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

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 …

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, …

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 …

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.

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 …

Jan 26, 2026 · The meaning of MICROORGANISM is an organism (such as a bacterium or protozoan) of microscopic or ultramicroscopic size.

Feb 21, 2023 · Microorganisms are often illustrated using single-celled, or unicellular organisms; however, some unicellular protists are visible to the naked eye, and some multicellular species are …

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 …