Tomato Juice Agar (TJA)

Tomato Juice Agar (TJA)
Selective Medium for Lactic Acid Bacteria

Catalog Number: AS-1401

Overview
Tomato Juice Agar (TJA) is a selective, nutrient-rich solid medium designed for the isolation, cultivation, and enumeration of lactic acid bacteria, particularly Lactobacillus spp., from fermented foods, dairy products, and plant-derived substrates.

The formulation includes tomato juice as a natural source of vitamins, minerals, and organic acids, combined with peptones and glucose to support robust bacterial growth. Its slightly acidic pH (approximately 4.5–5.0) favours lactic acid bacteria while inhibiting many Gram-negative contaminants. TJA is widely used in food microbiology, fermentation research, and probiotic studies.

Applications
• Isolation and enumeration of Lactobacillus spp. and other lactic acid bacteria
• Quality control testing in fermented foods, beverages, and dairy products
• Microbiological analysis of plant-based fermented substrates
• Research on microbial ecology and probiotic organisms

Key Features & Benefits
• Acidic pH selectively favours lactic acid bacteria
• Tomato juice provides natural vitamins and growth factors
• Peptones and glucose support fastidious strains
• Promotes visible colony morphology for differentiation
• Suitable for plate, slant, or pour plate methods

Principle of the Medium
Tomato Juice Agar provides a mildly acidic environment that suppresses many non-acid-tolerant microorganisms while encouraging growth of lactic acid bacteria. Tomato juice contributes organic acids and micronutrients, while peptones supply nitrogen and amino acids. Glucose serves as a fermentable carbohydrate to promote active metabolism and colony development.

Typical Composition (per litre)
Tomato Juice – 200 mL
Peptone / Proteose Peptone – 5.0 g
Glucose – 5.0 g
Agar – 15.0 g
Purified Water – q.s. to 1 L

Final pH: 4.5–5.0 ± 0.2 at 25 °C

Preparation
Combine tomato juice, peptones, glucose, and purified water.
Adjust pH to 4.5–5.0 if required.
Heat with gentle agitation until completely dissolved.
Sterilise by autoclaving at 121 °C for 15 minutes.
Cool to 45–50 °C and dispense into Petri dishes, slants, or tubes as required.

Incubation
Incubate at 30–37 °C.
Typical incubation time: 48–72 hours.
Slow-growing strains may require up to 5–7 days.

Interpretation
Visible colonies indicate growth of lactic acid bacteria.
Colony size, colour, and morphology assist in preliminary species differentiation.

Storage & Stability
Dehydrated medium: Store at 15–30 °C in a dry, tightly sealed container
Prepared plates or slants: Store at 2–8 °C, protected from light
Use within the recommended shelf life for optimal performance

Intended Use
For laboratory research and microbiological quality control use only.
Not intended for human, animal, or food consumption.

Quality & Compliance
Manufactured under controlled conditions to ensure batch-to-batch consistency.
Suitable for food, dairy, and fermentation microbiology laboratories.
Performance comparable to leading international culture media suppliers.

Customs & Trade Information
HS / AHECC Code: 3821.00.00
Prepared culture media for the development or maintenance of microorganisms