HCM114 Bile Esculin Azide Agar

$199

Intended Use For the selective separation and enumeration of enterococci in food and water. Principle and Interpretation Tryptone and peptone are the sources of nitrogen and essential grow……

Introduction

Intended Use

For the selective separation and enumeration of enterococci in food and water.

Principle and Interpretation

Tryptone and peptone are the sources of nitrogen and essential growth factors. Yeast extract acts as well nitrogenous compounds and additionally the vitamin B12 complex. Sodium azide acts largely inhibits the growth of gram-negative bacteria while sparing enterococci, staphylococci and streptococci. Ox bile inhibits most gram positives but not enterococci. Enterococci hydrolyse esculin to esculetin and dextrose, which reacts with ferric citrate producing a brownish black precipitate around the colonies. Tolerance to bile and the ability to hydrolyze esculin is the traditional and reliable test for the identification of enterococci. (4). Sodium chloride maintains the osmotic balance of the medium and Agar is the solidifying agent.

Formulation

Ingredients/liter
Tryptone17.0g
Ox bile10.0g
Yeast extract5.0g
Sodium chloride5.0g
Peptone3.0g
aesculin1.0g
Ferric ammonium citrate0.5g
Sodium azide0.15g
Agar15.0g
pH 7.1±0.1 at 25°C

Preparation

Weigh 56.6g of dry powder of this product, add 1 L of distilled water or deionized water, stir, heat and boil until completely dissolved, and sterilize at 121℃ for 15 min.

Quality Control

Cultural characteristics observed after incubation at 35-37°C for 20-24hours.

Quality control strainsGrowthColony color
Enterococcus faecalis ATCC29212PR≥0.7Brown-black halo
Escherichia coli ATCC25922 inhibitedAbsence of brown-black halo

Sorage and Shelf Life

Keep container tightly closed, store in a cool, dry place, away from bright light. Storage period of 3 years.

Precautions

1. When weighing the dehydrated medium, please wear masks to avoid causing respiratory system discomfort

2. Keep container tightly closed after using to prevent clumping.

Waste Disposal

Microbiological contamination was disposed by autoclaving at 121°C for 30 minutes.

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