Red Pigment Formation by Interaction of Molds Part 2 Taxonomical Characteristics of Penicillium Strain L 9

Abstract

The previous study (1) revealed a phenomenon of red pigment formation by interaction of molds which are supposed to be of different genera. One of them is a Penicillium species which produces yellow pigment(s) in the CzAPEK solution, but not in or on other cultural media tested. By itself this mold can never produce the red pigment(s) in or on any medium examined, including the CZAPEK solution. The present paper shows that this species is Penicillium verruculosum and that the same phenomenon is brought about by several other strains of the same species.EXPERIMENTAL METHODS 1) Isolation of molds: The mold described here was isolated by the procedure reported in a previous paper (2). Namely, a paper label attached to a can of preserved food, on which several strains of molds had grown, was cut in pieces of about 5 cm square with a pair of flame-sterilized scissors. These pieces were incubated in Koji extract liquor for 5 to 7 days at 30°. After the ordinary purification method was applied, the pure single strain of Penicillium species L 9 was obtained from the plate culture.2) Mycological identification: Sucrose-CzAPEK agar and malt extract agar were generally used as culture media. Spores of the isolated strain, which had been incubated previously on the koji extract agar slant at 30° for 7 days, were inoculated at the center of agar plate in the Petri dishes, 86 mm in inner diameter. They were incubated at 30° and the developed colonies were observed at proper phases of growth. Spoi es and the other cultural characteristics of the mold were observed after 4-5 and 10-12 days' incubation in the dry state. Morphological observations were made either directly or with slices cut from the margin to the center of the colony. The size of each organ placed in the mounting fluid was determined in detail. Color tones of sporulation area and of colony reverse, coloring of the culture medium caused by pigment formation by the mold and their changes during incubation were observed after 4-5 and 10-12 days of incubation. Each color was described according to RIDGwAY's "Color Standard and Nomenclature." 3) Isolation of gluconic acid: Spores of the isolated mold were inoculated 9

Red Pigment Formation by Interaction of Molds Part 6 Medium Components Affecting Formation of the Pigments

“…It has been reported in our previous papers (1)(2)(3)(4)(5) that (i) the red pigments are produced by interaction of Penicillium verruculosum with Trichoderma viride or with several other strains of molds species, that (ii) the degree of pigment formation depends largely upon the balance of activities of both strains in the mixed culture, that (iii) the optimal conditions for pigment formation, such as of pH, temperature and oxygen supply coincide with those for mycelial growth, and that (iv) the process of sporulation of P. verruculosum plays the most significant role in the determining the degree of the cobiontic formation of the red pigments.…”

Red Pigment Formation by Interaction of Molds Part 4 Interaction Between P. Verruculosum and Various Molds

“…It was reported in previous papers (1)(2)(3) that some red pigments were produced by interaction between Penicillium verruculosum and some strains or species of the genera Penicillium and Trichoderma.…”