108 BACTERIOLOGICAL CHEMISTRY 



gciAc I'iisc to its name. It is active in very low concentra- 

 tions, of the order of 0-008 fig./ml., in stimulating 

 carbohydrate fermenting organisms, but not non-carbo- 

 hydrate fermenters. Pantotlienic acid loses its activity 

 towards some organisms, e.g. Str. liceirwlyticus , on cleavage, 

 by acid hydrolysis, into «-hydroxy- p p-dimethyl-y- 



^ Ji sXp CHOH C = 



butyrolactone, ^^Hs/T ' i' ' and p -alanine, 



CH2— 1 



NH2.CH2.CH2.COOH. This is similar to the failure of 

 some organisms to utilise glutamic acid instead of 

 glutamine, and to the readier use of nicotinamide than 

 of the acid. It appears to be associated with the inability 

 to form amide linkages other than in the a-position, that 

 in pantothenic acid being p- and that in glutamine 

 being y-- 



The effect of pantothenic acid is usually increased 

 by relatively large amounts of meso-inositol and by 

 extremely small amounts of bio tin. 



Active pantothenic acid has been sjnithesised from 

 its inactive component parts. 



Among organisms for which pantothenic acid is a 

 growth factor are the lactic acid bacteria, hsemolytic 

 streptococci, C. diphtherice gravis and Proteus morganii. 



The way in which panthothenic acid enters into the 

 metaboUsm of micro-organisms is not yet understood. 



Phosphopyridine Nucleotides. — Diphosphopyridine 

 nucleotide, Co-enzyme I, which is constituted as nicotin- 

 amide -ribose -phosphate -phosphate -ribose -adenine , has 

 been shown to be identical with the F-factor required 

 by H. influenzce and which is supplied by extracts of 

 many bacteria, yeasts, blood and plant and animal 

 tissues. A mixture of nicotinamide and adenylic acid 

 cannot replace Co -enzyme I in the metabolism of 

 H. influenzce. The co -enzyme is a co -dehydrogenase 

 (see Chapter XII). 



