Poly , living systems

When phosphate is the limiting factor, the induction mechanism is more difficult to deduce. However, bacteria, like all other living systems, are not able to generate ATP by phosphorylating ADP in the absence of phosphate. It seems quite plausible that, under these conditions, 2/H/ do not flow away. As in the two previously mentioned limitations, 2/H/ remain and acetyl-CoA becomes available, thus both substrates could be assimilated and deposited intracellularly as poly(3HB). 

Poly(e-caprolactone) is another practically important polyester formed by ionic polymerization of the cyclic ester. Cationic polymerization requires relatively high temperatures this enhances proton transfer and decreases the molecular weight, whereas anionic polymerization provides living systems. 

The oxidation product has been isolated as its 2,4-dinitrophenylhydrazone and corresponds with -keto-6-aminovaleric acid. Putrescine, arginine, Manske s 1 (+) acetylornithine (118) and other related amino acids are oxidized much less readily if at all. The same authors have extracted an ornithine dehydrogenase from the young roots of Datura tatula. It requires the cooperation of a coenzyme not yet identified, and appears unable to oxidize putrescine and amino acids other than ornithine and to a lesser extent glutamic. Either of these systems, or the two linked into a H-transfer chain, would seem able to catalyze the oxidation of ornithine in the living tissues. No carbon dioxide was released from ornithine by the poly-phenolase system but on addition of an unwashed belladonna tissue-suspension carbon dioxide was liberated, presumably by decarboxylation of the a-keto-5-aminovaleric acid formed by the oxidation. 

The bacterial polyhydroxyalkanoates (PHAs) and their principal representative poly(3-R-hydroxybutyrate) (PHB) create a competitive option to conventional synthetic polymers such as polypropylene, polyethylene, polyesters et al. These polymers are nontoxic and renewable. Their biotechnology output does not depend on hydrocarbon production as well as their biodegradation intermediates and resulting products (water and carbon dioxide) do not provoke the adverse actions in environmental media or living systems [1-3]. Being enviromnent friendly [4], the PHB and its derivatives are used as the alternative packaging materials, which are biodegradable in the soil or different humid media [5, 6]. 

Poly(R-malic acid) was recently foimd in living systems and is thus a synthetic polymer that is also a true biopolymer. ... 

Polymers can be obtained directly from living systems such as plants, animals, insects and microbes. Biopolymers like cellulose, wool, poly(hydroxyl butyrate) and natural rubber are examples of this class. 

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