Microbiology being a department
Microbiology (from Greek μῑκρος, mīkros, "small", bios, "life"; and, -logia) is the study of microscopic organisms, either unicellular (single cell), multicellular (cell colony), or acellular (lacking cells).Microbiology encompasses numerous sub-disciplines including virology, mycology, parasitology, and bacteriology.
As you begin to explore the world of microorganisms, one of the first things you’ll
notice is their extraordinary diversity – of structure, function, habitat and applications.
Microorganisms (or microbes) inhabit every corner of the globe, are indispensable to life on Earth, are responsible for some of the most deadly human diseases and form the basis of many industrial processes. Yet until a few hundred years ago, nobody knew they existed!
In this opening chapter, we offer some answers to three questions
_ Why is it such an important subject?
_ How have we gained our present knowledge of microbiology?
Bacteria neatly fit this definition, but what about fungi and algae? These two groups each contain members that are far from microscopic. On the other hand, certain animals, such as nematode worms, can be microscopic, yet are not considered to be the domain of the microbiologist. Viruses represent another special case; they are most certainly microscopic (indeed, most are submicroscopic), but by most accepted definitions they are not living. Nevertheless, these too fall within the remit of the microbiologist.
In the central section of this book you can read about the thorny issue of microbial classification and gain some understanding of just what is and what is not regarded as a microorganism.
Why is microbiology important?
To the lay person, microbiology means the study of sinister, invisible ‘bugs’ that cause disease. As a subject, it generally only impinges on the popular consciousness in news
4 MICROBIOLOGY: WHAT, WHY AND HOW?
coverage of the latest ‘health scare’. It may come as something of a surprise therefore to learn that the vast majority of microorganisms coexist alongside us without causing any harm. Indeed, many perform vital tasks such as the recycling of essential elements, without which life on our planet could not continue.
Other microorganisms have been exploited by humans for our own benefit, for instance in the manufacture of antibiotics and foodstuffs . To get some idea of the importance of microbiology in the world today, just consider the following list of some of the general areas in which the expertise of a microbiologist might be used:
_ medicine
_ environmental science
_ food and drink production
_ fundamental research
_ agriculture
_ pharmaceutical industry
_ genetic engineering.
The popular perception among the general public, however, remains one of infections and plagues. Think back to the first time you ever heard about microorganisms; almost certainly, it was when you were a child and your parents impressed on you the dangers of ‘germs’ from dirty hands or eating things after they’d been on the floor. In reality, only a couple of hundred out of the half million or so known bacterial species give rise to infections in humans; these are termed pathogens, and have tended to dominate our view of the microbial
world.
A pathogen is an organism with the potential to cause disease.
In the next few pages we shall review some of the landmark developments in the
