Fermentation Production,Quality Evaluation And Characterization Of Functional Active Components Of Functional Monascus

Lovastatin in functional Monascus plays an important role in reducing blood lipids and other aspects.However,at present,the main way of commercial production of functional Monascus is solid-state fermentation,which generally has problems such as difficult to control fermentation conditions and uneven product quality.In this paper,the extraction process of lovastatin from functional red yeast rice（RYR）flour was optimized,and the physicochemical properties of functional RYR flour on the market were compared and evaluated.Furthermore,the technological conditions for lovastatin production in Monascus rubra by liquid fermentation were further established,in order to provide theoretical and experimental basis for the industrial production of lovastatin based on liquid fermentation.The optimal zero level and fluctuation region were determined by exploring the effects of solvent type,ethanol concentration,liquid-solid ratio,extraction temperature and extraction time,and then the best extraction conditions of lovastatin from functional RYR flour were obtained by response surface design and validation experiments.The results showed that the extraction rates of lovastatin and acid-type lovastatin could reach 90.24±0.59%and 95.62±0.52%,respectively,with 55%ethanol solution as solvent,liquid-solid ratio of 40 m L/g and ultrasonic power of 300 W for40 min at 60℃.The functional RYR flour F1 with the lovastatin content of 3.07 mg/g was obtained by solid-state shallow dish culture of Monascus rubra GN01 using long-shaped rice as the substrate.Through the evaluation and comparison of F1 and13 kinds of commercial functional RYR flour,it was found that the water content was lower than 10%,but the content of citrinin in three kinds of commercial functional RYR flour exceeded the standard.In the functional RYR flour produced by the same factory,with the increase of lovastatin content,the total sugar content showed a downward trend,while the crude protein content and ergosterol content showed an upward trend.The total sugar,reducing sugar and lovastatin contents in F1 were relatively lower than those in the commercially RYR flour.However,crude protein content,saccharification power,γ-aminobutyric acid content,ergosterol content,and the proportion of acid type lovastatin were significantly higher.Using Monascus rubra GN01 as the production strain,the seed medium for effectively relieving hyphal agglomeration was obtained by screening the seed medium and adding surfactants（g/L）:glucose 30,peptone 17.5,glycerol 70,KH₂PO₄2,Na NO₃ 2,Mg SO₄·7H₂O 1,Span 80 0.5.The optimal fermentation medium was obtained by optimizing the seed medium（g/L）:glycerol 80,peptone 26.37,KH₂PO₄ 2,Mg SO₄·7H₂O 1 and Span 80 0.5.After optimizing the temperature condition,it was found that the best culture condition was 30℃for 1 day and then changed to 25℃for fllowing culture,and the best culture period was 18 days.Under these conditiongs,the highest yield of lovastatin was 923.49 mg/L,and the acid lovastatin accounted for85.16%,which were better than the results reported in most reports.Through exploring the influences of stirring impeller speed,stirring impeller combination and dissolved oxygen concentration,the optimal conditions for lovastatin production of Monascus in 5 L fermenter were obtained as follows:the three-layer paddle combination of six straight leaves,six folded leaves and six straight leaves was adopted,the dissolved oxygen was correlated with the rotating speed to fix at 40%,the upper and lower limits of rotating speed were 450 r/min and 50 r/min,respectively,and the ventilation rate was 1 vvm.After being cultured at 30℃for one day,the temperature was changed to 25℃,and the biomass and lovastatin yields on the 14th day were 17.9 g/L and 462.94 mg/L.It was found that the lovastatin content in the mycelium was consistent with that in the solid-state shallow dish fermentation,while the ergosterol content was increased by 43.63%.