A method for isolating an altered bioactive fraction from a stress-induced aquatic photosynthetic organism, said method comprising: providing an aquatic photosynthetic organism； culturing the aquatic photosynthetic organism under stress-induced culture conditions comprising subjecting the photosynthetic organism to a stress factor or a plurality of stress factors to produce a stress-induced photosynthetic organism that has an altered bioactive fraction and suitable for use in the isolation of the bioactive fraction altered from it； wherein the stress factor or plurality of stress factors is selected from the group consisting of: ultraviolet light stress by applying UVB radiation of 1 or 2 mW / cm2 from 3 to 12 hours a day； ozone stress by ozone injection to obtain a redox potential of 200 to 400 and a dissolved O2 concentration of 7.0 to 9.0 mg / l； osmotic stress by applying an osmolality of culture medium of 600 to 1200 mOs / kg； reduce hydrostatic pressure compared to that of the original conditions； and a combination thereof, and in which the stress factor or plurality of stress factors alter at least one characteristic of at least one bioactive fraction isolated from the stress-induced photosynthetic organism compared to a corresponding bioactive fraction isolated from an organism photosynthetic not induced by stress； separate the stress-induced photosynthetic organism into cell juice and a component of cell walls； treating cell juice under effective conditions to produce a bioactive fraction, wherein said bioactive fraction is selected from the group consisting of a cell serum fraction, a membrane fraction, a cell juice supernatant fraction, and a fraction of cell serum filtrate； and isolating said bioactive fraction from the treated cell juice, wherein the isolated bioactive fraction has at least one altered characteristic compared to a corresponding bioactive fraction isolated from a photosynthetic organism not induced by stress, wherein said aquatic photosy
