Dehydrated culture media
LMDA Agar
Multi-differential agar that has the capacity to differentiate among a great variety of bacteria, including bacteria found in the beer.
- Cat. No.
- LC-1084
- Category
- Dehydrated culture media
- Format
- 500 g
- Storage
- 2 to 25 °C
- Minimum guaranteed shelf life
- 15 months
LMDA Agar is a nutrient medium that detects most organisms commonly found in the brewery.
Key features
Applications
Differentiation of microorganisms of the brewing industry.
Industry
Alcoholic beverages.
Preparation
84.8 g in one liter of distilled water; boil for one minute, sterilize in autoclave at 121 °C for 15 minutes.
Principles and uses
Beer is not a very appropriate medium for the development of bacteria due to its characteristics, such as the low quantity of available nutrients, the presence of alcohol, carbon dioxide and sulfur dioxide, as well as low conservation temperatures. Beer filtration and pasteurization phases also contribute to the stabilization of the product against microorganisms.
The number of genera and species which usually contaminate it is limited. As is the case with wild yeasts, the contaminating bacteria cause turbidity and generate anomalous smells.
Acid producing bacteria can be identified by the presence of a clear zone around the colonies. Further identification is facilitated by the characteristic color reactions. Cycloheximide can be added to the medium to inhibit the growth of culture yeast. If you wish to detect yeasts, don't add cycloheximide and incubate under the same conditions (time and temperature) in aerobic conditions.
Technical specifications
| Solubility | Slight precipitate |
|---|---|
| Appearance | Fine powder |
| Color of the dehydrated medium | Beige |
| Color of the prepared medium | Bluish green |
| Final pH (25 °C) | 5.5 ± 0.2 |
| Amount per litre | 84.8 g |
Formula
| Ingredient | g/L |
|---|---|
| Glucose | 10 |
| Bacteriological agar | 15 |
| Bromocresol green | 0.022 |
| Calcium carbonate | 5 |
| Calcium pantothenate | 2 |
| Citric acid | 1.1 |
| Dipotassium phosphate | 0.5 |
| Ferrous sulfate | 0.01 |
| Magnesium sulfate | 0.2 |
| Manganese sulfate | 0.01 |
| Monopotassium phosphate | 0.5 |
| Peptonized milk | 20 |
| Sodium chloride | 0.01 |
| Tomato juice | 20 |
| Tween 80 | 0.5 |
| Yeast extract | 10 |
Preparation and use
Preparation
Suspend 84.8 grams of the medium in one liter of distilled water. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Dispense into appropriate containers and sterilize in autoclave at 121 °C for 15 minutes. If desired, add 0.007 grams of cycloheximide.
Instructions for use
Inoculate and incubate at 30 °C in anaerobic conditions for 4-7 days.
Quality control
Microbiological test
Incubation conditions: 30 °C, anaerobic conditions / 4-7 days.
| Microorganism | Specification | Characteristic reaction |
|---|---|---|
| Pediococcus damnosusATCC 29358 | Good growth | Change in the color of the medium from green to brownish-yellow. Small green colonies. |
| Pediococcus acidilacticiATCC 8042 | Good growth | Change in the color of the medium from green to brownish-yellow. Greyish green colonies. |
| Lactobacillus brevisATCC 8287 | Good growth | Light change in the color of the medium from green to brownish-yellow. Greyish blue colonies. |
| Lactobacillus fermentumATCC 9338 | Good growth | Change in the color of the medium from green to brownish-yellow. Greenish white colonies with green center. |
Bibliography
- Beer Spoilage Bacteria and Hop Resistance. Kanta Sakamoto and Wil N. Konings.
- Max Louise and H. W. Schoenlein, Compilation of Culture Media.
What you receive
The product
Shipped under controlled temperature when the product requires it.
Lot certificate
Every lot comes with its certificate.
Tracked shipment
Follow your shipment live, from our warehouse to your lab.
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Frequently asked questions
Can I ask for formats other than those listed?
Yes: custom formats and OEM packs are available on request. Tell us the quantities you need.
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