Growth and Extracelluler Polysaccaride Production of Porphyridium cruentum In Various Photoperiod

Abstract

Porphyridium cruentum is a kind of red microalgae (Rhodophyta) that can grow and produce polysaccharides. Polysaccharides are produced on the cell, then released and accumulated by extracellular into medias. This study aimed to determine the optimum growth and production of extracellular polysaccharides (EPs) from P. cruentum in various photoperiods. The cultivation was done with the photoperiods at 24:0, 18:6, 12:12 and 06:18 h (light:dark) during 40 days using modified medium F/2. The growth is determined by measuring optical density (OD) and dried biomasses, the productions of EPs are determined by dried weight polysaccharides as a result of precipitation. The results showed that OD at photoperiod 24:0 has the highest value 0.876 ± 0.0645 unit of absorbance, biomass concentrations are highest in the photoperiod 24:0 and 12:12 respectively 716.12 ± 123 mg-l and 696.5 ± 74.5 mg-l, the highest production of EPs on the photoperiod 12:12 is 1.310 ± 130.26 mg-l. 12:12 hours (light: dark) photoperiod is optimally used in P. cruentum cultivations with high biomass and extracellular polysaccharide results.