Technical Data
Lactobacilli MRS Broth, w/o Dextrose (Powder)
Microbiological Grade
Storage 4C    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 Phosphate2.0
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: Dissolve 35.15 grams in 800-900ml of ddH2O stirring gently with heating until completely solubilized. Adjust pH of the medium to the desired level. Add additional water to bring the solution to1L. Dispense into appropriate containers, loosen caps and autoclave for 15 minutes at 121C (15psi). Use appropriate alternate carbohydrates as needed.

Storage and Stability: Store powdered media at 4C. 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 35C for 3 days, or at 30C 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: As Reported

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.