【摘要】：γ-氨基丁酸(GABA)是一種重要的中樞神經(jīng)系統(tǒng)抑制劑,具有鎮(zhèn)靜安神、增強(qiáng)記憶力、降低血壓、治療癲癇、調(diào)節(jié)激素分泌等多項重要功能。米糠中含有的谷氨酸脫羧酶(GAD),可以催化谷氨酸(Glu)發(fā)生脫羧反應(yīng)來制備γ-氨基丁酸(GABA)。本論文以米糠為原料進(jìn)行γ-氨基丁酸(GABA)的制備研究。 本文對利用米糠谷氨酸脫羧酶生物轉(zhuǎn)化生產(chǎn)γ-氨基丁酸的工藝進(jìn)行了研究,通過單因素和正交試驗,優(yōu)化得到最佳生產(chǎn)工藝為:選擇Na2HPO_4-檸檬酸緩沖液進(jìn)行實驗,底物谷氨酸鈉濃度0.04mol/L,緩沖液濃度0.02mol/L,料液比1:8,40℃水浴反應(yīng)反應(yīng)時間14h,可得到GABA2.2mg/mL, GABA含量10.50%。 通過對制備得到的GABA溶液中的組分分析,本文分別選擇離子交換分離純化方法及反膠束萃取的純化方法對生產(chǎn)得到的GABA溶液進(jìn)行提取分離的研究。對GABA原溶液采用離子交換法進(jìn)行提取純化研究。以GABA含量和回收率以及富集液中蛋白、糖的截留率為指標(biāo)進(jìn)行超濾預(yù)處理的研究,實驗結(jié)果表明,當(dāng)選用MWCO10KDa的超濾膜進(jìn)行實驗時,超濾透過液中GABA的含量由原來的10.50%增至17.33%。分別通過靜態(tài)及動態(tài)吸附、洗脫試驗,考察影響離子交換容量的各種因素,并確定最佳優(yōu)化工藝為:選擇D001樹脂,調(diào)節(jié)上樣液pH為2.0,以2mg/mL的濃度上樣吸附,吸附完全后以2mol/L的氨水濃度進(jìn)行洗脫。在此工藝條件下,可得溶液中GABA含量79.27%,GABA總回收率82.28%。 實驗同時采用反膠束萃取法對GABA溶液進(jìn)行提取純化的對比研究。實驗對不同因素指標(biāo)進(jìn)行反膠束萃取動力學(xué)研究并判斷反膠束萃取傳質(zhì)過程的控制類型。又分別對反膠束萃取GABA的前萃及后萃實驗工藝進(jìn)行了優(yōu)化,得到最佳前萃條件為:AOT 50mmol/L,W0 40,GABA 2.5mg/mL,pH 2.0,NaCl濃度100mmol/L,溫度25℃,萃取時間20min;最佳后萃條件為:溫度55℃,萃取時間30min,水相pH值9.0;在此工藝條件下對GABA原溶液進(jìn)行分離純化研究,得萃取液中GABA含量80.95%,GABA總回收率64.49%。
[Abstract]:緯-aminobutyric acid (GABA) is an important inhibitor of central nervous system, which has many important functions such as calming, improving memory, lowering blood pressure, treating epilepsy, regulating hormone secretion and so on. Glutamate decarboxylase (GAD), in rice bran can catalyze the decarboxylation of glutamate (Glu) to produce 緯 -aminobutyric acid (GABA). In this paper, the preparation of 緯-aminobutyric acid (GABA) from rice bran was studied. In this paper, the process of producing 緯 -aminobutyric acid by biological transformation of rice bran glutamic acid decarboxylase was studied. By single factor and orthogonal test, the optimum production process was obtained as follows: the Na2HPO-4citric acid buffer solution was selected for the experiment. The concentration of sodium glutamate was 0.04 mol / L, the concentration of buffer was 0.02 mol / L, the ratio of solid to liquid was 1: 840 鈩，

本文編號：2165338