The Oral Yeast-Lactobacillus Relationship III. Growth Enhancement of Lactobacillus casei by Candida albicans and Saliva

¹ Dental and Microbiological Research Section, Oklahoma Medical Research Institute, Oklahoma City

A study of the capacity of an oral strain of C. albicans to fortify its growth medium with amino acids demonstrated that only lysine was detectable after 3 days' growth. However, after 6-9 days' incubation the medium had been supplemented with all the amino acids required by an oral strain of L. casei.

It was also noted that conditioning a medium with the C. albicans or supplementing it with saliva appreciably decreased the initial stationary phase and increased the growth rate of the Lactobacillus. In addition, saliva was observed to increase maximum growth. This effect could be reproduced by addition to the medium of a digest of casein that had a relatively high concentration of peptides. It could not be duplicated by increasing vitamin and amino acid levels of the medium.