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Media for Growth of Anaerobes

Thioglycollate Medium

To nutrient broth add

0.1% sodium thioglycollate.

0.05% powdered agar.

1% glucose.

1/500,000 methylene blue.

Sterilize at 10 lb for 15 minutes. The sodium thioglycollate maintains anaerobic conditions present after

autoclaving assisted by glucose and the agar, which

prevents convection currents in the medium; methylene

blue acts as an indicator.

Microbiology and Bacteriology 831

Robertson’s Cooked Meat Medium

Mince 500 grams of fat free ox heart (fresh) and place in

500 mL of boiling distilled water and allow it to boil for

some time. Drain off the liquid through a muslin filter

and while still hot, press the minced meat in a cloth and

dry partially by spreading it on a cloth or filter paper.

In this condition, it can be introduced into the bottle.

Place about 2.9 g of dried meat in a bottle and cover with

10 mL of nutrient broth or the infusion broth filtered from

the meat to which is added 0.25% sodium chloride, 0.5%

peptone and pH is adjusted to 7.7. Put the caps on the

bottles and autoclave at 15 lb for 20 minutes. The material

to be inoculated is introduced towards the bottom of the

tube in contact with the meat.

MacConkey’s Medium

(For enteric gram-negative bacilli)

Peptone 20 g

Sodium taurocholate 5 g

Distilled water 1000 mL

Sodium chloride 5 g