Dehydrated culture media
Modified Nocive Brewers Bacteria Agar Base
Selective medium for the detection of contaminating, spoilage microorganisms in brewery.
- Cat. No.
- LC-1438
- Category
- Dehydrated culture media
- Format
- 500 g
- Storage
- 2 to 25 °C
- Minimum guaranteed shelf life
- 15 months
Modified Nocive Brewers Bacteria Agar Base is a medium used for the detection of beer spoilage bacteria.
Key features
Applications
Detection and selective enrichment of microorganisms of the brewing industry.
Industry
Alcoholic beverages.
Preparation
66.3 g in 500 mL of distilled water and 500 mL of beer without gas; boil for one minute, sterilize in autoclave at 121 °C for 15 minutes.
Principles and uses
This medium contains a wide variety of nutrients including pancreatic digest of casein, yeast extract, beef extract, dextrose and maltose. These nutrients favour the growth of spoilage microorganisms in beer and other samples. Potassium acetate (instead of sodium acetate) makes the medium less inhibitory for the growth of spoilage bacteria that deteriorate beer and other samples. Polysorbate 80 is incorporated to neutralize phenols, hexachlorophene and formalin. L-Cysteine hydrochloride is the reducing agent. Disodium phosphate acts as a buffer system. Bacteriological agar is the solidifying agent.
Technical specifications
| Solubility | Without residues |
|---|---|
| Appearance | Fine powder |
| Color of the dehydrated medium | Beige |
| Color of the prepared medium | Pink-red |
| Final pH (25 °C) | 5.8 ± 0.2 |
| Amount | 66.3 g in 500 mL of distilled water and 500 mL of beer without gas |
| Storage | 2 to 25 °C |
Formula
| Ingredient | g/L |
|---|---|
| Bacteriological agar | 15 |
| Beef extract | 2 |
| Dextrose | 15 |
| Disodium phosphate | 2 |
| Maltose | 15 |
| Pancreatic digest of casein | 5 |
| Polysorbate 80 | 0.5 |
| Yeast extract | 5 |
| L-Malic acid | 0.5 |
| L-Cysteine HCl | 0.2 |
| Chlorophenol red | 0.07 |
| Potassium acetate | 6 |
Typical formula in g/L, adjusted and/or supplemented as required to meet performance criteria.
Preparation and use
Preparation
Suspend 66.3 grams of the medium in 500 mL of distilled water and 500 mL of beer without gas. Mix well and dissolve by heating with frequent agitation. Boil for one minute until complete dissolution. Sterilize in autoclave at 121 °C for 15 minutes. Cool to 45-50 °C, mix well and dispense into plates.
Instructions for use
Pour plate method:
- Deposit 1 mL of the initial suspension and/or diluted sample in an empty Petri dish.
- Add 12-15 mL of agar cooled to 44-47 °C in each Petri dish and mix gently moving the plate.
- Allow the plates to solidify and incubate in an inverted position at a temperature of 30-35 °C for 4 days.
- Take the acid-producing colonies and carry out the catalase and Gram stain tests.
Quality control
Microbiological test
Incubation conditions: 30-35 °C / 4 days.
| Microorganism | Specification | Characteristic reaction |
|---|---|---|
| Pediococcus damnosusATCC 29358 | Good growth | Acid production (trace yellow-yellow) |
| Pediococcus acidilacticiATCC 8042 | Good growth | Acid production (trace yellow-yellow) |
| Lactobacillus brevisATCC 8287 | Good growth | Acid production (trace yellow-yellow) |
Bibliography
- Back, 1980 Brauwelt 1562
- Dacha, 1981, Brauwelt 1778
What you receive
The product
Shipped under controlled temperature when the product requires it.
Lot certificate
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Tracked shipment
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Frequently asked questions
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