Miscellaneous Reactions

Flashcards about miscellaneous reactions

Catalase

An enzyme that protects microbes from the negative effects of oxygen by breaking down hydrogen peroxide into water and oxygen gas.

Catalase Test Positive Result

The formation of bubbles when a colony of bacteria is mixed with hydrogen peroxide, indicating the presence of catalase.

Oxidase Test

A test looking for the presence of cytochrome c oxidase, an enzyme involved in the electron transport chain.

Cytochrome c Oxidase

The last enzyme involved in the electron transport chain, responsible for binding electrons to the final electron acceptor.

Oxidase Test Positive Result

A purple color change on the filter paper disc after adding a colony of bacteria and oxidase reagent.

DNase

An enzyme that some bacteria produce to break down DNA in their environment.

DNase Test

A test using differential media containing DNA and an indicator to detect the presence of DNase.

DNase Test Positive Result

A clear halo around bacterial growth on DNase media, indicating that the DNA has been digested.

Esculin Hydrolysis

The process of bacteria breaking down esculin.

Bile Esculin Agar

A selective and differential media used to identify the ability to hydrolyze esculin, containing bile salts.

Esculin Hydrolysis Positive Result

The media turns black, after stabbing down into the bile esculin agar.

Motility

The ability of bacteria to move, typically due to the presence of flagella.

Motility Test

A test using less dense agar in a test tube to observe bacterial growth away from the stab line.

Motility Test Positive Result

Fuzzy, generalized growth away from the stab line in motility media, indicating the presence of flagella.

Nonmodal Bacteria

Growth concentrated around the stab line.