Utilization of local fertilizer and spring water combination for growth medium of Stanieria HS-48 (cyanobacteria) as a biofuel feedstock

The study of NPK fertilizer medium had been done and it can be used for microalgae growth including cyanobacteria. Stanieria has the potential as a biofuel feedstock because it contains lipid in the form of fatty acids. Strain HS-48 was isolated from Ciater hot spring located in West Java, Indonesia. This study aimed to determine the best concentration of local NPK fertilizer that good growth medium for Stanieria HS-48. Stanieria HS-48 was grown on the BBM as a control, Lab. Alam water, NPK 350 ppm, and NPK 1050 ppm. This study was conducted for 14 days with 2 repetitions in each treatment. The average cell density (cell/mL) of Stanieria HS-48 at peak in Lab. Alam water was 1.7375×10⁵, BBM was 2.1125×10⁵, NPK 350 ppm was 5.0375×10⁵, and NPK 1050 ppm was 5,875×10⁵. Meanwhile, the growth rate (r) at NPK 350 ppm was higher rather than NPK 1050 ppm. Based on macroscopic observations, the NPK 350 ppm had a green color and the NPK 1050 ppm had a yellowish color. The result of the study showed that NPK 350 ppm was a good growth medium for Stanieria HS-48.