Definition of retain. transitive verb. 1a : to keep in possession or useb : to keep in one's pay or service; specifically : to employ by paying a retainerc : to keep in mind or memory : remember.
However, some gram- positive bacteria may also have capsules. Examples for gram-negative bacteria with capsules: Escherichia â¦coli, Klebsiella pneumoniae, Salmonella. Examples for gram-positive bacteria with capsules : Bacillus megaterium, Streptococcus pyogenes, Sterptococcus pneumoniae.
The spiral bacteria are spirilla (singular form is spirillus) and the rod-shaped bacteria are bacilli (singular form is bacillus). The coccus (plural form is cocci) bacteria are spherical and are usually found in clusters or chains.Bacilli have a large surface area that helps them take in nutrients, but they may dry out easily.Cocci do not dry out as quickly and retain water, but they absorb nutrients slowly.he coccus (plural form is cocci) bacteria are spherical and are usually found in clusters or chains. Bacilli have a large surface area that helps them take in nutrients, but they may dry out easily. Cocci do not dry out as quickly and retain water, but they absorb nutrients slowly.