Polyhydroxyalkanoates bacteria

Many bacteria are able to synthesize polyesters of hydroxyalkanoic acids and to accumulate these water insoluble polyhydroxyalkanoic acids (PHA) in the cytoplasm as inclusions and as storage compounds for energy and carbon these in-... 

Keywords. Polyhydroxyalkanoates, PHA biosynthesis genes, Recombinant bacteria, Fermentation... 

STEINBUCHEL, A., HUSTEDE, E, LffiBERGESELL, M PIEPER, U., TIMM, A., VALENTIN, H., Molecular basis for biosynthesis and accumulation of polyhydroxyalkanoic acid in bacteria, FEMS Micribiol. Rev., 1992,103,217-230. 

Polyhydroxyalkanoates (PHAs) are biological polyesters that are produced by a wide variety of bacteria as osmotically inert carbon- and energy-storage compounds that accumulate in the form of granules (see Fig. 1). 

Polyhydroxyalkanoate (PHA) is a polyester of hydroxyalkanoates synthesized by numerous bacteria as an intracellular carbon and energy storage compound and accumulated as granules in the cytoplasm of cells... 

An additional advantage of the polyhydroxyalkanoates is that the polymers can be produced by fermentation. Certain types of bacteria produce PHAs for energy storage when they are grown in glucose solution in the absence of specific nutrients. The polymer forms as discrete granules within the bacterial cell, and it is then removed by extraction to give a white powder that can be melted and modified into a variety of different products. 

Within this context, the search for a material that is durable while in use and degradable after its disposal has led to the emergence of biodegradable plastic— materials that decompose into carbon dioxide and water as the final result of the action of microorganisms such as bacteria and fungi [5]. Polyhydroxyalkanoates (PHAs) constitute examples of such materials. 

Polyhydroxyalkanoates are produced by bacteria for storage purposes.318 Monsanto (formerly Zeneca) formerly produced 1000 tons/yr of a random copolymer of 3-... 

Polymers derived from renewable resources (biopolymers) are broadly classified according to the method of production (1) Polymers directly extracted/ removed from natural materials (mainly plants) (e.g. polysaccharides such as starch and cellulose and proteins such as casein and wheat gluten), (2) polymers produced by "classical" chemical synthesis from renewable bio-derived monomers [e.g. poly(lactic acid), poly(glycolic acid) and their biopolyesters polymerized from lactic/glycolic acid monomers, which are produced by fermentation of carbohydrate feedstock] and (3) polymers produced by microorganisms or genetically transformed bacteria [e.g. the polyhydroxyalkanoates, mainly poly(hydroxybutyrates) and copolymers of hydroxybutyrate (HB) and hydroxyvalerate (HV)] [4]. 

Abstract Polyhydroxyalkanoate (PHA) is a plastic-like material synthesized by many bacteria. PHA serves as an energy and carbon storage componnd for the bacteria. PHA can be extracted and purified from the bacterial cells and the resulting product resembles some commodity plastics such as polypropylene. Because PHA is a microbial product, there are natural enzymes that can degrade and decompose PHA. Therefore, PHA is an attractive material that can be developed as a bio-based and biodegradable plastic. In addition, PHA is also known to be biocompatible and can be used in medical devices and also as bioresorbable tissue engineering scaffolds. In this chapter, a brief introduction about PHA and the fermentation feedstock for its production are given. 

Ali N, Suhaimi NS (2009) Performance evaluation of locally fabricated asymmetric nanofiltration membrane for Batik industry effluent. World Appl Sci J 5 46-52 Alias Z, Tan IKP (2005) Isolation of palm oil-utilising, polyhydroxyalkanoate (PHA)-producing bacteria by an enrichment technique. Bioresour Technol 96 1229-1234 Allen AD, Anderson WA, Ayorinde FO, Eribo BE (2010) Biosynthesis and characterization of copolymer poly(3HB-co-3HV) from saponified Jatropha curcas oil by Pseudomonas oleovorans. J Ind Microbiol Biotechnol 37 849-856 Allen AD, Anderson WA, Ayorinde F, Eribo BE (2011) Isolation and characterization of an extracellular thermoalkanophilic P(3HB-co-3HV) depolymerase from Streptomyces sp. INI. Int Biodeterior Biodegrad 65 777-785... 

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... 

Valentin HE, Dennis D (1997) Production of poly(3-hydroxybutyrate-co- 4-hydroxybutyrate) in recombinant Escherichia coli grown on glucose. J Biotechnol 58 33—38 Valentin HE, Lee EY, Choi CY, Steinbuchel A (1994) Identification of 4-hydroxyhexanoic acid as a new constituent of biosynthetic polyhydroxyalkanoic adds from bacteria, Appl Microbiol Biotechnol 40 710-716... 

Polyhydroxyalkanoates (PHAs) are very interesting polyesters synthesized by many types of bacteria. Numerous researchers from all over the world have carried out various smdies on PHAs. There is already a wealth of knowledge about all aspects of PHAs in the literatures. 

S. CastroSowinski, S. Burdman, O. Matan, Y. Okon, Natural functions of bacterial polyhydroxyalkanoates, in G.-Q. Chen (Ed.), Plastics from Bacteria Natural Functions and r Ucations, Microbiology Mono-gr hs, 14, Springer-Verlag, Berlin, Heidelberg, 2010, pp. 39-61. 

Chen, G. Plastics completely synthesized by bacteria polyhydroxyalkanoates. Microbiol. Monogr. 14, 17-37 (2010)... 

Renner, G., Schellauf, F. and Braunegg, G., 1998, Selective enrichment of bacteria accumulating polyhydroxyalkanoates in multistage continucnis culture. Food technol. Biotechnol. 36 (3) 203-207... 

Many bacteria can use glycerol as a carbon source. As it is a by-product of the production of bio-diesel it can be achieved chet ly. Therefore it seems to be a good alternative to glucose for die production of Polyhydroxyalkanoates. Sodiumvalerate is often used as a precursor in order to obtain the copolymer Poly-3-hydroxybutyrate-co-3-hydroxyvalerate. As Biorelated Potymers Sustainable Polymer Science and Technology Edited by Chiellini et al., Kluwer Academic/Plenum Publishers, 2001 147... 

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