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Bacterial enzymes
- microorganisms produce a variety of enzymes
- each enzyme catalyzes specific chemical reaction within the protein
- the production of specific enzymes are characteristic used to differentiate between organisms
- some enzymes: urease, catalase, coagulase
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Urease
- this enzyme catalyzes the breakdown of urea into ammonia and carbon dioxide
- culutre media is phenol red as a pH indicator - acidic
- when ammonia is released, the pH becomes alkaline causing the indicator to change from peach to dark pinkUrea is usually alkaline
- Urease production is a characteristc of the genus Proteus
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Catalase
- is an enzyme that catalyzes the breakdown of hydrogen peroxide to water and gaseous oxygen
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Coagulase
- the enzyme coagulase causes plasma to clot
- plasma is the liquid portion of blood
- Staph a. is the only pathogenic organism that produces coagulase
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Catalase +
is always Staphylococcus
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Catalase -
- is always Streptococcus
- Remember T in the middle for -
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Coagulase +
is always Staphyloccocus aureus
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Coagulase -
is always Staphyloccocus epidermis
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Urease +
- is alway Proteus
- usually described as Gram negative rod, urease +
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