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.
Gram positive and Gram negative bacteria have a different type of cell wall, and therefore, a different reaction to the dye and to some other chemicals, including antibiotics (chemicals that can sometimes kill bacteria).nlike animals and plants, bacteria have pili, flagella, and most have a cell capsule. Bacterial cells include the following: Diet: Bacteria have a wide range of diets. Some are heterotrophs (they eat other organisms) and others are autotrophs (they make their own food).