Streptococcus activity detected by:
a) Fermentation.
B) Catalase.***
C) …..x
d) ……x
Catalase test
This test is used to differentiate those bacteria that prodce the enzyme catalase as staphylococci from non-catalase producing bacteria such as streptococci.
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Catalase is an enzyme belonging to the category of oxidoreductases that catalyzes the decomposition of hydrogen peroxide (H2O2) in oxygen and water.
This enzyme uses the heme and manganese group as a cofactor.
2 H
2O
2 2 H
2O + O
2
Hydrogen peroxide is a residue of the cellular metabolism of many living organisms and has, among others, a protective function against pathogenic microorganisms, mainly anaerobes, but given its toxicity it must be rapidly transformed into less dangerous compounds.
This function is performed by this enzyme that catalyzes its decomposition in water and oxygen.
In addition, catalase is used in the textile industry for the elimination of hydrogen peroxide, as well as to a lesser extent it is used in the cleaning of contact lenses that have been sterilized in a solution of hydrogen peroxide.
The congenital absence of catalase is the cause of an acatalasemia (or acatalasia), the Takahara disease that is manifested by the absence of catalase activity in the red blood cells and with severe gangrenous infections of the mouth, which can lead to the loss of teeth and severe destruction of the jaws and soft regions that covers them. Congenital disease of Japan (2 of 100,000 inhabitants suffer from this disorder).
Positive reaction of the catalase test.
The complete mechanism of catalase is not known, yet the chemical reaction occurs in two stages:
The enzyme is presented as a homotetramer and is located in the peroxisomes.
This enzyme can act as a peroxidase for many organic substances, especially for ethanol that acts as a hydrogen donor.
The enzymes of many microorganisms, such as Penicillium simplicissimum, which exhibit catalase and peroxidase activity, are often called catalase-peroxidases.
-----------------------
Catalase is an enzyme belonging to the category of oxidoreductases that catalyzes the decomposition of hydrogen peroxide (H2O2) in oxygen and water.
This enzyme uses the heme and manganese group as a cofactor.
2 H
2O
2 2 H
2O + O
2
Hydrogen peroxide is a residue of the cellular metabolism of many living organisms and has, among others, a protective function against pathogenic microorganisms, mainly anaerobes, but given its toxicity it must be rapidly transformed into less dangerous compounds.
This function is performed by this enzyme that catalyzes its decomposition in water and oxygen.
In addition, catalase is used in the textile industry for the elimination of hydrogen peroxide, as well as to a lesser extent it is used in the cleaning of contact lenses that have been sterilized in a solution of hydrogen peroxide.
The congenital absence of catalase is the cause of an acatalasemia (or acatalasia), the Takahara disease that is manifested by the absence of catalase activity in the red blood cells and with severe gangrenous infections of the mouth, which can lead to the loss of teeth and severe destruction of the jaws and soft regions that covers them. Congenital disease of Japan (2 of 100,000 inhabitants suffer from this disorder).
Positive reaction of the catalase test.
The complete mechanism of catalase is not known, yet the chemical reaction occurs in two stages:
- H
2O
2 + Fe(III)-E → H
2O + O=Fe(IV)-E
- H
2O
2 + O=Fe(IV)-E → H
2O + Fe(III)-E + O
2
The enzyme is presented as a homotetramer and is located in the peroxisomes.
This enzyme can act as a peroxidase for many organic substances, especially for ethanol that acts as a hydrogen donor.
The enzymes of many microorganisms, such as Penicillium simplicissimum, which exhibit catalase and peroxidase activity, are often called catalase-peroxidases.
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Community dentistry