APT Broth (All Purpose Tween Broth) 
CAT No: AS‑1121
High‑Performance Lactic Acid Bacteria Enrichment Medium for Food Microbiology & Probiotic Research
 
Overview
APT Broth (All Purpose Tween Broth), CAT No: AS‑1121, is a highly enriched, non‑selective liquid medium developed by Evans & Niven (1951) and optimized by Deibel et al. for the cultivation, enrichment, and enumeration of lactic acid bacteria (LAB). It is particularly effective for heterofermentative lactobacilli (Lactobacillus brevis, Lb. buchneri, Lb. viridescens), Pediococcus, Leuconostoc, and Weissella species isolated from meat products, fermented foods, beverages, and probiotic cultures.
The inclusion of Tween 80 supplies essential fatty acids, enabling luxuriant growth of fastidious LAB strains that grow poorly or not at all on simpler media such as MRS or tomato juice broth.
 
Applications
Enrichment and cultivation of heterofermentative and oleic acid‑requiring lactic acid bacteria
Propagation of starter and probiotic cultures from meat and dairy sources
Most Probable Number (MPN) enumeration of LAB in food quality control workflows
Maintenance of stock cultures of difficult‑to‑grow lactobacilli and pediococci
 
Key Features & Benefits
Contains Tween 80 – critical for luxuriant growth of oleic acid‑dependent LAB
Supports vigorous growth of strains that fail on MRS or tomato juice media
Standard reference broth in USDA and food‑industry protocols for LAB
Excellent performance under microaerophilic or anaerobic incubation conditions
 
Typical Composition (per liter)
 
Component
Amount (g/L)
Casein enzymic hydrolysate
12.5
Yeast extract
7.5
Dextrose (Glucose)
10.0
Sodium citrate
5.0
Sodium chloride (NaCl)
5.0
Dipotassium phosphate (K₂HPO₄)
5.0
Magnesium sulphate (MgSO₄·7H₂O)
0.8
Manganese chloride (MnCl₂·H₂O)
0.14
Ferrous sulphate (FeSO₄·7H₂O)
0.04
Polysorbate 80 (Tween 80)
0.2
Thiamine hydrochloride
0.001
Final pH at 25 °C
6.7 ± 0.2
 
Preparation Instructions
Dissolve 46.2 g of dehydrated APT Broth powder in 1 L distilled water.
Heat gently with frequent agitation until completely dissolved.
Dispense into tubes or bottles.
Autoclave at 121 °C for 15 minutes.
 
     Do not overheat (to protect Tween 80 and vitamins).
Cool to room temperature before inoculation.

 
 
Incubation Conditions
Temperature: 30–35 °C
Time: 24–72 hours
Atmosphere: Microaerophilic or anaerobic (5–10% CO₂ incubators or anaerobic jars)
 
Storage & Stability
Dehydrated medium: Store below 30 °C, dry and protected from moisture/light
Prepared broth: Store at 2–8 °C; use within 4 weeks
 
Intended Use
APT Broth CAT: AS‑1121 is intended for laboratory, food microbiology, and probiotic research use only. Not for human or animal consumption, clinical diagnostic use without validation, or household applications.