1887

Abstract

SUMMARY: A solidified medium (NP medium) was devised which supported luxuriant growth of type B. It consists of peptone, extracts of yeast and liver, blood, glucose and certain other compounds essential as nutrients and/or for poising oxidation-reduction potential. The peptone could be replaced by a commercial preparation of acid-hydrolysed casein or a mixture of 18 amino acids, but the presence of cysteine and either ascorbic acid, thioglycollate (mercapto-acetate) or dithiothreitol (DTT) was essential for consistent rapid and luxuriant surface growth. Blood was not essential in media supplemented with cysteine and DTT, although in its presence the number of colonies which developed was maximal and the formation of zones of haemolysis facilitated the location of smaller colonies. When supplemented with cysteine+DTT several other solidified media, none of which contained yeast—or liver—extract, supported good growth. By incorporating antitoxin into certain clear blood-free plating media containing cysteine+DTT it was possible to show that only some bacilli of a culture produced colonies which developed opaque haloes of toxin antitoxin flocculum. A liquid version of the NP medium was also devised.

Loading

Article metrics loading...

/content/journal/micro/10.1099/00221287-53-3-415
1968-10-01
2019-10-15
Loading full text...

Full text loading...

http://instance.metastore.ingenta.com/content/journal/micro/10.1099/00221287-53-3-415
Loading
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error