A microorganism, or microbe, [a] is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from …

Microorganisms is a scientific, peer-reviewed, open access journal of microbiology, published monthly online by MDPI.

Jan 16, 2026 · The major groups of microorganisms—namely bacteria, archaea, fungi (yeasts and molds), algae, protozoa, and viruses—are summarized below. Links to the more detailed articles on …

Mar 28, 2024 · In summation, a microorganism is a minuscule living entity invisible to the unaided eye. This broad classification encompasses a plethora of organisms, including bacteria, archaea, algae, …

Nowhere is that statement truer than in the world of microorganisms. Microorganisms (also called microbes) are organisms which share the property of being only individually seen by microscopy.

Aug 4, 2025 · Microorganisms—organisms too small to be seen with the naked eye—pervade every corner of the planet. They flourish in soil, water, air, and even the most extreme environments …

Microorganisms differ from each other not only in size, but also in structure, habitat, metabolism, and many other characteristics. While we typically think of microorganisms as being unicellular, there are …

Learn more about the structure of microbes, the different phases of growth, how they reproduce, and what byproducts they create. Harvard experts are exploring how we can work with, defend against, …

Microorganisms can be found almost anywhere in the taxonomic organization of life on the planet. Bacteria and archaea are almost always microscopic, while a number of eukaryotes are also …

Microorganisms, also known as microbes, are tiny living organisms that are invisible to the naked eye. They include a diverse group of microscopic life forms such as bacteria, archaea, fungi, protists, and …