Technical Data
Lactobacilli MRS Broth, w/o Dextrose (Powder)
Microbiological Grade
Storage 4°C    Shipping RT
Formulation g/Liter
Ammonium Citrate2.0
Beef Extract10.0
Magnesium Sulfate0.1
Manganese Sulfate0.05
Enzymatic Digest of Animal Tissue10.0
Polysorbate 801.0
Potassium Phosphate Dibasic2.0
Sodium Acetate5.0
Yeast Extract5.0
Formula may be adjusted and/or supplemented as required to meet performance specifications.
Enzymatic Digest of animal tissue, beef extract and yeast extract are the carbon, nitrogen and vitamin sources used to satisfy general growth requirements in Lactobacilli MRS Broth. Dextrose, a fermentable carbohydrate, is absent to allow selection using fifferent carbohydrates. Sodium acetate is an inhibitory agent. Sodium acetate and ammonium citrate act as selective agents as well as energy sources. Potassium phosphate is the buffering agent. Magnesium sulfate and manganese sulfate provide cations used in metabolism. Polysorbate 80 is a surfacant, facilitating uptake of nutrients by Lactobacilli.

Suitable for use in the cultivation of Lactobacilli from dairy products and other materials. Lactobacilli MRS Broth is based on the formulations of deMan, Rogosa and Sharpe (MRS). This medium supports luxuriant growth of Lactobacilli from oral, fecal, dairy and other sources.

Directions per Liter: Suspend 35.15 grams of powdered medium in 1L of purified water. Heat with frequent agitation and boil for 1 minute to completely dissolve the powder. If required, add 20 grams of glucose. Autoclave at 121°C for 15 minutes. Test samples of the finished product for performance using stable, typical control cultures.

Storage and Stability: Store powdered media at 4șC. Opened bottles should be capped tightly and kept in a dark, low humidity environment. Prepared media should be kept refrigerated and used within a short period of time.Test procedure: Samples can be inoculated directly into Lactobacillus MRS Broth. Incubate broth tubes at 35°C for 3 days, or at 30°C for 5 days in an aerobic atmosphere. Subculture growth in broth tubes to appropriate solid media.Results: Growth of Lactobacillus spp. should appear turbid. Growth can be subcultured onto appropriate media for use in additional procedures. Refer to appropriate references for recommendation on the identification of Lactobacillus spp.Limitations: Due to varying nutritional requirements, some strains may be encountered that grow poorly or fail to grow on this medium. Organisms other than Lactobacilli may grow in this medium. Isolates must be confirmed as Lactobacilli by appropriate biochemical testing.

Appearance: Yellow to tan, homgeneous free flowing powder

Solubility: Yellow to orange, clear, complete

pH: 6.3-6.7

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.

1. deMan, J. C., M. Rogosa and M. E. Sharpe, 1960. A medium for the cultivation of lactobacilli. J. Bacteriol. 23:130. 2. MacFaddin, J. F. 1985. Media for the isolation-cultivation-identification-maintenance of medical bacteria, vol. 1 Williams & Wilkins, Baltimore, MD. 3. Vanderzant, C. and D. F. Splittstoesser (eds.). Compendium of methods for the microbiological examination of foods, 3rd ed. American Public Health Association, Washington, D. C. 4. Murray, P. R., E. J. Baron, M. A. Pfaller, F. C. Tenover and R. H. Yolken (eds.). 1995. Manual of clinical microbiology, 6th ed. American Society for Microbiology, Washington, D. C.