Explain what you saw in this experiment and why it was this answer Q8. What is the identity of colony A?(1613) A. Staphylococcus aureus B. Streptococcus pyogenes C. Enterococcus faecium D. Clostridium tetani E. Lactobacillus delbrueckii F. Pasteurella multocida H. Helicobacter pylori I. Vibrio parahaemolyticus J. Mycobacterium tuberculosis Colony A was subjected to Gram's staining. Crystal violet (purple) was used as the primary stain, acetone-alcohol as the decolorizer, and safranin (pink) as the counterstain. The staining result (pink in color) was reviewed under the phase-contrast microscope (Fig. 1). Colony A was then subjected to an oxidase test. The oxidase test is used to determine if a bacterium produces certain cytochrome c oxidases. The reagent turns dark blue when oxidized (oxidase positive) and turns colorless when reduced (oxidase negative). Colony B turns the reagent colorless in the test (Fig. 2). ig. 2.

1. Explain what you saw in this experiment and why it was this answer
Q8. What is the identity of colony A?(1613) A. Staphylococcus aureus B. Streptococcus
pyogenes C. Enterococcus faecium D. Clostridium tetani E. Lactobacillus delbrueckii F.
Pasteurella multocida H. Helicobacter pylori I. Vibrio parahaemolyticus J. Mycobacterium
tuberculosis
Colony A was subjected to Gram's staining. Crystal violet (purple) was used as the primary stain,
acetone-alcohol as the decolorizer, and safranin (pink) as the counterstain. The staining result
(pink in color) was reviewed under the phase-contrast microscope (Fig. 1). Colony A was then
subjected to an oxidase test. The oxidase test is used to determine if a bacterium produces certain
cytochrome c oxidases. The reagent turns dark blue when oxidized (oxidase positive) and turns
colorless when reduced (oxidase negative). Colony B turns the reagent colorless in the test (Fig.
2). ig. 2