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 …

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

Oct 13, 2025 · The major groups of microorganisms—namely bacteria, archaea, fungi (yeasts and molds), algae, protozoa, and viruses—are summarized below. Links to the more detailed …

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 …

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, …

Aug 4, 2025 · Microorganisms form the biochemical scaffolding upon which all macroscopic life depends. They manage nutrient cycles, influence weather patterns, control atmospheric …

Microorganisms are very diverse and are found in all three domains of life: Archaea, Bacteria, and Eukarya. Archaea and bacteria are classified as prokaryotes because they lack a cellular …

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, …

Apr 29, 2017 · A microorganism is a living thing that is too small to be seen with the naked eye. Examples of microorganisms include bacteria, archaea, algae, protozoa, and microscopic …