Closed photobioreactors for microorganism cultivation

A closed photobioreactor for growing a microorganism culture in an aqueous medium, the photobioreactor comprising:

• a vessel comprising a vessel floor, a vessel cover positioned substantially-parallel thereto, and at least one vessel wall positioned perpendicular to the vessel floor and vessel cover, defining an internal cavity for containing the microorganism culture in the aqueous medium, wherein the vessel cover comprises a plurality of openings;
• and
• a plurality of transparent pipes attached to the vessel cover configured to accommodate a plurality of light sources within lumens thereof, wherein each of the transparent pipes extends through one of the openings, wherein each transparent pipe has a first open end located out of the internal cavity of the vessel, and a second end, wherein a first portion of each transparent pipe is connected to the vessel cover or the vessel, and a second portion of each transparent pipe is located within the internal cavity,
• wherein each of the transparent pipes is substantially sealed to one of the openings, so that the internal cavity is isolated from the surrounding environment of the vessel,
• and wherein the first portion of each transparent pipe is connected to the vessel cover, and
• wherein the vessel cover comprises a plurality of hollow cover extensions, wherein each hollow cover extension extends from one of the openings upward, and has a first open end offset upward from the vessel cover and a second open end at the level of the vessel cover, wherein the first portion of each transparent pipe extends through one of the hollow cover extensions and is retained thereby.