Coliform Agar ES, Chromocult ® (Chromocult Coliform Agar ES) (Chromocult Enhanced Selectivity Agar)

[所属分类:培养基配方] [发布时间:2020-5-21] [发布人:] [阅读次数:] [返回]

山东拓普生物工程有限公司

Shandong Tuopu Biol-Engineering Co.,Ltd

Coliform Agar ES, Chromocult ®
(Chromocult Coliform Agar ES)
(Chromocult Enhanced Selectivity Agar)

培养基配方
Composition per liter:
Agar.......................................................................10.0g
MOPS ......................................................................10.0g
KCl.........................................................................7.5g
Peptone ....................................................................5.0g
Bile salts.................................................................1.15g
Na-propionate...............................................................0.5g
6-Chloro-3-indoxyl-β- D -galactopyranoside ...............................0.15g
5-Bromo-4-chloro-3-indoxyl-β- D -glucuronic acid ..........................0.1g
Isopropyl-β- D -thiogalactopyranoside .....................................0.1g
pH 7.0 ± 0.2 at 25°C
Source: This medium is available from Merck.
Preparation of Medium:  Add components to distilled/deionized
water and bring volume to 1.0L. Mix thoroughly and heat with frequent
agitation until components are completely dissolved (approximately 45
min). Do not autoclave. Cool to 45°–50°C. Pour into sterile Petri dish-
es. The plates should be clear and colorless.
Use: For the detection of E.coli and total coliforms. The combination
of suitable peptones and the buffering using MOPS allows rapid
growth of coliforms and an optimal transformation of the chromogenic
substrates. The amount of bile salts and propionate largely inhibit
growth of Gram-positive and Gram-negative accompanying flora. The
simultaneous detection of total coliforms and E.coli is achieved using
the combination of two chromogrenic substrates. The substrate
Salmon™--β- D -GAL is split by β- D -galactosidase, characteristic for
coliforms, resulting in a salmon to red coloration of coliform colonies.
The detection of the β- D -glucuronidase, characteristic for E. coli, is
cleaved via the substrate X-β- D -glucuronide, causing a blue coloration
of positive colonies. As E. coli splits Salmon™-β- D -GAL as well as X-
β- D -glucuronide, the colonies turn to a dark violet color and can be eas-
ily differentiated from the other coliforms being salmon-red.