Dehydrated Culture Medium
Nutrient-rich broth for the cultivation and maintenance of bifidobacteria, including Bifidobacterium longum subsp. infantis
Cat. No. AS-113978.65 g/LpH 6.8 ± 0.2Non-selective brothAnaerobic incubation
At a glance
- Target organismsBifidobacteria
- Incubation35–37 °C, anaerobic
- Time24–72 h
- Sterilisation121 °C, 15 min
Manufactured in Melbourne. TDS and SDS available. Batch COA on request.
Overview
Bifidobacterium Broth is a nutrient-rich liquid medium for the cultivation and maintenance of bifidobacteria, particularly Bifidobacterium longum subsp. infantis (formerly B. infantis). Tryptone, peptone, yeast extract, tomato juice solids, dextrose and polysorbate 80 supply the amino acids, vitamins, carbohydrate and growth factors these fastidious organisms need.
The medium is non-selective and has a final pH of 6.8 ± 0.2. It must be incubated under anaerobic conditions.
Key features
- Rich nutrient base of two peptones, yeast extract and dextrose
- Tomato juice solids supply growth factors for bifidobacteria and lactic acid bacteria
- Can be made into a solid medium by adding 15 g/L agar
Principle of the Medium
| Component | Function |
|---|---|
| Tryptone and peptone | Peptides, amino acids and nitrogen |
| Yeast extract | B vitamins, nucleotides and trace nutrients |
| Tomato juice solids | Organic acids and growth-stimulating factors |
| Dextrose | Fermentable carbohydrate and energy source |
| Polysorbate 80 | Supplies oleic acid, which bifidobacteria and lactic acid bacteria incorporate into their cell membranes |
The medium contains no reducing agent. Use freshly prepared or pre-reduced medium and anaerobic incubation for best recovery.
Typical Composition
| Ingredient | g/L |
|---|---|
| Tryptone | 20.00 |
| Peptone | 10.00 |
| Yeast extract | 10.00 |
| Tomato juice solids | 16.65 |
| Dextrose (glucose) | 20.00 |
| Polysorbate 80 (Tween 80) | 2.00 |
| Total | 78.65 |
Final pH 6.8 ± 0.2 at 25 °C. Formula may be adjusted and/or supplemented to meet performance specifications.
Applications
| Field | Typical use |
|---|---|
| Probiotic development and QC | Propagation of bifidobacteria for product development and quality control |
| Food and dairy research | Cultivation of bifidobacteria from fermented dairy and functional foods |
| Gut microbiota research | Maintenance and subculture of bifidobacteria stock cultures |
| Teaching laboratories | Demonstrating anaerobic cultivation of beneficial gut bacteria |
Comparable Products
| Manufacturer | Product | Relationship |
|---|---|---|
| HiMedia Laboratories | M1395 Bifidobacterium Broth | Same published formulation |
Frequently Asked Questions
Does Bifidobacterium Broth need anaerobic incubation?
Yes. The medium contains no reducing agent, so incubate under anaerobic conditions at 35–37 °C for 24–72 hours. For demanding strains, 0.5 g/L L-cysteine hydrochloride can be added.
Is it selective for bifidobacteria?
No. Lactic acid bacteria and other anaerobes will also grow. For selective enumeration in milk products, ISO 29981 | IDF 220 specifies TOS-propionate agar with mupirocin.
Can I make a solid medium?
Yes. Add 15 g/L agar before autoclaving.
How much powder do I need?
78.65 g per litre of purified water. A 500 g pack makes about 6.3 litres.
Intended use: 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.
Mode of Action
Tryptone and peptone supply nitrogen and amino acids, yeast extract supplies B vitamins, and dextrose is the energy source. Tomato juice solids provide growth factors, and polysorbate 80 supplies oleic acid for membrane synthesis. The medium is non-selective and contains no reducing agent, so anaerobic incubation is required.
Preparation
- Suspend 78.65 g of powder in 1 litre of purified or distilled water.
- Heat with frequent mixing until completely dissolved.
- Dispense into tubes or flasks.
- Sterilise by autoclaving at 121 °C for 15 minutes.
- Cool before use. Heat stored medium in a boiling water bath for 10–15 minutes and cool without shaking, to remove dissolved oxygen before inoculation.
Optional: add 15.0 g/L agar for a solid medium. For demanding strains, 0.5 g/L L-cysteine hydrochloride may be added as a reducing agent.
