Utilization of different nitrogen sources for the growth of microalgae isolated from mangrove leaves in Banda Aceh - Indonesia

The aim of this research was to investigate utilization of different nitrogen sources used for the growth of microalgae and determined the optimum period of the growth. The microalgae had been isolated previously from mangrove leaves in Banda Aceh, Indonesia and has been identified morphologically. Three different nitrogen sources i.e., yeast extract, monosodium glutamate or MSG and sodium nitrate were used. The biomass production was measured by optical density using spectrophotometer. The results showed that MSG stimulated microalgae to produce the highest amount of biomass (0.38 g/L/day) followed by yeast extract with 0.33 g/L/day, but both were statistically not significant. Sodium nitrate developed the lowest OD value with the amount of dried biomass only 0,16 g/L/day. Correlation analysis indicated the yield of biomass was positively related, r = 0.953, with the optical density of the cultures. The OD values of yeast extract, MSG and sodium nitrate cultures were 1.20, 1.18 and 0.82, respectively. The optimum time for microalgae growth was at day 9 in which 4.41 g/L of dried biomass was accumulated in the culture where MSG was used. The maximum yield of dried biomass for yeast extract was 4.22 g/L followed by 2.58 g/L for sodium nitrate.