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The catalase test is done by placing a drop of hydrogen peroxide on a microscope slide. An applicator stick is touched to the colony, and the tip is then smeared onto the hydrogen peroxide drop. If the mixture produces bubbles or froth, the organism is said to be 'catalase-positive'. Staphylococci [47] and Micrococci [48] are
A fibrin clot formed in a test tube by the coagulase reaction. The tube test uses rabbit plasma that has been inoculated with a staphylococcal colony (i.e., Gram-positive cocci which are catalase positive). The tube is then incubated at 37 °C for 1.5 hours. If negative, then incubation is continued up to 18 hours.
The catalase test tests whether a microbe produces the enzyme catalase, which catalyzes the breakdown of hydrogen peroxide. Smearing a colony sample onto a glass slide and adding a solution of hydrogen peroxide (3% H 2 O 2) will indicate whether the enzyme is present or not. Bubbling is a positive test while nothing happening is a negative ...
Slow growing M. marinum and M. szulgai are positive in the 14-day arylsulfatase test. [2] Catalase, semiquantitative activity. Most mycobacteria produce the enzyme catalase, but they vary in the quantity produced. Also, some forms of catalase are inactivated by heating at 68°C for 20 minutes (others are stable).
Klebsiella aerogenes, [2] previously known as Enterobacter aerogenes, is a Gram-negative, oxidase-negative, catalase-positive, citrate-positive, indole-negative, rod-shaped bacterium. [3] Capable of motility via peritrichous flagella, [ 4 ] it is approximately one to three microns in length.
To test the broth for indole production, Kovac's reagent. Kovac's reagent consist of amyl alcohol and para-dimethylaminobenzaldehyde and concentrated hydrochloric acid . Kovac's reagent is actually used to determine ability of an organism to separate indole from amino acid tryptophan and it is added after incubation.
Indole test positive: appearance of pink layer at top (e.g. Escherichia coli) Like many biochemical tests on bacteria, results of an indole test are indicated by a change in color following a reaction with an added reagent. Pure bacterial culture must be grown in sterile tryptophan or peptone broth for 24–48 hours before performing the test.
A. faecalis is a Gram-negative bacterium which appears rod-shaped and motile under a microscope. It is positive by the oxidase test and catalase test, but negative by the nitrate reductase test. It is alpha-hemolytic and requires oxygen. A. faecalis can be grown at 37 °C, and forms colonies that lack pigmentation. [1]