Several unstable brown and albino strains were found among heterocaryons between yellow and albino auxotrophs of Aspergillus sojae. The frequencies of occurrence of these strains differed according to the component strains employed. Their properties are as follows: (1) Growth on minimal medium are normal, hence prototrophic. (2) On complete medium, they form brown or albino colonies occasionally with green and yellow sectors. (3) Upon conidiation, the brown strains segregate brown, yellow, and green progeny. On the other hand, the albino strains segregate into albino and green progeny. The green segregants are prototrophic diploid when judged from their cytological properties and genetic stability. The yellow and albino segregants are haploid; their nutrient requirements are the same as those of the parental haploid strains. Based on the above, the brown and albino strains are inferred to be a kind of heterocaryons possessing haploid and diploid nuclei. The mechanism of the appearance of brown strains from the combination of albino and yellow auxotrophs is discussed.
A strain of Penicillium which produces red pigments by interaction with a strain of Trichoderma was isolated and identified as P. verruculosum by its taxonomical characteristics. The strain was found to produce a considerably large amount (12 to 13%) of gluconic acid when grown, under constant shaking, in a liquid medium containing 4% glucose. While this mold does not form any pigment in its pure culture it causes a production of red pigments-both in the mycellia and in the culture medium -when grown together with some other molds, especially with Trichoderma L 6 which has also been isolated in our laboratory . It was found that the same phenomenon is brought about also by some other strains of P. verruculosum. The significance of the formation of pigments by interactions of two fungal strains, which has never been reported in the literature, was discussed.
A strain of Trichoderma which produces red pigments by interaction with Penicillium verruculosum was isolated and identified as Trichodermaviride L 6 according to its taxonomical characteristics. Survey was made of the occurrence of red pigment formation in coupled cultures of various strains belonging to Trichoderma species, P. verruculosum as well as some representative species of the genus Penicillium. It was suggested that the red pigment(s) may derive from some colorless precursor formed by P. verruculosum, which is later converted to the colored material by the action of T. viride or some other molds.
Investigations were made on the phenomenon of red pigment formation occurring in co-biontic cultures of Penicillium verruculosum with various other molds belonging to the genera Aspergillus, Rhizopus, Mucor and those belonging to the classes Deuteromycetes and Basidiomycetes. Many species of Aspergillus were found to induce the pigment formation in co-cultures with several strains of P. verruculosum. An exception was Aspergillus tamarii which produced yellow pigment(s) in its mycelia under the same condition. The red pigment formation was seldom observed in the combinations of P. verruculosum with some species of Rhizopus and Mucor. It occurred occasionally in the combinations of various species of Deuteromycetes with strain I.A.M. 7073 of P. verruculosum, but scarcely with other strains of P. verruculosum. Strains I.A.M. 7064 and 7073 of P. verruculosum produced the red pigments when grown together with various molds belonging to Basidiomycetes. Some species, especially Glieophyllumsepiarium and Daedalea gercina, produced yellow or brown pig-ment(s) at the contact margin of their colonies with that of P. verruculosum. Thus, the formation of red pigments by P. verruculosum in its cobiontic cultures with other molds was found to be a phenomenon of fairly common occurrence.
Three species of the genus Microascus, M. trigonosporus Emmons et Dodge, M. cirrosus Curzi, and M. cinereus (Emile-Weil et Gaudin) Curzi, were described as new findings in Japan. Comparative morphological observations made with these isolates and seven cultures received from European collections have shown the questionable value of perithecial or conidial characteristic as dependable taxonomic criteria, which necessitated the use of the features of ascospores as criteria for the separation of species. A key to the species based on this principle was presented.
A new species of yeast belonging to the Genus Pichia Hansen was isolated from exudation of a tree stump, (Carpinus spec.) in Japan. The name Pichia saitoi was proposed for this microorganism. A characteristic feature of this species is in its unique shape of ascospores.
1.From the cells of a strain of Lactobacillus casei a flavin nucleotide-linked DPNH peroxidase was isolated in an almost homogeneous state, and it was revealed to have flavin adenine dinucleotide as prosthetic group. The preparation possessed weak activities of DPNH oxidase and dehydrogenase. 2. The enzyme itself showed absorption maxima at 370 and 446mμ, and in the presence of DPNH there appeared a broad absorption at around 550mμ conconitantly with partial disappearance of the absorption at around 450mμ. The absorption at around 450mμ. The absorption at around 550 mμ disappeared on addition of hydrogen peroxide together with DPNH to the enzyme.