Study On The Effect Of Flavonoids On The Fermented Products Of Monascus Purpureus 5046 And The Design Of Monascus Fenmentation Factory

Monascus is a filamentous fungus that can produce Monascus pigment,monacolin K,γ-aminobutyric acid and many other secondary metabolites with important economic value.Monascus pigment is widely used in the food industry as a natural pigment.MK has the function of lowering blood lipids and is used in the production of medicines and health products.However,during the fermentation process,Monascus can produce a mycotoxin called citrinin.The discovery of citrinin has raised concerns about the safety of Monascus and its related products.China is a big producer and consumer of Monascus and related products.It is important to explore the production process of low-yield or no orange mold for the industrial production of Monascus products.Flavonoids are important secondary metabolites in the process of plant growth.Different types of flavonoids have different biochemical properties due to certain structural differences.Monascus purpureus 5046 is a kind of Monascus species with low citrinin production.The effects of flavonoids on the production of pigment and citrinin by Monascus purpureus 5046 under liquid fermentation and solid state fermentation were investigated.Transcriptomic method to explore the possible mechanism of flavonoids production is of great significance to comprehensively explore the related research on reducing the production of citrinin by Monascus.Therefore,this study attempts to explore the effect of flavonoids on the production of pigment and citrinin by Monascus purpureus and its possible mechanism.Combining engineering practice,I designed a fermentation plant with an annual output of 300 tons of Monascus pigment.The main research contents are as follows:(1)The effects of flavonoids on secondary metabolites such as pigment and citrinin produced by liquid shake flask fermentation of Monascus purpureus 5046 were investigated.The study found that the most suitable carbon source for the liquid shake flask fermentation of Monascus purpureus 5046 was rice.When the rice flour content was 20 g/L,a higher yield of Monascus pigment could be obtained after 8 days of fermentation.By detecting the production of fermentation broth pigment and citrinin in the medium after adding seven flavonoids,it was found that adding 2.0 g/L quercetin could reduce the production of citrinin in Monascus by 91.17%,while the production of monascus pigment was 91.17%.After optimizing the amount of quercetin added,it was found that adding 0.5 g/L quercetin could significantly reduce the yield of citrinin of Monascus purpureus 5046,but limited by the solubility of quercetin,quercetin.With the addition of the element exceeds 2.0 g/L,its effect no longer changes significantly.In addition,an unknown substance with a relative molecular weight of about 390 was found during the experiment,which may be mistaken for monacolin K when detected by ordinary HPLC,but the substance can be identified by HPLC-MS.It was found that this substance is not monacolin K,and it needs to be explored by follow-up research.(2)The effect of quercetin on the transcriptome level of Monascus purpureus 5046 was explored.The genome of Monascus purpureus YY-1 was used as the reference genome for referenced transcriptome sequencing.The results showed that the gene matching degree of Monascus purpureus used in this study was 93%,indicating that the reference genome was well selected.After analyzing the relevant data,it was found that the correlation coefficients between samples in the same group were all above 0.8,indicating that the correlation coefficients between samples were strong.A total of 365 DEGs were found by sequencing,of which 207 were significantly up-regulated and158 were significantly down-regulated.But no related genes involved in citrinin biosynthesis were found in these DEGs.The enrichment analysis found that these DEGs were mainly enriched in the sugar metabolism-related pathways of Monascus,and sugar metabolism was an important physiological metabolic process of Monascus.I speculate that quercetin might affect some processes of sugar metabolism of Monascus which then may affect biosynthesis of secondary metabolites of Monascus.(3)The effects of flavonoids on the solid-state fermentation of Monascus purpureus 5046 to produce pigment and citrinin were investigated.Firstly,I screened out the medium with higher pigment of Monascus purpureus 5046.Then the carbon source and other conditions of the medium were optimized,and the best formula was determined: 2% glucose,0.5% maltose,1% tryptone,0.5% yeast extract,2% agar.Monascus purpureus 5046 can produce more Monascus pigments after 9 days of growth in this medium.Then,the effects of four flavonoids on Monascus purpureus5046 under solid-state fermentation conditions were explored,and it was found that quercetin had the best effect.The yield of citrinin from Monascus purpureus decreased by 79.26%.(4)Combining engineering practice,I designed a fermentation plant with an annual output of 300 tons of Monascus pigment.The site selection of the factory was determined,and the graphic design drawing of the factory,the graphic design drawing of the production workshop and the design flow chart were drawn.The economic calculation of the factory found that the total annual operating cost of the factory was15.26 million yuan.After all the 300 tons of monascus pigments produced by the factory were sold,the sales fund was 36 million yuan,and the annual net profit after deducting production costs and related taxes reached 15.56 million yuan.