Incubation and Interpretation
| Parameter | Condition |
|---|---|
| Atmosphere | Anaerobic (anaerobic jar or cabinet) |
| Temperature | 35–37 °C |
| Time | 24–72 hours, depending on strain and application |
| Positive result | Turbidity (growth) in the broth |
Growth does not identify the organism. Confirm identity by Gram stain (Gram-positive, irregular or branched rods), catalase test (negative) and further biochemical or molecular methods.
Limitations
- Non-selective: lactic acid bacteria and other anaerobes in a sample will also grow.
- Poor anaerobiosis is the most common cause of poor growth.
- For selective enumeration in milk products, ISO 29981 | IDF 220 specifies TOS-propionate agar with mupirocin.
- Strain-to-strain variation in growth rate is normal.
Literature and References
- Atlas RM. Handbook of Microbiological Media, 4th ed. CRC Press; 2010.
- Wehr HM, Frank JF (eds). Standard Methods for the Examination of Dairy Products, 17th ed. APHA; 2004.
- Mattarelli P, Biavati B, Holzapfel WH, Wood BJB (eds). The Bifidobacteria and Related Organisms. Academic Press; 2018.
- Mattarelli P, Bonaparte C, Pot B, Biavati B. Proposal to reclassify the three biotypes of Bifidobacterium longum as three subspecies. Int J Syst Evol Microbiol. 2008;58:767–772.
- Roy D. Technological aspects related to the use of bifidobacteria in dairy products. Lait. 2005;85:39–56.
Hazard Identification
Not classified as hazardous according to the GHS (Rev. 7) as adopted in Australia under the model WHS Regulations. Not Dangerous Goods under the ADG Code.
Fine powder can form combustible dust concentrations in air. Dust may cause mild mechanical irritation of the eyes and respiratory tract. Contains casein-derived material: people with milk protein allergy should avoid exposure.
Composition
| Ingredient | CAS No. | % w/w |
|---|---|---|
| Tryptone (enzymatic digest of casein) | 91079-40-2 | 25.4 |
| Peptone | 73049-73-7 | 12.7 |
| Yeast extract | 8013-01-2 | 12.7 |
| Tomato juice solids | Not available | 21.2 |
| D-Glucose (dextrose) | 50-99-7 | 25.4 |
| Polysorbate 80 | 9005-65-6 | 2.5 |
First Aid
| Route | Action |
|---|---|
| Inhalation | Move to fresh air. Seek medical advice if symptoms persist. |
| Skin | Wash with soap and water. |
| Eyes | Rinse with water for several minutes. Seek medical advice if irritation persists. |
| Ingestion | Rinse mouth. Do not induce vomiting. Seek medical advice if unwell. |
Poisons Information Centre (Australia, 24 h): 13 11 26
Handling, Spills and Disposal
- Avoid generating and breathing dust. Weigh in a ventilated area.
- Spills: sweep up or HEPA-vacuum without raising dust; wash the area with water.
- Unused product: dispose of as non-hazardous waste under local regulations.
- Inoculated medium: treat as potentially biohazardous and decontaminate (for example by autoclaving) before disposal.
Quality Control Specification
Each batch is tested for growth performance. Anaerobic incubation at 35–37 °C for 24–48 hours.
| QC organism | Strain | Inoculum (CFU) | Expected result |
|---|---|---|---|
| Bifidobacterium longum subsp. infantis | ATCC 25962 | 50–100 (≤ 100) | Good to luxuriant |
| Bifidobacterium bifidum | ATCC 15696 | 50–100 (≤ 100) | Good to luxuriant |
| Bifidobacterium breve | ATCC 15698 | 50–100 (≤ 100) | Good to luxuriant |
Physical and Chemical Tests
| Test | Specification |
|---|---|
| Appearance, powder | Cream to yellow, homogeneous, free-flowing |
| Solubility | Dissolves completely on heating (78.65 g/L) |
| Appearance, prepared medium | Amber, clear solution |
| pH, prepared medium (25 °C) | 6.60–7.00 |
The information on this page is provided in good faith as a guide to the properties and use of this product and does not constitute a warranty of fitness for a particular purpose. Users are responsible for confirming suitability for their application. Ausamics Pty Ltd · ABN 56 676 640 467 · 36/25 Trafalgar Road, Epping VIC 3076, Australia · support@ausamics.com