Study Of Monascus Anka Producing Monascus Pigment And Glucoamylase

In this paper, parameters affecting red pigment and glucoamylase production in Monascus anka 9311 were optimized under submerged cultivation. The effects of carbon sources, nitrogen sources, liquid volume, and inoculum on accumulation of Monascus pigment and glucoamylase activity were studied. The optimum cultivation parameters were obtained by orthogonal experiment; and the stability of the pigment affected by light, temperature and pH value were investigated. Also the optimum citrinin HPLC detection conditions and citrinin content in the Monascus fermention liquid were studied. The main research results were as follows:1 Using UV-2450 spectrophotometer, the biggest absorption peak wavelength of Monascus anka 9311 fermentation liquid were 495nm and 425nm. Comparing the extraction effects of different solvents, the amount of water soluble pigment was higher than that of alochol soluble pigment. Through single and orthogonal experiments, the optimum cultivation condition of M. anka 9311 was obtained: temperature 32℃, cultivation time 5 d, and initial pH5.75. The color value of fermented liquid was reached 263.5 U/mL when the strain cultivated under optimum pigment production condition A2B1C2D3 (glycerol 10%, peptone 1.5%, inoculation level 6%, and liquid volume 75 mL). The glucoamylase activity of fermented liquid was reached 409.6 U/mL when fermented under optimum glucoamylase production condition A1B1C3D2 (glycerol 9%, peptone 1.5%, inoculation level 7%, and liquid volume 75 mL). The color value and glucoamylase activity of fermented liquid were reached 260.3 U/mL and 404.0 U/mL, respectively when fermwnted under the optimum orthogonal experiment condition A2B1C2D2, which was glycerol 10%, peptone 1.5%, inoculum level 6%, liquid volume 75 mL.2 The stability of Monascus pigment was affected by light, temperature and pH value in some extent. When reserved for 10 days, the retention rate of pigment was 20.8% when irradiated by sun light, 86.5% irradiated by natural light at room temperture, and 97.0% in dark at room temperture. The tempertrue had less influence on the stability of Monascus pigment. However with the heating time extending, the color value of the pigment would gradually decrease. After 12h treatment under 40℃, 60℃, and 80℃, its retention rate were 95.0%, 92.0%, and 90.7%, respectively. And the Monascus pigment had higher stability with pH5~9.3 The HPLC detection condition of citrinin was obtained. Chromatogram columniations: Shimadzu VP-ODS C18 (5μm, 150 mm×4.6 mm); mobile phase: pure methanol; pH2.5; fluorescence detector, wavelength:λex=331 nm,λem=500 nm; column temperature: 30℃; flow-velocity: 0.8 mL/min; sample size: 10μL. There was a linear relationship between the contents of the standards citrinin and the peak area of the chromatogram chart with the R2 value 0.9999. The lowest detection level of citrinin was 0.02 mg/L under the condition above.In this study, No citrinin was detected in the Monascus fermention liquid.