A method for culturing algae, which has ability of producing the highly unsaturated fatty acid, and/or the photosynthetic pigment, and/or the polysaccharide, in the high concentration in the medium, said method comprising the step of:
- cultivating algae in a cultivation apparatus under light irradiation and aeration conditions to manufacture the algae abundantly containing the highly saturated fatty acid, and/or the photosynthetic pigment, and/or the polysaccharide, wherein said cultivation apparatus comprises a main body of the cultivation apparatus and a gas discharging apparatus;
- and
- the main body of the cultivation apparatus is the cultivation apparatus with a dome shape, conical shape, or cylindrical shape, wherein
- the cultivation apparatus with the dome shape comprises an external hemispheric dome made from a clear material, an the internal hemispheric dome made from the clear material, and a bottom part connecting bottom parts of both the domes, and a cylindrical opening member is installed on the top part of the external hemispheric dome and the discharging apparatus for the culture solution is installed on the bottom part;
- the cultivation apparatus with the conical shape comprises an external conical circumferential wall made of the clear material, an internal conical circumferential wall made from the clear material, and a bottom part connecting bottom end parts of both the circumferential walls, and a cylindrical opening member is installed on the top part of the external conical circumferential wall and the discharging apparatus for the culture solution is installed on the bottom part;
- or, the cultivation apparatus with the cylindrical shape comprises an external cylindrical circumferential wall having an upper wall made of the clear material, an internal cylindrical circumferential wall having an upper wall made of the clear material, and a bottom part connecting bottom end parts of both the circumferential walls, and a cylindrical opening member is installed on the central part of the upper wall of the external cylindrical circumferential wall and the discharging apparatus for the culture solution is installed on the bottom part;
- the gas discharging apparatus is configured by opposite two square base boards, a bubble leading member, of which section has a square shape lacking a side or a reversed U-shape, opened downward, and a discharge nozzle, the bubble leading member is installed with inclination to an upper side face of the square base board, forms the upper wall made by extending an inclined wall of the upper face of the bubble leading member by bending almost horizontally in the upper end part, and has a side wall extending from both the side ends of the inclined wall and the upper wall, and each of the bottom end parts of both the side walls are jointed on the two upper side faces of the square based board, and the discharge nozzle is rotatably attached through a via hole made in the bottom part of the inclined wall.