PROBLEM TO BE SOLVED: To provide a more simple and inexpensive bioreactor apparatus.SOLUTION: There is provided a method for operating a closed photobioreactor for cultivation of phototrophic microorganisms. The photobioreactor comprises a culture liquid, and is partially or completely surrounded by water of a water body. A density difference between the culture liquid and surrounding water is provided such that the position of the photobioreactor in the water body is controlled. There is provided a closed photobioreactor for cultivation of phototrophic microorganisms. The photobioreactor is adapted to comprise the culture liquid and to be partially or completely surrounded by the water of the water body. The photobioreactor comprises means for determining the density difference between the culture liquid and the surrounding water.SELECTED DRAWING: Figure 1aCOPYRIGHT: (C)2017,JPO&INPIT【課題】より簡単でより安価なバイオリアクター装置を提供する。【解決手段】光合成微生物の培養のための閉鎖型光バイオリアクターを操作する方法。光バイオリアクターは培養液を含み、水塊の水に部分的にまたは完全に囲まれる。培養液と周辺水との間の密度差は、水塊における光バイオリアクターの位置が制御されるように提供される。光合成微生物の培養のための閉鎖型光バイオリアクター。光バイオリアクターは、培養液を含み、水塊の水に部分的にまたは完全に囲まれるのに適している。光バイオリアクターは、培養液と周辺水との間の密度差を決定するための手段を含む。【選択図】図1a
