纳滤技术用于氨基酸溶液的提纯

为进一步分离提纯已用超滤处理的γ-氨基酸（GABA）发酵液，用两款纳滤膜先后处理超滤的滤波。MWCO为800的SR2膜对氨基酸和盐均无明显的截留作用，可以截留较大的分子。MWCO为200的SR3膜能将氨基酸很好地截留，对盐也有一定的截留作用。两款纳滤膜分离与离心分离和超滤一起，可以脱除GABA发酵液中的大部分杂质，使GABA的纯度达到31．63％，取得了较好的分离效果。

Application of Nanofiltration in Purification of Amino Acid Solutions

For the purpose of further purification of the GABA fermentation broth,two nanofiltration membranes were used to treat the ultrafiltration permeate.The SR2 membrane with MWCO value of 800 had no retention effect on the amino acid and the salt.It could be used to separate the large molecules.The SR3 membrane with MWCO value of 200 had a good retention on amino acid and a partial retention on the salt.It could be used in the concentration of the solution.The two nanofiltration combined with the centrifugation and ultrafiltration could separate the large portions of impurities in the fermentation broth, then bright the purity of GABA up to 31.63%.As a result,good purification effect was achieved.