|
用途：
Lactobacilli Agar AOAC is used for maintaining stock cultures
for microbiological assays of vitamins and amino acids.
Lactobacilli Broth AOAC is used for preparing inocula for
microbiological assays of vitamins and amino acids.
原理：
Peptonized milk and yeast extract provide the nitrogen, amino
acids and vitamins sources in Lactobacilli Agar AOAC and
Lactobacilli Broth AOAC. Dextrose is a carbon source to facilitate organism growth. Tomato juice creates the proper
acidic environment. Monopotassium phosphate is a buffering
agent. Polysorbate 80 acts as an emulsifier. Agar is the solidifying agent in Lactobacilli Agar AOAC.
Directions for Preparation from Dehydrated Product
1. Suspend the powder in 1 L of purified water:
Difco Lactobacilli Agar AOAC – 48 g;
Difco Lactobacilli Broth AOAC – 38 g.Mix thoroughly.
2. Heat with frequent agitation and boil for 2-3 minutes to
completely dissolve the powder.
3. Autoclave at 121°C for 15 minutes.
4. Test samples of the finished product for performance using
stable, typical control cultures.
过程：
Stock Cultures
1. Prepare stock cultures in one or more tubes of sterile
Lactobacilli Agar AOAC.
2. Inoculate the medium using an inoculating needle.
3. Incubate at 30-37°C for 18-24 hours.
4. Store at 2-8°C.
5. Transfer at weekly or twice monthly intervals.
Inoculum
1. Subculture from a 16-24 hour stock culture into 10mL Lactobacilli Broth AOAC.
2. Incubate at 35-37°C for 16-24 hours or as specified in
specific assay procedures.
3. Centrifuge the culture and decant the supernatant.
4. Resuspend cells in 10 mL of sterile 0.9% NaCl solution or
sterile single-strength basal assay medium.
5. Wash the cells by centrifuging and decanting the supernatant two additional times unless otherwise indicated.
6. Dilute the washed suspension 1:100 with sterile 0.9% NaCl
or sterile single-strength basal assay medium or as indicated.
Where applicable, inoculum concentration should be adjusted
according to limits specified in the references.
For a complete discussion on vitamin assay methodology refer
to appropriate procedures outlined in the references. |