Photobioreactor (PBr) is a system that usually used for producing high amount of biomass. This system was designed for supplying multiple factor that providing a good biological condition for growth of the microalgae contained in the system. This research used Synechococcus sp. HS-9, an indigenous cyanobacteria isolated from Rawa Danau hot spring, Banten. This strain was selected because their ability to adapt and reproduce. Synechococcus sp. HS-9 was inoculated into two units of tubular photobioreactor (tPBr) along with NPK medium and then observed using turbidimeter. This strain of cyanobacteria is grown up to 4.44 x 106 cells/mL (tPBr-1) and 4.29 x 106 cells/mL (tPBr-2) (cell number) or 56.5 NTU (tPBr-1) and 55.9 NTU (turbidity) after eleven days. The results showed that combination of NPK media, tPBr system, and Synechococcus sp. HS-9 are producing potential biomass for biofuel feedstock. This research also proved that use of NPK media as growth medium are promising, because of the good efficiency of cost production.
Keywords: Tubular, Photobioreactor, Synechococcus sp., NPK, Biofuel.