Identification Of Kefir Source Microbial And Its Impact On Production Of Rg3

Ginseng(Panax ginseng C.A.Meyer)belongs to the Araliaceae grasses.The effects of Ginseng were recorded in Compendium of Materia Medica,a book written by famous physician,pharmacologist Li of Ming Dynasty,which illustrated that ginseng can be conductived to the blood flow,Qi and blood.Modern Medicine shows that ginseng has advantageous features in anti-oxidation,anti-aging and anti-fatigue.Ginsenosides is the main biologically active substance of ginseng,many previous studies often use ifferent solvents to extract ginsenosides from ginseng,the residue have a lot of nutrient such as ginseng polysaccharide,ginseng protein More efficiently using of ginseng has become one of the hot topics in ginseng study.This study chooses an edible microbial resources-Kefir grains to ferment the ginseng pulp liquid(Fresh ginseng after pretreating with ginseng slurry solution),to reach the full use of ginseng.It aims to improve the contents of rare ginsenoside Rg3,while takes into account the stability and controllability of the industrial production of food.The following four aspects with the conclusions are as follows:(1)The content of Rg3 and total saponins in Kefir fermented ginseng pulpConcluded that fermentation group(sample)Ginsenoside Rb1 decreased by 41% ?ginsenoside Rd content increased by 104%,the ginsenoside Rg3 increased by 134%,the biotransformation rate of ginsenoside Rg3 was 27%.(2)The dynamic changes of microorganisms during Kefir grain fermentation by metagenomic methodThis study used a metagenomic method analysises kefir grains fermented ginseng slurry,the composition of the kefir grains fermented ginseng slurry 's microorganism was analyzed for the first time from the metagenome level.The study found,kefir grains fermented ginseng slurry sample the dominant bacteria levels of phylm is Firmicutes;fungi dominant phylm is Ascomycota.The dominant fungi levels of genus is Lactobacillus;dominant genus of fungi is Kluyveromyces,in order to use the traditional culture method to screening the microorganisms from kefir grain fermentation slurry which can be transformed ginsenoside Rg3 provide basic theoretical data.(3)Screening beta-glucosidase microorganismsUsing a modified esculin medium from kefir grains fermented ginseng slurry to screened strain which can ferment transformed Rg3,Combined strain colony morphology and 26 S rDNA D1 / D2 region of the nucleic acid sequence analysis identified microbes,bacteria species with Kluyveromyces marxianus homology similarity of 99%.(4)Optimization of ginsenoside Rg3 by Marx Kluyveromyces fermentated ginseng pulpIn summary,the response surface graph analysis function derivation means of analysis parameters gensing water ratio,fermentation time,the impact of Marx marxianus inoculation,this three factors on target(of Rg3 content)response value,three factors to ginsenosides Rg3 content of the order: the gensing water ratio> yeast inoculation amount> fermentation time,the response surface design and analysis,optimum extraction conditions as gensing water ratio is 1: 2.7,the fermentation time is 3 days,the inoculum Marx marxianus is 3 %,the ginsenoside Rg3 content is 3.3298 mg / g.