Search results
Results from the WOW.Com Content Network
This is sometimes called green hemolysis because of the color change in the agar. Other synonymous terms are incomplete hemolysis and partial hemolysis. Alpha-hemolysis is caused by the bacteria's production of hydrogen peroxide, which oxidizes hemoglobin and produces the green oxidized derivative methemoglobin.
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 result.
If the bacteria are cultured after the exposure to lactoperoxidase-thiocyanate-hydrogen peroxide on nutrient agar under aerobic conditions, they may not grow, whereas they grow readily on blood agar under anaerobic conditions." [27] In its antimicrobial capacity, lactoperoxidase appears to acts synergistically with lactoferrin [28] and lysozyme ...
The cytochrome system is usually only present in aerobic organisms that are capable of using oxygen as the terminal electron acceptor. The end-product of this metabolism is either water or hydrogen peroxide (broken down by catalase). [1]
Blood agar plates (BAPs) contain mammalian blood (usually sheep or horse), typically at a 5–10% concentration. BAPs are enriched, and differential media is used to isolate fastidious organisms and detect hemolytic activity. β-Hemolytic activity will show lysis and complete digestion of red blood cell contents surrounding a colony.
Into a second flask, add charcoal, yeast extract, alpha-keto-glutarate, and agar. Mix the dry powders. Pour the buffer solution into the second flask containing the dry powders and mix. Carefully heat to dissolve the agar, then sterilize by autoclaving at 121 °C for 15 minutes. Immediately place the medium in 50 °C water bath.
CNA agar is commonly used in clinical microbiology laboratories to isolate pathogenic Gram-positive bacteria such as Staphylococcus, Enterococcus, Streptococcus, diphtheroids, and Listeria from clinical specimens. [1] A common use for CNA agar is commonly used for the detection of Streptococcus agalactiae carriage in pregnant women. [2]
1.5% agar - this gives the mixture solidity; 0.5% sodium chloride - this gives the mixture proportions similar to those found in the cytoplasm of most organisms; distilled water - water serves as a transport medium for the agar's various substances; pH adjusted to neutral (6.8) at 25 °C (77 °F). Nutrient broth has the same composition, but ...