TOS-PROPIONATE AGAR (BASE)

General description

TOS-Propionate Agar (Base), in combination with the selective supplement Lithium-Mupirocin (MUP), enables direct detection of viable bifidobacteria in stater cultures and various milk products such as fermented and unfermented milk, milk powder, and baby food. The inhibition of the growth of other lactic acid bacteria eliminates the presumptive confirmation of bifidobacteria. The detection of bifidobacteria is done by using the plate count method with an anaerobic incubation at 37°C.

Application

TOS-Propionate Agar (Base) is suitable for the enumeration of bifidobacteria in milk products.

Features and Benefits

• GranuCult^® offers superior granulated culture media
• Safe and sustainable due to reduced risks associated with fine dust and toxic substance inhalation, resulting in a safer work environment
• Excellent wettability, solubility, and free-flowing properties
• Convenient, with minimal component separation and clumping, even under warm or humid conditions
• High batch-to-batch reproducibility
• Prolonged shelf life of up to five years
• High number of test strains exceeding all regulatory demands
• Granulation technology allows many supplements to be included, with no need to add these separately

Principle

Bifidobacteria are Gram-positive, non-spore-forming anaerobic rods. The combination of peptone from casein and yeast extract gives a rich nutrient base for the excellent growth of bifidobacteria. The addition of magnesium sulfate further supports the growth of pre-injured bifidobacteria. Ammonium sulfate serves as a nitrogen source, potassium dihydrogen phosphate and di-potassium hydrogen phosphate buffer the medium in the neutral pH zone, and L-Cysteine serves as a reducing agent to give the necessary anaerobic condition in the media. Galactooligosaccharide TOS is a specific growth factor for all bifidobacteria, whereas other lactic acid bacteria cannot utilize it. In combination with sodium propionate, which inhibits the accompanying flora, TOS Propionate agar is already very selective and specifically supports the growth of bifidobacteria. Lithium-Mupirocin inhibits the growth of lactobacilli, lactococci, streptococci, and leuconostocs, whereas bifidobacteria grow unhindered. The typical accompanying flora of milk products is specifically inhibited. In combination with TOS Propionate agar, mupirocin is so selective that, in most cases, only bifidobacteria grow to form visible colonies, with no need for confirmation.

Analysis Note

Appearance (clearness): clear
Appearance (colour): yellowish
pH-value (25 °C): 6.5 - 6.9
Testing in addition of MUP-Selective supplement (100045.0010 ).
Recovery on test medium (Bifidobacterium animalis subsp. lactis ATCC 27536): ≥ 70 %
Recovery on test medium (Bifidobacterium breve ATCC 15700): ≥ 70 %
Recovery on test medium (Bifidobacterium longum ATCC 15707): ≥ 70 %
Growth (Lactobacillus casei ATCC 393 (WDCM 00100)): no growth
Growth (Lactobacillus delbrueckii subsp. bulgaricus ATCC 11842 (WDCM 00102)): no growth
Growth (Streptococcus salivarius subsp. thermophilus DSM 20259): no growth
Incubation: 72 hrs. at 37°C, anaerobic.

Footnote

We offer two media types: the superior granulated GranuCult^® and the cost-efficient powdered NutriSelect^® culture media, depending on your needs.
The designations basic, plus, or prime are added to indicate the quality control level, from basic quality control to standard QC plus to prime for full regulatory compliance.

Legal Information

GRANUCULT is a registered trademark of Merck KGaA, Darmstadt, Germany

NutriSelect is a registered trademark of Merck KGaA, Darmstadt, Germany