Bacterial polymers poly

Animal biomass. Vegetal biomass. Wood, Cellulose, Lignins, Hemicelluloses, Natural rubber, Suberin, Tannins, Rosins, Terpenes, Annual plants. Starch, Vegetable oils, Hemicelluloses, Mono and disaccharides, Polylactic acid. Algae, Chitin, Chitosan, Proteins, Cellulose whiskers. Bacterial polymers. Poly (hydro xyalkanoates). Bacterial cellulose... 

GPC proved to be a method extraordinarily well suited to the analysis and purification of 9-phenylcarbazole monodendrons, naturally branched polymers.12 Monodendrons up to generation four, molecular weight 16.6 kDa, were separated by GPC. Branching, introduced into bacterially produced poly(hydroxy butyrate) by co-polymerization with hydroxyvaleric acid, was analyzed by GPC in chloroform with on-line viscometry.13... 

For large-scale recombinant production of bacterial polymers, non-polymer producing bacteria were exposed to biosynthesis pathways. Polymers such as PHA, CGP (cyanophycin granule peptide), HA (hyaluronic acid), and PGA [poly-y-glutamate] were produced by these methods [89, 85-96]. For example, recombinant E.coli [89] was fermented for the lai e-scale production of PHA [89]. In addition the PHB biosynthesis genes of Ralstonia eutropa were harbored in E.coli to produce poljmers such as PHA composed of (R)-S-hydroxybutyrate and (R)-3-hydroxyvalerate and/or (R)-3-hydroxyhexanoate which showed preferable properties for use in industrial applications [97-99, 85-96]. 

Presently enzymes can hardly be used to degrade artificial synthetic polymers unless it is under special conditions. It is worth noting that compounds like poly(vinyl alcohol), PVA, bacterial polymers and poly(e-caprolatone), PCL, that are biodegradable under outdoor conditions are degraded abiotically and thus very slowly in an animal body where they are not biodegradable. Despite this difficulty the number of artificial polymers proposed as biodegradable biomaterial candidates to replace biopolymers or biostable polymers is increasing. 

Furuhashi Y, Imamura Y, Jikihara Y, Yamane H (2004) Higher order structures and mechtmical properties of bacterial homo poly(3-hydroxybutyrate) fibers prepared by cold-drawing and annealing processes. Polymer 45 5703-5712... 

Yamamoto T, Kimizu M, Kikutani T, FirruhasM Y, Cakmak M (1997) The effect of drawing and annealing conditions on the structure and properties of bacterial poly(3-hydroxybutyrate-co-3-hydroxyvalerate) fibers. Int Polym Process XII 29-37 Yamrme H, Terao K, Hiki S, Kimirra Y (2001) Mechanical properties and higher order structure of bacterial homo poly(3-hydroxybutyrate) melt spun fibers. Polymer 42 3241-3248... 

This chapter gives a general introduction to the book and describes briefly the context for which the editors established its contents and explains why certain topics were excluded from it. It covers the main raw materials based on vegetable resources, namely (i) wood and its main components cellulose, lignin, hemicelluloses, tannins, rosins and terpenes, as well as species-speciflc constituents, like natural rubber and suberin and (ii) annual plants as sources of starch, vegetable oils, hemicelluloses, mono and disaccharides and algae. Then, the main animal biomass constituents are briefly described, with particular emphasis on chitin, chitosan, proteins and cellulose whiskers from molluscs. Finally, bacterial polymers such as poly(hydroxyalkanoates) and bacterial cellulose are evoked. For each relevant renewable source, this survey alerts the reader to the corresponding chapter in the book. 

Poly(Hydroxyalkanoates) Unlike bio-based PE, PET, and PEA, the poly(hydroxyalkanoates) (PHA) are bioplastics synthesized by bacteria. It was the first bacterial polymer to be harvested commercially. PHAs are deposited within the bacterial cells of many species as a lipoic material (Bnrdon, 1946). It is also unusual in that PHAs though hydrophobic still rapidly biodegrade in the environment. All bacterial polymers are not necessarily biodegradable (Steinbuchel, 2005) PHAs biodegradability is attributed to its saturated polyester chemical structure. 

The polymer (Mn = 81,000 with polydispersity = 1.8, Tg = 4°C) had a white cream color and was elastomeric. This is the first report of poly(3-hydroxyalkanoates) containing a sulfur atom in the strnctnre produced from bacteria. It may be supposed that (133) will usher in a new era of bacterial polymers. 

In this case study, surfaces of a commonly consumed plastic polymer, poly(ethylene terephthalate) (PET), were exposed to bacterial communities present in samples of coastal seawater. The PET was the sole carbon and energy source provided for the bacteria, to maximise the desirability for bacteria to interact with the surface. Changes in the elemental and chemical composition of the PET surfaces were detected by XPS. 

Another trend in TPEEs development is related to biodegradable copolymers. For example, the bacterial polymers are of great interest as organic materials, such as poly(3-hydroxyalkanoate)s, which are potential thermoplastic elastomers. 

D. R. Ruka, G. R Simon, and K. M. Dean, In situ modifications to bacterial cellulose with the water insoluble polymer poly-3-hydroxybutyrate. Carbohydr. Polym. 92,1717-1723 (2013). 

Barud HS, Souza JL, Santos DB, Crespi MS, Ribeiro CA, Messaddeq Y et al. Bacterial cellulose/poly (3-hydroxybutyrate) composite membranes. Carbohydr Polym 2011 83 1279-84. 

Biodegradable, tetracycline-loaded microparticles made of two polymers, poly lactide-co-glycolic and zein, which were compressed into monolithic devices and proposed in the treatment with antibiotics within the periodontal pocket against bacterial infections (Oliveira de Sousa et al., 2011). Sustained release of tetracycline was obtained, and the proportion of zein in the inserts had a great impact on the drug release. 

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