things as small as .02 nanometers), atomic force microscopy (which can create images of any material), scanning tunneling microscopy (which generates 3D images), and immunoelectron microscopy (which uses antibodies to detect intracellular structures).
|E. coli bacteria. Public domain image. SOURCE.|
Ruth Ley is an Assistant Professor at the Department of Molecular Biology and Genetics, Cornell University. She has been awarded the National Institutes of Health (NIH) New Innovator award and the Packard Fellowship, and was a Packard Fellow, Hartwell Investigator, and Beckman Young Investigator.
She has worked on research involving the effects of fire on woodlands, nitrogen content of water due to microorganisms in soil, and bacteria in the gut of a range of animals (including humans), sequencing over 20,000 genes and comparing them with microorganisms from humans, rats, cows, and gorillas. Her current research team focuses on symbionts and the affect their mammalian hosts have on their diversity in the gut.
It's amazing how many microorganisms are around, on, and in everything, isn't it?
-----The Golden Eagle