Reinforced Clostridial Broth w/o Agar is formulated by Hirsch and Grinsted (1). It can be used to initiate growth from small inocula and to obtain the highest viable count of Clostridia. Barnes and Ingram used the broth medium for diluting an inoculum of vegetative cells of Clostridium perfringens (2). It can be used in studies of spore forming anaerobes, especially Clostridium butyricum in cheese, for enumeration of Clostridia in tube dilution counts or for preparation of plates for isolation (3). Other spore forming anaerobes, Streptococci and Lactobacilli also grow in these media. These are enriched but nonselective media.
Casein enzymic hydrolysate, yeast extract, beef extract, starch, L-cysteine and sodium acetate provide all the necessary nutrients for the growth of Clostridia. Dextrose is a fermentable carbohydrate in the medium while sodium chloride maintains osmotic equilibrium. These media can be made selective by addition of 15-20 mg Polymyxin B per litre of media (1).
Directions: Suspend 37.5 grams in 1000 ml distilled water. Heat if necessary to dissolve the medium completely. Dispense as desired. Sterilize by autoclaving at 10 lbs pressure (115°C) for 15 minutes.