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A hint of the Greek word bios, meaning "life", can be seen in microbe. Microbes, or microorganisms, include bacteria, protozoa, fungi, algae, amoebas, and slime molds. Many people think of microbes as simply the causes of disease, but every human is actually the host to billions of microbes, and most of them are essential to our life. Much research is now going into possible microbial sources of future energy; algae looks particularly promising, as do certain newly discovered or created microbes that can produce cellulose, to be turned into ethanol and other biofuels.

Examples of microbe in a Sentence

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Perhaps the mission's biggest discovery was the existence of perchlorate, an oxidizing chemical that can be food for some microbes while toxic for others. Tariq Malik, Space.com, 4 Aug. 2026 These microbes help produce short-chain fatty acids (SCFAs) such as acetate, propionate, and butyrate, which support intestinal barrier integrity and immune regulation. Christopher Bergland, Verywell Health, 3 Aug. 2026 When ships are stationary for periods of days or weeks, the submerged parts of the vessel can become colonized by microbes, algae and other marine organisms. Christopher Cann, USA Today, 2 Aug. 2026 Food waste to renewable natural gas Here, a special cocktail of microbes will feed on the slurry, releasing gases, like methane, as a waste product. Christopher McFadden, Interesting Engineering, 1 Aug. 2026 See All Example Sentences for microbe

Word History

Etymology

International Scientific Vocabulary micr- + Greek bios life — more at quick entry 1

First Known Use

1878, in the meaning defined above

Time Traveler
The first known use of microbe was in 1878

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Cite this Entry

“Microbe.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/microbe. Accessed 9 Aug. 2026.

Medical Definition

: microorganism, germ
used especially of pathogenic bacteria

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