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Merck
CN

02538

Raka-Ray Agar

NutriSelect® Plus, powder, selective for lactic acid bacteria, pack of 500 g, suitable for microbiology

Synonym(s):

Lactic Acid Bacteria Selective Agar Base

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About This Item

NACRES:
NA.85
UNSPSC Code:
41171609
Manufacturer/tradename:
NutriSelect® Plus
Form:
powder
Suitability:
Pediococcus spp., selective for lactic acid bacteria
Application(s):
agriculture
bioburden testing
food and beverages, microbiology

Key Documents

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sterility

non-sterile

form

powder

Quality Level

200

shelf life

limited shelf life, expiry date on the label

composition

N-acetyl glucosamine, 0.5 g/L , agar, 17.0 g/L , betaine hydrochloride, 2.0 g/L , casein enzymic hydrolysate, 20.0 g/L , diammonium hydrogen-citrate, 2.0 g/L , fructose, 5.0 g/L , glucose, 5.0 g/L , liver concentrate, 1.0 g/L , magnesium sulphate, 2.0 g/L , maltose, 10.0 g/L , manganese sulfate, 0.66 g/L , monopotassium phosphate, 2.0 g/L , potassium aspartate, 2.5 g/L , potassium glutamate, 2.5 g/L , yeast extract, 5.0 g/L

packaging

pack of 500 g

manufacturer/tradename

NutriSelect® Plus

final pH

5.4±0.2 (25 °C)

application(s)

agriculture
bioburden testing
food and beverages, microbiology

storage temp.

2-8°C

suitability

Pediococcus spp., selective for lactic acid bacteria

Related Categories

General description

Raka-Ray Agar was formulated by Saha, Sondag and Middlekauff to monitor the brewing process and analyze it for a wide range of bacteria. The media is found to be superior to several other media for the cultivation of Lactobacilli and Pediococci. It also suppresses the growth of non-lactic acid facultative bacteria that are often associated with lactic beer spoilage.

Application

Raka-Ray Agar is recommended for selective isolation of lactic acid bacteria encountered in beer and the brewing process.

Preparation Note

Suspend 38.5 g in 500 ml of distilled water. Bring to the boil and dissolve the medium completely. Distribute into tubes or bottles and sterilize by autoclaving at 121°C for 15 minutes. Cool to 50-55°C and add contents of 1vial of lactic acid bacteria selective supplement (Cat. No. 14121). Add 3.5 ml of Cycloheximide solution (Cat. No. 18079). Mix well and pour into sterile petri dishes or dispense as desired.

Analysis Note

Casein enzymic hydrolysate, liver concentrate, yeast extract provide carbon, nitrogen, amino acids, minerals, vitamins, trace elements and other essential nutrients for growth. Potassium aspartate and potassium glutamate are additional sources of amino acids. Maltose is to detect lactobacilli, which cannot utilize glucose as a carbon source and fructose is the carbon source of Lactobacillus fructivorans. Glucose is needed as the fermentative energy source for the Pediococci. Sorbitan mono-oleate act as a stimulant for lactic acid bacteria in general. Also, N-acetyl glucosamine, liver concentrate yeast extract and betaine hydrochloride are used as growth stimulating agents. Diammonium hydrogen-citrate and Monopotassium phosphate are the buffering agents while Magnesium and Manganese are important trace elements for Lactobacillaceae. The addition of phenylethanol inhibits Gram-negative organisms, while amphotericin B and cycloheximide inhibits growth of yeasts and molds.

Other Notes

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

pictograms

Exclamation mark
GHS07

signalword

Warning

hcodes

H319

Hazard Classifications

Eye Irrit. 2

Storage Class

11 - Combustible Solids

ppe

Eyeshields, Gloves, type N95 (US)

Regulatory Information

动植物来源培养基
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Certificates of Analysis (COA)

Lot/Batch Number
BCCN4983
BCCM1100
BCCK4941
BCCJ0015
BCCJ6116

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Sixty years of Amphotericin B: An Overview of the Main Antifungal Agent Used to Treat Invasive Fungal Infections
Infectious diseases and therapy, 1-33 (2021)
C. Van Keer et al.
Journal of the Institute of Brewing, 89, 361-361 (1983)
The genera lactobacillus and carnobacterium
Hammes, WALTER P and Hertel, CHRISTIAN
The Prokaryotes: Vol. 1: Symbiotic Associations, Biotechnology, Applied Microbiology, 4, 320-403 (2006)
European Brewing Convention
Journal of the Institute of Brewing, 87, 303-303 (1981)

Articles

Culture Method for Beer Quality Control

Traditional methods are based morphology, staining methods, enzyme reactions (metabolism) and diverse media.

Probiotics and Human Health

Probiotics exhibit an inhibitory effect on pathogens, help prevent chronic intestinal inflammatory diseases or atopic syndromes, and support the immune system.

Microbiological Media & Detection

Cost-effective molecular biology method for lactobacilli detection is presented as an alternative to PCR-based methods.

Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.

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