Enhancement of Astaxanthin Content in Spirogyra sp. by Oxidative Stress with The Addition Hydrogen Peroxide

• Main Author: Arwafa Cita, Juang
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/43250
• Institution: Institut Teknologi Bandung

The utilization of fresh water macroalgae Spirogyra sp. in Indonesia is limited to be the raw material of fish feed, even though the algae was known to produce various kind of high value secondary metabolites such as astaxanthin. The accumulation of astaxanthin can be further increased by applying oxidative stress using H2O2. The goal of this study is to evaluate the effect of H2O2 on astaxanthin accumulation in Spirogyra sp. biomass by using varied H2O2 consentration of 0,01, 0,1, and 1 mM. H2O2 was added to the cultivation medium on the sixth day of cultivation when the biomass growth have reached the maximum level. Spirogyra sp. was cultivated in transparent containers measuring 16×16×7.5 cm. The cultivation container was placed on cultivation racks illuminated by flouresens lamp with an intensity of 2000-2500 lux, the cultivation temperature is kept at 25 ± 1oC, pH 7.2-7.8, aeration of 1 vvm. Spirogyra sp. was harvested every two days accompanied by weighing of wet weight, dry weight, and nitrate measurement using spectrophotometric methods. Spirogyra sp. was dried with freeze drying method. Astaxanthin was extracted with maceration method using methanol: dichloromethane (3:1). The astaxanthin content was determined through the high performance liquid chromatography (HPLC) with a column of reverse phase 18C, the mobile phase of methanol: aquabides (95:5). The addition of 0,1 mM H2O2 can increase the astaxanthin content from 0,039 mg/g to 0,207 mg/g (4,3 times larger than control) after 8 days of cultivation.. However, oxidative stress caused by the addition of H2O2 was shown to affect the biomass yield of Spirogyra sp. The biomass of Spirogyra sp. cultivated with 0,1 H2O2 decreased by 48,57%. The productivity of astaxanthin in Spirogyra sp. was estimated by combining the effect of oxidative stress on astaxanthin content and biomass yield. The highes productivity was shown by Spirogyra sp. cultivated wit 0,1 mM H2O2 for 8 days periode with astaxanthin productivity of 7,830 kg/ha.year, 1,35 times higher than control. The results of this study indicate the addition of H2O2 can increase astaxanthin content, but accompanied by a decrease in biomass production.