Selective Broth · Lactic Acid Bacteria
Rogosa Broth (LBS)
Acidified selective broth for the cultivation and enrichment of lactobacilli from dairy, fermented foods, probiotics, oral and faecal samples.
Cat. No. AS-145159.73 g/LpH 5.4 ± 0.2Selective BrothDo Not Autoclave
Key principle: a low pH (5.4) combined with a high acetate concentration suppresses most accompanying flora, while lactobacilli, which tolerate acid and acetate, grow well.
At a Glance
FormatDehydrated powder
Use rate59.73 g/L
Acid addition1.32 mL/L acetic acid
Heat treatment90–100 °C, 2–3 min
Incubation35–37 °C, 2–3 days
AtmosphereAnaerobic / CO₂
Intended Use
Rogosa Broth (LBS) is a selective liquid medium for the cultivation, enrichment and enumeration (MPN) of Lactobacillus and related lactic acid bacteria (including Lacticaseibacillus, Lactiplantibacillus and Limosilactobacillus) from foods, dairy products, probiotic preparations, and oral and faecal specimens.
For laboratory microbiological testing, quality control and research use only. Not intended for direct use in food, human or veterinary therapeutic applications, diagnosis, or consumption.
Principle & Biochemistry
Casein peptone and yeast extract supply nitrogen, vitamins and growth factors. D-Glucose (20 g/L) is the sole fermentable carbon and energy source. Polysorbate 80 provides oleic acid, which stimulates the growth of many lactobacilli. Magnesium, manganese and iron salts are essential cofactors; manganese is particularly important for lactobacilli, which use it to protect against oxidative stress.
Selectivity comes from the acetate buffer system. High sodium acetate, together with glacial acetic acid added during preparation, gives a final pH of 5.4. At this pH, a large fraction of the acetate is undissociated acetic acid, which crosses bacterial membranes and inhibits most Gram-negative bacteria, streptococci, staphylococci and many yeasts. Ammonium citrate adds further inhibition. Lactobacilli tolerate both the low pH and the acetate, so they grow selectively.
Formulation (g/L)
| Ingredient | g/L |
|---|---|
| Casein Peptone (Tryptone) | 10.0 |
| Yeast Extract | 5.0 |
| D-Glucose | 20.0 |
| Polysorbate 80 (Tween 80) | 1.0 |
| Potassium Dihydrogen Phosphate | 6.0 |
| Sodium Acetate | 15.0 |
| Ammonium Citrate | 2.0 |
| Magnesium Sulfate·7H₂O | 0.575 |
| Manganese Sulfate·4H₂O | 0.12 |
| Iron(II) Sulfate·7H₂O | 0.034 |
| Total | 59.73 |
Merck-type LBS formulation. Selective agents shown in amber. Final pH 5.4 ± 0.2 at 25 °C after the addition of glacial acetic acid. Formula may be adjusted to meet performance standards.
Key Applications
Dairy & Fermented FoodsSelective enrichment of lactobacilli from yoghurt, cheese, fermented milks and fermented vegetables.
Probiotic ProductsSelective cultivation and MPN-type enumeration of lactobacilli in probiotic and starter cultures.
Oral & Gut ResearchEnrichment of lactobacilli from saliva, plaque and faecal samples in research settings.
Spoilage InvestigationDetection of lactobacilli in beer, wine, juices and meat products.
Teaching LaboratoriesDemonstrating selective media and acid tolerance in university and TAFE practicals.
Culture MaintenanceSelective growth of lactobacilli from mixed cultures before subculture to agar.
Advantages & Considerations
Advantages
- High selectivity against Gram-negative and most Gram-positive flora
- Liquid format suits enrichment and MPN enumeration
- No autoclaving required, which saves time
- Well-established formulation with decades of published use
Considerations
- Not fully specific: some pediococci, leuconostocs, enterococci and yeasts may grow
- Some fastidious or acid-sensitive lactobacilli may be partially inhibited
- Turbidity is presumptive; subculture to a solid medium and confirm isolates
- Heat-treated, not autoclaved: prepare aseptically and use promptly
Expected Results
| Organism | Growth | Appearance |
|---|---|---|
| Lactobacillus spp. and related genera | Good | Turbidity, often with a white sediment |
| Escherichia coli | Inhibited | No turbidity |
| Staphylococcus aureus | Inhibited | No turbidity |
Related Standards (for user reference)
- Rogosa M., Mitchell J.A. and Wiseman R.F. (1951): original description of the medium
- APHA Compendium of Methods for the Microbiological Examination of Foods
- APHA Standard Methods for the Examination of Dairy Products
Frequently Asked Questions
Why must this broth not be autoclaved?
