What are the 5 branches of microbiology?

Microbiology is a diverse field that is often broken into several distinct sub-fields of study. These sub-fields are often known as branches of microbiology, and there are five primary branches that most people will encounter in their studies. 

Microbiologists who specialize in one of these areas may find themselves working in a specific department at an academic institution or using that knowledge to perform research for a company or other business. 

These five branches of microbiology each have their own set of skills and knowledge requirements. This article will answer the question “what are the 5 branches of microbiology?” as well as define what is microbiology.

What are the 5 branches of microbiology?

The 5 branches of microbiology are the following:

  • Bacteriology
  • Virology
  • Immunology
  • Genetics
  • Epidemiology

What is Microbiology?

Microbiology is the study of microorganisms or tiny organisms. These organisms are too small to be seen with the naked eye and can only be observed using microscopes. 

There are many fields within the study of microbiology, and these different branches all explore unique aspects of microorganisms and they’re important in this growing field. 

These branches all play specific roles in our understanding of microorganisms. For example, bacteriology is the branch that focuses on bacteria as the primary subject matter. 

Microbiologists study the tiny organisms that live almost everywhere on Earth. There are many fields of microbiology, but there are five main branches that you will commonly hear about. 

Microbiologists who specialize in one of these branches may have different job opportunities, educational requirements, and career paths. 

These five main branches of microbiology are general areas of concentration for a microbiologist. It is important to note that there is an overlap between these fields. 

For example, a biologist who specializes in the genetics of bacteria can easily move from one field to another. Each branch has its own sub-specialties and career opportunities.


Bacteriology is the study of bacteria. Like most branches of microbiology, bacteriology dates back to the earliest days of microbiology, often being lumped together with mycology and protozoology under the field of general microbiology. 

Today, bacteriology is its own distinct field, with bacteriologists specializing in the study of a specific group of organisms while other microbiologists may focus on a different group entirely. 

Bacteriologists often focus specifically on pathogenic bacteria, those that cause disease. Studying these pathogens can help us understand why they are so harmful to human beings, how we can combat them, and how we can avoid contracting them in the first place. 

This field is vital to the medical field because it allows doctors to learn how to stop infectious diseases in their tracks before they become serious.


Virology is the study of viruses. Virologists specialize in the study of the many different viruses that infect everything from plants to humans, looking at the different ways these viruses infect and replicate. 

They study how these viruses are transmitted between hosts and how we can use this information to fight them. Virologists often work specifically with human viruses like the virus that causes polio or herpes. 

They may also specialize in animal viruses, like those that can affect the livestock. In many cases, these viruses are a threat to humans only because we share a species with their primary host, so studying the viruses in their original host can help us protect ourselves. Other virologists may study plant viruses or even bacterial viruses.


Immunology is the study of the immune system, which is the body’s natural defense against disease. This field has expanded greatly over the years as we have discovered not only the basic functions of the immune system but also how it interacts with other systems in the body. 

This expansion has resulted in the creation of several sub-fields within immunology, including microbiology and immunopathology. Immunologists often focus their research on the specific mechanisms of the immune system and how those can be manipulated to fight disease. 

This can include creating vaccines or designing drugs that alter the immune system in specific ways. Immunology is also used in forensics to determine how much danger a person might pose based on their immune system. 

Immunology is a very broad field that has applications in almost every area of modern medical research. This means that microbiologists who want to work in immunology have many potential research avenues to choose from.


Parasitology is the science of parasites. It is a sub-discipline of microbiology that deals with the study of the parasite’s biology and parasitic diseases. 

It also includes the molecular biology, ecology, evolution, distribution, biochemistry, physiology, and medical functions of parasites, including the response of the host to different agents.

Before, parasitology is limited to the study of arthropods, parasitic protozoa, and helminths. The study of parasites in humans is focused on clinical parasites and includes their relationship with host and environment, morphology, and their life cycle.

Generally speaking, there are two categories of parasites found in our environment and these are the following:

  • Endoparasites
  • ectoparasites

Endoparasites live inside their host because dependent on their hosts and cannot live without them. Therefore may be facultative parasites,  accidental parasites, and obligate parasites. Ectoparasites are parasites that live outside the surface of their host.


Mycology is the scientific discipline that is concerned with the study of fungi, their relationships to each other, their interaction with other organisms, and the unique genetic and biochemical characteristics as well as the taxonomy that sets them apart from other microorganisms.

Fungi are a group of microorganisms that includes mushrooms and yeasts which are very important, especially in the field of medicine and pharmaceutical. Because of mycology, many antibiotic drugs such as penicillin had been developed and used for the treatment of several ailments.

There are currently over 50,000 identified species of fungi that have been found in many environments across the biosphere. Some fungi have no impact on human beings and are free-living while others are either harmful or beneficial to humans and other organisms.

Aside from medicine, the development in mycology has brought an important application in other industries such as cosmetics, food, baking, and the making of dyes and inks.


All of these branches can be incredibly rewarding, but they also come with inherent dangers and risks that are present in all scientific research. As microbiologists learn more about the world around them, they also increase the potential for creating dangerous new pathogens or triggering deadly pandemics. Viruses like Ebola and Zika gained traction in the media because they can kill humans, but bacteria like E. coli also pose a significant threat to human health. Even organisms that are beneficial to us, like probiotics, can still cause harm in the wrong circumstances. This is why microbiologists often find themselves working in regulated or even classified environments. In these settings, even the smallest mistake could have disastrous consequences, so proper training and research are essential.

Frequently Asked Questions (FAQs): what are the 5 branches of microbiology?

Who is called the father of microbiology?

The founding father of microbiology is Antoni van Leeuwenhoek (1632-1723), who is a cloth trader from Delft. He used simple microscopes made in his home to discover the invisible world of microorganisms.

What are the two types of bacteria?

The two types of bacteria are the following

  • Aerobes, or aerobic bacteria – grow only in the presence of oxygen. Some Aerobes are harmful to the human environment, such as fouling, problems with water clarity, corrosion, and bad smells. 
  • Anaerobes, or anaerobic bacteria – grow only where there is an absence of oxygen.

What are the major classes of microorganisms?

The major classes of microorganisms are the following:

  • Viruses
  • Prions
  • Parasites
  • Fungi and yeasts
  • Bacteria


Schlegel, H. G., & Zaborosch, C. (1993). General microbiology. Cambridge university press.

Tortora, G. J., Funke, B. R., & Case, C. L. (2018). Microbiology: an introduction. Pearson.

Prescott, L. M. (2002). Microbiology.

Branches of Microbiology. Retrieved from https://microbiologynote.com/branches-of-microbiology/

Branches of Microbiology | General MicroScience. Retrieved from https://www.generalmicroscience.com/microbiology/branches-of-microbiology/

What are the Branches of Microbiology? | UF Microbiology & Cell. Retrieved from https://microbiologyonline.ifas.ufl.edu/about/articles/what-are-the-branches-of-microbiology/