AlgaeNRG: A new flat-panel system for high efficiency photobioreactors

In order to replace fossil fuel derived petrochemicals and meeting the growing global demand for clean and environmentally safe functional biochemicals, microalgae are the best candidates. New systems are continuously developed to improve microalgae growth efficiency in both close and open environments. Higher yield per hectare is obtained by employing flat panel photobioreactors that, unlike open ponds systems, allow a better use of space. Here we present a newly developed flat panel photobioreactor system (under patent) with a defined circulation path tested for microalgal culture. This innovative system has been designed to minimize the effect of cells mutual shading and increase the surface to volume ratio exposure to light. Component's materials which are based on existing technology also allow consistent costs breakdown and fast breakeven times. Preliminary tests have been made using different microalgae under photoautotrophic conditions with a modified BG11 medium and an artificial PAR illumination of 150 ?mol m-2 s-1 in a day/night cycle of 16/8 h consisting of both fluorescent and LED-based light. With these parameters the maximum yield obtained was for Scenedesmus obliquus 0.2 g L-1 day-1 D.W. Microscopical analyses performed by the use of confocal laser scanning microscopy and chemical analyses by gas chromatography and liquid chromatography coupled to mass spectrometry allowed to evaluate the effects of stress conditions on microalgae morphology and chemical composition, respectively. Stress conditions were studied by the use of osmotic shocks and pulse UV-B irradiation of cultured algae. The formation of oil bodies and the production of both triglycerides and carotenoids was observed.