γ-氨基丁酸发酵液的絮凝和脱色工艺研究

Study on flocculalion and decolorization conditions of γ-aminobutyric acid fermentation broth

以壳聚糖作为絮凝剂,对γ-氨基丁酸发酵液的絮凝工艺进行了正交实验优化,确定了最佳的絮凝工艺条件为pH5.0、壳聚糖用量0.1g/L以及温度20℃,此条件下絮凝率可达97.3%,γ-氨基丁酸损失率仅为1.2%。然后采用大孔脱色树脂对絮凝后的发酵液进行脱色,实验结果表明,用440nm的吸光度能准确表征发酵液中的色素浓度,SD300大孔吸附树脂对GABA发酵液具有较高的脱色率和GABA得率,优化的脱色pH和脱色温度分别为pH5.0和25℃。该研究结果为从发酵液中分离提纯γ-氨基丁酸奠定了良好的基础。

The flocculation conditions of γ-aminobutyric acid fermentation broth were optimized by an orthogonal experiment using chitosan as the flocculant. The favorable conditions of floccutation were pH 5.0, flocculant concentration 0.1g/L, and temperature 20℃. The flocculation ratio could reach 97.3% with the loss of γ-aminobutyric acid only about 1.2% under above conditions. And then the decolorization conditions of fermentation broth after flocculation were studied by macroreticular resins.The absorbance of 440nm measured the concentration of pigment accurately.The resulted showed that SD300 exhibited higher decolorizing ratio with high recovery rate of GABA.The optimized decolorizing pH and temperature were 5.0 and 25℃.This research result lay a foundation for separation and purification γ-aminobutyric acid from fermentation broth.