Organisms do not have the cytochrome c oxidase that oxidizes the test reagent.
TMPD. The oxidase test is a test used in microbiology to determine if a bacterium produces certain cytochrome c oxidases. It uses disks impregnated with a reagent such as N,N,N′,N′-tetramethyl-p-phenylenediamine (TMPD) or N,N-dimethyl-p -phenylenediamine (DMPD), which is also a redox indicator. These both catalyze the transport of electrons from donor compounds (NADH) to electron acceptors (usually oxygen). The test reagent, TMPD dihydrochloride acts as an artificial electron donor for the enzyme oxidase. The oxidase test is used to identify bacteria that produce cytochrome c oxidase, an enzyme of the bacterial electron transport chain. (note: All bacteria that are oxidase positive are aerobic, and can use oxygen as a terminal electron acceptor in respiration. This does NOT mean that they are strict aerobes. Bacteria that are oxidase-negative may be anaerobic, aerobic, or facultative; the oxidase negative result just means that these organisms do not have the cytochrome c oxidase that oxidizes the test reagent. They may respire using other oxidases in electron transport.). Oxidase Test. The oxidase test identifies organisms that produce the enzyme cytochrome oxidase. Cytochrome oxidase participates in the electron transport chain by transferring electrons from a donor molecule to oxygen.  Biochemical Tests. Oxidase Test. NOTE: This test is for Gram-negative organisms. The oxidase test determines whether a microbe can oxidize certain aromatic amines, for example, p-aminodimethylaniline, to form colored end products. This oxidation correlates with the cytochrome oxidase activity of some bacteria, including the genera Pseudomonas and Neisseria. The oxidase test is used to identify bacteria that produce cytochrome c oxidase, an enzyme of the bacterial electron transport chain. Bacteria that are oxidase-negative may be anaerobic, aerobic, or facultative; the oxidase negative result just means that these organisms do not have the cytochrome c oxidase that oxidizes the test reagent. From Wikipedia, the free encyclopedia. An oxidase is any enzyme that catalyzes an oxidation-reduction reaction, especially one involving molecular oxygen (O 2) as the electron acceptor. In reactions involving donation of a hydrogen atom, oxygen is reduced to water (H 2 O) or hydrogen peroxide (H 2 O 2).  This does NOT mean that they are strict aerobes. Bacteria that are oxidase-negative may be anaerobic, aerobic, or facultative; the oxidase negative result just means that these organisms do not have the cytochrome c oxidase that oxidizes the test reagent. They may respire using other oxidases in electron transport The oxidase test detects the presence of a cytochrome oxidase system that will catalyse the transport of electrons between electron donors in the bacteria and a redox dye-tetramethyl-p-phenylene-diamine. The dye is reduced to deep purple color. 1 The oxidase test is used to determine if an organism possesses the cytochrome oxidase enzyme. 2  The test is used as an aid for the differentiation of Neisseria, Moraxella, Campylobacter and Pasteurella species (oxidase positive). The clear oxidase reagent turns blue when cytochrome oxidase adds electrons to the chemical instead of to oxygen, as it normally does. Development of the blue color is positive for presence of the enzyme cytochrome oxidase. The color change does not occur in a negative test. Because of the expense and instability of oxidase reagent, this test is rarely performed in that manner.  The oxidase test is a test used in microbiology to determine if a bacterium produces certain cytochrome c oxidases. These both catalyze the transport of electrons from donor compounds (NADH) to electron acceptors (usually oxygen). The test reagent, TMPD dihydrochloride acts as an artificial electron donor for the enzyme oxidase.
https://en.wikipedia.org/wiki/Oxidase_test http://learn.chm.msu.edu/vibl/content/oxidase.html http://www.austincc.edu/microbugz/oxidase_test.php http://web.mst.edu/~microbio/Lab_Supplement/Oxidase.html http://microbeonline.com/oxidase-test-principle-procedure-and-oxidase-positive-organisms/ https://en.wikipedia.org/wiki/Oxidase http://microbeonline.com/oxidase-test-principle-procedure-and-oxidase-positive-organisms/ http://www.microbiologyinfo.com/oxidase-test-principle-uses-procedure-types-result-interpretation-examples-and-limitations/ http://www.vumicro.com/vumie/help/VUMICRO/Oxidase_Test.htm https://en.wikipedia.org/wiki/Oxidase_test
what does a negative oxidase test mean