Question

Andy performed an Ornithine Decarboxylase test on his unknown sample. The following image shows what the tube looked like following 24 hours of incubation at 35 +2°C. What information can Andy get from this Viru the mano in arester detail

Answer 1

ornithine decarboxylase test is to determine whether the bacteria can metabolize ornithine amino acid. initially bacteria metabolizes glucose to decrease the pH level, to activate the ornithine decarboxylase enzyme for metabolizing ornithine. the drop in pH level indicated by colour change from purple to yellow which is given in the image. when the ornithine decarboxylase enzyme is activated and metabolized the colour changes back to purple i.e, yellow to purple.

from the observation, it is clear that colour change from purple to yellow indicates the metabolism of glucose to activate ornithine decarboxylase. so the microorganism prepares itself for metabolism of ornithine. therefore the inference can be given as the inoculum metabolized glucose.