The Breeding Of High Yield And Reducing Glutathione Strain And Fermentation Conditions

Glutathione (GSH) is a biologically active thiol tripeptide having important physiological function. Glutathione have functions of radiation-proof, anti-oxidation, detoxification treatment eye disease and have great potentials and market.Glutathione.It is also widely used in food processing, cosmetics, medicine and other fields. However we are not yet large-scale production of glutathione. The glutathione of our country depend on importation and the price is high. so it is urgent to Study on gluthatione production.The project mainly for GSH low yield and high cost of the problem, based on the conditions of fermentation strains the breeding, the two aspects of microorganism fermentation production glutathione in-depth research, to provide some references to the industrialization.We have obtained369glutathione-producing strains after from nature, repeated screening, and got6higher yield strains by rescreening. We selected strain PT-7(pt), a high yield and good stability, as the original strain through stability testing. We obtained mutant pt-32-3by the method of UV mutagenesis, ZnCl2and methionine alternately screening, GSH production of the strains is150%of the original strain, and verified its good stability through genetic stability experiments. The strain was identified as Candida spp. by using morphologic observationand18SrDNA sequencing.Single factor experiments, response surface experiments and orthogonal test has been optimized for pt-32-3medium to determine the optimum fermentation condition:glucose4%,peptonel.7%,KH2PO40.2%,(NH4)2SO40.4%,MgSO40.14%,ZnSO40.001%;pH5.0,inoculu mconcentration8%,temperature25℃,liquid medium volume40mL/250mL.The yield of GSH is167.84mg/L, and the yiele of biomass increased by39.49%and7.5%and intracellular GSH content has also increased by30.25%.Studying different types of amino acid affected on accumulation of GSH in the pt-32-3. Been verified experiment compared before and after optimization and join the precursor amino acids for GSH production results show that, before and after the optimization of fermentation conditions for GSH production is very significant optimization before adding the precursor amino acid.GSH average yield of307.37mg/L, which is3.55times andl.86times than the pre-optimization or amino acids is not added. intracellular GSH content of23.07mg/g, which is2.79times and1.67times than the pre-optimization or amino acids is not added.