钙离子浓度对聚球藻Synechococcus钙化过程的影响<br>Effects of Calcium Concentration on Biocalcification of Synechococcus

Abstract

微藻的生物钙化现象是自然界水体中沉积物形成和碳循环的重要组成部分，对生物钙化现象的研究，有利于人类更好的应对全球气候变化。但目前对微藻生物钙化现象的研究还不充分。本文中对典型钙化蓝藻聚球藻Synechococcus的生物钙化现象进行了实验室研究，考察了水体中钙离子的初始浓度对生物钙化过程的影响。实验测定了藻类生长的变化、溶液pH值、碱度及钙离子浓度的变化，并用扫描电子显微镜观察了沉淀的生成情况。结果表明，聚球藻的存在明显促进了溶液中碳酸钙沉淀的生成。但是溶液中钙离子浓度过高未对碳酸钙沉淀过程产生积极影响。实验条件下，钙离子初始浓度190 mg/L是形成碳酸钙沉淀的最佳条件。 Biocalcification of microalgae is important for the precipitation of calcium carbonate and carbon cycle in nature. Getting knowledge of biocalcification is in favor of dealing with the global climate changes. However, the research of biocalcification is not sufficient at present. In this study, the effects of calcium concentration on biocalcification of Synechococcus PCC 7942 were investigated on laboratory scale. The growth of algae, the solution pH, alkalinity and the concentration of Ca2+ were measured during the experiments, while the precipitation was detected with scanning electron microscopy at the same time. The results showed that the existence of Synechococcus PCC 7942 promoted the precipitation of calcium carbonate in solution. But higher calcium concentration in solution has no active effects on the precipitation process. Under the experimental conditions, the most suitable concentration of calcium was 190 mg / L.