Polyhydroxy butyrate

The basis of phenotypic discrimination of closely related species via Raman spectroscopy lies in its sensitivity to the intracellular molecular components including extrachromosomally encoded phenotypes, such as the Bacillus anthracis or B. thuringiensis toxins or polyglutamic acid capsules. Other prominent examples are cell storage materials like the polyhydroxy butyric acid (PHB), carotenoid-based pigments like sarcinaxanthin, hemoproteins like cytochrome or calcium dipicolinate (CaDPA). Raman spectra of single bacteria, in which the latter four intracellular substances occur, are shown in... 

Fig. 19.2. Micro-Raman spectra of different single bacterial cells normal bacterial Raman spectrum of Staph, wameri compared to Raman spectra with enhanced amounts of subcellular components calcium dipicolinate for a spore of B. pumilus polyhydroxy butyric acid (PHB) in B. megaterium cytochrome in Staph, cohnii and sarcina xanthin in M. luteus...

Leaf, T. A., and F. Srienc. 1998. Metabolic modeling of polyhydroxy butyrate biosynthesis. Biotechnol Bioeng 57 557-70. 

Higher molecular weight PHB and its copolymers with poly(3-hydroxy-valerate) (PHV) can be synthesized from racemic P-butyrolactone and P Valerolactone, using an oligomeric alumoxane catalyst. These polyesters, with only partial stereoregularity, are less susceptible to enzymatic degradation than the bacterial ones. Polyhydroxy-butyrate-valerate (PHBV) is produced by Monsanto as Biopol . 

MAS Mas, A., Sledz, J., and Schue, F., Membranes de microfiltration en polyhydroxy-butyrate et poly(hydroxybutyrate-co-hydroxyvalerate) Influence du pourcentage d unites hydroxyvalerate. Bull. Soc. Chim. Belg., 105,223, 1996. 

During the process of biotechnical synthesis - usually a fermentative process - polymers primarily composed of micro-organisms are derived (one product, e.g. is Biopol). These polymers serve as energy storage for the micro-organisms. In comparison, starch fulfills the task of energy storage in plants. The most important example of fermented biopolymers to be mentioned here is polyhydroxy butyric acids and their copolyesters (one product is, e.g., Biopol). ... 

Akita, S., Einaga, Y., Miyaki, Y, Fujita, H. (1976). Solution Properties of Poly(D-P-hydroxybutyrate). 1. Biosynthesis and Characterization. Afacw/wofecnte, 9,774-780. Rebrov, A. V., Diibinskii, V. A., Nekrasov, Y. P., Bonartseva, G. A., Shtanun, M., Antipov, E. M (2002). Structure Phenomena at Elastic Deformation of Highly Oriented Polyhydroxy butyrate. Po/ywier Science (Russian), 44A, 347-351. 

Macromolecules may be classified according to different criteria. One criterion is whether the material is natural or synthetic in origin. Cellulose, lignin, starch, silk, wool, chitin, natural rubber, polypeptides (proteins), polyesters (polyhydroxy-butyrate), and nucleic acids (DNA, RNA) are examples of naturally occurring polymers while polyethylene, polystyrene, polyurethanes, or polyamides are representatives of their synthetic counterparts. When natural polymers are modified by chemical conversions (cellulose —> cellulose acetate, for example), the products are called modified natural polymers. 

PBT Polybutylene terephthalate PC Polycarbonate PCL Poly-caprolactone PE Polyethylene PEI Polyether imide PES Polyether sulfide PET Polyethylene terephthalate PHA Polyhydroxy alkanoate PHB Polyhydroxy butyrate PLA Poly-lactic acid PMMA Polymethyl methacrylate PP Polypropylene PPE Polyphenylene ether PPO Polyphenylene oxide PPS Polyphenylene sulfide PS Polystyrene PSF Polysulfone... 

Barkoula NM, Garkhail SK, Peijs T (2010) Biodegradable composites based on flax/polyhydroxy-butyrate and its copolymer with hydroxyvalerate. Ind Crops Prod 31 34-42... 

