Not available outside of the UK & Ireland.

Application

M-17 Broth is a selective medium for Streptococcus thermophilus for examination of yogurt and for the enrichment Streptococcus thermophilus in the dairy industry.

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.

General description

M-17 Broth is a selective medium for Streptococcus thermophilus in the common examination of yoghurt. It is superior to other comparable culture media for the cultivation of the fastidious species such as S. cremoris, S. diacetilactis and S. lactis. Mutants which are incapable of metabolizing lactose can also be isolated on these media. Tryptone, meat peptone, soya peptone, yeast extract and meat extract provide carbonaceous, nitrogenous compounds, vitamin B complex and other essential growth factors. Lactose is the fermentable carbohydrate and ascorbic acid is stimulatory for the growth of lactic Streptococci. Magnesium sulphate provides essential ions to the organisms. Sodium glycerophosphate increases the buffering capacity of the medium, this promotes the growth of lactic streptococci and inhibits lactobacilli growth.

Legal Information

NutriSelect is a registered trademark of Merck KGaA, Darmstadt, Germany

GRANUCULT is a registered trademark of Merck KGaA, Darmstadt, Germany

Preparation Note

Suspend 42 g of powder in 1 litre of distilled water and let it soak. Heat to boiling and dispense into suitable containers. Sterilize by autoclaving at 121°C for 15 minutes.