Hardy Diagnostics HUGO


Cat. no. K15 Lactobacilli MRS Broth, 16x125mm Tube, 9ml 20 tubes/box
Cat. no. K17 Lactobacilli MRS Broth, 16x125mm Tube with Durham Tube,
20 tubes/box
Cat. no. K317 Lactobacilli MRS Broth, 20x125mm Tube, 18ml 20 tubes/box
Cat. no. U203 Lactobacilli MRS Broth, 500ml Polycarbonate Bottle, 500ml 10 bottles/box


Hardy Diagnostics Lactobacilli MRS Broth is recommended for the isolation, enumeration and cultivation of Lactobacillus spp.

This product is not intended to be used for the diagnosis of human disease.


MRS Broth was developed by deMan, et al., to provide luxuriant growth of lactobacilli isolated from oral, fecal, and other specimen sources. (6) Lactobacilli MRS Broth is an improved medium for lactobacilli, it supports good growth and is particularly useful for a number of fastidious strains which grow poorly on other general media.

Peptone and dextrose provide the carbon, nitrogen and other elements necessary for growth. Tween ® 80, acetate, magnesium and manganese provide growth factors needed for culturing a variety of lactobacilli. Those ingredients may also inhibit the growth of some organisms other than lactobacilli. In addition, tomato juice is not required. In a slightly modified form, it can also be used as a basal medium for fermentation tests.


Ingredients per liter deionized water:*

Dextrose 20.0gm
Peptic Digest of Animal Tissue 10.0gm
Beef Extract 10.0gm
Yeast Extract 5.0gm
Sodium Acetate 5.0gm
Disodium Phosphate 2.0gm
Ammonium Citrate 2.0gm
Tween ® 80 1.0gm
Magnesium Sulfate 0.1gm
Manganese Sulfate 0.05gm

Final pH 6.5 +/- 0.3 at 25ºC.

* Adjusted and/or supplemented as required to meet performance criteria.


Storage: Upon receipt store at 2-8ºC. away from direct light. Media should not be used if there are any signs of contamination, deterioration, discoloration, or if the expiration date has passed. Product is light and temperature sensitive; protect from light, excessive heat, moisture, and freezing.



1. Samples can be inoculated directly into Lactobacilli MRS Broth.

2. Incubate broth tubes at 35 degrees C. for 3 days, or at 30ºC. for 5 days, in an aerobic atmosphere.

3. Subculture growth in broth tubes to an appropriate solid media.


Growth of Lactobacilli will produce turbidity in Lactobacilli MRS Broth. Growth may be subcultured onto the appropriate media for use in additional procedures. Refer to appropriate references for recommendations on the culture of Lactobacillus spp. (1-5)



Standard microbiological supplies and equipment such as loops, other culture media, swabs, applicator sticks, incinerators, and incubators, etc., as well as serological and biochemical reagents, are not provided.


Test Organisms Inoculation Method* Incubation Results
Time Temperature Atmosphere
Lactobacilli MRS Broth with Durham Tube:
Lactobacillus fermentum
ATCC ® 9338
A 18-24hr 35°C Aerobic Growth; gas in durham tube
Lactobacillus acidophilus
ATCC ® 4356
A 1-7
35°C Aerobic Growth; no gas in durham tube
Lactobacilli MRS Broth:
Lactobacillus acidophilus
ATCC ® 4356
A 1-7
35°C Aerobic Growth
Weisella paramesenteroides
ATCC ® 33313
A 1-7
35°C Aerobic Growth

User Quality Control


Lactobacilli MRS Broth should appear clear, with a very slight opalescence, and dark amber in color.

L. fermentum growing in Lactobacilli MRS Broth L. acidophilus growing in Lactobacilli MRS Broth

Lactobacillus fermentum (ATCC ® 9338) growing in Lactobacilli MRS Broth (Cat. no. K17). The bubble in the Durham tube was indicative of gas production. Incubated aerobically for 24 hours at 35ºC.

Lactobacillus acidophilus (ATCC ® 4356) growing in Lactobacilli MRS Broth (Cat. no. K17). Incubated aerobically for 24 hours at 35ºC.


1. Jorgensen., et al. Manual of Clinical Microbiology, American Society for Microbiology, Washington, D.C.

2. Tille, P., et al. Bailey and Scott's Diagnostic Microbiology, 12th ed. C.V. Mosby Company, St. Louis, MO.

3. Isenberg, H.D. Clinical Microbiology Procedures Handbook, Vol. I, II & III. American Society for Microbiology, Washington, D.C.

4. Koneman, E.W., et al. Color Atlas and Textbook of Diagnostic Microbiology, J.B. Lippincott Company, Philadelphia, PA.

5. MacFaddin, J.F. 1985. Media for Isolation, Cultivation, Identification, Maintenance of Bacteria, Vol. I. Williams & Wilkins, Baltimore, MD.

6. deMan, Rogosa and Sharpe. 1960. Journal of Applied Bacteriology; 23(1) 130-135.

7. Quality Assurance for Commercially Prepared Microbiological Culture Media, M22. Clinical and Laboratory Standards Institute (CLSI - formerly NCCLS), Wayne, PA.

ATCC is a registered trademark of the American Type Culture Collection.
Tween is a registered trademark of ICI Americas, Inc.