Degradation of microbial polyesters.
Microbial polyhydroxyalkanoates (PHAs), one of the largest groups of thermoplastic polyesters are receiving much attention as biodegradable substitutes for non-degradable plastics. Poly(D-3-hydroxybutyrate) (PHB) is the most ubiquitous and most intensively studied PHA. Microorganisms degrading these polyesters are widely distributed in various environments. Although various PHB-degrading microorganisms and PHB depolymerases have been studied and characterized, there are still many groups of microorganisms and enzymes with varying properties awaiting various applications. Distributions of PHB-degrading microorganisms, factors affecting the biodegradability of PHB, and microbial and enzymatic degradation of PHB are discussed in this review. We also propose an application of a new isolated, thermophilic PHB-degrading microorganism, Streptomyces strain MG, for producing pure monomers of PHA and useful chemicals, including D-3-hydroxycarboxylic acids such as D-3-hydroxybutyric acid, by enzymatic degradation of PHB.
Tokiwa
Yutaka
Y
National Institute of Advanced Industrial Science and Technology, Tsukuba Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan. y.tokiwa@aist.go.jp
Calabia
Buenaventurada P
BP
D020155:3-Hydroxybutyric Acid / Q000378:metabolism*; D000473:Alkanes / Q000378:metabolism; D001419:Bacteria / Q000378:metabolism*; D001672:Biocompatible Materials / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D003247:Conservation of Natural Resources; D006868:Hydrolysis; D007220:Industrial Waste / Q000517:prevention & control*; D011091:Polyesters / Q000378:metabolism*; D011108:Polymers; D013045:Species Specificity
D000473:Alkanes; D001672:Biocompatible Materials; D007220:Industrial Waste; D011091:Polyesters; D011108:Polymers; C111948:poly(hydroxyethanoate); D002265:Carboxylic Ester Hydrolases; C022417:poly-beta-hydroxybutyrate depolymerase; D020155:3-Hydroxybutyric Acid