Spontaneous liberation of intracellular polyhydroxybutyrate granules in Escherichia coli.
Despite receiving much attention as a biodegradable substitute for conventional non-biodegradable plastics, the commercial use of polyhydroxybutyrate (PHB) remains limited because of its high production cost. In order to reduce the recovery/purification cost, which forms over half of the total production cost, we have developed a new cultivation method which enables spontaneous liberation of PHB by modulation of the initial inoculum size and the medium composition in recombinant Escherichia coli harboring Alcaligenes eutrophus phbCAB genes. In flask cultivation using a low cell inoculum and 2x LB medium containing 21% glucose, autolysis of 80.2% as well as yields of 85.2 g/l of PHB and a PHB content of 99.0% (w/w) were obtained. The glucose conversion rate was 0.43. The strategies developed in this study can minimize complex and unfavorable efforts required for efficient recovery/purification processes, thereby enabling biodegradable plastic to be produced by the recombinant E. coli so as to compete with conventional non-biodegradable plastic.
Jung
Il Lae
IL
Department of Radiation Biology, Environmental Radiation Research Group, