This bacterial growth medium was developed in 1971 for ''

Lactococcus ''Lactococcus'' is a genus of lactic acid bacteria that were formerly included in the genus ''Streptococcus'' Group N1. They are known as homofermenters meaning that they produce a single product, lactic acid in this case, as the major or only pr ...

'' species isolated from milk products. It was originally called M16 medium, but in 1975 Terzaghi and Sandine added disodium- β-glycerophosphate to the medium as a buffer, and named the new growth medium M17 medium. It was later found that the addition of disodium-β-glycerophosphate inhibits the growth of many ''Lactobacillus'' species.

Typical composition

Per 950 mL: *5.0 g Pancreatic digest of casein *5.0 g Soy

Peptone Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A p ...

*5.0 g

Beef extract Meat extract is highly concentrated meat stock, usually made from beef or chicken. It is used to add meat flavour in cooking, and to make broth for soups and other liquid-based foods. Meat extract was invented by Baron Justus von Liebig, a Germ ...

*2.5 g

Yeast extract Yeast extracts consist of the cell contents of yeast without the cell walls; they are used as food additives or flavorings, or as nutrients for bacterial culture media. They are often used to create savory flavors and umami taste sensations, a ...

*0.5 g

Ascorbic acid Vitamin C (also known as ascorbic acid and ascorbate) is a water-soluble vitamin found in citrus and other fruits and vegetables, also sold as a dietary supplement and as a topical 'serum' ingredient to treat melasma (dark pigment spots) an ...

*0.25 g

Magnesium sulfate Magnesium sulfate or magnesium sulphate (in English-speaking countries other than the US) is a chemical compound, a salt with the formula , consisting of magnesium cations (20.19% by mass) and sulfate anions . It is a white crystalline solid, ...

*19.0 g Disodium- β-glycerophosphate *11.0 g

Agar Agar ( or ), or agar-agar, is a jelly-like substance consisting of polysaccharides obtained from the cell walls of some species of red algae, primarily from ogonori (''Gracilaria'') and "tengusa" (''Gelidiaceae''). As found in nature, agar is ...

Preparation: *1. Heat with frequent agitation and boil for 1 minute to completely dissolve. *2. Autoclave at 121 °C for 15 minutes. Cool to 50 °C. *3. Add 50 ml filter sterilized 10% lactose solution and mix well (the lactose can be exchanged to other carbohydrates e.g. glucose, resulting in GM17 medium)

References

{{Growth media Microbiological media