Scientists define microbiology as the study of microorganisms, which are creatures too small to see with the naked eye. These microorganisms include bacteria, viruses, fungi, algae, archaea, prions and protozoa. Although microorganisms are small, they're important, because they can cause disease and food spoilage, and can influence climate change. Some microorganisms also have beneficial effects on our lives: different branches of microbiology use various types of microorganisms to create fertilizers, lubricants, ethanol and to leach toxic materials from the soil or water.

Branches of Microbiology

Like many fields of science, it's possible to break down the branches of microbiology in more than one way. One approach is to define microbiology specialties, based on the types of microorganisms you study:

• Bacteriology: The study of bacteria.
  
• Mycology: The study of fungi.
  
• Phycology: The study of algae.
  
• Parasitology: The study of parasites.
  
• Virology: The study of viruses.
  

Although all types of microorganisms are small, the biology among the types differs considerably. Take bacteria and viruses -- both cause disease. Bacteria are single-celled creatures. Viruses are smaller and don't have a cellular structure; they're just a small outer shell around strands of genetic material. Bacteria in our bodies can make us sick, but they can also offer benefits, such as when stomach bacteria digests food. Viruses don't benefit us. They penetrate our cells and use the machinery there to create more viruses, flooding our bodies.

The Applied Microbiology Definition

Another way to define microbiology branches is to divide them into pure or applied microbiology, meaning science that focuses on research or science, which focuses on obtaining practical results. Pure microbiology, for example, includes microbial geneticists, who study genetics in bacteria, viruses, fungi and in other microorganisms. Immunologists study bacteria as part of their research on the immune system and on how the immune system works.

On the applied side, medical microbiology focuses on diagnosing, treating and preventing infectious diseases. Microbiologists who specialize in biotechnology, look at ways to create useful products from microbes. Scientists may apply microbiology to study micro-organisms in the air, the water, sewage, food or in milk.

A water specialist, for example, might study whether water in a particular area is infected with microbes, or she might find ways to purify the water. Air microbiologists research ways in which disease bacteria spread through the air, for example by breathing, sneezing or coughing. Milk microbiology applies scientific knowledge to prevent micro-organisms from causing milk spoilage and therefore causing people who drink milk to become ill. Medical microbiologists keep bacteria from infecting us, causing illness.

Becoming a Micro-Specialist

To specialize as any type of microbiologist, you'll need a bachelor's degree, at least. Usually, your degree will be in microbiology. However, a related field such as biochemistry or cell biology, which includes substantial microbiological course work, could be sufficient.

Like numerous scientific fields, undergraduate students in microbiology focus heavily on core courses, such as on microbial genetics and microbial physiology. Electives such as environmental microbiology or virology enable the students to explore different branches, so that they may develop a feel for what interests them. Probably, their coursework will also include classes in biochemistry, statistics and computer science, because computers are indispensable to microbiological work in the 21st century. Having experience working in the lab is essential for students' future careers. In addition to course work, many microbiology students take internships to improve their lab skills.

In graduate school, microbiologists begin to specialize in their desired branch, such as virology or parasitology. To carry out independent research, they'll probably need to keep working toward a doctorate. Those who hold Ph.D. degrees in microbiology usually start out with post-doctoral research positions, working under experienced scientists. This helps build credentials and helps students develop the know-how so that they may work on their own. They may end up leading a research team, or move to the administrative side, preparing budgets or schedules for ongoing research.