Mycological Examination of Domestic Unpolished Rice and Mycotoxin Production by Isolated Penicillium islandicum

Abstract

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 25ΐ 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.

Mycotoxins that Affect the Human Cardiovascular System

“…toxicarium), which produced citreoviridin [53,55]. Among isolates from imported rice, Tsunoda et al found Penicillium islandicum, which produced brownish, discolored rice containing two hepatotoxic metabolites: luteoskyrin and cyclochlorotine [53,56]. Toxic disturbances associated with the consumption of rice contaminated with Penicillium species occurred and became known as "Yellow rice syndrome" [56,57].…”

“…Among isolates from imported rice, Tsunoda et al found Penicillium islandicum, which produced brownish, discolored rice containing two hepatotoxic metabolites: luteoskyrin and cyclochlorotine [53,56]. Toxic disturbances associated with the consumption of rice contaminated with Penicillium species occurred and became known as "Yellow rice syndrome" [56,57]. Although no human cases of poisoning have been recorded, mycotoxicologists recommended that the Japanese government take action to protect citizens against "yellow rice poisoning" caused by a metabolite of Penicillium citreoviride called citreoviridin.…”

Mycotoxins that Affect the Human Cardiovascular System

“…toxicarium), which produced citreoviridin [53,55]. Among isolates from imported rice, Tsunoda et al found Penicillium islandicum, which that produced brownish, discolored rice containing two hepatotoxic metabolites: luteoskyrin and cyclochlorotine [53,56]. Toxic disturbances associated with the consumption of rice contaminated with Penicillium species occurred and became known as "Yellow rice syndrome" [56,57].…”

“…Currently, many other authors attribute Keshan disease to the mycotoxin citreoviridin [60,63,66,67]. Tsunoda et al found that P. citrinum was responsible for yellowish rice, which was associated with the high nephrotoxic toxicity produced by citrinin [53,56].Moldy millet or maize, but not wheat, eaten for 4-12 months produced an outbreak of Keshan disease. Rats fed with 4 mg/kg (body weight) of citreoviridin-contaminated grain every day for 4-6 weeks exhibited necrosis of myocardium and cell mitochondrial swelling, proliferation and damage, identical to what was observed in cases of death from Keshan disease.…”

“…Among isolates from imported rice, Tsunoda et al found Penicillium islandicum, which that produced brownish, discolored rice containing two hepatotoxic metabolites: luteoskyrin and cyclochlorotine [53,56]. Toxic disturbances associated with the consumption of rice contaminated with Penicillium species occurred and became known as "Yellow rice syndrome" [56,57]. Although no human cases of poisoning have been recorded, mycotoxicologists recommended that the Japanese government take action to protect citizens against "yellow rice poisoning" caused by a metabolite of Penicillium citreoviride called citreoviridin.…”