[Mycological examination of domestic unpolished rice and mycotoxin production by isolated Penicillium islandicum].
Fungi growing on domestic rice were examined from April to June, 2003. One hundred samples of rice, which had been harvested in the autumn of 2002, were collected from the local market, and 15 samples of stored rice, which had been harvested in 2001 and stored in warehouses under government control, were used as samples. From each sample, 50 grains (100 grains in total) were plated on potato-dextrose agar (PDA) and malt yeast 40% sucrose agar (M40YA) containing chloramphenicol after being washed with sterile distilled water to remove any microorganisms on the surface, and incubated at 25 degrees C for a week. For most of the rice samples harvested in the preceding year, the proportion of grains infected with fungi was less than 20% of the total grains tested. In about half the samples of rice stored for one and half years, more than 80% of the grains were infected with fungi that grew on M40YA. The major genera of fungi isolated from the rice harvested in the preceding year were Penicillium and Alternaria, and those from the rice stored for one and a half years were Aspergillus, Penicillium and Eurotium. P. islandicum, A. versicolor, A. ochraceus and others were isolated as possible mycotoxin-producers in the mycoflora of domestic rice. P. islandicum was isolated from 3 samples, and 82% of the grains were infected with this fungus in one sample. All three isolates from these samples appeared to produce luteoskyrin on Czapek yeast extract agar, based on TLC and HPLC analysis.
Sakai
Ayako
A
National Institute of Health Sciences, Setagaya-ku, Tokyo, Japan.
Tanaka
Hiroki
H
Konishi
Yoshiko
Y
Hanazawa
Ryo
R
Ota
Toshiko
T
Nakahara
Yoshiyuki
Y
Sekiguchi
Shoji
S
Oshida
Emi
E
Takino
Masahiko
M
Ichinoe
Masakatsu
M
Yoshikawa
Kunie
K
Yoshizawa
Takumi
T
Takatori
Kosuke
K
D001230:Aspergillus / Q000302:isolation & purification; D009183:Mycotoxins / Q000096:biosynthesis*; D009285:Naphthoquinones / Q000378:metabolism; D012275:Oryza / Q000382:microbiology*; D010407:Penicillium / Q000302:isolation & purification* / Q000378:metabolism*
D009183:Mycotoxins; D009285:Naphthoquinones; C100224:luteoskyrin