Frontiers in Marine Science (Jun 2014)
Galactan polysaccharides extraction from invasive algae <i>Asparagopsis armata</i> (Harvey) of the Peniche coast.
Abstract
Marine macroalgae are important sources of sulfated polysaccharides with different structure according to each species of algae. These compounds from the seaweeds of the division Rhodophyta are mainly galactans consisting entirely of galactose or modified galactose units. Galactans, like agar and carrageenan have important biotechnological and commercial applications in several industries. The red seaweed Asparagopsis armata (Harvey), originally from the Pacific Ocean, is well established in Peniche beaches (west of Portugal) and other European locations and was classified as an invasive species. These red algae show complex hybrid galactans in their composition. The water–soluble polysaccharides were extracted from the gametophyte form of the seaweed, collected in March 2013 from Peniche coast, using a hot water extraction procedure. The yield (%) of the extraction and the galactose ratio content (mmol glucose %) were calculated. The polysaccharides were characterized by Infrared spectroscopy. The yield of polysaccharides was 16% and the calculated galactose ratio was 0.30 mmol glucose %. No significant statistical differences between the extraction procedures and the yield result were found. The FTIR spectra presented different bands, such as a band at 843.59 cm-1, characteristic of C4-O-S in galactose unit and a band at 764.68 cm-1 of C2-O-S (3.6-anidrogalactose). The complex hybrid galactans extracted from A. armata are easily obtained from simple extraction procedures. Nevertheless, a better molecular characterization is required, in order to determine the potential of these seaweeds as a galactan source, and compare these polysaccharides with other galactans obtained from other Rodophyta species.
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