Welcome to Agar Wars.
Malt Extract and Rose Bengal are two of the most commonly used agars for testing yeasts and moulds . They both adequately perform the job but if they were both thrown into an agar war arena, which would emerge as the ultimate yeasts and moulds tester? There's only one way to find out....
First, let's take a look at the contender's stats.
In the blue corner, weighing in at 26 grams, we have Malt 'the mega' Extract. The malt extract has a formidable array of testing ability. Its bacterial growth is suppressed helping it to detect yeasts and moulds in tests.
This agar is used for the detection and isolation of yeasts and moulds. The Malt Extract agar on our dipslides suppresses the growth of bacteria.
This is a general purpose agar. It can be used to test a large variety of samples including:
- Industrial Fluids
- Cooling Towers
Malt Extract agar is also ideal for testing for xerophiles (organisms that thrive despite little water).
Now, in the Red corner, measuring in at 10.8cm tall with a PH of Neutral, Rose 'right hand' Bengal'.
This agar is selective for yeasts and moulds in food. It can also be used for testing other samples such as cosmetics.
Colonies on Rose Bengal agar are fairly easy to analyse / count as they often show as vibrant pink dots. This agar also restricts the growth of bacteria.
Rose Bengal agar is recommended for testing:
- Fresh foods
- Protein / meat
- Environmental applications
Rose Bengal has a neutral pH and is preferable to acidic agars for testing spoilage organisms.
Unlike Malt Extract agar, Rose Bengal is not used for clinical samples.
This agar is ideal for applications that require longer / higher temperature incubation.
Cue anticlimax.... Neither! It depends on what you would like to test for! As Malt Extract agar tests a wider variety of samples, this definitely gives it an advantage. However, Rose Bengal offers much more ease when analysing results due to the vibrant colonies that display on this agar.
Therefore, I'd like to announce that this match is a dead heat and that no particular agar has won outright today.
Join us another day for more Agar Wars!
Selective media for detecting and enumerating foodborne yeasts - Beuchat LR