Prolonged heating at pH 5.4 degrades the carbohydrates and other heat-sensitive components and reduces performance. The published method uses a short heat treatment (90–100 °C for 2–3 minutes) instead. Prepare the medium aseptically and use it promptly.
What is the difference between AS-1451 and the related Rogosa broth?
Both are acidified, acetate-selective broths. The related product is AS-1407 Rogosa SL Broth (glucose, arabinose and sucrose formulation). Choose the formulation that matches your reference method.
What is the difference between Rogosa broth and MRS Broth?
MRS Broth (pH 6.2) is a general, non-selective medium for lactic acid bacteria. Rogosa broth (pH 5.4) is selective for lactobacilli because of its lower pH and higher acetate content.
Which incubation conditions should be used?
Incubate at 35–37 °C for 48–72 hours under anaerobic conditions or with 5–10% CO₂. Lower temperatures (e.g. 30 °C) may suit some food-derived strains.
Technical Specifications
| Catalogue No. | AS-1451 |
| Product type | Dehydrated culture medium (broth) |
| Appearance (powder) | Cream to light yellow, homogeneous, free-flowing |
| Appearance (prepared) | Light yellow, clear to slightly opalescent solution |
| Use rate | 59.73 g/L |
| Final pH | 5.4 ± 0.2 at 25 °C |
| Heat treatment | 90–100 °C, 2–3 min. Do not autoclave. |
| Pack size | 500 g |
| Storage (powder) | 2–8 °C, dry, tightly closed |
| Documents | TDS, SDS; batch COA on request |
Applications
- Dairy and fermented food testing
- Probiotic product enumeration (MPN)
- Oral and faecal microbiology research
- Beverage spoilage investigation
- Teaching laboratories
Preparation
- Suspend 59.73 g of powder in 1 L of purified water.
- Heat gently with stirring until completely dissolved.
- Add 1.32 mL of glacial acetic acid and mix thoroughly.
- Dispense into tubes or flasks.
- Heat at 90–100 °C for 2–3 minutes. Do not autoclave.
- Cool before inoculation. Check the pH of a cooled sample: 5.4 ± 0.2 at 25 °C.
Glacial acetic acid is corrosive and flammable. Handle it in a fume hood and wear gloves and eye protection.
Storage & Stability
Store the dehydrated medium at 2–8 °C in a dry place, tightly closed and protected from light. The powder is hygroscopic. Use before the expiry date on the label. Store prepared broth at 2–8 °C protected from light, and use it promptly.
Technical Data Sheet — Rogosa Broth (LBS)
TDS-AS-1451 · Rev 1.0 · November 20261. Product Identification
| Product name | Rogosa Broth (LBS) |
| Catalogue No. | AS-1451 |
| Product type | Dehydrated microbiological culture medium (broth) |
| Manufacturer | Ausamics Pty Ltd, Epping, VIC, Australia |
2. Intended Use
Selective cultivation, enrichment and enumeration (MPN) of lactobacilli and related lactic acid bacteria from foods, dairy products, probiotic preparations, and oral and faecal samples. For laboratory use only.
3. Mode of Action
Sodium acetate and added acetic acid form an acetate buffer at pH 5.4. Undissociated acetic acid inhibits most accompanying flora, and ammonium citrate adds further inhibition. Acid-tolerant lactobacilli grow using the carbohydrates, peptones, yeast extract, Tween 80 and metal cofactors.
4. Formulation (g/L)
| Ingredient | g/L |
|---|---|
| Casein Peptone (Tryptone) | 10.0 |
| Yeast Extract | 5.0 |
| D-Glucose | 20.0 |
| Polysorbate 80 (Tween 80) | 1.0 |
| Potassium Dihydrogen Phosphate | 6.0 |
| Sodium Acetate | 15.0 |
| Ammonium Citrate | 2.0 |
| Magnesium Sulfate·7H₂O | 0.575 |
| Manganese Sulfate·4H₂O | 0.12 |
| Iron(II) Sulfate·7H₂O | 0.034 |
| Total | 59.73 |
5. Physical Specifications
| Powder appearance | Cream to light yellow, homogeneous, free-flowing |
| Prepared medium | Light yellow, clear to slightly opalescent solution |
| Final pH (25 °C) | 5.4 ± 0.2 (after acetic acid addition) |
6. Preparation
- Suspend 59.73 g of powder in 1 L of purified water.
