通过筛选耐受高浓度Ca²⁺且钙化速率较高的藻株，分析初始Ca²⁺浓度对其生长和钙化效果的影响。从喀斯特地区湖泊水样分离得到多株微藻，筛选出钙化能力较高的斜生栅藻（Scenedesmus obliquus）B-7。收集藻细胞并进行扫描电镜观察和能谱仪（SEM-EDS）分析，发现细胞表面存在针状霰石形貌的钙化结晶，具有明显的钙化现象。进一步在不同Ca²⁺浓度下培养藻株B-7，测定细胞生长和培养基pH随时间的变化情况及Ca²⁺消耗量，结果表明，初始Ca²⁺浓度与细胞生长呈负相关。从细胞生长和生物钙化量综合考虑，400 mg/L Ca²⁺为藻株B-7进行生物钙化提供了适宜的环境；在此质量浓度下，生物钙化程度最大，生物钙化率达到86.09%。

This work aims to screen out microalgal strains with strong Ca²⁺-resistant ability and high calcification rate,and investigate the effects of initial Ca²⁺ concentration on the growth and calcification of the selected microalgal strains.Several microalgal strains are isolated from water samples of Karst regions.Among them,Scenedesmus obliquus B-7 exhibits the highest calcification rate in Ca²⁺-rich media.Microalgal cells are collected,and analyzed by scanning electron microscope and energy disperse spectroscopy (SEM-EDS).It is found that calcification crystals with needle-like aragonite morphology are observed on the cell surface,which implies an in vivo calcification phenomenon.Furthermore,B-7 microalgal strain is cultured under a series of initial Ca²⁺ concentrations.The changes of cell growth and medium pH with time,and Ca²⁺ consumption are measured.It is found that cell growth is negatively correlated with initial Ca²⁺ concentration.In consideration of both cell growth and biocalcification,the optimum initial Ca²⁺ concentration is 400 mg·L^-1,in which the highest biocalcification proportion of 86.09% can be obtained.

赵前(1994-),男,硕士研究生,研究方向为微藻固碳的研究,515326063@qq.com