A study on the production of citrinin by Monascus spp.

The mycotoxin citrinin was detected by TLC and by HPLC in Monascus cultured on ,,red rice, collected from various manufacturers. Most ,,red rice samples (n = 32) contained citrinin in a range from 0.2 mg/kg to 140 mg/kg, while citrinin was not detected in three red rice samples. Monascus strains were isolated from these samples of red rice, and some strains (Monascus anka and Monascus ruber) were identified as potential citrinin producers when cultivated in YES medium. Cultivation of one strain in solid and submerged cultures (synthetic medium) was carried out to aim at citrinin-free production of Monascus pigment. When monosodium glutamate or histidine were used as the sole nitrogen source to cultivate Monascus ruber strain JH-2 (a potential citrinin producer in liquid culture), no citrinin was detected in the fermented broth, while fermentation on rice or wheat resulted in high toxin concentrations. Finally, aspects of citrinin determination methods (TLC, HPLC) for high color value red rice samples are discussed in this paper.