Flocculation with clays is a promising and environmentally friendly way to remove algal blooms. Physiological responses of Microcystis aeruginosa NIES- 843 under the stress of chitosan modified kaolinite (CMK) loading were first reported in this paper. Compared with the control, the contents of chlorophyll a (Chl a) and carotenoids showed no significant difference at a CMK loading of 40 mg/l, but the phycocyanin content was significant lower than the control at this loading level. The contents of Chl a, carotenoids, phycocyanin and allophycocya...