WHOLE SALIVA AS A SOURCE OF CERTAIN GROWTH FACTORS FOR AN ORAL STRAIN OF LACTOBACILLUS

¹ Harvard School of Dental Medicine, Boston, Mass.

1) Whole human saliva used without any concentration satisfactorily replaced the mineral salt fraction of a synthetic medium capable of supporting growth and maximal acid production of an oral strain of Lactobacillus acidophilus.

2) Whole saliva, even when concentrated sevenfold, did not serve as a substitute for casein hydrolysate or for tryptophane of the synthetic medium.

3) Concentrated whole saliva did aid in the production of slight growths and low acid production when substituted in turn for thiamin hydrochloride or calcium pantothenate or nicotinic acid.

4) These findings indicate that the nitrogenous substances essential for maximum acid production with this organism are, either not present in sufficient amounts in whole saliva even when concentrated sevenfold, or are not in a form available for use by the organism.