Statistical Optimization for Monacolin K and Yellow Pigment Production and Citrinin Reduction by Monascus purpureus in Solid-State Fermentation

Abstract

Monacolin K and yellow pigment, produced by Monascus sp., have each been proven to be beneficial compounds as antihypercholesterolemic and anti-inflammation agents, respectively. However, citrinin, a human toxic substance, was also synthesized in this fungus. In this research, solidstate fermentation of M. purpureus TISTR 3541 was optimized by statistical methodology to obtain a high production of monacolin K and yellow pigment along with a low level of citrinin. Fractional factorial design was applied in this study to identify the significant factors. Among the 13 variables, five parameters (i.e., glycerol, methionine, sodium nitrate, cultivation time, and temperature) influencing monacolin K, yellow pigment, and citrinin production were identified. A central composite design was further employed to investigate the optimum level of these five factors. The maximum production of monacolin K and yellow pigment of 5,900 mg/kg and 1,700 units/g, respectively, and the minimum citrinin concentration of 0.26 mg/kg were achieved in the medium containing 2% glycerol, 0.14% methionine, and 0.01% sodium nitrate at 25°C for 16 days of cultivation. The yields of monacolin K and yellow pigment were about 3 and 1.5 times higher than the basal medium, respectively, whereas citrinin was dramatically reduced by 36 times.

Enhancement of antioxidant activity of monascal waxy corn by a 2‐step fermentation

“…This indicated that the monacolin K and citrinin contents were enhanced by the 2-step fermentation, which were about 4 and 3 times higher than those of the conventional method. The obtained monacolin K and citrinin contents from our study were much less than those of Jirasatid et al (2013), where the maximum monacolin K content of 5900 mg kg À1 and the minimum citrinin content of 0.26 mg kg À1 from the optimisation study were achieved in the medium containing 2% glycerol, 0.14% methionine, and 0.01% sodium nitrate at 25°C for 16 days of cultivation, showing that the appropriate enrichment medium provided higher monacolin K and citrinin contents. Chairote et al (2008) have reported that the production of monacolin K obtained from Monascus fermentation using glutinous rice (high amylopectin substrate) as substrate was found in the range of 3.13-33.54 mg kg À1 .…”

“…The obtained monacolin K and citrinin contents from our study were much less than those of Jirasatid et al . (), where the maximum monacolin K content of 5900 mg kg −1 and the minimum citrinin content of 0.26 mg kg −1 from the optimisation study were achieved in the medium containing 2% glycerol, 0.14% methionine, and 0.01% sodium nitrate at 25 °C for 16 days of cultivation, showing that the appropriate enrichment medium provided higher monacolin K and citrinin contents. Chairote et al .…”

“…Monacolin K and citrinin contents of 2-step fermentation were simultaneous with pigment production and growth of M. purpureus. Pattanagul et al (2008) suggested that mevinolin (monacolin K) and citrinin synthesis depended upon Monascus mycelial growth, while Jirasatid et al (2013) reported that the secondary metabolites from Monascus such as monacolin K and citrinin were formed together during yellow pigment production. The contents of monacolin K and citrinin in the conventional fermentation were 16.83 mg kg À1 dry weight and 3.55 lg kg À1 dry weight, respectively, and the maximum monacolin K and citrinin contents were produced by the 2-step fermentation after 8 days, which were 79.72 mg kg À1 dry weight and 10.57 lg kg À1 dry weight, respectively.…”

Application of red pigment producing edible fungi for development of a novel type of functional cheese

“…strains are devoid of lactose consuming capability (Shi & Pan, 2010;Tseng, Chen, & Lin, 2000), pretreatment with beta-galactosidase was necessary when WPC was used as a solid substrate for favorable growth of the tested strains. Referring to the previous studies on the red pigment and lovastatin productivity (Ahn, Jung, Hyung, Haam, & Shin, 2006;Jirasatid, Nopharatana, Kitsubun, Vichitsoonthonkul, & Tongta, 2013), incubation temperature was defined at 25°C. Among nine strains, M. purpureus AHU 9085 and 9087 and M. ruber NBRC 9203 and 32318 showed red pigment production on WPC medium, which was apparently independent of the initial culture pH condition.…”

Effect of the cultivation mode on red pigments production from Monascus ruber

“…It is known that production of pigments and citrinin by Monascu s species is dependent on the culture conditions, because various bioprocess improvements have been attempted to favour high production of pigments and reduce citrinin formation (Wang et al ., ; Jirasatid et al ., ; Zhang et al ., ). In this regard, it was shown that the pigment production was favoured, whereas citrinin accumulation was disfavoured when Monascus sp was cultured under dark condition in the presence of caprylic acid (Zhou et al ., ).…”