Part of Thermo Fisher Scientific

Thermo Scentific
 
 
 

Dehydrated Culture Media

MALT EXTRACT AGAR

Code: CM0059

A medium for the detection, isolation and enumeration of yeasts and moulds. Bacteria may be suppressed by the addition of lactic acid.

Typical Formula*

gm/litre

Malt extract

30.0

Mycological peptone

5.0

Agar

15.0

pH 5.4 ± 0.2

* Adjusted as required to meet performance standards

Directions
Suspend 50g in 1 litre of distilled water and boil to dissolve. Sterilise by autoclaving at 115°C for 10 minutes.

If it is desired to adjust the medium to pH 3.5, cool to 55°C and add approximately 2-3ml of 10% Lactic Acid SR0021 to 100ml Malt Extract Agar. Once acidified with lactic acid, the medium should not be re-heated.

Description
This medium, similar to the one described by Galloway & Burgess1 is recommended for the detection, isolation and enumeration of yeasts and moulds. For mycological counts it may be desirable to prepare the more acid medium in order to suppress bacterial growth.
Also see Wort Agar.

Storage conditions and Shelf life
Store the dehydrated medium at 10-30°C and use before the expiry date on the label.
Store the prepared medium at 2-8°C.

Appearance
Dehydrated medium: Straw coloured, free-flowing powder
Prepared medium: Amber coloured gel

Quality control

Positive controls:

Expected result

Aspergillus niger ATCC® 9642 *

White mycelium, black spores

Candida albicans ATCC® 10231 *Good growth; cream coloured colonies

Negative control:

 

Uninoculated medium

No change

* This organism is available as a Culti-Loop®

Precautions
Avoid overheating as the acid pH will soften the agar in the presence of heat.

Reference
1. Galloway L.D. and Burgess R.(1952) Applied Mycology and Bacteriology 3rd Edition Leonard Hill, London. pp54 and 57.

 
©2001 - 2024 Oxoid Limited, All rights reserved.
Copyright, Disclaimer and Privacy Policy | Conditions of Sale | About Us | Cookies
Thermo Fisher Scientific Inc.