Microbiologists typically do the following:

• Plan and conduct complex research projects, such as improving sterilization procedures or developing new drugs to combat infectious diseases
• Perform laboratory experiments that are used in the diagnosis and treatment of illnesses
• Supervise the work of biological technicians and other workers and evaluate the accuracy of their results
• Isolate and maintain cultures of bacteria or other microorganisms for study
• Identify and classify microorganisms found in specimens collected from humans, plants, animals, or the environment
• Monitor the effect of microorganisms on plants, animals, other microorganisms, or the environment
• Review literature and the findings of other researchers and attend conferences
• Prepare technical reports, publish research papers, and make recommendations based on their research findings
• Present research findings to scientists, nonscientist executives, engineers, other colleagues, and the public

Many microbiologists work in research and development conducting basic research or applied research. The aim of basic research is to increase scientific knowledge. An example is growing strains of bacteria in various conditions to learn how they react to those conditions. Other microbiologists conduct applied research and develop new products to solve particular problems. For example, microbiologists may aid in the development of genetically engineered crops, better biofuels, or new vaccines.

Microbiologists use computers and a wide variety of sophisticated laboratory instruments to do their experiments. Electron microscopes are used to study bacteria, and advanced computer software is used to analyze the growth of microorganisms found in samples.

It is increasingly common for microbiologists to work on teams with technicians and scientists in other fields, because many scientific research projects involve multiple disciplines. Microbiologists may work with medical scientists or molecular biologists while researching new drugs, or they may work in medical diagnostic laboratories alongside physicians and nurses to help prevent, treat, and cure diseases.

The following are examples of types of microbiologists:

Bacteriologists study the growth, development, and other properties of bacteria, including the positive and negative effects that bacteria have on plants, animals, and humans.

Clinical microbiologists perform a wide range of clinical laboratory tests on specimens collected from plants, humans, and animals to aid in detection of disease. Clinical and medical microbiologists whose work involves directly researching human health may be classified as medical scientists.

Environmental microbiologists study how microorganisms interact with the environment and each other. They may study the use of microbes to clean up areas contaminated by heavy metals or study how microbes could aid crop growth.

Industrial microbiologists study and solve problems related to industrial production processes. They may examine microbial growth found in the pipes of a chemical factory, monitor the impact industrial waste has on the local ecosystem, or oversee the microbial activities used in cheese production to ensure quality.

Mycologists study the properties of fungi such as yeast and mold. They also study the ways fungi can be used to benefit society (for example, in food or the environment) and the risks fungi may pose.

Parasitologists study the life cycle of parasites, the parasite-host relationship, and how parasites adapt to different environments. They may investigate the outbreak and control of parasitic diseases such as malaria.

Public health microbiologists examine specimens to track, control, and prevent communicable diseases and other health hazards. They typically provide laboratory services for local health departments and community health programs.

Virologists study the structure, development, and other properties of viruses and any effects viruses have on infected organisms.

Many people with a microbiology background become high school teachers or postsecondary teachers.