Polyhydroxy alkanoates

Polyhydroxyalkanoates (PHAs) are a family of polyesters produced by bacterial fermentation, with the potential to replace conventional hydrocarbon-based polymers. PHAs occur naturally in a variety of organisms, but the microorganisms can be employed to tailor their production in cells. Polyhydroxybutyrate (PHB), the simplest PHA, was discovered in 1926 by Maurice Lemoigne as a constituent of the bacterimn Bacillus megaterium [31]. 

PHAs are potential biodegradable replacements for conventional bulk commodity plastics and, therefore, promote sustainable 

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When polyester-hydrolyzing activity was isolated using synthetic polyesters such as polycaprolactone, and the enzyme was examined in detail, it was found that it was a cutinase that was responsible for the hydrolysis [113]. Similarly, the polyester domains of suberin were found to be degraded by cutinase. Cutinase is a polyesterase, and similar enzymes may be widely distributed and can degrade a variety of natural and synthetic polyesters. Microbial polyhydroxy-alkanoic acids that are attracting increasing attention as biodegradable polyesters can be hydrolyzed by bacterial polyesterases that share some common features with cutinases [114] and this area is covered in another chapter [115]. 

Lee MY, Park WH, Lenz RW (1998) International Symposium on Biological Polyhydroxy-alkanoates 98 P77... 

Studies on the bulk pyrolysis of polyhydroxybutyric acid from Bacilli and of bacterial polyalkanoates have shown the formation of 2,3-butenoic acid and 2,3-pentenoic acid (18) The presence of 2,3-butenoic acids and pentenoic acid in the pyrolysate of the particulate matter from sample 20C is interpreted as an indication of polyhydroxy-alkanoates in the sample. These mixed polyesters of hydroxy acids with 4, 5 and sometimes 6 carbon atoms are especially abundant in activated sludges (19). The occurrence of m/z 86 and 100 as abundant mass peaks in the spectra of the fluvial material and as very characteristic peaks in the discriminant function spectrum indicates that a significant amount of the mud fraction may consist of sewage debris. This impression was confirmed by identification of a number of other pyrolysis products in the data file. 

POL 11] PoLLET E., Averous L., Production, chemistry and properties of polyhydroxy-alkanoates , in Plackett D. (ed.). Biopolymers New Materials for Sustainable Films and Coatings, John Wiley Sons, New York, pp. 65-86,2011. 

Bacterial polyesters (polyhydroxy alkanoates) Poly(3-hydroxy butyrate), poly(3-hydroxy valerate) Some micro-organisms, especially bacteria, can synthesise biocompatible aliphatic polyesters, which have potential in medical applications. 

Jaeger K-E, Steinbtichel A, Jendrossek D (1995) Subtrate specificities of bacterial polyhydroxy-alkanoate depolymerases and lipases bacterial lipases hydrolyze poly(tt)-hydroxyalkanoates). Appl Environ Microbiol 61 3113-3118... 

Wang J, Yue Z-B, Sheng G-P, Yu H-Q (2010) Kinetic analysis on the production of polyhydroxy-alkanoates from volatile fatty acids by Cupriavidus necator with a consideration of substrate inhibition, cell growth, maintenance, and product formation. Biochem Eng J 49 422-428 Wang Y, Yamada S, Asakawa N, Yamane T, Yoshie N, Inoue Y (2001) Comonomer compositional distribution and thermal and morphological characteristics of bacterial poly(3-hydroxybu-tyrate-co-3-hydroxyvalerate)s with high 3-hydroxyvalerate content. Biomacromolecules 2 1315-1323... 

B. Hazer, A. Steinbiichel, Increased diversification of polyhydroxy-alkanoates by modification reactions for industrial and medical applications, Appl. Microbiol. Biotechnol. 74 (1) (2007) 1-12. 

Y. Poirier, C. Nawrath, C. Somerville, Production of polyhydroxy-alkanoates, a family of biodegradable plastics and elastomers, in bacteria and plants. Bio/Technology 13 (1995) 142-150, doi 10.1038/ nbt0295-142. 

The book is organized in several chapters and deals with the most important biopolymer classes like the different polysaccharides (starch, cellulose, chitin), lignin, proteins and (polyhydroxy alkanoates) as raw materials for bio-based plastics, as well as with materials derived from bio-based monomers like lipids, poly(lactic acid), polyesters, polyamides and polyolefines. Additional chapters on general topics - the market and availability of renewable raw materials, the importance of bio-based content and the aspect of biodegradability - provide important information related to all bio-based polymer classes. 

Plastics Completely Synthesized by Bacteria Polyhydroxy alkanoates... 

Park SJ, Lee SY (2005) Systems biological approach for the production of various polyhydroxy-alkanoates by metaboUcally engineered Escherichia coli. Macromol Symp 224 1-9 Park SJ, Park JP, Lee SY (2002) Metabolic engineering of Escherichia coli for the production of medium-chain-length polyhydroxyalkanoates rich in specific monomers. FEMS Microbiol... 

Polysaccharides 1 Proteins, Lipids 1 PolyHydroxy-Alkanoates (PHA) 1 Polylactides Polycaprolactones (PCL)... 

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... 

Noda I. Solvent extraction of polyhydroxy-alkanoates from biomass facilitated by the use of marginal nonsolvent, US. Patent 5,821,299.1998. 

Yu J, Chen LXL. Cost-effective recovery and purification of polyhydroxy-alkanoates by selective dissolution of cell mass. Biotechnol Progr 2006 22 547-53. 

Hu SG, Jou CH, Yang MC. Antibacterial and biodegradable properties of polyhydroxy-alkanoates grafted with chitosan and chitooligosaccharides via ozone treatment. J Appl Polym Sci 2003 88 2797-2803. 

Microbially synthesised polyhydroxy alkanoates 10.3.2.4.1 Poly-3-hydroxybutyrate... 

Biobased polymers are those made from natural or organic ingredients, such as starch from corn, potato, tapioca, rice, or wheat (Narayan 2006a, 201 lb). Biobased polymers can also be made from oils, such as palm seed, linseed, soy bean, or fermentation products, like polylactic acid (PEA), polyhydroxy alkanoate (PHA), and polyhydroxybutyrate (PHB). BPI World provides a listing of compostable plastic resins, bags, cutlery, and packaging (BPI World 2013). 

Biomass products from agro-resources (agro-polymers) These bioplastics are either synthesized naturally from plants and animals, or entirely synthesized from renewable resources. This class includes starch, cellulose, proteins, lignin, chitosan, poly lactic acid (PLA) and polyhydroxy-alkanoates/polyhydroxybutyrates. A recent breakthrough in this class of bioplastics is the development of technology to synthesize polymers like polyethylene, polypropylene and nylon from biological resources ... 

Currently, application opportunities for poly()5-hydroxybutyrates) (PHB) - a member of the polyhydroxy alkanoate group - are being explored. Only very mild body reactions were detected with PHB implants during an implantation time of 12 months, there were no indications of chronic inflammation reactions. Enzymes accelerate hydrolytic degradation of PHB [954]. 

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