In this course, you will be introduced to the hidden world of microorganisms, learn how these
organisms are studied, and become aware of the position, role and importance of microorganisms
in the world. Microbiology is a science that is not much more than a century old. It is thus a young,
vigorous and modern science. Microbiology has had profound influence on almost every sector of
human interest: health, agriculture, food, environment. It has given rise to molecular biology and
biotechnology. Even if you do not plan to specialize in microbiology, it is important to develop an
understanding of microbiology and the power of the microbe.
While one of the most important drivers for the development of the science of microbiology was the
recognition that many diseases are caused by microorganisms, in reality, only a very small fraction
of microorganisms cause diseases. In fact, for most of the time that microorganisms have existed
on earth, there were no multicellular organisms available to infect. The physiological activities of
microorganisms resulted in the formation of a biosphere that allowed some of them to evolve into
multicellular organisms. Even today, microorganisms comprise >50% of the earthâs biomass. Most
of these microorganisms are "friendly".
Microorganisms have been very important as model systems in the study of biochemistry and
genetics. Most of the fundamental biochemical and genetic principles of life were developed
through the study of microorganisms. Microbial cells can be cultured to high densities in the
laboratory, facilitating biochemical analysis, and they are easy to manipulate genetically.
Although microbial cells do not differentiate into distinct tissues, as multicellular organisms do, they
do associate with other similar cells as populations. These populations associate with other
populations in communities. Interactions within microbial communities occur at several levels, with
waste products of some organisms provided as nutrient for other organisms. In the process, the
properties of a given ecosystem are often altered.
Microorganisms have fascinated me since I was first introduced to their world as an undergraduate
student. I am looking forward to sharing some of the wonders of this world with you. I hope that you
enjoy the course.
An introduction to (1) the historical origins of microbiology; (2) the concepts
of cell structure and function (3) the concept of microbial diversity.
Make sure to understand the following:
Pasteur's experimental disproof of
All living organisms, except viruses, are made up of cells (see
). Each cell is surrounded
, which separates the outside of the cell from the cytoplasm.
in that they contain membrane enclosed structures (