Study On The Production Of Single Cell Protein By Fermentation Of Yellow Water

A large amount of organic wastewater produced in the course of production and processing of soybean products is usually discharged after simple treatment,which can cause environmental pollution and waste of resources.Through the use of microorganisms under certain conditions fermentation to obtain SCP at the same time,reduce the amount of organic matter in wastewater,so as to achieve the purpose of purification of wastewater.Through the Plackett-Burman test,the response surface test and add nutrients to determine the optimum parameters of yellow serofluid fermentation,to promote fermentation.The results of the study are as follows:1.Selection of strains and their ratio:according to the determination results of nutrient composition and content of whey,selection of available carbohydrates,proteins,lipids and other nutrients bacteria,biological fermentation method to solve yellow serofluid when producing SCP strains and the ratio of the problem;after the study selected endomycopsis fibuligera(CICC 31258)and Candida lipolytica(CICC 32457),Candida utilis(CICC 31268),g.candidum(SH501)as the fermentation strain;through the analysis of orthogonal test data and knowledge,the best mixed proportion of yeasts for fermentation endomycopsis fibuligera:Geotrichum Candida lipolytica:yeast:Candida utilis =2:1:1:2 or 3:1:1:2.2.Optimization of fermentation broth:according to the content of carbohydrate,lipid and protein in the yellow water,the C/N of the fermentation broth was adjusted and the effective compound inorganic salt was added to improve the yield and the effect of wastewater treatment.The C/N of fermentation broth was adjusted by hydrolysis of com starch to make C/N=5.Through orthogonal test,it was found that the composition and content of compound nutrients were 0.15%,calcium chloride,calcium hydrogen phosphate,potassium hydrogen phosphate,potassium chloride,potassium sulfate,potassium phosphate,and hydrogen peroxide.The content of compound nutrients was as follows:Magnesium Sulfate,calcium chloride,potassium hydrogen phosphate two.3.Fermentation process and parameters:the best level of each factor was determined by single factor experiment.The use of Plackett-Burman test were significant factors influencing yellow serofluid fermentative production of SCP as the initial pH,fermentation time,liquid volume.The response surface design was used to optimize the significant factors.The results showed that the fermentation temperature was 28 3.22g/100mL,initial pH6,fermentation time of h was 43 SCP,inoculation amount was 6%,and the liquid volume was 140 mL/250mL.4.Expand the fermentation mode:on the basis of laboratory table,expand the scale of fermentation,provide the basis for the treatment of wastewater.By using self-made IL and 5L fermentation device research of semi continuous fermentation conditions and fermentation conditions for the final 48h of fermentation time and fermentation temperature was 28 deg.C,ventilation time interval l0min,the use of self-made 1L fermentation device SCP yield was 2.79g/100mL,using self-made 5L device SCP fermentation yield was 2.61g/100mL.5.SCP index evaluation and determination of water quality:through the analysis of the SCP amino acid composition,physicochemical index and health index,the results showed that SCP protein content reached 30.2%,rich in amino acid composition,health indicators in line with national requirements,is a kind of nutritious,safe and reliable source of protein.After the fermentation,the organic components in the yellow water decreased significantly,COD decreased 46.4%,BOD decreased by.It is a great help to the production and wastewater treatment.