Mutagenesis Breeding Of Serratia Marcescens And Fermentation Production Of Lycopene

On the basis of the Serratia marcescens RZ21 which had been preserved in our laboratory and can produce prodigiosin(PG),we used the combination of physical and chemical mutagenesis method on the strain and got the mutant strain RZ21-a.Then studied on the culture medium and fementation conditions of RZ21-a,and studied on the technological process of the Supercritical CO2 Fluid Extraction technique which had been applied to extract the prodigiosin produced by RZ21-a.Using UV-LiCl and Microwave-DES composite mutagenesis induced RZ21.Results showed that the two methods all made the production of prodigiosin increased.RZ21-a could produce more prodigiosin and the prodigiosin production reached 35.38 mg/L which increased 20%than the yield strain;RZ21-b's prodigiosin production reached 31.28 mg/L which increased 6%than the yield strain.It can be seen that the UV-LiCl mutagenic effect was better than the Microwave-DES mutagenesis.The RZ21-a's culture medium and fermentation conditions had been studied on.Finally it concluded that the optimal culture medium:sucrose 25g/L,peptone 25g/L.The best fermentation conditions:30ml/250ml bottle liquid volume,pH6.0,temperature of 28?,153 rpm,quantity of 4%,cultivate it under the dark environment for 48h.Under such condition the prodigiosin production can be 1219.03 mg/L.Centrifuge the fermented liquid and dry the solid bacteria,and then use the Superitical CO2 Fluid Extraction to extract the pigment.Study on the extraction temperature,extraction time,the kinds of entrainer and solid particle mesh.Eventually the best condition was extraction temperature 45?,extraction time 2.5h,30%methanol as entrainer,20?40 mesh.Prodigiosin was identified by UV full wavelength scan and mass spectrometry after extraction,separation and purification of HPLC.Its relative purity was up to 98.26%.