Isolation from liver of new factors essential for the growth of Lactobacillus helveticus and Streptococcus lactis R

Abstract

Four fractions containing 3 or 4 different growth factors for L. helveticus and S. lactis were obtained from by-products in the manufacture of commercial liver extracts. One of these (HL2) is probably identical with folic acid. The other 3 factors are CHCl3-soluble, and can replace folic acid as a growth factor. Two of these (HL1 and HL3) are absorbed on "Decalso," HL4 is not. HL1 and HL4 are very active while HL3 is only slightly active. HL3 and HL4 exert a synergistic action on each other.