【作者】 张文会；

【导师】 姚汝华；

【作者基本信息】 华南理工大学 ， 发酵工程， 1994， 博士

【摘要】 本论文对谷氨酸结晶理论及其应用进行了研究，研究了谷氨酸阴离子(GA~王)和晶种对谷氨酸结晶二次成核速率及晶体生长速率的影响；并进行谷氨酸结晶理论的应用研究，通过超声波刺激成核的方式制得粒度为20～80μm的微细谷氨酸晶粒，以此为晶种进行发酵液中谷氨酸的等电点法结晶实验，得出添加微细晶种的谷氨酸结晶新技术。研究结果表明，二次成核速率随晶种粒度和晶种量减少而减少；在高过饱和度时GA~王对成核有促进作用，而在低过饱和度时则有抑制作用；晶体生长速率随粒度减小而增大；GA~王对晶体生长有抑制作用；结晶时使用粒度小的晶种可得到粒度分布较均匀的晶体。与添加粗谷氨酸晶种的常规结晶法相比，添加微细晶种的新型结晶法得到粒度更大更均匀的晶体；提取收率提高2—3个百分点，结晶时间和沉降时间都减少6小时左右；高谷氨酸浓度下结晶时可完全得到α型晶体；同时还研究得出了微细晶种的最适添加量和添加时的最适PH。更多还原

【Abstract】 In this thesis, the theory of L-glutamic acid (GA) crystallization and its application was studied. Nucleation and growth rates of secondary nuclei of GA were investigated when different concentration of its anion form (GA~王) coexisted and different size and quantity of seeds were added. The application of the theory was also studied. The fine seed crystals with radius 20~80μm were prepared with inductor ultrasonic waves acting on supersaturated solution of GA, with which the broth was seeded in the proceeding of iso-electric point isolation of GA. A new method of GA crystallization in the broth with addition of fine seed crystals, instead of crude crystals of GA which often used as seeds in the traditional method of crystallization, was obtained. The results show that, the secondary nucleation rates increase with increases of size and quatity of seeds, and are suppressed by GA~王 at lower supersaturation, and promoted at higher one . The growth rates of crystals decrease with increases of crystal size and concentration of GA~王 coexisted. More uniform crystals are obtained when seeds with smaller size are added in the crystallization. By using the new method of crystallization with addition of fine seeds, larger and more uniform crystals are obtained, the yield increases 2~ 3%, and the period of crystallization and precipitation decreases 6 hours更多还原