Bacteria n.p. : See Bacterium.

Bacteria pl. : of Bacterium

Example:
What type of Bacteria would grow in a reused water bottle?

Taxonomy
bacteria, organisms, cells, nutrients, bacterial cells, species, proteins, eukaryotes, bacterial species, endospores, pathogens, biofilms, cytoplasm, cell wall, microorganisms, organelles, antibiotics, species of bacteria.

Defination from the web:
... Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals. ... In industry, bacteria are important in sewage treatment, the production of cheese and yoghurt ...