Marine algae brown macroalgae

Rhodophyta, second largest, most primitive group of macroalgae present in more diverse environments, is compared to the other types of marine algae. It produces various types of antibacterial products but the numbers of antibacterial products from these species are low when compared to the brown algae (Ginsburg, 2003 Stegenga et ah, 1997). 

In the field of pharmacology, the biologically active polysaccharides (PSs) that are derived from natural sources have attained a special place for the development of drug lead molecules. Marine macroalgae contain a significant amount of soluble PSs and have potential function as dietary fiber. Specially, brown marine algae are known to produce fimctional PSs such as alginates and fucoidans. Seaweed-derived PSs have been... 

The taxonomic diversity of freshwater macroalgae represents a counterpoint to the diversity of these groups in marine systems. Fewer than 3% of the 4,000 species of rhodophytes occupy freshwater habitats, and most occur in lotic, or flowing-water, systems (Sheath 2003). Similarly, only five of the seven species of freshwater brown algae (Phaeophyceae) have been recorded from North America (Wehr 2003). In contrast, more than 75% of the over 4,000 species of aquatic chlorophytes have been isolated from freshwater habitats, including many filamentous and colonial forms (Graham and Wilcox 2000). 

To date, no clear evidence of inducible defenses among freshwater macroalgae has been reported, in contrast to their marine algal counterparts. For example, certain species of marine brown algae increase phlorotannin production in response to damage by mesograzers (Amsler and Fairhead 2006 see Chaps. 3 and 7). Whether Chara and Cladophora, two species of freshwater chlorophytes with putative allelopathic activity, increase allelochemical concentration in response to competitors remains to be seen (see Sect. 5.7.3). 

Confirmation of the presence of four arsenosugars, a class of compounds found in other marine macroalgae (Francesconi and Edmonds, 1997), was reported in a study of the marine brown alga Fucus distichus (Harrington et at., 1997). 

Marine plants fall into two major types macroalgae and vascular plants. Macroalgae, or seaweeds as they are commonly called, are multicellular autotrophs with unique adaptations for their marine habitats. Seaweeds occur in three different colors green, red, and brown, depending on the pigments they contain. Many types of macroscopic algae are found in the intertidal zone, whereas vascular plants are rare there and are primarily represented by a few species of marine grasses. 

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