OPTIMASI KADAR N, P, DAN RASIO N:P UNTUK PRODUKSI BIOMASSA DAN ASTAKSANTIN PADA SPIROGYRA SP. MENGGUNAKAN ANALISIS RESPONSE SURFACE METHODOLOGY (RSM) DAN PEMODELAN KINETIKA

• Main Author: Delfi Zafira, Nadia
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/68468
• Institution: Institut Teknologi Bandung

Astaxanthin is a carotenoid compound with very strong antioxidant properties. Astaxanthin is widely used in the beauty and health industry so that the need for astaxanthin continues to increase. This compound can be produced by green algae, including the macroalga Spirogyra sp. which are often found in Indonesian freshwaters. However, the astaxanthin level in Spirogyra sp. is still low. Therefore, a cultivation method is needed to increase the production of astaxanthin in Spirogyra sp. This research was conducted to determine the optimum levels of N and P to increase the production of astaxanthin in Spirogyra sp. Cultivation was carried out for 14 days on Blue Green medium with an inoculum concentration of 6 g/L. The levels of N/P in the medium were varied to 1.1/0.01; 1.1/0.03; 1.1/0.09; 2.2/0.01; 2.2/0.03; 2.2/0.09; 6.6/0.01; 6.6/0.03; and 6.6/0.09 mM. Sampling of dry weight of biomass, nitrate content in the medium, and astaxanthin content were carried out every 3 (three) days. The dry biomass was then extracted by maceration method using acetone solvent. This extract was then analyzed using High Performance Liquid Chromatography (HPLC) with a C18 column, HPLC grade methanol: aqueous (95:5) eluent with a flow rate of 1 mL/min, and a UV-Vis Photodiode array detector at ? 482 nm. . In this study, the highest accumulation of biomass was found at levels of N and P of 1.1 and 0.03 mM, namely as much as 485 mg dry weight with a growth rate of 0.2203 day-1. RSM analysis was then carried out in order to determine the optimum values of N and P levels for the cultivation of Spirogyra sp. which were 0.83 and 0.04 mM . The highest accumulation of astaxanthin was found in biomass cultivated in medium with N/P 1.1/0.01 mM, which is 0.067-0.269 mg/g dry weight with the highest accumulation on the 12th day of cultivation. RSM analysis was also carried out in order to obtain determine the optimum values of N and P levels for astaxanthin accumulation in Spirogyra sp. which were 0.94 mM and 0.01 mM. Logistics, Monod, and Luedeking-Piret modeling for all variations have been carried out to obtain certain parameters with the values of growth rate. 0.08 to 0.32 day-1, ?max 0.18±0.02 day- 1, kN 68.2±24.2 mg/L, ki 301,8±78,5 mg/L, YN 0.93±0.68 g biomass/nitrate , ?0.36±0.69, ? -0.01±0.02, and kd 0.04±0.03. Based on the results of the study, the highest astaxanthin productivity was found in the biomass cultivated at levels of N 1.1 mM and P 0.09 mM, which is 0.07?g/cm2/day. In this study, the accumulation of biomass increased as the N content and N:P ratio decreased. The accumulation of astaxanthin increased as the levels of N and P decreased. This indicated that deficiency of N and P could increase the production and productivity of astaxanthin in Spirogyra sp