Abstract
A. israeli, as indicated by study of 6 strains, was unable to decompose protein material into such simpler compounds as indole or H2S; it also was not able to raise the alkalinity of media or precipitate Ca from an inorganic CaCl2 soln. that did not contain phosphate ions. A. israeli, as indicated by a study of 6 strains, contains alkaline phos-phatase and, therefore, may cause precipitation of Ca phos-] phates from the saliva and initiate calculus formation.