YEAST EXTRACT AGAR (C15-1296-959)

General description

Yeast extract agar is a granulated medium to enumerate the total microbial count from water and other materials. The granules ensure rapid and uniform dissolution in water. It also prevents clumping of the medium and inhalation of the airborne powder. Yeast extract and peptone provide nitrogenous compounds, vitamin B complex, and other growth nutrients. This medium does not contain any inhibitors or indicators and it is relatively rich in its nutrients.

Application

Yeast extract agar is recommended to determine the total microbial content from water and other materials.

Analysis Note

Appearance (clearness): clear
Appearance (colour): yellowish to yellowish-brown
pH-value (25 °C): 7.0 - 7.4
Growth promotion test in accordance with the current version of DIN EN ISO 11133.
Incubation: 44 ± 4 hours at 36 ± 2 °C aerobic
Inoculum on reference medium (Escherichia coli ATCC 8739 (WDCM 00012)):

Inoculum on reference medium (Escherichia coli ATCC 25922 (WDCM 00013)):

Inoculum on reference medium (Bacillus subtilis ATCC 6633 (WDCM 00003)):

Inoculum on reference medium (Pseudomonas aeruginosa ATCC 27853 (WDCM 00025)):

Colony count (Escherichia coli ATCC 8739 (WDCM 00012)):

Colony count (Escherichia coli ATCC 25922 (WDCM 00013)):

Colony count (Bacillus subtilis ATCC 6633 (WDCM 00003)):

Colony count (Pseudomonas aeruginosa ATCC 27853 (WDCM 00025)):
Recovery on test medium (Escherichia coli ATCC 8739 (WDCM 00012)):
≥ 70 %
Recovery on test medium (Escherichia coli ATCC 25922 (WDCM 00013)):
≥ 70 %
Recovery on test medium (Bacillus subtilis ATCC 6633 (WDCM 00003)):
≥ 70 %
Recovery on test medium (Pseudomonas aeruginosa ATCC 27853 (WDCM 00025)):
≥ 70 %
Incubation: 68 ± 4 hours at 20 - 25 °C aerobic
Inoculum on reference medium (Escherichia coli ATCC 8739 (WDCM 00012)):

Inoculum on reference medium (Escherichia coli ATCC 25922 (WDCM 00013)):

Inoculum on reference medium (Bacillus subtilis ATCC 6633 (WDCM 00003)):

Inoculum on reference medium (Pseudomonas aeruginosa ATCC 27853 (WDCM 00025)):

Colony count (Escherichia coli ATCC 8739 (WDCM 00012)):

Colony count (Escherichia coli ATCC 25922 (WDCM 00013)):

Colony count (Bacillus subtilis ATCC 6633 (WDCM 00003)):

Colony count (Pseudomonas aeruginosa ATCC 27853 (WDCM00025)):
Recovery on test medium (Escherichia coli ATCC 8739 (WDCM 00012)):
≥ 70 %
Recovery on test medium (Escherichia coli ATCC 25922 (WDCM 00013)):
≥ 70 %
Recovery on test medium (Bacillus subtilis ATCC 6633 (WDCM 00003)):
≥ 70 %
Recovery on test medium (Pseudomonas aeruginosa ATCC 27853 (WDCM 00025)):
≥ 70 %
A recovery rate of 70 % is equivalent to a productivity value of 0.7.
The indicated colony counts result from the sum of a triple determination.
Reference media: Yeast Extract Agar

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