Bacterial polyesters polyhydroxybutyrate

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]. 

PHAs are biodegradable bacterial polyesters used as a substitute for nonbiodegradable petroleum polyester products. Polyhydroxybutyrate (PHB) is the most studied example of... 

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. 

Somleva MN, SneU KD, Beaulieu JJ, Peoples OP, Garrison BR, Patterson NA (2008) Production of polyhydroxybutyrate in switchgrass, a value-added co-product in an important UgnoceUu-losic biomass crop. Plant Biotechnol J 6 663-678 Steinbuchel A, Fuchtenbusch B (1998) Bacterial and other biological systems for polyester production. Trends Biotechnol 16 419-427... 

Chiellini E, Solaro R (1996) Biodegradable polymeric materials. Adv Mater 8 305-313 Cyras VP, Commisso MS, Mauri AN et al (2007) Biodegradable double-layer films based on biological resources polyhydroxybutyrate and cellulose. J Appl Polym Sci 106 749-756 De Koning GJM (1993). Prospects of bacterial poly[(R)-3-hydroxyalkanoates]. Center for Polymers and Composites (CPC), Eindhoven University of Technology, Eindhoven Doi Y (1990) Microbial polyesters. Wiley, New York... 

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]. 

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