葡萄糖对杜氏盐藻3-磷酸甘油脱氢酶活性的影响

Effects of glucose on activities of Glycerol-3-phosphate dehydrogenase of Dunaliella salina

关键词:  杜氏盐藻  葡萄糖  甘油  3-磷酸甘油脱氢酶

Key words:  Dunaliella salina  glucose  glycerol  glycerol-3-phosphate dehydrogenase

摘要:

杜氏盐藻是一种抗渗透能力强的单细胞绿藻,甘油在其渗透调节过程中具有重要作用。葡萄糖对杜氏盐藻细胞数量的增加效果不明显,但对盐藻细胞内甘油积累有显著促进作用,在0～15 g/L范围内葡萄糖的浓度与胞内甘油积累显著相关(R²=0.9604,P=0.01); 葡萄糖浓度达到15 g/L时,胞内甘油积累量达到最高值7.80 pg/cell,是对照的1.88倍,胞内甘油积累量与葡萄糖的消耗量极显著相关(R²=0.9982,P=0.01)。葡萄糖对盐藻细胞内总蛋白、3-磷酸甘油脱氢酶(GPDH)酶活和比活都有显著影响,在15 g/L葡萄糖时这3个值达到最大值,分别是对照的1.354、4.384、3.229倍。数据显示葡萄糖浓度在15 g/L时细胞内蛋白质含量增加不多,但GPDH酶活和比活却大幅度增加; 葡萄糖导致的渗透压的变化可能诱导新的同功酶的合成。

Abstract:

D.salina is the single-cell green alga with strong anti-osmosis ability,and glycerol has the very important role in the process of osmosis regulation. Glucose(Glu)had weak effect on the increase of cell density of D.salina,but could obviously promote the accumulation of intracellular glycerol(Gly)of the alga,and the effect linearly correlated remarkably with intracellular Gly concentration(R²=0.9604,P=0.01),when the concentration of glucose was between 0-15 g/L. Upon Glu being 15 g/L,the accumulation of intracellular Gly reached maximal value of 7.80 pg/cell,which was 1.88 times of the control treatment. Intracellular Gly concentration linearly correlated remarkably with the consumption of Glu(R²=0.9982,P=0.01). Glu could clearly increase the intracellular protein content,activity of glycerol-3-phosphate dehydrogenase(GPDH),and the total amount of intracellular protein,activity of GPDH,specific activity of GPDH reached maximal values,which were 1.354,4.384 and 3.229 times of that of control treatment,respectively,when the concentration of Glu was at 15 g/L. Data indicated that,when Glu being at 15 g/L,the amount of intracellular protein just increased slightly,while the activity and the specific activity of GPDH increased very dramatically; the change of osmostic pressure resulted by Glu might induced the synthesis of some new isoenzymes.