镉胁迫对蛋白核小球藻生物膜生理特性的影响

Effects of Cadmium Stress on Physiological Characteristics of Chlorella pyrenoidosa Biofilm

文章以附着在聚氯乙烯载体上的蛋白核小球藻生物膜为研究对象,研究了镉胁迫下蛋白核小球藻生物膜的生理活性、抗氧化性和生物累积性等生理特性。结果表明:蛋白核小球藻生物膜在低浓度镉的胁迫下能保持相对稳定的增长,20.0 mg/L镉浓度对蛋白核小球藻生物膜的生长则表现出抑制作用,生物量仅为对照组的79.19%,胞外多聚糖的产量可达(99.28±1.19)mg/L;15.0 mg/L镉浓度胁迫下蛋白核小球藻生物膜超氧化物歧化酶活性最大值达到(290.50±4.55)U/g;过氧化氢酶活性随着镉浓度和处理时间的不断增加而增加,在20.0 mg/L镉浓度最高值达到(528.75±20.17)U/g;蛋白核小球藻生物膜对镉的生物累积量可达4.72 g/kg;傅里叶变换红外光谱表征分析得出蛋白核小球藻生物膜的生物累积效果可能与藻细胞表面存在的-NH_(2)、C-H等官能团有关;伪二阶动力学更适合描述蛋白核小球藻膜对镉的吸附过程。

Taking Chlorella pyrenoidosa biofilm attached to PVC carrier as the research object,the effects of cadmium stress on physiological characteristics of Chlorella pyrenoidosa biofilm,such as physiological activity,antioxidant activity and bioaccumulation,were studied.The results showed that the growth of Chlorella pyrenoidosa biofilm was relatively stable under the stress of low concentration of cadmium,while the growth of Chlorella pyrenoidosa biofilm was inhibited by 20.0 mg/L cadmium,the biomass was only 79.19%of the control group,and the production of extracellular polysaccharide was(99.28±1.19)mg/L.Under 15.0 mg/L cadmium stress,the activity of superoxide dismutase in Chlorella pyrenoidosa biofilm reached the maximum value of(290.50±4.55)U/g;the activity of catalase increased with the increase of cadmium concentration and treatment time,and the maximum value was(528.75±20.17)U/g at 20.0 mg/L cadmium concentration;the bioaccumulation of cadmium in Chlorella pyrenoidosa biofilm reached 4.72 g/kg.Fourier transform infrared spectroscopy analysis showed that the bioaccumulation effect of Chlorella pyrenoidosa biofilm might be related to the presence of-NH_(2),C-H and other functional groups on the surface of algae cells;pseudo second order kinetics was more suitable to describe the adsorption process of cadmium by Chlorella pyrenoidosa biofilm.