Polyhydroxyalkanoates review

Weusthuis RA, Huijberts GNM, Eggink G (1997) Production of mcl-poly(hydroxy-alkanoates) (review). In Eggink G, Steinbiichel A, Poirier Y, Witholt B (eds) 1996 International Symposium on Bacterial Polyhydroxyalkanoates. NRC Research Press, Ottawa... 

It has already been pointed out that it is not only PolyPs but other anionic polymers, such as [X)I y-ft -hy< I rox ybutyrate, which may form metachromatic granules in the cells of prokaryotes. However, recently a number of methods for differential staining of PolyPs and polyhydroxyalkanoate-containing granules in cells have been developed (see the review of Serafim et al, 2002). 

Lee, S. Y., Choi, J., and Wong, H. H. 1999b. Recent advances in polyhydroxyalkanoate production by bacterial fermentation mini-review. Int. J. Bio. Macromol., 25, 31-36. 

Polyester is a general term referring to any polymer where the monomers are linked by ester bonds and includes the biodegradable microbially derived polyhydroxyalkanoates, which, as they are naturally produced, are beyond the scope of this article (for a review see Kim Rhee, 2003). Most synthetic polyesters in large-scale use are the aromatic poly(ethylene tetraphthalate) or poly(butylene tetraphthalate) polyesters as they have excellent material properties and are used in a wide range of applications including plastic containers, fibres for synthetic fabrics, films... 

The synthesis of bacterial storage compounds is reviewed in Chapter 10, focusing on two systems, namely polyhydroxyalkanoic acids and cyanophycin. Bacterial storage compounds are very interesting biopolymers having attractive material properties, sometimes similar to those of the petrochemical-based polymers. 

Anderson, A. J., Dawes, E. A. (1990). Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates. Microbiological Reviews, 54(4), 450-472. 

Lee SY, Choi JI (1998) Effect of fermentation performance on the economics of poly(3-hydroxy-butyrate) production by Alcaligenes latus. Polym Degrad Stab 59 387-393 Lee SY, Choi J, Wong HH (1999) Recent advances in polyhydroxyalkanoate production by bacterial fermentation mini-review. Int J Biol Macromol 25 31-36 Lee SY, Lee KM, Chan HN, Steinbiichel A (1994) Comparison of recombinant Escherichia coli strains for synthesis and accumulation of poly(3-hydroxybutyric acid) and morphological changes. Biotechnol Bioeng 44 1337-1347... 

Sunada K, Watanabe T, Hashimoto K (2003) Studies on photoktUing of bacteria on Ti02 thin film. J Photochem Photohiol A Chem 156 227-233 Suriyamongkol P, Weselake R, Narine S, Moloney M, Shah S (2007) Biotechnological approaches for the production of polyhydroxyalkanoates in microorganisms and plants - A review. Biotechnol Adv 25 148-175... 

Zinn, M., Witholt, B. and EgU, T. (2001) Occurrence, synthesis and medical application of bacterial polyhydroxyalkanoate. Advanced Drug Delivery Reviews, 53, 5-21. 

ValappU, S.P., Misra, S.K., Boccaccini, A.R. and Roy, I. (2006) Biomedical applications of polyhydroxyalkanoates, an overview of animal testing and in vivo responses. Expert Review of Medical Devices, 3(6), 853-868. 

The class of polyhydroxyalkanoates (PHAs) is very versatile, with the largest group being the medium-chain-length (mcl) PHAs which consist of enantiomerically pure (i )-hydroxy fatty acids of between and Cj units. Since the discovery in 1983 of the Witholt group (de Smet et al. 1983) at the University of Groningen in the Netherlands, more monomers have been described in the literature (see also Gudrin et al. 2009 and review by Kim et al. 2007). 

The first strategy, based on the use of starch for the production of other chemicals was recently reviewed by Robertson et al. [58], Koutinas et al. [59], Kennedy et al. [60] and Otey and Doane [61]. Three different approaches are applied in this context (i) starch as a raw matraial for the production of monomers used in the synthesis of polymers which can be non-biodegradable, such as polyethylene, or biodegradable, such as PLA (the main biodegradable commercial polymer whose monomer, lactic acid, can be obtained from the fermentation of starch [62]) (ii) as a raw material for the production of biopolymCTs like polyhydroxyalkanoates (of which PHB is the main member) (iii) as a raw material for the production of glucose, dextrin and other hydroxyl-containing monomers used in the production of mixed compositions based on starch and other monomers. 

Pouton, C.W., Akhtar, S., 1996. Biosynthetic polyhydroxyalkanoates and their potential in drug delivery. Advanced Drug Delivery Reviews 18, 133—162. 

Jendrossek, D., Handrick, R., 2002. Microbial degradation of polyhydroxyalkanoates. Annual Review of Microbiology 56 (1), 403—432. 

Kadouri, D., Jurkevitch, E., Okon, Y, and Castro-Sowinski, S. Critical Reviews in Microbiology. Ecological and agricultural significance of bacterial polyhydroxyalkanoates, 31(2), 55-67 (2005). 

Doi, Y, Kawaguchi, Y, Koyama, N., Nakamura, S., Hiramitsu, M., Yoshida, and Kimura, U. (1992). Synthesis and degradation of polyhydroxyalkanoates in Alcaligenes eutrophus. FEMS Microbiological Reviews 103, 103-108. 

Amass W, Amass A, Tighe BA (1998) Review of biodegradable polymers uses, current developments in the synthesis and characterization of biodegradable polyesters, blends of biodegradable polymers and recent advances in biodegradation studies. Polym Int 47 89-144 Anderson AJ, Dawes EA (1990) Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates. Microbiol Rev 54 450-472 Anderson AJ, Haywood GW, Dawes EA (1990) Biosynthesis and composition of bacterial poly(hydroxyalkanoates). Int J Biol Macromol 12 102-105 Bowien B, Kusian B (2002) Genetics and control of CO(2) assimilation in the chemoautotroph Ralstonia eutropha. Arch Microbiol 178 85-93... 

A wide range of microorganisms have been shown to be able to accumulate polyhydroxyalkanoates. The structure of the sidechain can be modified by careful choice of the microorganism and carbon substrate. Many excellent reviews have already been published on the biosynthesis of these materials [6, 7,8] and Table 5.1 represents a summary of the range of copolymers that have been reported. It is therefore the intention of the current authors not to concentrate on the biochemical aspects of these polymers but instead to deal with the physical and material properties. 

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