Molecular weight polyhydroxyalkanoates

Petrovic, Z.S., Milic, J., Xu, Y. and Cvetkovic, I. (2010) A chemical route to high molecular weight vegetable oil-based polyhydroxyalkanoate. Macromolecules (Washington, DC, United States), 43(9), 4120-4125. 

CeccomUi G, PizzoU M, Scandola M (1993) Effect of a low-molecular-weight plasticizer on the thermal and viscoelastic properties of miscible blends of bacterial poly(3-hydroxybutyrate) with cellulose acetate butyrate. Macromolecules 26 6722-6726 Chanprateep S, Kikuya K, Shimizu H, Shioya S (2(X)2) Model predictive controller for biodegradable polyhydroxyalkanoate production in fed-batch culture. J Bacterid 95 157-169 Chen GQ, Wu Q (2005) The application of polyhydroxyalkanoates as tissue engineering materials. Biomaterials 26 6565-6578... 

Polyhydroxyalkanoates (PHAs) represent an important group of biodegradable plastics. They are produced by various bacteria in many grades, differing in composition, molecular weight and other parameters [1, 2]. The formation of a particular material, either homo or copolymra depends on the type of bacteria, but even more important are the conditions of polymer formation, mainly the substrate used for feeding the bacteria and the conditions of their growth. 

The first biosynthetic system for LA-based polyesters was created in recombinant E. coli (Taguchi et al., 2008). A coenzyme A (CoA) transferase gene and the engineered polyhydroxyalkanoate synthase gene were introduced into E. coli, and the one-step biosynthesis of the LA-incorporated copolyester, P(6 mol% LA-co-94 mol% 3HB), with a number-average molecular weight of 1.9 x 10, was successfully demonstrated. To date, the E. coli platform has been used to produce various LA-based polymers incorporating 3-hydroxybutyrate (3HB), 3-hydroxyvalerate, 3-hydroxyhexanoate, and 2-hydroxy acids(Shozui et al., 2009 Yamada et al., 2009 Han et al., 2011 Matsumoto et al., 2011). 

Asrar J, Mitsky TA, Shah DT (2000) Polyhydroxyalkanoates of narrow molecular weight distribution prepared in transgenic plants. Monsanto Company, St Louis, MO... 

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