• Applied Biological Chemistry
• /
• v.33 no.2
• /
• pp.169-173
• /
• 1990

The anthraquionone mycotoxin, skyrin, is produced by Penicillium islandicum. DF-100 which was extracted from grapfruit seed extract and is a natural organic complex inhibited the biosynthesis of skyrin by Penicillium islandicum. This study was carried out to determine the potential of DF-100 to support Penicillium islandicum and skyrin production. DF-100 inhibited the growth of the fungus at 750ppm or less and caused complete inhibition of skyrin production at 500ppm or less. DF-100 appears to block the incorporation of emodinathrone into skyrin and an enzymatic step in the skyrin biosynthetic pathway which lies before skyrinanthrone.

• Applied Biological Chemistry
• /
• v.27 no.3
• /
• pp.151-157
• /
• 1984

Skyrin was extracted from Penicillium islandicum cultivated on synthetic Czapek-Dox medium. A preliminary experiment in Penicillium islandium using $[^{14}C]$-acetate proved the incorporation of $[^{14}C]$ into skyrin. In the cell-free system using the fungus $[^3H]$-emodin and $[^3H]$-emodinanthrone were shown to give some reliable evidences far the biosynthesis of skyrin. The incorporation of $[^3H]$-emodin was less significant than that of $[^{3}H]$-emodinanthrone. As a result of the cell-free experiment, the biosynthetic pathway of skyrin by the fungus was suggested as follows: $emodinanthrone{\rightarrow}emodin{\rightarrow}skyrin$.

• The Plant Pathology Journal
• /
• v.24 no.4
• /
• pp.469-473
• /
• 2008

We have previously obtained a representative isolate KU101 of the predominant Penicillium species from rice under indoor storage conditions. In this study we attempted to characterize isolate KU101 using its morphological and molecular characteristics. When the micro- and macroscopic characteristics of isolate KU101 were compared with the P. islandicum reference isolate KCCM 34763, isolate KU101 was generally identical to those of isolate KCCM 34763, however, isolate KU101 grew faster and produced more orange to red pigments than isolate KCCM 34763. In a molecular-based identification, the nuclear sequence of the ITS1-5.8S-ITS2 region of isolate KU101 was most closely related to that of P. islandicum. Therefore, these results indicated that isolate KU101 from stored rice could be identified as P. islandicum, some isolates of which are known to produce mycotoxins.

• Korean Journal of Food Science and Technology
• /
• v.7 no.3
• /
• pp.154-158
• /
• 1975

Effects of combined treatments of radiation-heat and radiation-chemicals on the survival of mycotoxin-producing molds Aspergillus flavus and Penicillum islandicum conidia were investigated. Combined treatments of gamma-radiation and heat (10 minutes at $50^{\circ}C\;or\;55^{\circ}C$) showed a synergistic effect, causing remarkable decreases in $D_{10}$ values and induction doses in the two molds. Combined treatments of gamma-radiation and chemicals (sorbic acid) had no synergistic effect. Asp. flavus was more resistant to heat and sorbic acid than was Pen. islandicum.

• Korean Journal of Microbiology
• /
• v.12 no.3
• /
• pp.101-114
• /
• 1974

The fine structure of HeLa cells treated with several mycotoxin-producing fungi (Aspergillus flavus ATCC 15517, Aspergillus parastiticus RIB 1037, Penicillium toxicarium RIB 4002, Penicillium cirinum SWU)238, Penicillium islandicum IFO 5235, Penicillium tadum IFO 5787 and Pencillium brunneum RIB 1172) has been examined and some details have been descried. The normal HeLa cell have numerous microvilli, large ovoid nucleus, pleomorphic mitochondria, electron-dense body, Golgi complex, mid-body and endoplasmic reticulum etc. Certain specific structural changes induced by culture filtrates of several mycotoxin-producing fungi have been noted. These alterations induced disappearance of Golgi complex, rER vacuolization, nucleolus attachment to the nuclear envelope nad appearance of certain vacuoles. There were not any changes by the treatment of culture filtrates of non-toxic fungi and only cell debris of some specimens can be observed by the injury of culture filtrates. The experimental animals treated with mycotoxin-producing fungi (Aspergillus flavus ATCC 15517, Aspergillus parasilicus RIB 1037, Penicillum citrinum SWU 238, Penicillium toxicarium RIB 4002, and Penicillium islandicum IFO 5235) were mal cells treated with culture filtrates.

• Korean Journal of Food Science and Technology
• /
• v.10 no.1
• /
• pp.46-51
• /
• 1978

One of yellowed rice toxins, luteoskyrin, was investigated with respect to its identification, quantitation and producibility by Penicillium islandicum isolated from deteriorated rice. 1) Luteoskyrin was best resolved by thin-layer chromatography with silica gel G plate impregnated with 0. 5 N oxalic acid and acetone : n-hexane : water (6 : 3 : 1.5, upper layer) solvent system. The isolated yellow spot showed maximum absorption bands at 426 and 448 nm and changed to purple color upon exposure to sunlight for $2{\sim}3$ hours. 2) Detection limit for luteoskyrin was 4 ppm in elution-colorimetry and 0.1 ppm in densitometry after TLC. Assuming that the tolerance for luteoskyrin in rice is set below 3.68 ppm, densitometry is usable for its screening in grain samples 3) Producibility of luteoskyrin by Pen. islandicum was shown to be 11 mg/g mycelial mat in liquid culture and 40 mg/g autoclaved rice.