- Heat gently with stirring until completely dissolved.
- Add 1.32 mL of glacial acetic acid and mix thoroughly.
- Dispense into tubes or flasks.
- Heat at 90–100 °C for 2–3 minutes. Do not autoclave.
- Cool before inoculation. Check the pH of a cooled sample: 5.4 ± 0.2 at 25 °C.
7. Quality Control (Performance)
Incubation: 35–37 °C, 48–72 h, anaerobic or 5–10% CO₂.
| Organism | Strain | Inoculum (CFU) | Expected result |
|---|---|---|---|
| Lacticaseibacillus rhamnosus | ATCC 9595 | ≤100 | Good growth (turbidity) |
| Limosilactobacillus fermentum | ATCC 9338 | ≤100 | Good growth (turbidity) |
| Lactiplantibacillus plantarum | ATCC 8014 | ≤100 | Good growth (turbidity) |
| Escherichia coli | ATCC 25922 | ≥10⁴ | Inhibited |
| Staphylococcus aureus | ATCC 25923 | ≥10⁴ | Inhibited |
8. Storage & Shelf Life
Dehydrated medium: 2–8 °C, dry, tightly closed, protected from light. Use before the expiry date on the label. Prepared broth: 2–8 °C, protected from light; use promptly.
9. Limitations
Some pediococci, leuconostocs, enterococci, bifidobacteria and yeasts may grow. Some lactobacilli may grow poorly. Broth cultures are presumptive; subculture to a solid selective medium and confirm isolates with Gram stain, catalase test and identification methods.
10. References
- Rogosa M., Mitchell J.A., Wiseman R.F. (1951). A selective medium for the isolation and enumeration of oral and fecal lactobacilli. J. Bacteriol. 62:132–133.
- Rogosa M., Mitchell J.A., Wiseman R.F. (1951). A selective medium for the isolation and enumeration of oral lactobacilli. J. Dent. Res. 30:682–689.
- Salfinger Y., Tortorello M.L. (eds) (2015). Compendium of Methods for the Microbiological Examination of Foods, 5th ed. APHA.
- Zheng J. et al. (2020). A taxonomic note on the genus Lactobacillus. Int. J. Syst. Evol. Microbiol. 70:2782–2858.
Safety Data Summary — Rogosa Broth (LBS)
SDS-AS-1451 · Rev 1.0 · November 2026 · Full 16-section SDS available on requestHazard Classification
Not classified as hazardous according to the criteria of the GHS (Rev. 7) as adopted under the Australian Work Health and Safety Regulations. No hazard pictogram or signal word is required.
The glacial acetic acid added during preparation is not part of this product. It is a hazardous chemical (flammable, causes severe skin burns and eye damage). Refer to its own SDS.
Handling & Protection
- Avoid creating and breathing dust. Use with adequate ventilation.
- Wear laboratory coat, gloves and safety glasses.
- Wash hands after handling.
First Aid
- Inhalation: Move to fresh air.
- Skin: Wash with soap and water.
- Eyes: Rinse with water for several minutes. Seek medical advice if irritation persists.
- Ingestion: Rinse mouth. Seek medical advice if feeling unwell.
Poisons Information Centre (Australia): 13 11 26 · Emergency: 000
Storage & Disposal
Store at 2–8 °C, dry and tightly closed. Dispose of unused powder according to local regulations. Autoclave or otherwise decontaminate used cultures before disposal as biological waste.
Transport
Not regulated as dangerous goods for road (ADG), sea (IMDG) or air (IATA) transport.
Quality & Certificate of Analysis
AS-1451 · Batch-specific COA available on requestEach batch of Rogosa Broth (LBS) is manufactured in Melbourne and tested internally before release. A batch-specific Certificate of Analysis is available on request. Please quote the batch number printed on the label.
Release Specifications
| Test | Specification |
|---|---|
| Appearance (powder) | Cream to light yellow, homogeneous, free-flowing |
| Appearance (prepared) | Light yellow, clear to slightly opalescent solution |
| pH (25 °C, after acid addition) | 5.2 – 5.6 |
| Growth: L. rhamnosus ATCC 9595 | Good growth |
| Growth: L. plantarum ATCC 8014 | Good growth |
| Inhibition: E. coli ATCC 25922 | Inhibited |
| Inhibition: S. aureus ATCC 25923 | Inhibited |