文献类型：期刊文献

英文题名：Flocculation of Chlamydomonas reinhardtii with Different Phenotypic Traits by Metal Cations and High pH

作者：Fan, Jianhua[1,2,3];Zheng, Lvhong[1];Bai, Yunpeng[1];Saroussi, Shai[3];Grossman, Arthur R.[3]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai, Peoples R China;[2]East China Univ Sci & Technol, Dept Appl Biol, Shanghai, Peoples R China;[3]Carnegie Inst Sci, Dept Plant Biol, 290 Panama St, Stanford, CA 94305 USA

年份：2017

卷号：8

外文期刊名：FRONTIERS IN PLANT SCIENCE

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000415668900001)】；

基金：This work was sponsored by Natural Science Foundation of Shanghai 17ZR1406700, National Natural Science Foundation of China 21505044, and the "Chenguang Program" supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission 14CG27. The authors gratefully acknowledge financial support from China Scholarship Council 201606745004.

语种：英文

外文关键词：flocculation; cell wall deficient; Chlamydomonas; multivalent metal ions; microalgae; pH; algal biotechnology

摘要：Concentrating algal cells by flocculation as a prelude to centrifugation could significantly reduce the energy and cost of harvesting the algae. However, how variation in phenotypic traits such as cell surface features, cell size and motility alter the efficiency of metal cation and pH-induced flocculation is not well understood. Our results demonstrate that both wild-type and cell wall-deficient strains of the green unicellular alga Chlamydomonas reinhardtii efficiently flocculate (> 90%) at an elevated pH of the medium (pH 11) upon the addition of divalent cations such as calcium and magnesium (> 5 mM). The trivalent ferric cation (at 10 mM) proved to be essential for promoting flocculation under weak alkaline conditions (pH similar to 8.5), with a maximum efficiency that exceeded 95 and 85% for wild-type CC1690 and the cell wall-deficient sta6 mutant, respectively. Near complete flocculation could be achieved using a combination of 5 mM calcium and a pH > 11, while the medium recovered following cell removal could be re-cycled without affecting algal growth rates. Moreover, the absence of starch in the cell had little overall impact on flocculation efficiency. These findings contribute to our understanding of flocculation in different Chlamydomonas strains and have implications with respect to inexpensive methods for harvesting algae with different phenotypic traits. Additional research on the conditions (e.g., pH and metal ions) used for efficient flocculation of diverse algal groups with diverse characteristics, at both small and large scale, will help establish inexpensive procedures for harvesting cell biomass.