Editing Polyhydroxybutyrate (section)

{{Short description|Polymer}}
[[File:Micrografia di cristalli sferulitici di poli(idrossi butirrato) (PHB).jpg|thumb|Polymeric crystals of PHB observed by polarizing optical microscope.]]

'''Polyhydroxybutyrate''' ('''PHB''') is a [[Polyhydroxyalkanoates|polyhydroxyalkanoate]] (PHA), a [[polymer]] belonging to the [[polyester]]s class that are of interest as bio-derived and [[biodegradable plastic]]s.<ref>{{cite book |doi=10.1002/14356007.n05_n07 |chapter=Carbohydrates as Organic Raw Materials |title=Ullmann's Encyclopedia of Industrial Chemistry |year=2010 |last1=Lichtenthaler |first1=Frieder W. |isbn=978-3-527-30673-2 }}</ref> The poly-3-hydroxybutyrate (P3HB) form of PHB is probably the most common type of polyhydroxyalkanoate, but other polymers of this class are produced by a variety of organisms: these include poly-4-hydroxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO) and their [[copolymer]]s.