Macroalgae

There is a further complication in shallow lakes containing macrophytes (aquatic flowering plants, pteridophytes, and macroalgae). These take up and accumulate nutrients from the water and from the aquatic soil in which they are rooted (sediment). Although these plants are sometimes classed as nuisance weeds, they nevertheless act as an important alternative sink for nutrients which are denied to the plankton. In recent times, a key role of macrophytes in the successful and sustained management of water quality has been identified and explained. ... 

Unless otherwise indicated, studies were performed using cell suspension cultures. Red macroalga. 

Hara 1, T Sakurai (1998) Isolation and characterization of vanadium bromoperoxidase from a marine macroalga iicHowia stolonifera. J Inorg Chem 72 23-28. 

Ice scouring of the intertidal zone in arctic waters makes this virtually sterile. This was noted more than 170 years ago by Keilhau (1831)—so that attention was directed to components of the subtidal zone to which little attention had previously been directed, and which was expected to be particularly sensitive to oil spills. Changes in the components of the macrobenthos including infauna, epibenthos, and macroalgae were examined, and attention was also directed to the histopathological and biochemical responses of bivalve molluscs that were affected in different ways by exposure to the dispersed and the undispersed oil. 

Figure 1 The microbial fouling process on surfaces of certain macroalgae in aquatic environments is controlled by the selective oxidation of bromide with hydrogen peroxide and bromoperoxidase. Although chloride is many orders of magnitude more abundant in the sea, bromide is oxidized to hypobromous acid in situ.

DMSP (21) is produced by many marine micro- and macroalgae and is especially prominent in dinoflagellates and haptophytes. The nontoxic DMSP (21) fulfills multiple cellular functions including cryoprotection, the involvement as osmolyte in osmoregulation and as a methyl donor in transmethylation reactions [18]. 

At the Ebro delta, P. pectinatus is mainly found in the least brackish areas, while Ruppia cirrhosa inhabits transitional zones between freshwater and seawater. Mixed stands of Zostera noltii, R. cirrhosa, and the floating macroalga Chaetomorpha linum develop in saline areas [37]. 

Menendez M, Herrera J, Comm FA (2002) Effect of nitrogen and phosphorus supply on growth, chlorophyll content and tissue composition of the macroalga Chaetomorpha linum (O.F. Mlill), Kiitz, in a Mediterranean Coastal Lagoon. Sci Mar 66 355-364... 

Approximate maximum concentration factors for selected transuranics in marine sediments, macroalgae, and fish... 

Handbook on the Toxicology of Metals. Second edition. Volume II Specific Metals. Elsevier, New York. Abalde, J., A. Cid, S. Reisiz, E. Torres, and C. Herrero. 1995. Response of the marine macroalga Dunaliella tertiolecta (Chlorophycea) to copper toxicity in short time experiments. Bull. Environ. Contam. Toxicol. 54 317-324. 

Brown macroalga, Laminaria hyperborea 250 Reduced growth of sporophytes in 8-10 days 2... 

Thursby, G.B. and R.L. Steele. 1984. Toxicity of arsenite and arsenate to the marine macroalgae Champia parvula (Rhodophyta). Environ. Toxicol. Chem. 3 391-397. 

Table 32.23 Approximate Maximum Concentration Factors for Selected Transuranics in Marine Sediments, Macroalgae, and Fish...

More than half of the reported secondary metabolites from macroalgae are isoprenoids. Terpenes, steroids, carotenoids, prenylated quinines, and hydroqui-nones make up the isoprenoid class, which is understood to derive from either the classical mevalonate pathway, or the mevalonate-independent pathway (Stratmann et al. 1992). Melavonic acid (MVA) (Fig. 1.2) is the first committed metabolite of the terpene pathway. Dimethylallyl (dl meth al lal) pyrophosphate (DMAPP) (Fig. 1.3) and its isomer isopentenyl pyrophosphate (IPP, Fig. 1.3) are intermediates of the MVA pathway and exist in nearly all life forms (Humphrey and Beale 2006). Geranyl (ja ran al) (C10) and famesyl (C15) units are generated by head-to-tail (Fig. 1.3) condensation of two (for C10) or three (for C15) 5-carbon DMA-like isoprene units, identifiable in final products by the characteristic fish-tail repeating units, as traced over the structure of a sesquiterpene in Fig. 1.3 (Humphrey and Beale 2006). Additional IPP condensation with famesyl pyrophosphate (FPP)... 

The second largest class of compounds reported from macroalgae is the polyketides, which comprise approximately a quarter of known algal compounds (Blunt et al. 2007). Polyketides are polymers of acetate (C2) and occasionally propionate (C3) and are very similar to fatty acids in their biosynthetic origin. Polyketides can be found in plants, animals, bacteria, and fungi. With a range of activities as broad as their structures, the polyketides are a diverse family of natural products classified based upon the polyketide synthases (PKSs) responsible for their biosynthesis, primarily type I and type II. 

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