Immobilized Bacillus Thuringiensis Produces L-ornithine

L-ornithine has biological activity,it exists in a variety of cells and tissues in organism,and it is important for human liver cells.The reason is that it not only acts as a precursor material,plays an important role in amino acid metabolism,but also plays an important role in the urea cycle,helping the organism to lift too much ammonia and reduce its toxicity to the body.There are several ways to produce L-ornithine at home and abroad,they are,extraction method,chemical method,enzymatic method and fermentation method.This paper uses enzymatic conversion of arginine to produce L-ornithine.In this paper,a large number of bacterial cells are obtained by suitable fermentation conditions,and then immobilized cells are prepared by preparing PVA-microcrystalline cellulose composite hydrogel,finally,the continuous transformation is carried out using packed bed reactor.We provide a certain theoretical basis and ideas for L-ornithine production in the future.In the experiment,Bacillus thuringiensis is enlarge cultured.The training time is 20h,the temperature is 35?,the ventilation is 1.5vvm,the stirring rate is 300r·min^-1,and the inoculation amount is 1.0%.In this study,PVA-microcrystalline cellulose is used to prepare immobilized cells.The concentration of PVA is 0.1g·mL^-1,the concentration of SiO2 is 0.04g·mL^-1,the concentration of microcrystalline cellulose is 0.04g·L^-1,The amount of free bacteria is 0.1g··L^-1,the freezing temperature is-4?,the freezing time?single?is 26h,and the number of freezing and thawing times is 3 times.In this experiment,the experiment is carried out to study the conversion of arginine from immobilized cells in shaker.The amount of arginine added in the reaction solution is 50g·L^-1,and the amount of immobilized cells per 100 mL of the solution is 20g,the shaker speed is 150r·min^-1,the conversion time is 24h.In this experiment,the conditions of immobilized cell transformed arginine in packed bed reactor are determined.The packed bed size is 40mm x 300mm,the residence time is 16h,and the concentration of arginine is 6%.The packed bed reactor can be continuously converted for 12 days.The molar conversion of arginine is maintained at 81.45%on average,it means the concentration of L-ornithine is maintained at 37.08g·L^-1 per day.