Chris=Michiels%LMM%AGR at agr.kuleuven.ac.be wrote:
>> What is the exact reason why some bacteria with a respiratory chain and
> using oxygen as a terminal electron acceptor are oxidase-negative
cytochrome c using oxidases will give a positive staining, but those
which only use quinoles as substrate do not. Some organisms also have
several terminal oxidases so despite being cyt c oxidase negative
this must not automatically result in a negative stain. The test is
not that much specific.