Take the Pure L Glutamine fermentation broth and microfilter it through a ceramic membrane (0.3μm pore size, microfiltration pressure 2.0-3.5MPa) at 28°C. The liquid is concentrated at 37°C to 16.7% of the volume of the filtrate, that is, the concentration ratio is 6 times. The obtained concentrated liquid is cooled to below 10°C to crystallize, and then undergoes plate and frame dehydration (the plate and frame filter pressure is 0.4-0.8MPa, and the water injection pressure 1.4MPa) to obtain the first Pure L Glutamine crude product and filtrate, and the filtrate was sent to prepare compound fertilizer;
Add water to the crude L-glutamine, adjust it to a suspension with a mass percentage of 25%, and then go through plate and frame dehydration again (the conditions are the same as above), separate and obtain the second Pure L Glutamine crude product and mother liquor, and the mother liquor is for use; the second Pure L Glutamine Add water to the L Glutamine crude product to adjust it to a solution with a mass percentage of 5%, and then add activated carbon for decolorization. The amount of addition depends on the actual color of the suspension. 16.7%, that is, the concentration ratio is 6 times. The resulting concentrated solution is cooled to below 5°C to crystallize, and then centrifuged to obtain the finished L-glutamine product and the refined mother liquor. The refined mother liquor is used for later use.
After HPLC detection, the yield of Pure L Glutamine was 55%, and the purity was above 98.5%. At the same time, the same source and weight of L-glutamine fermented liquid were used to extract the traditional method, and the final obtained L-glutamine was detected, and the yield was 53%, and the purity was above 98.5%, and there was no significant difference between the two. Sexual difference shows that the extraction method described in this method can guarantee product quality on the basis of saving procedures.
Take 5000 ml of fermentation broth (containing Pure L Glutamine70mg/ml), add 1 g of flocculant and mix, the protein will settle, take out the supernatant, and mix it with JK-008 strongly acidic cation exchange resin and 711 type anion exchange resin at 1:1 After adsorption on the ion exchange resin, it was eluted with 0.1 N aqueous sodium chloride solution. Collect the eluate. After decolorizing at room temperature with 10 grams of activated carbon, concentrate below 45°C until a large amount of crystals are precipitated. Cool to 0°C, filter out L-glutamine crystals, wash with water and alcohol, and dry under vacuum at 0.098pa at 45°C. Obtain 238 grams of L-glutamine, yield: 68%.
Add 100 grams of L-glutamic acid and 60 grams of phthalic anhydride into a 500ml flask, control the temperature of the oil bath at 150±5 ℃, react for 45 minutes after melting, pour into boiling water while it is hot, cool and crystallize to obtain phthaloyl -98.2 grams of L-glutamic acid (yield 87%) and 27.5 grams of L-pyroglutamic acid (yield 85%); 30 grams of phthaloyl L-glutamic acid were boiled in acetic anhydride for 15 minutes to produce Phthaloyl-L-glutamic anhydride 24.7 grams (yield 88%); 20 grams of this anhydride is directly reacted with 25% concentrated ammonia water at room temperature, because the reaction is more intense, there is heat of reaction released, preferably slowly Add acid anhydride or start the reaction under cooling conditions, and the reaction can generally be completed within ten minutes. After distilling off ammonia, concentrating, and acidifying, 18.5 grams of phthaloyl-L-glutamine can be precipitated (87% yield) ; Dissolve 10 grams of phthalyl-Pure L Glutamine directly in 40 ml of 5% hydrazine hydrate aqueous solution at room temperature for two days, acidify with sulfuric acid, adjust the pH to 2, and filter to remove phthalic hydrazide and Hydrazine sulfate hydrate was precipitated to obtain 5.2 g of phthalic hydrazide (yield 89%). The clear liquid was concentrated under reduced pressure to adjust the pH value to 6.0, and 4.8 g of Pure L Glutamine crude product was crystallized (yield 90%), which was washed with ethanol 4.2 grams of fine product were refined (total yield 51%).
