2 0 0 0 OA 本邦産有胞子性樹液酵母について
A taxonomic survey has been made of ascosporogenous yeasts found in exudates occurring on tree stumps of broad-leaved trees in Japan during the periods of April and July of 1967,1968,1972,and 1973. The samples were collected in test tubes by using cotton pieces. Usually within 2 to 7 days after collecting, a loopful of the sample was streaked directly on carrot juice-koji extract agar medium containing 100 ppm of chloramphenicol. At the same time, samples were enriched by 2 kinds of liquid media besides the koji extract, i.e., sodium acetate-peptone-yeast extract, and glucose-nitrate media, both supplemented with 100 ppm of chloramphenicol, for 3-7 days at 25℃ followed by streaking on the agar media mentioned above. The pure cultures were identified mainly by the procedures described in "The Yeasts" edited by Lodder (1970). Out of 334 strains identified, this paper deals with the species belonging to the genera Saccharomyces, Schizosaccharomyces, Pichia, and Debaryomyces.Among these a new species of Pichia naganishii is proposed beased on the reasons menitioned below.Pichia naganishii Kodama sp. n.The strain studied resembles Pichia angophorae Miller et Barker and Pichia bovis van Uden et do Carmo-Sousa, in both the shape of the ascopore and the assimilation pattern of the routine five sugars.However, in contrast to P. angophorae, this strain does not form pseudomycelium, nor does it ferment sucrose and maltose but assimilates _L-arabinose, _D-ribose, _L-rhamnose, glycerol and erythritol, and can grow at 37℃. Also, this strain is differentiated from P. bovis, in that it assimilates in addition to the above carbon compounds, ribitol and galactitol, and furthermore heterogamous conjugation preceds its ascus formation.Single strain (LKB-747) of this species was isolated from exudate of Camellia sp. in Nagasaki prefecture.