樹葉に見出された酵母について I

抄録

(1) Several strains of yeasts were isolated, from the leaves of the trees mentioned below:-(a) The Pinus densiflora SIEB. et Zucc. in the Toyama Prefecture; May 1947, June 1948 and May 1949. (b) 9 species of the needle leaved trees and 8 species of the broad leaved trees chiefly in the precinct of the Tokyo University; from Oct. to Nov. 1949.
(2) 23 strains of yeasts were selected from the 37 strains which were isolated by the author and their morphological and physiological characteristics were investigated.
(3) Identified strains are as follows;-Saccharomyces, Hansenula in sporogenous yeasts. Torulopsis, Kloeckera, Rhodotorula in asporogenous yeasts. Though the author did'nt succeed in the spore formation, a strain was acertaine a species of the Pichia from other characteristics. A strain which is closely relatod to Saccharomyces cerevisiae HANSEN seems to appear specifically on the pine leaves, especially during early summer time and has been shown to be useful in the industrial applications.
(4) In the frequency of appearance on leaves, asporogenous yeasts, especially the Torulopsideae, surpass sporogenous yeasts.
(5) It has been found that the frequency of appearance varies according to seasons.
(6) It is not quite sure that every kind of trees has its own yeast, but it seems according to the author's investigation that there are species which have some limited distribution for the definite species of the trees.
(7) It has been found that the growth of the yeasts is promoted by the extract of the leaves of some of the above mentioned plants.