Noun
a genus of motile peritrichous bacteria that contain small Gram-negative rod
Source: WordNetBacterial lawns (often of Serratia marcescens ) are also used extensively when as an assay method when using bacteriophage as tracers in studies of groundwater flow. Source: Internet
Gammaproteobacteria are the largest subgroup which includes Acinetobacter, Pseudomonas, Escherichia, Salmonella, and Serratia species. Source: Internet