透性化细胞海藻糖合成酶的制备及其催化合成海藻糖的工艺优化

Optimization of trehalose synthesis by whole cell catalysis and preparation of trehalose synthase from permeable cells

笔者以麦芽糖为底物,开展经渗透细胞技术处理得到的透性化细胞海藻糖合成酶催化制备海藻糖的新工艺开发。首先,对比不同透性化试剂对异源表达海藻糖合成酶的大肠杆菌工程菌的透性化处理效果,发现使用硫酸粘杆菌素时海藻糖合成酶的催化转化率高达64.6%,是传统超声破碎的2.63倍;其次,通过参数优化获得硫酸粘杆菌素透性化处理的最佳条件,即:1.5 g/L的硫酸粘杆菌素在30℃下处理60 min,得到的海藻糖合成酶活性最高,为5 209 U/mL;最后,利用透性化处理后的大肠杆菌工程菌进行全细胞催化制备海藻糖工艺研究,结果表明:以质量分数25%的麦芽糖为底物,在pH 7.5、30℃条件下,获得海藻糖的转化率为65.6%;进一步通过离心收集细胞进行反复催化试验,在20批次之后,转化率仍维持在62.5%,显示了良好的应用前景。

Maltose is used as the substrate to synthesize trehalose using a novel whole-cell catalysisstrategy with trehalose synthase expressed inside the cells of Escherichia coli.First,comparing the effect ofdifferent permeability agents on recombined E.coli,we found that the conversion rate of trehalose reached64. 6% with colistin sulfate, 2. 63 times higher than that of traditional ultrasonic crushing method.Second,we optimized parameter of permeation treatment.Results show that the highest activity of trehalosesynthase was 5 209 U/ mL when using 1.5 g / L colistin sulfate as the permeability agent,reacting for 60min at 30 ℃. Last, the conditions for the whole-cell catalytic reaction were investigated as well. The conversion rate of trehalose was 65. 6% at pH 7. 5 and 30 ℃,with 25% maltose as the substrate. Theconversion rate of trehalose almost kept stable and remained 62？ 5% even after 20 batches,which showeda good application prospect.