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What is the component in the SIM deep tubes that makes this medium suitable to detect the production of indole?
The ingredients in SIM Medium enable the determination of three activities by which enteric bacteria can be differentiated.
Sodium thiosulfate and ferrous ammonium sulfate are indicators of hydrogen sulfide production. The ferrous ammonium
sulfate reacts with H2S gas to produce ferrous sulfide, a black precipitate.1 The casein peptone is rich in tryptophan, which is
attacked by certain microorganisms resulting in the production of indole. The indole is detected by the addition of chemical
reagents following the incubation period. Motility detection is possible due to the semisolid nature of the medium. Growth
radiating out from the central stab line indicates that the test organism is motile.
What else can I help you with?
What is the component in the SIM deep tubes that makes the medium suitable to detect the production of indole by bacteria?
The component in SIM deep tubes that makes the medium suitable to detect the production of indole by bacteria is tryptophan. Bacteria that possess the enzyme tryptophanase can break down tryptophan to produce indole, which can be detected by the addition of Kovac's reagent that reacts with indole to form a red color.
Principle of ehrlich's test?
Ehrlich's test is a presumptive test for the presence of indole compounds, such as tryptophan, in a sample. It relies on the reaction between indole compounds and p-dimethylaminobenzaldehyde to produce a blue-colored complex. This test is commonly used in microbiology to detect the indole production by bacteria such as Escherichia coli.
What are the ingredients in Ehrlich's indole reagent?
Ehrlich's reagent, used to detect the presence of indole compounds, typically consists of p-dimethylaminobenzaldehyde dissolved in a strong acid, such as hydrochloric acid or sulfuric acid.
What ingrediant could be eliminated if the medium was strictly used for indole production?
Trytophan
How can you describe the smell of indole?
Indole has a distinct fecal odor, often described as musty with earthy undertones. Some people also detect a slightly floral or fruity scent, reminiscent of jasmine or orange blossoms.
What is the component in the SIM deep tubes that makes the medium suitable to detect the production of indole by bacteria?
The component in SIM deep tubes that makes the medium suitable to detect the production of indole by bacteria is tryptophan. Bacteria that possess the enzyme tryptophanase can break down tryptophan to produce indole, which can be detected by the addition of Kovac's reagent that reacts with indole to form a red color.
What is SIM tube media used for?
SIM (Sulfide-Indole-Motility) tube media is used to differentiate bacteria based on their ability to produce hydrogen sulfide, indole, and exhibit motility. It contains ferrous sulfate to detect hydrogen sulfide production, tryptophan to test for indole production, and a semi-solid agar to assess motility. This media is commonly used in microbiology labs to identify and characterize microorganisms.
Principle of ehrlich's test?
Ehrlich's test is a presumptive test for the presence of indole compounds, such as tryptophan, in a sample. It relies on the reaction between indole compounds and p-dimethylaminobenzaldehyde to produce a blue-colored complex. This test is commonly used in microbiology to detect the indole production by bacteria such as Escherichia coli.
What is Staphylococcus aureus sim test results?
Staphylococcus aureus is negative for motility, and positive for the indole production. The SIM test tests for sulfur reduction, indole production and motility. Positive for indole production means tryptophan is broken down into indole and pyruvate and will give a red color. Motility, you will see the bacteria move outside of the stab. Positive for sulfur reduction will give a black color in the medium.
What are the ingredients in Ehrlich's indole reagent?
Ehrlich's reagent, used to detect the presence of indole compounds, typically consists of p-dimethylaminobenzaldehyde dissolved in a strong acid, such as hydrochloric acid or sulfuric acid.
What ingrediant could be eliminated if the medium was strictly used for indole production?
Trytophan
What factors dictate the choice of tests included in a combination medium?
The hydrogen sulfide production, motility, and indole production.
How can you describe the smell of indole?
Indole has a distinct fecal odor, often described as musty with earthy undertones. Some people also detect a slightly floral or fruity scent, reminiscent of jasmine or orange blossoms.
Does proteus vulgaris produce h2s?
Yes, it does. It is Indole Production positive, H2S positive, and Motility positive. This can all be seen using SIM agar. Yes, it does. It is Indole Production positive, H2S positive, and Motility positive. This can all be seen using SIM agar.
Explain the chemical mechanism for detecting indole in a bacterial culture?
Indole is extracted from the medium and into the reagent layer (Kovac's) by the acidified butyl alcohol component and forms a complex with the p-dimethylaminobenzaldehyde, yielding the cherry red color seen when the culture is indole positive.
Why determine motility and h2s before adding kovac's reagent?
You will do this regardless since Indole is part of the SIM media....this media will turn black if H2S is present and you read it for motility just like standard motility media. It must incubate for 24-28 hrs before doing the indole portion. Hope this helps.
What is salkowski's reaction and its mechanism?
salkowski's reaction is carried out using salkowski's reagent (1 ml of 0.5 M FeCl3 + 50 ml of 35 % perchloric acid ). It is used for colorimetric estimation of indole derivates, it produces pink colour. A trace of hydrogen peroxide induces the oxidation reaction which produces the colour and hastening its intensity.
