Microbial degradation of polyhydroxyalkanoates.
Polyesters such as poly(3-hydroxybutyrate) (PHB) or other polyhydroxyalkanoates (PHA) have attracted commercial and academic interest as new biodegradable materials. The ability to degrade PHA is widely distributed among bacteria and fungi and depends on the secretion of specific extracellular PHA depolymerases (e-PHA depolymerases), which are carboxyesterases (EC 3.1.1.75 and EC 3.1.1.76), and on the physical state of the polymer (amorphous or crystalline). This contribution provides a summary of the biochemical and molecular biological characteristics of e-PHA depolymerases and focuses on the intracellular mobilization of storage PHA by intracellular PHA depolymerases (i-PHA depolymerases) of PHA-accumulating bacteria. The importance of different assay systems for PHA depolymerase activity is also discussed.
Jendrossek
Dieter
D
Institut für Mikrobiologie, Allmandring 31, D-70550 Stuttgart, Germany. imbdj@po.uni-stuttgart.de
Handrick
Rene
R
D000595:Amino Acid Sequence; D001419:Bacteria / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D007424:Intracellular Fluid / Q000378:metabolism / Q000382:microbiology; D008969:Molecular Sequence Data; D011091:Polyesters / Q000737:chemistry / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
D011091:Polyesters; D002265:Carboxylic Ester Hydrolases; C077226:poly(3-hydroxyalkanoic acid) depolymerase