Microorganisms

thumb|upright=1.35|A Colony (biology)#Microbial colonies|cluster of [[Escherichia coli bacteria magnified 10,000 times]]

In biology, a pathogen (, "suffering", "passion" and , "producer of"), in the oldest and broadest sense, is any organism, agent or micro-organism that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ.

organism consisting of only one cell

right|thumb|upright=1.5|Clockwise from top right: Amoeba proteus, Actinophrys sol, [[Acanthamoeba sp., Nuclearia thermophila., Euglypha acanthophora, neutrophil ingesting bacteria.]]

Parakaryon myojinensis, also known as the Myojin parakaryote, is a highly unusual species of single-celled organism known only from a single specimen, described in 2012. It has features of both prokaryotes and eukaryotes but is apparently distinct from either group, making it unique among organisms discovered thus far. It is the sole species in the genus Parakaryon. It is part of the domain Parakarya.

Methylotrophs are a diverse group of microorganisms that can use reduced one-carbon compounds, such as methanol or methane, as the carbon source for their growth; and multi-carbon compounds that contain no carbon-carbon bonds, such as dimethyl ether and dimethylamine. This group of microorganisms also includes those capable of assimilating reduced one-carbon compounds by way of carbon dioxide using the ribulose bisphosphate pathway. These organisms should not be confused with methanogens which on the contrary produce methane as a by-product from various one-carbon compounds such as carbon diox

Trimastix is a genus of excavate protists, the sole occupant of the order Trimastigida. Trimastix are bacterivorous, free living and anaerobic. It was first observed in 1881 by William Kent. There are few known species, and the genus's role in the ecosystem is largely unknown. However, it is known that they generally live in marine environments within the tissues of decaying organisms to maintain an anoxic environment. Much interest in this group is related to its close association with other members of Preaxostyla. These organisms do not have classical mitochondria, and as such, much of the r

any life form too small for the naked human eye to see that lives in a marine environment

Microbivory (adj. microbivorous, microbivore) is a feeding behavior consisting of eating microbes (especially bacteria) practiced by animals of the mesofauna, microfauna and meiofauna.

Cable bacteria are filamentous bacteria that conduct electricity across distances over 1 cm in sediment and groundwater aquifers