| 产品名称： | TOS丙酸盐琼脂；BSC丙酸盐琼脂；双歧杆菌选择计数琼脂基础；TOS-MUP琼脂基础；转糖基半乳糖苷低菌糖琼脂；TOS培养基 |
|---|---|
| 英文名称: | BSC Propionate Agar；TOS-propionate agar medium acc. ISO ；Bifidobacteria Selective Count Agar Base；TOS-MUP Agar Base；Transgalctosylated oligiosaccharide agar medium |
| 培养基类型: | 选择性培养基 |
| 级别: | for microbiology |
| 品牌： | ELITE-MEDIA（艾礼培养基） |
| 产品目录号: | M1008-01、M1008-02 |
| 产品规格: | 250g、500g |
| 保存条件: | 室温（8-25℃），避免阳光直射 |
| 产品外观: | 淡黄色至淡棕色均一粉末 |
| 颜色与澄清度: | 淡黄色凝胶，半透明 |
| 注意事项: | 避免摄入、呼入、皮肤接触 |
| 相关产品: |
双歧杆菌选择性添加剂A 双歧杆菌选择性添加剂B |
产品描述：
TOS丙酸盐琼脂培养基（TOS-propionate agar medium）也称双歧杆菌选择计数琼脂基础（Bifidobacteria Selective Count Agar Base）、BSC丙酸盐琼脂（BSC Propionate Agar）、TOS-MUP琼脂（TOS-MUP Agar）、转糖基半乳糖苷低菌糖琼脂（Transgalctosylated oligiosaccharide agar medium），被推荐用于菌落计数法计数奶制品中总双歧杆菌数。原理：
莫匹罗星锂是一种抑菌剂，能够抑制乳杆菌、乳球菌、链球菌和明串珠菌。加入乙酸后可使培养基pH降低，增加选择性。培养基配方
| 组分 | g/L |
| 酪蛋白水解物 | 10 |
| 酵母提取物 | 1 |
| 磷酸二氢钾 | 3 |
| 磷酸氢二钾 | 4.8 |
| 硫酸铵 | 3 |
| 硫酸镁，七水 | 0.2 |
| L-半胱氨酸盐酸盐，一水 | 0.5 |
| 丙酸钠 | 15 |
| 低聚半乳糖 | 10 |
| 琼脂 | 15 |
| pH值 | 6.3 +/- 0.2 |
双歧杆菌选择性添加剂A
| 组分 | 每瓶含量 |
| 莫匹罗星 | 25mg |
| 无菌蒸馏水 | 5mL |
双歧杆菌选择性添加剂B
| 组分 | 每瓶含量 |
| 冰乙酸 (1%) | 5ml |
配制方法：
用1000ml蒸馏水重悬62.02g脱水培养基，加热煮沸至完全溶解。115°C 高温蒸汽灭菌15 min。待培养基冷却至50°C左右时加入2瓶莫匹罗星锂添加剂（双歧杆菌选择性添加剂A），混匀后倒平板。为进一步提高培养基的选择性，可以加入2瓶乙酸添加剂（双歧杆菌选择性添加剂B）。
注意：
该培养基对热敏感，过度加热会显著影响培养基的功能。
实验方法：
Test Procedure:Dried milk products (e.g. infant formula):
Mix the content of a closed sample pack if possible or use a sterile spatula to get a homogenous sample. Weigh 90g of diluent (Quarter-strength Ringer solution) in each of the 250 ml pre-sterilized bottles. Add 10g of the test sample into the bottle with the diluent at 45°C. To dissolve the test sample, swirl slowly. Place in the water bath (45°C) while shaking occasionally. Cool down under running tape water for 2 minutes. Keep all suspension for 30 minutes in the fridge and start directly with the examination.
Yoghurt and yoghurt-like products:
Mix the content of a closed sample pack if possible or use a sterile spatula to get a homogenous sample. Weigh 90g of diluent (Quarter-strength Ringer solution) in each of the 250 ml pre-sterilized bottles. Add 10g of the test sample into the bottle with the diluent at 45°C. To dissolve the test sample, shake and start with the examination as fast as possiplbe
Examination:
Do 1:10 dilution steps with dilution solution until the a concentration of 200-500 cfu/ml is obtained. Transfer 1 ml of the appropiate dilutions into a petri dish and add 12-15 ml medium (in duplicates). Mix gently and let solidify. The time between ending the preparation of the primary dilution until addition of culture medium shall not exceed 15 min.
Imediately after solidification of the medium, invert all Petri dishes in the anaerobic culture jar or anaerobic incubator at 37°C for 72 hrs ± 3 hrs. Count the colonies after incubation. Bifidobacterial colonies are recognized by their whitish colour and acetic acid odour. Some of the bifidobacterial strains may appear in different colony size as well as colony appearance on the same plate (1). Select typical colonies for microscopic examination.
Optional a F6PPK-assay can be performed to confirm the result.
