Evaluation the effect of initial pH variations to the growth of Indonesia Indigenous Synechococcus (Cyanobacteria) HS-7 and HS-9 in CT medium

Research that aims to know the effect of initial pH variation of CT medium to the growth of Indonesia Indigenous Cyanobacteria of the genus Synechococcus HS (Hot Spring)-7 and HS-9 were grown at temperature 35 °C had been performed. The growth was observed by calculation of cell density and chlorophyll content measurement of Synechococcus biomass. Cell density calculations were performed every day (t0-t21) while the measurement of chlorophyll content was performed for 10 days at t0, t1, t2, t3, t4, t7, t10, t14, t17, and t21. There were 5 variations of pH used in this research (pH 5, pH 6, pH 7, pH 8, and pH 9). Observations were done qualitatively based on the cell density while quantitatively based on statistical analysis using Friedman and Spearman tests. The results showed that the initial pH variation of CT medium affected the growth of Synechococcus HS-7 and HS-9. Synechococcus HS-7 and HS-9 grew well at pH 7. Based on statistical analysis there were correlation between the cell density and chlorophyll content, and the initial pH variation of the CT medium did not affect the growth of Synechococcus HS-7 and HS-9.