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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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Of course, a yeast that can survive on Mars is … well, a yeast that can survive on Mars, which could actually risk contaminating the planet with hardy and fast-multiplying Earth microbes. Kiona N. Smith, Space.com, 17 Sep. 2026 This is where studying microbes that already live in polluted environments gives us an advantage. Catherine Armbruster, The Conversation, 17 Sep. 2026 Rather than filtering contaminants out and concentrating them into waste, this method uses ozone gas and naturally occurring microbes to break contaminants down instead of just isolating them. Piper Heath, Los Angeles Times, 16 Sep. 2026 To deliver enough for even a small building, a functional brewery would need to be constructed – without emitting a bunch of carbon dioxide or risking your microbes. Mike McRae 16, New Atlas, 16 Sep. 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 20 Sep. 2026.

Medical Definition

: microorganism, germ
used especially of pathogenic bacteria
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