Word
bacterium
Phoneticsbac·teri·um
US/bækˈtɪɹiəm/
UK/bæktˈiəɹɪəm/
Definition
n. a tiny living thing that is so small you can only see it with a microscope. Some of these can make you sick, while others are helpful for your body.
n. a microscopic, single-celled organism that lacks a distinct nucleus and may be found in diverse environments. While many species are pathogenic, others are essential for processes like fermentation and digestion.
Examples
“The doctor said a bacterium caused the infection.”
“Scientists discovered a new bacterium in the soil that can break down plastic waste.”
“While a single bacterium is invisible to the naked eye, rapid reproduction can lead to the formation of visible colonies on a nutrient-rich agar plate within twenty-four hours.”
Examples
simple
“The doctor said a bacterium caused the infection.”
contextual
“Scientists discovered a new bacterium in the soil that can break down plastic waste.”
complex
“While a single bacterium is invisible to the naked eye, rapid reproduction can lead to the formation of visible colonies on a nutrient-rich agar plate within twenty-four hours.”
Usage
The word is the singular form; 'bacteria' is the plural form and is much more common in everyday speech.
Pitfall
this bacteria is
this bacterium is
Learners often use the plural 'bacteria' with a singular verb. 'Bacterium' is the singular form.
Real-World Examples
Common in science writing
“The team detected DNA from Yersinia pestis , the bacterium responsible for plague, in 18 of 46 individuals studied.” “More than 2bn years ago, a primitive cell engulfed a bacterium.” Etymology
From New Latin bactērium, from Ancient Greek βακτήριον (baktḗrion, “small staff”), from βακτηρία (baktēría).
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.