Lactose-TTC-Agar mit Tergitol-7 (LTTC)
| Shorthand symbol: | LTTC |
| Item number: | 40-1278 |
| Format: | Petri Dish, 90mm |
| Colour: | Blue-green |
| Storage conditions: | Dry, in closed bag at 4-10°C |
| Shelf-life: | 3 Months |
| pH: | 7.1 ± 0.2 at 25°C |
Lactose TTC Agar with Tergitol-7 is a selective and differential medium suitable for the isolation, enumeration and identification of Coliform bacteria in food and water samples. Tergitol-7 is added to this medium to inhibit the growth of Gram-Positive bacteria and to suppress the swarming of Proteus species.
Production of acid from the growth of Lactose-fermenting Coliform bacteria results in the colour of the Bromothymol Blue Indicator in the agar to turn yellow and an insoluble red substance formed by the reduction of Triphenyl-tetrazolium Chloride (TTC) by the coliform bacteria.
| in g per 1 litre of Nutrient medium | |
|---|---|
| Peptone | 10 |
| Meat Extract | 5 |
| Yeast Extract | 6 |
| Lactose | 20 |
| Bromthymol Blue | 0.05 |
| Tergitol-7 | 0.1 |
| 2,3,5-Tri-phenyltetrazolium Chloride (TTC) | 0.025 |
| Agar | 12 |
| *Adjusted as required to meet performance standards |
The Microbiological Performance Test is carried out in accordance with the requirements BS EN ISO 11133:2014 and PhEur. (Microbiological Examination of Non-Sterile Products in accordance with Chapter 2.6.13).
Productivity
Incubation conditions: 21 ± 3 Hours at 36 ± 2 °C; Incubation Conditions: 80 – 120 KBE
| Organism | Type Strain | Specification | Colony morphology | |
|---|---|---|---|---|
| Escherichia coli | NCTC 13167 / WDCM 00179 | 50 – 130 % | Typical, yellow colonies with yellow background | |
| Enterobacter aerogenes | ATCC 13048 / WDCM 00175 | 50 – 130 % | Orange-Yellow colonies | |
| Citrobacter freundii | ATCC 43864 / WDCM 00006 | 50 – 130 % | Orange-Yellow colonies |
Selectivity
Incubation conditions: 21 ± 3 hours at 36 ± 2 °C; Inoculation concentration: 10.000–1.000.000 CFU
| Organism | Type Strain | Specification | Colony morphology | |
|---|---|---|---|---|
| Enterococcus faecalis | ATCC 19433 / WDCM 00009 | Complete inhibition | - |
Specificity
Incubation conditions: 21 ± 3 hours at 36 ± 2 °C; Inoculation concentration: 1.000 – 10.000 CFU
| Organism | Type Strain | Specification | Colony morphology | |
|---|---|---|---|---|
| Pseudomonas aeruginosa | ATCC 27853 / WDCM 00025 | Good growth | Red colonies with blue background |
Microbial Contamination
Incubation conditions: 5–7 days at 20–25 °C and 5–7 days at 30–35 °C
| Specification |
|---|
| No microbial contamination |