Background:
The prototype of tubular photobioreactor designed and tested consists of integrated harvesting module and light panel for illumination of the culture during low-light conditions :
(rainy season) in an indoor environment. The photobioreactor can be operated in two modes :
1. Semi-outdoor: when plenty of sunlight is available outdoor, the tubular portion of the reactor can be fixed on an outdoor bracket and the indoor culture tank remains inside. 2. Indoor: During rainy season, the tubular portion can be attached to the metal frame attached :
to the main culture tank platform. The LED light panels fixed in the interior of the tubular segment are switched on for maintaining optimum light condition for the culture circulating through the tubular part of the photobioreactor. The design of the prototype is novel due to its semi-closed and semi-outdoor configuration, low energy requirement, integrated harvesting module and the portability and replicability of the prototypes for further upscaling of the biomass production. Further, the prototype of the photobioreactor facilitates an uninterrupted biomass production which is not possible during rainy season where open raceways are used.:
Technology Details:
The bioreactors designed for increased light availability can enhance the yield of biomass. In open raceway ponds, the light becomes a limiting factor for the cells at lower strata of the water column. In a tubular bioreactor, the availability of light can be increased by circulating the culture in a tubular (appx 1 inch diameter) portion which facilitates optimum light availability to all the cells. Therefore, new designs of bioreactors aimed through this project can bring a considerable improvement in the yield of biomass. An efficient protocol and extraction device for downstream processing of the biomass for value added compounds such as phycocyanin can also bring unprecedented change in the profitability of Spirulina industry. A unit equipped with cultivation and downstream processing of biomass for phycocyanin extraction will provide an edge to our country as the environmental conditions for Spirulina cultivation are more conducive than temperate countries where light availability and low temperature become limiting factors. Given the scarcity of water resources and the cost of laboratory grade chemicals, utilization of industry grade chemicals and amended wastewater from aquaculture units is key to the sustainability of the Spirulina biomass production ventures.