LGem has developed a unique two-phase flow tubular photo-bioreactor (PBR) for cultivation of micro-algae. In collaboration with manufacturers of transparent plastic or glass tubes LGem developed different designs, allowing cost effective construction of large scale PBRs. GemTube PBRs are scalable systems that are easy to operate. Fouling and accumulation of dissolved oxygen are prevented, while energy consumption is extremely low. The patented design of the PBR allows easy drainage, CIP cleaning and decontamination at a high level. Systems have been delivered around the world, to customers active in aquaculture, food and feed ingredients, cosmetics and pharmaceuticals.