Changes In Microbial Community Structure And Main Active Ingredients During The Traditional Fermentation Of Sojae Semen Praeparatum

Sojae semen praeparatum is a traditional Chinese medicinal and food homologous Chinese herbal medicine.It is made by decocting the auxiliary materials Artemisia annua and mulberry leaves,and fermenting them on the soaked and boiled mature seeds of leguminous plants as raw materials,which can relieve symptoms.,eliminate troubles,relieve depression and other effects.At present,the traditional natural fermentation process used in the production of light fermented fermented bean curd is complex,and the production cycle is relatively long.Compared with other fermented products,large-scale production cannot be achieved.Sojae semen praeparatum is a medicinal and food homologous variety that is closely related to human health and diet.It is very necessary to conduct comprehensive and in-depth research on it.In this study,32 naturally fermented light sojae semen praeparatum from 12 different regions were selected as the research objects,and the light sojae semen praeparatum that complied with the Pharmacopoeia was screened first.Then,the core fermenting microorganisms in the sojae semen praeparatum were preliminarily isolated by the traditional pure culture method,and the morphological observation was further applied,combined with the 16 S r DNA sequence identification method to identify the species,and then the isolated strains were screened.Finally,the optimization research was carried out on the conditions of pure fermented sojae semen praeparatum.The specific test results are as follows:(1)Firstly,32 collected samples of natural fermented sojae semen praeparatum were analyzed.Combined with the properties of light sojae semen praeparatum,high-performance liquid chromatography was used to target detection of isoflavones in light sojae semen praeparatum,including daidzein,genistein,daidzein,Glycine and Genistein.Obtained 30 servings of light sojae semen praeparatum in compliance with the Pharmacopoeia.(2)The total isoflavones and polysaccharide contents of the obtained 30 parts of sojae semen praeparatum were determined by UV spectrophotometer method and sulfuric acid phenol method,respectively.The lowest content of total isoflavones was obtained from TXY3 collected from Changchun City,Jilin Province,with a content of0.91 mg/g,and the highest obtained from YYR1 collected from Dandong City,Liaoning Province,with a content of 2.11 mg/g.The lowest polysaccharide content was YYR1 collected from Dandong City,Liaoning Province,with a content of 0.44 %,and the highest content was PY2 collected from Songyuan City,Jilin Province,with a content of 1.82 %.(3)80 strains of microorganisms were isolated and purified by morphological observation and 16 S r DNA sequence homology comparison analysis by microbial isolation and purification of sojae semen praeparatum samples.There are 66 strains of bacteria,including 38 strains of lactic acid bacteria and 26 strains of bacillus.There are 14 strains of fungi,including 10 moulds and 4 yeasts.(4)Using casein plate method,esculin coloration method,and agarose-fibrin plate method,55 strains with protease production ability were screened from 80 strains,and 48 strains with β-glucosidase ability were screened.There are 25 strains with the ability to produce plasmin.Combined with microbial enzyme-linked immunosorbent assay and factor analysis method for comprehensive evaluation,Bacillus subtilis LZL3-1 was screened out of the 12 strains capable of producing the above three enzymes at the same time.(5)Bacillus subtilis LZL3-1 pure strain was used to ferment sojae semen praeparatum.On the basis of the single factor experiment,the response surface analysis experiment was designed,and the optimal process for Bacillus subtilis LZL3-1 fermentation of sojae semen praeparatum was obtained as follows:fermentation time of 5.75 d,fermentation temperature of 29.29 °C,and inoculum amount of 14.89 %.At this time,the plasmin activity,the conversion rate of isoflavone glycosides and aglycones,and the total amount of free amino acids of the fermented soy bean samples were better than those of the fermented fermented soy bean samples under the same conditions.Advantage.