17222

WL Nutrient Agar

suitable for microbiology, NutriSelect^® Plus,

• Synonym(s): Wallerstein Laboratory Nutrient Agar
• UNSPSC Code: 41171605
• NACRES: NA.74

Properties

• Quality Level: 200
• sterility: non-sterile
• form: powder
• shelf life: limited shelf life, expiry date on the label
• composition: agar, 20 g/L ; bromocresol green, 0.022 g/L ; calcium chloride, 0.125 g/L ; casein enzymic hydrolysate, 5 g/L ; dextrose, 50 g/L ; ferric chloride, 0.0025 g/L ; magnesium sulfate, 0.125 g/L ; manganese sulfate, 0.0025 g/L ; monopotassium phosphate, 0.55 g/L ; potassium chloride, 0.425 g/L ; yeast extract, 4 g/L
• manufacturer/tradename: NutriSelect^® Plus
• technique(s): microbiological culture: suitable
• final pH: 5.5±0.2 (25 °C)
• application(s): bioburden testing; food and beverages; microbiology
• suitability: nonselective and differential for Candida spp.; nonselective and differential for Escherichia coli; nonselective and differential for Lactobacillus spp.; nonselective and differential for Pichia spp.; nonselective and differential for Proteus spp.; nonselective and differential for Saccharomyces spp.; nonselective and differential for Zygosaccharomyces spp.; nonselective and differential for bacteria (General Media); nonselective and differential for coliforms; nonselective and differential for molds (General Media); nonselective and differential for yeasts (General Media)

Description

General description

WL (Walerstein Laboratory) media follow the formula described by Green and Gray for the examination of materials related to brewing and for industrial fermentations containing mixed flora of yeasts and bacteria. Yeast extract is a source of vitamins, amino acids and trace elements. Casein enzymic hydrolysate provides nitrogen, amino acids and carbon. Dextrose is the main carbon and energy source. Potassium phosphate is the buffering agent. Several salts in the medium provide essential ions and help to maintain osmotic balance. Bromcresol green acts as pH indicator and agar as solidifying agent. WL Nutrient Agar is used for the examination of materials encountered in brewing and for industrial fermentations containing mixed flora of yeasts and bacteria.

Application

WL Nutrient Agar is suitable:

• for reviving yeast stock cultures and for population dynamics studies post fermentation
• for morphological characterization of yeast isolated from cheese
• for plating fermented wine for yeast species isolation

Preparation Note

Suspend 80.25 g in 1 litre distilled water. Boil to dissolve the medium completely. Sterilize by autoclaving at 121°C for 15 minutes. If desired, to obtain a pH of 6.5, add 1% solution of sodium bicarbonate.

Footnote

We offer two media types: the superior granulated GranuCult^® and the cost-efficient powdered NutriSelect^® culture media, depending on your needs.
The designations basic, plus, or prime are added to indicate the quality control level, from basic quality control to standard QC plus to prime for full regulatory compliance.

Legal Information

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

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

Safety Information

• Storage Class Code: 11 - Combustible Solids
• WGK: WGK 3
• Flash Point(F): Not applicable
• Flash Point(C): Not applicable
• Personal Protective Equipment: dust mask type N95 (US), Eyeshields, Gloves