M17 Broth
Also known as：M17 · M17 Broth Base · M17 Medium Base · M-17 Broth Base · M17 Liquid Medium Base
For the cultivation of lactic streptococci and for the propagation of their bacteriophages, following the addition of disodium glycerophosphate.
- Category
- Dehydrated Culture Media
- Dissolve per litre
- 23.25 g
- Pack sizes
- 500 g · 5 kg · 25 kg
- Certifications
- ISO 22000 · Halal
Data updated：2026-11-06
- Allergens
- Soy, Milk
Overview
M17 Broth is a broth (liquid) medium, intended for anaerobes and nutritionally demanding organisms. It is used to cultivate and count lactococci and Streptococcus thermophilus, often alongside MRS. STBIO manufactures it from food-grade raw materials in an ISO 22000 certified facility, with a COA for every batch. This is the Halal-certified version.
Principle
The medium is based on the formulation of Terzaghi and Sandine for the cultivation of lactic streptococci and their bacteriophages.¹ Peptone, soy peptone, beef extract, and yeast extract supply nitrogen, amino acids, peptides, and the B-group vitamins required by these nutritionally demanding organisms. Lactose is the fermentable carbohydrate and provides the carbon and energy source. Magnesium sulphate supplies essential cations, and ascorbic acid lowers the redox potential of the medium and stimulates growth. Disodium glycerophosphate, added at the time of preparation, provides strong buffering capacity. Lactic streptococci produce large amounts of lactic acid, and the resulting fall in pH injures the cells and limits growth; the glycerophosphate buffer holds the pH above the level at which this occurs, supporting higher cell densities. Unlike inorganic phosphate buffers, it does not precipitate calcium, so the medium can be supplemented with calcium salts for bacteriophage work.²
Media for anaerobes and fastidious organisms
Anaerobes and fastidious organisms require media containing reducing agents, blood, or infusion components, together with an anaerobic incubation environment. Some formulations need heat-labile supplements such as blood, serum, or antibiotics added after sterilisation; follow the preparation instructions for the timing and method.
Directions
Suspend 23.25 g of powder and 19.0 g of disodium glycerophosphate in 1 L of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Dispense into tubes or flasks. Sterilize by autoclaving at 121°C for 15 minutes. Test the finished medium for performance using stable, standard control cultures.
Cultural response
| Test organism | ATCC | Growth |
|---|---|---|
| Lactococcus lactis | 19435 | good-luxuriant |
| Streptococcus thermophilus | 19258 | good-luxuriant |
Product highlights
- Food-grade raw materials, produced in an ISO 22000 certified facility
- Halal certified, suitable for the Malaysian, Indonesian, and Middle Eastern markets
- Manufactured to the standard formulation, 23.25 g per litre
- Performance verified against standard control strains before release (Lactococcus lactis, Streptococcus thermophilus)
- Available in 500 g / 5 kg / 25 kg, from laboratory to industrial scale
- COA, specification sheet, and technical data sheet available; samples on request
- Manufactured in Taiwan with reliable supply
Food grade versus laboratory grade
Most culture media suppliers use laboratory-grade raw materials, which are held to lower standards for heavy metal residues, microbial contamination control, and traceability. That is adequate for pure research but not for applications with stricter raw-material requirements. STBIO manufactures with food-grade raw materials throughout, in a facility certified to ISO 22000 food safety management.
- Food microbiology laboratories working to ISO 17025 or equivalent requirements
- Biotech manufacturers exporting fermentation products and needing full raw-material traceability
- Organisations with ESG or compliance audit requirements across their supply chain
- Companies sourcing both Halal and non-Halal products who need one consistent material grade
Frequently asked questions
01How much powder per litre?
Use 23.25 g per litre of deionised water; preparation and sterilisation conditions are given on the specification sheet.
02Which organisms is it suitable for?
Lactic acid bacteria, Gram-positive, Probiotics, Lactococcus, Streptococcus, Lactococcus lactis, Streptococcus thermophilus. See the cultural response table and the specification sheet.
03Can it be used for food-grade applications?
Yes. It is made from food-grade raw materials in an ISO 22000 certified facility and is suitable for culturing starters for fermented products that are consumed directly.
04How is this product prepared?
Suspend 23.25 g of powder and 19.0 g of disodium glycerophosphate in 1 L of purified water. Heat with continuous stirring and bring to the boil for 1 minute. Dispense into tubes or flasks. Sterilize by autoclaving at 121°C for 15 minutes. Test the finished medium for performance using stable, standard control cultures.
05How do I request a bulk quotation, and can you provide a COA?
Yes. This product is available in 500 g, 5 kg, 25 kg. Tell us your application and volume when requesting a quotation; we reply within one working day and can supply the COA, specification sheet, and technical data sheet.
Used in these applications
References
- 1. Terzaghi B. E. and Sandine W. E., 1975. Improved medium for lactic streptococci and their bacteriophages. Appl. Microbiol., 29:807-813.
- 2. Atlas R. M., 2010. Handbook of Microbiological Media, 4th Ed., CRC Press, Boca Raton.