Oxidase test helps in identification of each bacterium except one:

Ans. is 'd' i.e., E. coliImage description - The oxidase test is used to identify bacteria that produce cytochrome C oxidase, an enzyme of the bacterial electron transport chain. When present, the cytochrome C oxidase oxidizes the reagent (tetramethyl - p - phenylenediamine) to (indophenols) purple color end product. When the enzyme is not present, the reagent remains reduced and is colorless.Oxidase positive bacteria - Mnemonics for Oxidase Positive Organisms - PVNCH (It's just an acronyms inspired by the famous mnemonic for Urease Positive organisms-PVNCH)-P: Pseudomonas spp, V: Vibrio cholerae, N: Neisseria spp, C: Campylobacter spp, H: Helicobacter spp/Haemophilus spp, Aeromonas spp and Alcaligens,