Mycosporine like amino acids in brown algae

Abstract

Seaweed, also known as macroalgae, represents organisms that shares similarities with plants, that can exist as single cell organisms or groups of cell forming a colony. They can usually be found attached to rocks or other hard enough substrata in seashore. In the midlle of the XIX century, the Irish botanist Willian Henry Harvey(18111866) divided macroalgae in 3 distinct groups. This division was based on the pigmantation: -phylum Ochrophyta(green algae) -phylum Rhodophyta(red algae) -phylum Phaeophyceae(brown algae) The members of this three groups are different in more then just pigmantation, like biochemical aspect regarding photosynthetic pigments, compound in the cells walls, chloroplasts structure, connections between cells in colony, storage compounds, presence of flagella or the absence of it. Phaeophyceae represents a group of macroalgae that, besides chlorophyll a and chlorophyll c, contains the xanthophyll pigment fucoxanthin that cause the caracteristic greenish-brown color. The color can range from dark brown to olive green, depending on the proportion in which the pigments are found. Most brown algae adaptated to marine environment, very few species are found in freshwaters. The brown pigmantation apparently is an important adaptation to deep sea. There are aproximatly 1500-2000 species of brown algae throughout the world, mostly been found in temperate zones in the Northern Hemisphere. Classification: Domain Eukaryota Kingdom Protista Phylum Heterokontophyta Class Phaeophyceae Phaeophyceae are a complex orgamism. The cell walls are compoused of cellulose and alginic acid. Alginic acid is a long chain heterpolysaccharide. Food reserves are usually represented by complex polysaccharides, sugars and higher alcohols. Laminarian is the main carbohydrate reserve. Brown algae (Fig.1) can be very variated regarding the size and form. It can vary from small filamentous epiphytes to the complex giant kelps (order Laminariales, can range between 1 metre and 100 metres). Like other evolved algae species, they present both sexual or asexual reproduction. Higher phaeophyta have a life cicle that presents generation alternation, meaning they have both diploid and haploid stages. The haploid stage is represented by the thallus and the diploid stages can be either isomorphic or heteromorphic. Sexual reproduction may be isogamous, oogamous, or anisogamous. There is evidence of the sex cromosome (Lewis R.J. 1998). Phaeophyta used to be harvest to for the extraction of iodine and potash. In recent years it has been extensivly used for extracting the alginic acid. Alginic acid can be derivated in alginate, which is used in industries. Alginate is a major colloidal gel that is used and as a stabilizer, emulsifier and binder.