Bacteria

¹

[bak-teer-ee-uh]

noun

(used with a singular or plural verb)

1. (in the three-domain system of classification) the taxonomic domain comprising the bacteria.

bacteria

²

[bak-teer-ee-uh]

plural noun

Microbiology.

singular

bacterium 

1. ubiquitous one-celled organisms, spherical, spiral, or rod-shaped and appearing singly or in chains, comprising numerous and variously classified phyla: among the inestimable number of species are those involved in fermentation, putrefaction, infectious diseases, and nitrogen fixation.

bacteria

/ bækˈtɪərɪə /

plural noun

1. a very large group of microorganisms comprising one of the three domains of living organisms. They are prokaryotic, unicellular, and either free-living in soil or water or parasites of plants or animals See also prokaryote

bacteria

1. sing. bacterium Microorganisms made up of a single cell that has no distinct nucleus. Bacteria reproduce by fission or by forming spores.

Some bacteria are beneficial to humans (for example, those that live in the stomach and aid digestion), and some are harmful (for example, those that cause disease).

Other Word Forms

• bacterial adjective
• bacterially adverb
• nonbacterial adjective
• nonbacterially adverb

Word History and Origins

Origin of Bacteria¹

First recorded in 1860–65; from New Latin; bacteria ( def. )

Origin of Bacteria²

First recorded in 1860–65; from New Latin, from Greek baktḗria, plural of baktḗrion, diminutive of baktēría “staff, cane”; bacterium

Word History and Origins

Origin of Bacteria¹

C19: plural of New Latin bacterium , from Greek baktērion , literally: a little stick, from baktron rod, staff

Example Sentences

Out of the 449 sites regularly tested this summer, 93% met minimum standards for levels of bacteria in the water, linked to sewage spills, agricultural pollution and other factors.

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When wheat roots release this extra compound into the surrounding soil, it assists specific bacteria that can convert nitrogen from the air into a form that nearby plants can absorb.

Read more on Science Daily

These cells are usually known for acting like tiny cleanup crews that remove bacteria, dead cells, and other unwanted material.

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In the new study, the researchers protected the bacteria by enclosing them, along with magnetic particles, inside small droplets of sodium alginate, a thickening ingredient commonly found in foods.

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Meanwhile, many other landfills are releasing unsafe amounts of methane, an odorless gas produced by bacteria that break down organic waste.

Read more on Los Angeles Times

When To Use

Plural word for bacteria

Bacteria is the plural form of the singular bacterium. Because microscopic bacterium is most often found in multiples, the plural form bacteria is more commonly used. The plurals of several other singular words ending in -um are also formed this way, such as memorandum/memoranda and curriculum/curricula.The irregular noun bacterium’s plural derives directly from its original pluralization in Latin and Greek. Bacteria is sometimes treated as a singular collective noun. However, this is not standard in English, and bacteria should be treated as a plural form.