Studies On Technology Of Ectoine Preparation

Compatible solutes refer to the matter which is compatible with the system in the cell and doesn't affect the function of large biological molecule.Ectoine,which belongs to it,is a usual compatible solute in moderately halophilic bacteria. Ectoine has great value and wide application in the fields of pharmaceutical,food,cosmetics,biological agents,enzyme preparation,agriculture and organic chemical synthetic drugs,electronic materials.Many people focus on its research.At present,people put a lot of interest in the selection of strain and preparation,in order to obtain the maximum yield of Ectoine.However,Ectoine is halophilic bacteria intracellular product. Its low production and high cost of production from separation,together restrict its use.Therefore,it is significant to study how to increase production.In order to improve the efficiency of Ectoine preparation,H. venusta DSM4743 is selected from the usual strains which can synthesis Ectoine as a best strain,because of its highest intracellutar concentration threshold of Ectoine.First of all,the impacts of carbon source,concentration of NaCl and yeast extract on the synthesizing Ectoine with H.venusta DSM4743 are investigated.Then the most optimum condition is got:MG medium,1.5mol/L NaCl and 0.5% yeast extract.Accordingly batch fermentation and fed-batch fermentation are used to investigate the efficiency of Ectoine synthesis.As the resorts show,fed-batch fermentation have the most efficient Ectoine synthesis.So fed-batch fermentation is a more superior method to synthetize Ectoine.In order to investigate the release rate of Ectoine when H.venusta DSM4743 is in the condition of down shock,the experiment of bacterial milking is done.After six cycles,the productivity of synthesized Ectoine can reach 14.7g/L and the amount of released Ectoine is 14.3g/L.The release rate of Ectoine is 97% on the average.And the efficiency of synthetize Ectoine is 2.1g/(L·d).A new method of synthetize of Ectoine is also tried by gradually increasing the concentration of NaCl in the medium.It shows that the amount of synthesized Ectoine and synthesized Ectoine by per unit biomass of the experimental group,which had added NaCl,are significantly higher than the contol group which had not added NaCl.