Hydroxybutyrate bacterial degradation

PHB Poly-3-hydroxybutyrate Bacterial storage polyester slowa degradation rate tiimi polylactic polymers... 

In the former case, a bacterial or fungal colony on the surface of the material releases an extracellular degrading enzyme which breaks down the polymer chains into smaller units (dimers and ohgomers), which then are absorbed through the microorganisms ceU membrane and metabolised as a source of nutrient (carbon). It has been proposed that this mechanism first hydrolyses the chains of the amorphous phase of poly-(3-hydroxybutyrate) (PHB) and then proceeds to attack the chains in the crystalline state. The enzymatic degradation rate decreases as the crystallinity increases [15, 16]. 

Poly(i )-3-hydroxybutyrate) (PHB) is an illustrative example for one of centers for the formation of the above-mentioned scientific-technological network and a basis for the development of various biopol5mier systems [1, 2], In recent decades, an intense development of biomedical application of bacterial PHB in the production of biodegradable polymer implants and controlled dmg release systems [3-6] needs for comprehensive understanding of the PHB biodegradation process. Examination of PHB degradation process is also necessary for development of novel... 

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... 

Scandola M, CeccomUi G, Doi Y (1990) Viscoelastic relaxations and thermal properties of bacterial poly(3-hydroxybutyrate-co-3-hydroxyvaleiate) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate). Int J Biol Macromol 12 112—117 Scharlemann JPW, Laurance WF (2008) How green are biofuels Sdence 319 43-44 Senior PJ, Dawes EA (1973) The regulation of poly-beta-hydroxybutyrate metabolism in Azotobacter beiqerinckii. Biochem J 134 225—238 Shah AA, Hasan F, Hameed A (2010) Degradation of poly(3-hydroxybutyrate-co-3-hydroxy-valerate) by a newly isolated Actinomadura sp. AF-555, from sod. Int Biodeterior Biodegrad 64 281-285... 

Several types of bacterial polyesters that are produced by biosynthesis are poly-3-hydroxybutyrate, poly-4-hydroxybutyrate, poly-3-hydroxyvalerate, poly-3-hydroxyhexanoate, poly-3-hydroxy-heptanoate, etc., and their respective copolymer combinations. Due to their ability to degrade naturally in variety of environments, they will find a lot of applications in disposal items, short-term packaging, and also considered biocompatible in contact with living tissues and can be used for biomedical applications (e.g., drug encapsulation, tissue engineering) (Chauhan, 2012). 

Besides the common polyhydroxybutyrate (PHB), other polymers of this class are produced by a variety of organisms such as poly-4-hydroxybutyrate, PHV, and polyhy-droxyhexanoate. PHV is a naturally occurring bacterial polyester, which was first isolated by Wallen and coworkers [172,173]. Also, PHV/PHB copolymers have been studied to make a wide range of thermally processable polyesters, which exhibit the necessary long-term degradation profile required for a degradable fracture fixation device [174]. 

Abate, R., Ballistreri, A., Impallomeni, G., and Montaudo, G., Thermal Degradation of Microbial Poly(4-hydroxybutyrate), Macromolecules, 71, 332,1994. Ballistreri, A., Garozzo, D., Giuffrida, M., and Montaudo, G., Microstructure of Bacterial Poly( 8-hydroxybutyrate-co-/3-hydroxyvalerate) by Fast Atom... 

Lee SY, Chang HN (1994) Effect of complex nitrogen source on the synthesis and accumulation of poly(3-hydroxybutyric acid) by recombinant Escherichia coU in flask and fed-batch cultures. J Environ Polym Degrad 2 169-176 Lee SY (1997) E. coU moves into the plastic age. Nat. Biotechnol 15 17-18 Lee SY, Lee Y, Wang E (1999) Chirtil compounds from bacterial polyesters sugars to plastics to fine chemicals. Biotechnol Bioeng 65 363-368... 

Abbate M, MartusceUi E, Ragosta G, Scarinzi G (1991) Tensile properties and impact behaviour of poly(D(-)3-hydroxybutyrate)/rubber blends. J Mater Sd 26 1119-1125 Abe H, Doi Y (2002) Side-chain effect of second monomer units on crystalline morphology, thermal properties, and enzymatic degradability for random copolyesters of (R)-3-hydroxybutyric add with (R)-3-hydroxyalkanoic acids. Biomacromolecules 3 133-138 Abe C, Taima Y, Nakamura Y, Doi Y (1990) New bacterial copolyester of 3-hydroxyalkanoates and 3-hydroxy-co-fluoroalkanoates produced by Pseudomonas oleovorans. Polym Commun 31 404 06... 

Abe H, Doi Y, Kumagai Y (1994a) Synthesis and characterization of poly[(R,S)-3-hydroxybu-tyrate-b-6-hydroxyhexanoate] as a compatibilizer for a biodegradable blend of poly[(R)-3-hydroxybutyrate] and poly(6-hydroxyhexanoate). Macromolecules 27 6012-6017 Abe H, Dd Y, Satkowski MM, Noda I (1994b) Miscibility and morphology of blends of isotactic and atactic poly(3-hydroxybutyrate). Macromolecules 27 50-54 Abe H, Matsubara I, Doi Y (1995) Physical properties and enzymic degradability of polymer blends of bacterial poly[(R)-3-hydroxybutyrate] and poly [(R,S)-3-hydroxybuty rate] stereoisomers. Macromolecules 28 844-853... 

Hocking PJ, Marchessault RH, Timmins MR, Lenz RW, Fuller RC (1996) Enzymatic degradation of single crystals of bacterial and synthetic poly(P-hydroxybutyrate). Macromolecules 29 2472-2478... 

Ravenelle F, Marchessault RH (2002) One-step synthesis of amphiphilic diblock copolymers from bacterial poly([/J]-3-hydroxybutyric acid). Biomacromolecules 3 1057-1064 Ravenelle F, Marchessault RH (2003) Self-assembly of poly([R]-3-hydroxybutyric aaA)-block-poly(ethylene glycol) diblock copolymers. Biomacromolecules 4 856-858 Renard E, Langlois V, Guerin P (2007) Chemical modifications of bacterial polyesters from stability to controlled degradation of resulting polymers. Corros Eng Sci Technol 42300-42310... 

---