Abstract: The invention relates to a method for cultivating photoautotrophic micro-organisms, comprising the following steps: provision of a photosynthesis layer, which contains a photosynthesis medium and photoautotrophic micro-organisms suspended therein, in a closed accommodation space having a gas-diffusion-inhibiting outer boundary, wherein the photosynthesis layer has an average thickness of no more than 10 mm; exposure of the photosynthesis layer without eddying or feeding through a gas in the photosynthesis medium while limiting the diffusive gas exchange of the accommodation space by the environment, wherein the supply of micro-organisms in the photosynthesis medium with hydrogen carbonate ions is maintained by storing hydrogen carbonate ions in the photosynthesis medium and/or providing a photosynthesis substrate in the form of carbon dioxide and hydrogen carbonate from a cell-free carbon storage medium outside the photosynthesis layer; and conducting a gas formed during photosynthesis out of the accommodatio

Abstract: A process for cultivation of photoautotrophic microorganisms is proposed comprising providing a photosynthesis layer (2) containing a photosynthesis medium and photoautotrophic microorganisms suspended therein in a closed inclusion space with an outer border (1) restricting gas diffusion, whereat the photosynthesis layer exhibits a mean thickness of not more than 10 mm, exposing the photosynthesis layer (2) to light without whirling a gas within or piping a gas through the photosynthesis medium under restriction the of the diffusive gaseous exchange between the inclusion space with the surrounding, whereat the supply of the microorganisms with bicarbonate ions is realized by storage of bicarbonate ions in the photosynthesis medium and/or delivery of a photosynthesis substrate in the kind of carbon dioxide and/or bicarbonate from a cell free carbon storage medium (4) localized outside of the photosynthesis medium, and channeling away the gas volume formed at photosynthesis.