The singular of 'bacteria' is 'bacterium'.

bacteria的单数形式是bacterium。

《牛津词典》

Now, a decade later, the first direct evidence for the functioning of proteorhodopsin in native marine bacteria is presented, based on mutational analysis in a marine bacterium.

十年之后的现在，通过对海洋细菌的变异分析，首个直接证明变形菌视紫质功能的证据被发现。

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Although conditions in Lake Fryxell should be ideal for purple sulfur bacteria, Fryx1 is a purple non-sulfur bacterium.

虽然弗里克·塞尔湖条件应为紫色硫细菌的理想条件，但Fryx1是一个紫色非硫细菌。

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So, you're familiar with some of these bacteria like salmonella, or the micro bacterium that causes tuberculosis are shown here.

所以 你们很熟悉像沙门氏菌这样的细菌,或者像这儿的引起结核的小细菌

耶鲁公开课 - 生物医学工程探索课程节选

The bacterium legionella pneumophila and related bacteria are common in natural water sources such as rivers, lakes and reservoirs, but usually in low numbers.

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DNA. Alternatively, it can be smuggled in inside a bacterium (splicing extra genes into bacteria for this purpose is easy).

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For the study, researchers from the University of Vermont analysed volatile organic compounds (VOCs) given off in exhaled breath by different bacteria as well as different strains of the same bacterium.

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