IDENTIFICATION OF EXTRACELLULAR CARBOHYDRATE FROM MARINE MICROALGAE PORPHYRIDIUM CRUENTUM

• Main Author: Laelalugina, Amila
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/33654
• Institution: Institut Teknologi Bandung

In the previous study, marine microalgae Porphyridium cruentum have been identified to produce oil (for biodiesel) and photosynthetic pigments (for sensitizing solar cells). However, the microalgal carbohydrates have not been reported yet. Therefore, the aim of this study is to identify the extracellular carbohydrate secreted by P. cruentum cells. The steps of the present research included the cultivation of microalgae using batch method, isolation of carbohydrate secreeted by P. cruentum using etanol precipitation, and characterization of carbohydrates by chemical assay (anthrone test, Molisch test, picric test, and iodine test), FTIR spectroscopy (infrared), and SEM-EDS (scanning electron microsopy-energy dispersive spectroscopy). The results showed that the density of P. cruentum cells harvested at 12th day was 29.71 ± 0.51 ×106 cells/mL with biomass concentration of 3.84 ± 0.39 g/L. When biomass heated at 162–500oC, the organic molecules of P. cruentum biomass was released as gas, and the amount of organic molecules in P. cruentum cell was 40.26% (w/w). The extracellular carbohydrate of P. cruentum was in the form of colorless gel, and turn into white powder when it freezedried. Positive results to anthrone test and Molisch test indicated that white powder of P. cruentum was carbohydrate, while negative results in picric test and iodine test indicated that the carbohydrate was non-monosaccharide as well as non-helical carbohydrate. Hydroxyl groups and acetal groups of extracellular carbohydrate of P. cruentum were identified at the wave number range of 3400–3500 and 858–1222 cm–1, respectively. In addtion, EDS result of extracelular carbohydrate of P. cruentum showed highly content of carbon and oxygen atoms.