GROWTH RESPONSE OF A MARINE YEAST, CRYPTOCOCCUS LAURENTII, TO THIAMINE.

Abstract

Repeated experimentations during the course of a month on the growth response of a marine yeast, Cryptococcus laurentii, to graded dosages of thiamine showed that the organism could respond linearly to micro-quantities of this vitamin. Continuation of these experiments after a break of five months revealed the loss in ability of the yeast to respond to the minute dosages earlier employed though the strain still exhibited a linear response to higher amounts of thiamine. Subsequent studies revealed that the organism had totally lost its dependency on the vitamin.