BROMOCRESOL PURPLE BASE BROTH

A liquid culture medium with indicator to carry out sugar fermentation studies.

Code: CB1/2031

Typical formula g/l

Gelatine peptone	10.00
Sodium chloride	5.00
Bromocresol purple	0.02

pH 6.8 ±0.2

Directions

Dissolve 15g of powder into 1 litre of distilled water. Add substrate to assay in the desired concentration and distribute into containers provided with Durham’s tubes. Sterilise in the autoclave at 121°C for 10 minutes. Heat up the autoclave before putting in the tubes to avoid sugar caramelisation. Addition of some sugars may require a pH adjustment. To study the fermentation of some sugars like Glucose, Maltose, Mannitol and Sucrose it is advisable to add them at a 10g/l concentration.

Description

Bromcresol Purple Base Broth is the liquid version suitable to determine, helped with Durham’s tubes, gas production on enterobacteria sensitive to phenol red.

In the ADSA=MICRO formulation, meat extract has been removed because it was unnecessary and moreover it provides little concentrations of fermentable sugars that could change the results. Some bacteria may ferment the carbohydrates in the medium, and then it changes to yellow, and if they produce gas, it is retained in the Durham's tube.

References

ATLAS, R.M., L.C. PARKS (1993) Handbook of Microbiological Media. CRC Press, Inc. London