海藻酸锶凝胶固定化含海藻糖合酶细胞的研究

Immobilization of Permeabilized Meiothermus sp. Cells Containing Trehalose Synthase by Entrapment in Strontium Alginate Beads

含有海藻糖合酶的亚栖热菌CBS-01菌株细胞经过透性化处理后,以海藻酸锶凝胶对透性化细胞进行了固定化,当加酶量为12U/g海藻酸钠时,所得固定化细胞的载酶量可达6U/g海藻酸钠。细胞固定化后,最适酶反应pH值由6.5升至7.0,最适酶反应温度未变,为60℃,但热稳定性有所提高,70℃保温60min时,固定化细胞的残存酶活为60%,而未固定化细胞的残存酶活约30%。间歇反应时,固定化细胞催化麦芽糖转化为海藻糖的转化率可达60%,重复使用10次,仍可保持约70%的酶活。

Permeabilized cells containing trehalose synthase from Meiothermus sp. CBS-01 was entrapped in strontium alginate beads. The immobilization capacity reached 6 units/g-alginate when the enzyme loading was 12 units/g-alginate. The optimum temperature was not affected by immobilization, and was 60℃, but the optimum pH was shifted from 6.5 to 7. The enzyme in alginate entrapped cells was more stable at 70℃ for 60 min with 60% of its original activity remained, whereas the enzyme in free cells retained 30% of activity. In batch manner, the immobilized cells could be continually reused 10 times with 30% loss of the enzyme activity, and a maximum conversion yield of 60% trehalose could be reached.