培养基配方

您现在的位置：网站首页 >> 培养基配方

Differential Broth for Lactic Streptococci

[所属分类:培养基配方] [发布时间:2021-11-16] [发布人:网站管理员2] [阅读次数:] [返回]

Differential Broth

for Lactic Streptococci

山东拓普生物工程有限公司培养基配方 http://www.topbiol.com

Composition per liter:

Sodium citrate...................................................20.0g

Arginine ..............................................................5.0g

Pancreatic digest of casein..................................5.0g

Yeast extract........................................................5.0g

K2HPO4...............................................................1.0g

Bromcresol Purple ............................................0.02g

Skim milk (11% solution)............................. 35.0mL

pH 6.2 ± 0.2 at 25°C

Preparation of Medium: Add components, except

skim milk solution, to distilled/deionized water and

bring volume to 800.0mL. Mix thoroughly. Add

35.0mL of skim milk solution. Bring volume to 1.0L

with distilled/deionized water. Place medium in a steam

bath for 15 min. Cool to 25°C. Adjust pH to 6.2. Distrib

ute 7.0mL volumes into screw-capped tubes that con

tain an inverted Durham tube. Autoclave for 15 min at

15 psi pressure–121°C. Allow autoclave to cool below

70°C before opening door.

Use: For the cultivation and differentiation of Lacto

bacillus lactis, Lactobacillus lactis subspecies cre

moris,

and

Lactobacillus lactis

subspecies

diacetylactis. Lactose-fermenting bacteria such as

Lactobacillus lactis subspecies cremoris turn the me

dium yellow. Arginine-utilizing bacteria such as Lac

tobacillus lactis initially turn the medium yellow but

then turn back to violet. Citrate-utilizing bacteria such

as Lactobacillus lactis subspecies diacetylactis turn

the medium violet and produce CO2 that is trapped as

a bubble in the Durham tube.