Microbiology

Microbiology is the scientific study of microorganisms, a diverse group of microscopic and near-microscopic organisms that include bacteria, archaea, fungi, protozoa, algae, and viruses. Microbiologists examine their cellular structure, metabolism, genetics, reproduction, and ecological roles, as well as their interactions with other organisms and with human health and industry.

Fields within microbiology include medical microbiology, which studies pathogens and disease processes; industrial or applied microbiology, which uses microbes to produce foods, pharmaceuticals, and enzymes; environmental microbiology, which investigates microbial processes in soil, water, and air; and microbial ecology, which examines how microorganisms interact within ecosystems. Other subfields include molecular microbiology, microbial genetics, virology, mycology, parasitology, and phycology. Techniques include microscopy, culture and isolation, staining, and a range of molecular methods such as PCR, sequencing, metagenomics, and bioinformatics.

The existence of microorganisms was first observed by Anton van Leeuwenhoek in the 17th century. The germ theory of disease, demonstrated by Louis Pasteur and Robert Koch in the 19th century, established that many diseases are caused by microbes. Advances in culture methods, aseptic technique, vaccines, antibiotics, and molecular biology have driven major progress.

Microbiology informs medicine, public health, and agriculture through diagnostics, vaccine development, and antimicrobial therapy. Industrial microbiology harnesses microbes for fermentation, enzyme production, and bioconversion. Environmental microbiology and bioremediation address pollution and resource cycling. The study of microbiomes reveals complex communities that influence health and ecosystems. Safety and ethics, containment, and biosafety practices (BSL levels) govern research with pathogenic or genetically modified organisms.