RELATION OF A GROWTH FACTOR REQUIRED BY LACTOBACILLUS CASEI ε TO THE NUTRITION OF THE CHICK

Abstract

The norit eluate factor previously shown to be required by Lactobacillus casei & has been further purified and appears to be required by t,he chick.The active material in solubilized liver* was concentrated by adsorption on norit A and elution with a solution containing 10 per cent ammonia and 50 per cent ethanol at 75".Adsorption and elution were repeated with Super Filtrol and norit A successively.The final product had an activity of 1 unit' in from 0.09 to 0.15 y of material per 10 cc. of medium and represents a lOO-to 200-fold concentration.Electrodialysis and esterification showed that t'he active compound is acidic and that at least part of the acidity is due to a carhoxyl group.Activity is destroyed by ni.trous acid, indicating the presence of a free amino group.This group was also suggested by acetylation and benzoylation.Recently Stokstad3 reported that the active compound is a nucleotide and partially replaceable by thymine and guanine.Since the bacterial factor has many properties in common with certain chick factors4 concentrates of it were fed to chicks with a ration of the following percentage composition:dextrin 47, purified casein 18, salts 5, soy bean oil 5, cartilage 15, and blackstrap molasses 10.Vitamins were added at the following levels per kilo of ration: thiamine 3 mg., riboflavin 3 mg., pyridoxine 4 mg.: pantothenic acid 15 mg., nicotinic acid