A microbiologist represented a type of scientist whose work was centered on the science of microbiology.
- Bacteriologists were engaged in bacteriology, focusing their research on the study of bacteria.
- Environmental microbiologists dedicated their efforts to environmental microbiology, examining microbial activities and functions within various environments.
- Food microbiologists were employed within the food sector, investigating disease-causing microorganisms that led to food spoilage and sickness.
- Industrial microbiologists typically operated within the realm of biotechnology, researching microorganisms capable of generating valuable and practical products.
- Medical microbiologists were practicing doctors (physicians) who elected to specialize in identifying and treating microbial-based illnesses in patients.
- Mycologists were involved in mycology, with their scholarly pursuits centered around the investigation of fungi.
- Protozoologists conducted research in protozoology, directing their studies towards protists.
- Virologists specialized in virology, concentrating their investigations on viruses.
- Microbial epidemiologists investigated the part that microorganisms play in both sickness and health.
- Immunologists studied the mechanisms the body uses to protect itself from viruses, bacteria, and similar threats.