Algae, polysaccharide biosynthesis

P aerugineum is a unicellular alga cultured under artificial or solar light in a freshwater medium supplied with CO2, in an outdoor bioreactor developed by Arad and Yaron. Algal growth was optimized for yield and for the properties of the blue color produced. The parameters that require close monitoring are light intensity and temperature, in order to avoid stress conditions that result in decreased color yield and solubility and increased biosynthesis of the polysaccharides that encapsulate the cells and are excreted into the medium. 

The 3-deoxy-D-ma/ino-2-octulosonic acid 8-phosphate synthase (KDO synthase or KdoS EC 4.1.2.16) is an enzyme involved in the biosynthesis of the eight-carbon sugar KDO [63], a constituent of the capsular polysaccharides (K-antigens) and outer membrane lipopolysaccharides (LPS, endotoxin) of Gram-negative bacteria [156], as well as of the cell wall of algae and a variety of plants [157], In vivo, the enzyme catalyzes the irreversible addition of 26 to D-arabinose 5-phosphate (Ara5P, 32) to form KDO 8-phosphate 33 [158]. The... 

Polysaccharides are usually obtained by biosynthesis in plants including algae or in animals some microbial polysaccharides are also now developed such as bacterial hyaluronan (HA), gellan or xanthan.[7-9]... 

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