Polyhydroxybutyrate PHB

H.,2010. Kinetic model for polyhydroxybutyrate (PHB) production by Hydrogenophaga pseudoflcwa and verification of growth conditions. Afr. J. Biot. 9, 3151-3157. 

The previous example related to manipulation of primary plant metabolism through creating a bypass within the existing system. There are also a range of studies that have looked at the production of novel substances within plants. One particularly relevant example is the production of a polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), in Arabidopsis thaliana. 

Figure 10.1 Schematic conception of the origin of life according to the idea of primarility of RNA (Spirin, 2001) with addition of the probable role of PolyPs and PolyP-polyhydroxybutyrate (PHB) complexes in the early stages of evolution.

Polyesters have played a prominent part in the development of biodegradable polymers. One of the first products developed as a biodegradable plastic in the early 1970s was based on a polyester belonging to the polyhydroxyalknoates (PHA) group, called polyhydroxybutyrate (PHB). 

Polyhydroxybutyrate (PHB) and polyhydroxyvalerate (PHV) are also being researched for use in medical devices. The PHB homopolymer is crystalline and brittle, whereas the copolymers of PHB with PHV are less crystalline, more flexible, and easier to process. These polymers typically require... 

The two most common PHAs are polyhydroxybutyrate (PHB) and a copolymer of polyhy-droxybutyrate and polyhydroxy valerate (PHBV). PHAs can be used as films, fibers, and coatings for hot beverage cups made of paper. 

Polyhydroxyalkanoic acids (PHAs) have been extensively researched since the 1970s because of the potential applications of these compounds as biodegradable substitutes for synthetic polymers. The most successful PHA products are the polyhydroxybutyrates (PHBs). The bacterium... 

Sinskey, A.)., and Stubbe,). (2000) Lipases provide a new mechanistic model for polyhydroxybutyrate (PHB) synthases characterization of the functional residues in Chromatium vinosum PHB synthase. Biochemistry, 39, 3927-3936. 

Another important family of biobased polyesters is the polyhydroxyalkanoates (PHAs) the most common members of this family are polyhydroxybutyrate (PHB) and its copolymer, polyhydroxybutyrate-valerate (PHBV). 

The nomenclature of PHAs and their classification are still in the process of evolving, because new structures are continuing to be discovered. The main biopolymer in the PHA family is a homopolymer polyhydroxybutyrate (PHB). The most conunon copolymer is poly(hydroxybutyrate-co-hydroxyvalerate) (PHBV), whose chemical structure is presented in Figure 9.4. However, there are others, such as poly(hydroxybulyrate-co-hydroxyhexanoate) (PHBHx), poly(hydroxybutyrate-co-hydroxyoctanoate) (PHBO) and poly(ltydroxybulyrate-co-hydroxyoctadecanoate) (PHBOd), for example. 

The polymer polyhydroxybutyrate (PHB), a polyester of 3-hydroxy-butanoic acid, is completely biodegradable as it is an ideal food for microbes. By copolymerization with another hydroxyacid, such as 3-hydroxypentanoic acid, the polymer can be tailored to take it suitable either for molded articles such as shampoo bottles or thin films for plastic envelopes or carrier bags. PHB is tradenamed Biopol by ICI. Most of the polymer that the company makes is used for packaging, agricultural products, and items of personal hygiene. Wella, the German hair-care company, sells its Sanara brand of shampoo in bottles made of Biopol and has reported increased sales as a result. 

Keywords Batik dye Cosmetics Electrospinning Facial oil Toxicity studies Oil blot Polyhydroxyalkanoate (PHA) Polyhydroxybutyrate (PHB)... 

Commodities organic acids, acrylamide, detergents, biopolymers, for example, biodegradable PLA and polyhydroxybutyrate (PHB), and enzymes... 

Polyhydroxybutyrate [PHB] is the most common type of polymer that falls in the category of polyhydroxyalkanoates. PHAs are generally classified into short-chain-length PHA (sCL-PHA) and medium-chain-length PHA (mCL-PHA) by the different number of carbons in their repeating units. 

Examples of biopolyesters include polyhydroxybutyrate [PHB] and polylactic acid (PLA] [7],... 

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]. 

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