title: Enhanced removal of Zn(2+) or Cd(2+) by the flocculating Chlorella vulgaris JSC-7.
abstract: Microalgae are attracting attention due to their potentials in mitigating CO2 emissions and removing environmental pollutants. However, harvesting microalgal biomass from diluted cultures is one of the bottlenecks for developing economically viable processes for this purpose. Microalgal cells can be harvested by cost-effective sedimentation when flocculating strains are used. In this study, the removal of Zn(2+) and Cd(2+) by the flocculating Chlorella vulgaris JSC-7 was studied. The experimental results indicated that more than 80% Zn(2+) and 60% Cd(2+) were removed by the microalgal culture within 3 days in the presence up to 20.0mg/L Zn(2+) and 4.0mg/L Cd(2+), respectively, which were much higher than that observed with the culture of the non-flocculating C. vulgaris CNW11. Furthermore, the mechanism underlying this phenomenon was explored by investigating the effect of Zn(2+) and Cd(2+) on the growth and metabolic activities of the microalgal strains. It was found that the flocculation of the microalga improved its growth, synthesis of photosynthetic pigments and antioxidation activity under the stressful conditions, indicating a better tolerance to the heavy metal ions for a potential in removing them more efficiently from contaminated wastewaters, together with a bioremediation of other nutritional components contributed to the eutrophication of aquatic ecosystems.
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Md Asraful
authors.initials: MA
authors.lastname: Alam
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Chun
authors.initials: C
authors.lastname: Wan
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China; State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: xqzhao@dlut.edu.cn.
authors.forename: Xin-Qing
authors.initials: XQ
authors.lastname: Zhao
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China.
authors.forename: Li-Jie
authors.initials: LJ
authors.lastname: Chen
authors.affiliation: Department of Chemical Engineering, University Center for Bioscience and Biotechnology and Research for Energy Technology and Strategy Center, National Cheng Kung University, Tainan 701, Taiwan.
authors.forename: Jo-Shu
authors.initials: JS
authors.lastname: Chang
authors.affiliation: School of Life Science and Biotechnology, Dalian University of Technology, Dalian 116024, China; State Key Laboratory of Microbial Metabolism and School of Life Science and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China. Electronic address: fwbai@sjtu.edu.cn.
authors.forename: Feng-Wu
authors.initials: FW
authors.lastname: Bai
mesh_terms: D000975:Antioxidants; D018533:Biomass; D002104:Cadmium / Q000302:isolation & purification*; D048408:Chlorella vulgaris / Q000254:growth & development / Q000378:metabolism*; D003362:Cost-Benefit Analysis; D005427:Flocculation; D015227:Lipid Peroxidation; D010788:Photosynthesis; D013482:Superoxide Dismutase; D015032:Zinc / Q000302:isolation & purification*
chemical_list: D000975:Antioxidants; D002104:Cadmium; D013482:Superoxide Dismutase; D015032:Zinc
keywords: Chlorella vulgaris; Cost-effective biomass recovery; Flocculation; Heavy metal removal; Microalgae