Abstract: A culturing device is provided with an accommodation portion that accommodates culturing solution and microalgae. The accommodation portion is inclined with respect to the vertical direction and is supported by a support body. In this state, microalgae are cultured. A gas gathering portion is provided at an upper part of a side wall of the inclined accommodation portion, the outer surface of the side wall facing obliquely upward. The gas produced by the microalgae is gathered by the gas gathering portion.

Abstract: A culturing device is equipped with an accommodation unit, and a convection generating unit provided in the accommodation unit. In the accommodation unit, microalgae are cultured while the convection generating unit generates convection in the culturing solution in the accommodation unit. During the culturing, a portion of the culturing solution is drawn in through collection pipes by the pump. Thereafter, the culturing solution that was drawn in is discharged from the collection pipes into the culturing solution inside the accommodation unit.

Abstract: A mixed gas generated in a methane fermentation tank is supplied to culture tanks. In the culture tanks, water as a culture solution is held and algae are cultured. Carbon dioxide contained in the mixed gas preferentially dissolves in water. That is, carbon dioxide is removed from the mixed gas. As a result, a concentration of methane, which is one component of the mixed gas, increases. The mixed gas is re-supplied to another culture tank or the same culture tank.

Abstract: A culture device by which microalgae can be satisfactorily cultured using a simple structure while suppressing an increase in energy consumption, and a culture method. A main body of this culture device comprises an accommodation part which accommodates contents and to which gas is supplied. The inner wall faces of the accommodation part are joined together to form a joined part which extends along the gas supply direction. A guide part and a circulation part, which are adjacent to each other across the joined part, are each along the extending direction of the joined part and communicated with each other via a guide part inlet and a guide part outlet. A gas supply port enables gas supply toward the guide part.

Abstract: Provided are a culture apparatus and a culture method with which microalgae can be cultured satisfactorily. The culture apparatus includes a plurality of culture tanks and a water storage tank, and cultures microalgae in a culture solution. Each of the plurality of culture tanks has a translucent accommodating portion containing the culture solution and microalgae. The volumes of the accommodating portions of the plurality of culture tanks are different from each other. The water storage tank has a translucent water storage unit for storing a stored water. The plurality of culture tanks are selectively arranged in the water storage unit.

Abstract: The present invention can: efficiently and readily produce glucose from microalgae that accumulate starch in their cells; and obtain ethanol. During a preparation step of the glucose production method, microalgae are prepared on which a saccharifying enzyme acts on starch accumulated inside the microalgae cells, without disrupting the cell walls. In a saccharification step, starch inside the cells is saccharified and glucose is generated, by adding a saccharifying enzyme to the microalgae without a disruption treatment. The ethanol production method has a step in which, after the saccharification step, the glucose undergoes alcoholic fermentation and ethanol is generated.

Abstract: In a culturing method, microalgae are cultured in a culturing solution while a gas containing carbon dioxide is supplied to the culturing solution. In an ion concentration acquisition step, an acquired value of a concentration of hydrogen carbonate ions in the culturing solution is obtained. In an ion concentration adjustment step, in the case that the acquired value does not reside within a set concentration range that is set beforehand, at least one of a temperature or a pH of the culturing solution is adjusted, whereby the concentration of hydrogen carbonate ions in the culturing solution is adjusted to reside within the set concentration range.

Abstract: In ethyl alcohol production using the self-fermentation of a microalga, a step of concentrating or collecting an algal body by centrifugal treatment, filtering treatment or the like is made unnecessary or simple to save labor for effort and equipment therefor is saved. The microalga belongs to Chlamydomonas sp., and is a variant strain which has an ability to produce ethyl alcohol under dark and anaerobic conditions and has acquired an ability to proliferate while aggregating. The microalga is proliferated and maintained under dark and anaerobic conditions to generate ethyl alcohol in this method for producing ethyl alcohol.

Abstract: In ethyl alcohol production using the self-fermentation of a microalga, a step of concentrating or collecting an algal body by centrifugal treatment, filtering treatment or the like is made unnecessary or simple to save labor for effort and equipment therefor is saved. The microalga belongs to Chlamydomonas sp., and is a variant strain which has an ability to produce ethyl alcohol under dark and anaerobic conditions and has acquired an ability to proliferate while aggregating. The microalga is proliferated and maintained under dark and anaerobic conditions to generate ethyl alcohol in this method for producing ethyl alcohol.