Algae amino

Tables 2, 3, and 4 hst compositional and nutritional data of selected algae. Mote extensive compilations on algae ate available (26,58). Algae tend to have lower contents of methionine than is deskable in human and animal nutrition and supplementation with this amino acid is necessary with many species (Table 4).

Table 3. Amino Acid Composition of Photosynthetically Grown Algae, g/16 g Nitrogen...

The product quaUty considerations for nonphotosynthetic microorganisms are similar to those for algae. Tables 6 and 7 present composition and amino acid analyses, respectively, for selected bacteria, yeasts, molds, and higher fungi produced on a large pilot-plant or commercial scale. Table 8 summarizes results of proteia quaUty and digestibiUty studies. 

Microbiological procedures which exploit the ability of bacteria and photosynthetic algae to incorporate exogenous labeled precursors such as 14CO2, SO%, and 32pQ3- [ can be used to label complex molecules in cells such as proteins (qv) and nucleic acids (qv), which are then processed to give labeled constituents such as uniformly labeled C-amino acids, C-nucleotides, C-fipids, LS-amino acids, etc (8). 

SuperchlorinationShock Treatment. Superchlorination or shock treatment of pool water is necessary since accumulation of organic matter, nitrogen compounds, and algae consumes free available chlorine and impedes disinfection. Reaction of chlorine with constituents of urine or perspiration (primarily NH" 4, amino acids, creatinine, uric acid, etc) produces chloramines (N—Cl compounds) which are poor disinfectants because they do not hydrolyze significantly to HOCl (19). For example, monochloramine (NH2CI) is only 1/280 as effective as HOCl against E. coli (20). 

In terms of amino acids bacterial protein is similar to fish protein. The yeast s protein is almost identical to soya protein fungal protein is lower than yeast protein. In addition, SCP is deficient in amino acids with a sulphur bridge, such as cystine, cysteine and methionine. SCP as a food may require supplements of cysteine and methionine whereas they have high levels of lysine vitamins and other amino acids. The vitamins of microorganisms are primarily of the B type. Vitamin B12 occurs mostly hi bacteria, whereas algae are usually rich in vitamin A. The most common vitamins in SCP are thiamine, riboflavin, niacin, pyridoxine, pantothenic acid, choline, folic acid, inositol, biotin, B12 and P-aminobenzoic acid. Table 14.4 shows the essential amino acid analysis of SCP compared with several sources of protein. 

How do Phytoplankton Cope with Enhanced UV Several investigators have reported the existence in Antarctic algae of UV-absorbing mycosporine amino acids identical to those of tropical and temperate marine species (37). These compounds absorb in the UV-B region of the spectrum and may act as sunscreens which may provide some measure of protection from damaging UV-B. 

Representatives of the major groups of algae are able to use a range of amino acids as nitrogen sources (Neilson and Larsson 1980). 

T. Happe, JD. Naber (1993) Isolation, characterization and N-terminal amino acid sequence of hydrogenase from the green alga Chlamydomonas reinhardtii. Eur. J. Biochem., 214 475-481... 

In another legume, Afzelia bella Harms (Caesalpinoidene), the same authors have isolated the new rrfree amino acids. The structure of the diacid 54 is based on mass, H, and l3C-NMR spectroscopy (95) the proposed absolute configuration of 54 was also demonstrated by X-ray diffraction (96). Compound 54 is probably identical with the diacid independently isolated from the red alga Chondria coerulescens (Crouan) Falk. (Rhodomelaceae) (97). 

A systematic investigation of amino acids present in algae was undertaken by Italian workers mainly for chemotaxonomic reasons. Besides known compounds, two simple new amino acids were isolated pyrrolidine-2,5-dicarboxylic acid (78) from Schizymenia dubyi (Chauv.) J. Ag. (Nemastomaceae) and pyr-... 

Uptake of small organic metal complexes over transport systems of organic metabolites may be possible, for example, of small organic acids like citrate or amino acids. However, only few examples of such processes have been studied so far. Increased uptake of cadmium by an alga has been observed in the presence of citrate and has been attributed to accidental transport of the metal-citrate complex over a citrate transporter [212]. Transport systems of inorganic anions may also play a role in metal transport. Silver uptake by algae was enhanced in the presence of thiosulfate. In this case, the silver thiosulfate complex was transported over a sulfate uptake system [213]. It remains to be demonstrated how widespread these processes may be for metal uptake in the aquatic environment [12]. 

Natural products derived from amino acids form a broad and divergent group, including simple amino acid derivatives, alkaloids, and small, often cyclic, polypeptides. Simple amino acid derivatives, which are not uncommon in algae, are often oxidation or rearrangement products of one of the 20 common amino acids. Alkaloids and polypeptides are more complex in their structural modifications. 

Krabs G, Bischof K, Hanelt D, Karsten U, Wiencke C (2002) Wavelength-dependent induction of UV absorbing mycosporine-like amino acids in the red alga Chondrus crispus under natural solar radiation. J Exp Mar Biol Ecol 268 69-82... 

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