• Food Science and Preservation
• /
• v.3 no.2
• /
• pp.149-154
• /
• 1996

In order to develovpment of new sterilizing method applied to food industry, effects of ozone treatment on microorganisms, associated with food hygiene were investigated. Microorganisms were immersed in water and sparged with ozonised air(ozone concentration, 3mg liter-1) at an air flow rate of 5 liter min-1. When organisms were treated with benzoic acid and sorbic acid of 0.4∼1.0g/$\ell$, respectively, they were not dectable perfectly. Sodium benzoate had an effect on Penicillium islandicum. When bacteria were sparged with ozonised air, Pseudomonas aeruginosa completely inhibited at 60 minutes, and the killing Aspergillus flavus and Penicillium islandicum. Also, all of bacteria were inactivated after immersed with ozonated water for 10minutes, but two fungal species were not effective.

• Korean Journal of Food Science and Technology
• /
• v.7 no.3
• /
• pp.148-153
• /
• 1975

Seven toxigenic molds isolated from deteriorated rice in Korea, Aspergillus clavatus, Asp. flavus var. columnaris, Asp. fumigatus, Asp. ochraceus, Penicillium citrinum, Pen. implicatum, and Pen. islandicum, were examined for their sensitivity toward Co-60 gamma rays for survival. Conidia of all tested species showed survival curves of sigmoidal type, from which decimal reduction doses were found to vary in the range of $14{\sim}33$ krad, induction doses, in the range of $12{\sim}56$ krad and inactivation factors at 200 krad, in the range of $4.6{\sim}12.8$, all at a dose rate of 11.56 krad/min. Dose rate effects on the radiosensitivity of Asp. flavus and Pen. islandicum conidia indicated that the higher dose rate (11.56 krad/min) caused decreases in decimal reduction doses as compared with the lower dose rate (2.67 krad/min).

• Mycobiology
• /
• v.46 no.3
• /
• pp.287-295
• /
• 2018

In this study, we evaluated the effect of different temperatures (10, 20, 30, and $40^{\circ}C$) and relative humidities (RHs; 12, 44, 76, and 98%) on populations of predominant grain fungi (Aspergillus candidus, Aspergillus flavus, Aspergillus fumigatus, Penicillium fellutanum, and Penicillium islandicum) and the biocontrol activity of Pseudomonas protegens AS15 against aflatoxigenic A. flavus KCCM 60330 in stored rice. Populations of all the tested fungi in inoculated rice grains were significantly enhanced by both increased temperature and RH. Multiple linear regression analysis revealed that one unit increase of temperature resulted in greater effects than that of RH on fungal populations. When rice grains were treated with P. protegens AS15 prior to inoculation with A. flavus KCCM 60330, fungal populations and aflatoxin production in the inoculated grains were significantly reduced compared with the grains untreated with strain AS15 regardless of temperature and RH (except 12% RH for fungal population). In addition, bacterial populations in grains were significantly enhanced with increasing temperature and RH, regardless of bacterial treatment. Higher bacterial populations were detected in biocontrol strain-treated grains than in untreated control grains. To our knowledge, this is the first report showing consistent biocontrol activity of P. protegens against A. flavus population and aflatoxin production in stored rice grains under various environmental conditions of temperature and RH.

• Applied Biological Chemistry
• /
• v.15 no.3
• /
• pp.193-198
• /
• 1972

Twenty seven specimens of deteriolated storage rice were collected all over Korea. Types of deteriolation were classified according to color outlooks, and for 48 grains of each specimen the causative storage microorganisms were isolated and identified. The following results were observed; 1. 27 specimens of deteriolated rice were classified according to color outlooks into 7 types: reddish yellow 1, light reddish yellow 3, light grayish yellow 4, light red 6, dark gray 7, light gray 3, and rice weevil type 3. 2. The most common storage microorganisms group which infected deteriolated Korean rice were Aspergillus glaucus group, especially species of A. amstelodami, A. chevalieri, A. montevidensis, and A. ruber, which were frequently associated with Penicillium, Brevibactereum, and Bacillus. 3. As a specific case sometimes a specimen of deteriolated rice was infected chiefly by one deminant species of microorganism. Five cases were observed: that is, by P. islandicum, P. lanosum, B. lentus, Pseudomonas cohaerans, Brev. lipolyticum. 4. No definite relationship was observed between color outlook types and the deteriolation causing microorganisms. Only the heavily infected rice by Penicillium islandicum expressed discernible reddish yellow color indicative of the infection by this mold. 5. Mycotoxin problem could be noted in one specimen of deteriolated imported rice heavily infected by P. islandicum. Other mycotoxin producing fungi, A. flavus, A. ochraceus, A. fumigatus were also detected, but their growth frequencies were so low that it might not be serious problem.