WALLERSTEIN NUTRIENT BROTH (WLN)

General description

Wallerstein Nutrient Broth is recommended for the isolation and cultivation of yeasts, molds and bacteria that grow in a low pH environment mainly in the beverage industry. Yeast extract in the medium is a source of trace elements, vitamins and amino acids. Peptone provides nitrogen, amino acids and carbon. Dextrose is a source of carbohydrates. Monopotassium phosphate buffers the media. Potassium chloride, calcium chloride, and ferric chloride are essential ions to help to maintain osmotic balance. Magnesium sulfate and manganese sulfate are sources of divalent cations. Bromocresol green is the pH indicator. The WL Nutrient medium plate incubated under aerobic conditions enables the growth of mainly yeast colonies, acetic acid bacteria, flavobacterium, proteus and thermophilic bacteria and under anaerobic condition enables the growth of lactic acid bacteria and Pediococcus. Bacterial colonies appear as non-pigmented to white, with a smooth or rough texture. Yeast appears as large creamy to white colonies.

Application

Wallerstein Nutrient Broth is used in the examination of materials encountered in brewing and for industrial fermentations containing mixed flora of yeast and bacteria. It is used in the beverage industry to detect bacteria, yeast, and mold in wines, beer and other fermentation products.

Features and Benefits

• Ready-to-use Liquid ampoule media solve numerous problems in microbiology laboratories where time, equipment, and trained personnel are often in short supply.
• They are available in convenient, single-test 2 mL plastic ampoules, eliminating the manipulation of glass ampoules and avoiding the waste and spoilage associated with bulk packaged media.

Specifications

Incubation Temperature: 35 °C ± 2 for bacteria; 30 °C ± 2 for yeasts and molds

Incubation Time: 48–72 hrs

Analysis Note

Bacterial colonies can appear non-pigmented to white, with a smooth or rough texture. Yeast appear as creamy, white larger colonies

QC organisms
L. fermentum (ATCC 9338)

S. cerevisiae (ATCC 9763)

Target Microorganisms: Lactic acid bacteria, yeast and mold

Legal Information

MICROFIL is a registered trademark of Merck KGaA, Darmstadt, Germany

MICROPRESURE is a registered trademark of Merck KGaA, Darmstadt, Germany

MILLIFLEX is a registered trademark of Merck KGaA, Darmstadt, Germany