Are there bacteria visible to the naked eye? © Getty Images

Are any bacteria visible to the naked eye?

The eye's the limit (except in one case).

Asked by: FOCUS

Yes. Most bacteria are too small to be seen without a microscope, but in 1999 scientists working off the coast of Namibia discovered a bacterium called Thiomargarita namibiensis (sulfur pearl of Namibia) whose individual cells can grow up to 0.75mm wide.

Its comparatively huge size is due to a hydrogen sulfide-filled gaseous cavity, which causes it to blow up like a balloon.

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