CRITERION™ m GREEN YEAST AND FUNGI BROTH

Cat. no. C7540 CRITERION™ m Green Yeast and Fungi Broth 146gm
Cat. no. C7541 CRITERION™ m Green Yeast and Fungi Broth 500gm
Cat. no. C7542 CRITERION™ m Green Yeast and Fungi Broth 2kg
Cat. no. C7543 CRITERION™ m Green Yeast and Fungi Broth 10kg
Cat. no. C7544 CRITERION™ m Green Yeast and Fungi Broth 50kg

INTENDED USE

Hardy Diagnostics CRITERION™ m Green Yeast and Fungi Broth is recommended for the detection of yeast and fungi in beverages using membrane filtration.

This dehydrated culture medium is a raw material intended to be used in the making of prepared media products, which will require further processing, additional ingredients, or supplements.

SUMMARY

CRITERION™ m Green Yeast and Fungi Broth is a complex formula used for the isolation of fungi and yeasts from beverages. The formulation is rich in nutrients which allows for excellent fungal growth. It contains yeast extract, pancreatic digest of casein, and peptic digest of animal tissue which provides necessary growth nutrients. Dextrose is the source of fermentable carbohydrate. Bacterial growth is inhibited by the low pH and bromcresol green is used as the pH indicator. The fungal colonies will appear green due to the diffusion of the dye into the colonies. The broth may turn yellow due to the production of acidic end products caused by the fermentation of dextrose.

FORMULA

Gram weight per liter: 73.0gm/L
Dextrose 50.0gm
Yeast Extract 9.0gm
Pancreatic Digest of Casein 5.0gm
Peptic Digest of Animal Tissue 5.0gm
Magnesium Sulfate 2.1gm
Monopotassium Phosphate 2.0gm
Amylase 50.0mg
Thiamine 50.0mg
Bromcresol Green 26.0mg

Final pH 4.6 +/- 0.2 at 25ºC.

* Adjusted and/or supplemented as required to meet performance criteria.

STORAGE AND SHELF LIFE

Store the sealed bottle(s) containing dehydrated culture medium at 2-30ºC. Dehydrated culture medium is very hygroscopic. Keep lid tightly sealed. Protect dehydrated culture media from moisture and light. The dehydrated culture media should be discarded if it is not free-flowing or if the color has changed from its original light green.

Store the prepared culture medium at 2-8ºC.

PRECAUTIONS

METHOD OF PREPARATION FOR DEHYDRATED CULTURE MEDIA

1. Suspend 73.0gm of the dehydrated culture media in 1 liter of distilled or deionized water.

2. Heat as needed to dissolve completely.

3. Sterilize in the autoclave at 121ºC. for 15 minutes.

PROCEDURE AND INTERPRETATION OF RESULTS

For information on procedures and interpretation of results, consult listed references.

LIMITATIONS

Actually colony color will be hidden due to uptake of the bromcresol green dye.

MATERIALS REQUIRED BUT NOT PROVIDED

Standard microbiological supplies and equipment such as autoclaves, incinerators, and incubators, etc., are not provided.

QUALITY CONTROL

Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Aspergillus brasiliensis
formerly A. niger
ATCC ® 16404

J 48hr 35°C Aerobic Growth
Saccharomyces cerevisiae
ATCC ® 9763
J 48hr 35°C Aerobic Growth

User Quality Control

PHYSICAL APPEARANCE

CRITERION™ m Green Yeast and Fungi Broth powder should appear homogeneous, free-flowing, and light green in color. The prepared media should appear clear to slightly hazy, and green in color.

REFERENCES

1. Compendium of Methods for the Microbiological Examination of Foods, 3rd ed. 1992. APHA, Washington, D.C.


ATCC is a registered trademark of the American Type Culture Collection.

062916gr