Natural polymers bacteria

Poly-(3-hydroxybutanoic acid) (PHB), belongs to the large family of poly-(hydroxyalkanoates) (PHAs), high molecular weight natural polymers produced by various microorganisms and stored in cell cytoplasm (200). Low molecular weight PHB, also present in bacteria and are primarily involved in transport of ions and DNA across inner bacterial membrane (201). PHB could be developed as a valuable biocompatible material with possible applications in gene delivery after cytotoxic, safety, and efficacy evaluations. 

Cellulose is the most abundant natural polymer on the planet. The chief source of cellulose is plant fibers. Certain types of bacteria also synthesize cellulose, which can be obtained as a continuous film by cultivating the bacteria in a glucose solution. Cellulose is also secreted by such marine chordates (truncates) as the sea squirt [26]. 

Biopolymers are polymers formed in nature during the growth cycles of all organisms hence, they are also referred to as natural polymers. The biopolymers of interest in this review are those that serve in nature as either structural or reserve cellular materials. Their syntheses always involve enzyme-catalyzed, chain-growth polymerization reactions of activated monomers, which are generally formed within the cells by complex metabolic processes. The most prevalent structural and reserve biopolymers are the polysaccharides, of which many different types exist, but several other more limited types of polymers exist in nature which serve these roles and are of particular interest for materials applications. The latter include the polyesters and proteins produced by bacteria and the hydrocarbon elastomers produced by plants (e.g. natural rubber). In almost all cases (natural rubber is an exception), all of the repeating units of these biopolymers contain one or more chiral centers and the repeating units are always present in optically pure form that is, biopolymers with asymmetric centers are always 100% isotactic. 

Jem KJ, van der Pol JF, de Vos S (2010) Microbial lactic acid, its polymer poly(lactic acid), and their industrial applications. In Chen G-Q (ed) Plastics from bacteria natural function and applications, vol 14., Microbiology MonographsSpringer, Berlin, pp 323-346 Jendrossek D (2005) Fluorescence microscopical inyestigation of poly(3-hydroxybutyrate) granule formation in bacteria. Biomacromolecules 6 598-603 Jendrossek D (2009) PolyhydroxyaUcanoate granules are complex subcellular organelles (Carbonosomes). J Bacteriol 191 3195-3202... 

In fact, the general rule is that the more similar a polymer s structure to a natural polymer, the easier for the degrading miCTOorganisms such as bacteria to colonize and degrade the polymer. ... 

Xu, J. (2010) Microbial succinic acid, its polymer poly(butylene succinate), tmd applications, in Plastics from Bacteria Natural Functions and Applications, Microbiology Monographs (ed G.Q. Chen), Springer-Verlag, Heidelberg-Berlin, Germany, pp. 347-388. 

PVB is a natural polymer, produced in Burkholderia saccharin bacteria. Biofilms can be produced by casting processes. The films have been characterized by a variety of methods. The properties are highly influenced by the presence of a plasticizer, i.e., PEG. The thermal properties are comparable with domestic and industrial packing materials (19). 

Since a wide variety of bacteria are accumulating PHAs as intracellular storage material this natural polymer is considered as a potential substitute for petrochemical plastics (24). Medium chain length t es are semicrystalline elastomers with a low melting point. 

Jem K, van der Pol J, de Vos S. Microbial lactic acid. Its polymer poly(lactic acid) and their industrial applications. In Chen GQ, editor. Plastics from Bacteria-Natural Functions Applications. Heidelberg Springer-Verlag 2010. p 323-346. 

Cellulose is the most abundant natural polymer [31]. Although commonly associated with plants [32], it can also be found as a naturally produced polymer in eukaryotes, namely the sea squirts [33], oomycetes [34] and different algae [35], as well as in prokaryotic bacteria [36,37]. 

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