Composites of polyhydroxy butyrate, a natural biodegradable thermoplastic P-hydroxy add, with TCP have been prepared by conventional melt processing technologies (extrusion, injection, or compression molding) [2, 17, 18]. In vitro experiments in SBF produced an apatite like stmcture on the composite surface suggesting bioactivity. When immersion in SBF was extended to 2 months or more, the onset of matrix degradation could be followed by the decrease in storage modulus. 

I 3-Ketothiolase 2 acetoacetyl CoA reductase 3 3-hydroxybutyryl CoA polymerase 4 polyhydroxy butyrate depolymerase 5 hydrolase 6 3-hydroxybutyrate dehydrogenase 7 CoA-trans-ferase... 

Otari SV, Ghosh JS. Production and characterization of the polymer polyhydroxy butyrate-copolyhydroxy ralerate by Bacillus megaterium NCIM 2475. Curr Res J Biol Sci 2009 1 23-6. 

Polyhydroxy- butyrate Polyhydroxybutyrate and its copolymer with polyhydroxyvalerate were blended with dextran or ainylose and compressed into disc shape. Dextran and ainylose were to enhance the enzyme degradability. Hydrolysis of polyhydroxybutyrate and its copol iTier. Also degradation by amylas< when blended sith amylose. Yasin and Tighe, 1993... 

Comparisons of thermal properties of polymer before and after reinforcement with multiwalled carbon nanotubes have also been reported for polyhydroxy butyrate-co-hydroxy valerate [52] and polycaprolactomy composites [55],... 

Synthetic Polyethylene, polylactic acid, polypropylene, polyglycolic acid, polyhydroxy butyrate, polyanhydride, polyacrylamide. 

Huang, T. Y, Duan, K. J., Huang, S. Y, and Chen, C.W. (2006). Production of polyhydroxy-butyrates from inexpensive extruded rice bran and starch by Haloferax mediterranei. Journal of Industrial Microbiology and Biotechnology 33, 701-706. 

Polyaryletherketones (PAEK) have been used for many years in secondary medical devices such as surgical instruments. The use of PAEK in implantable devices was first patented by ICI in 1987 [1]. ICI developed a number of high-value medical applications based around its polyhydroxy butyrate resorbable products (later part of Zeneca Biopolymers) but was relatively inactive in implantable PAEK. In the meantime BASF developed a number of applications based on PEKEKK, but it was not until 1999 that Victrex launched... 

Jiang T, Hu P. Radiation-induced graft polymerization of isoprene onto polyhydroxy-butyrate. Polym J 2001 33 647-653. 

The top left quarter of Figure 10.4 comprises thermosetting bio-derived resins that typically do not feature in packaging applications and so will not be discussed further. Most interestingly, in the context of biodegradable, renewable materials is the top right quarter that comprises polylactic acid (PLA), starch, polyhydroxy butyrate, whey protein, and so on. Each of the petrochemical and non-petrochemical derived IWSPs are discussed in turn below. 

The antimicrobial activity of sophorolipids can be exploited for the treatment of acne vulgaris, as Propionibacterium acnes, an acne causing bacteria is very susceptible to sophorolipids. Ashby et al." developed a polyhydroxy butyrate-based scaffold for the optimal delivery of sophorolipids to skin. 

FIGURE 16 Representative melting and glass transition temperatures of bio and fossil based polymers (PCL-Str - Polycaprolactone/Starch blends, PC - Polycaprolactone, mcPHA - medium chain Polyhydroxyalkanoates, Ali-coPES - Aliphatic (co)Polyesters, PUBAf -Polyhydroxy Butyrate/valerate, and PEA - Polyester Amides). 

Jung, I., Phyo, K., Kim, K., Park, H., and Kim, 1.2005. Spontaneous liberation of intracellular polyhydroxy-butyrate granules in Escherichia coli. Res Microbiol 156 865-73. 

Xu J, Guo BH, Zhang ZM, Chen GQ and Wang XF, Topography of polyhydroxy-butyrate banded spherulites. Chem J Chinese Univ., 2002, 23 1216-1218. 

For uses of these products - specific keyword. Most promising is the development of large-scale production of novel - biodegradable plastics - polyhydroxy butyric acid and - polylactic acid. According to forecasts by the chemical industry, 200000 mt sucrose or equifunctional sugars will be needed for EU production in the year 2000. 

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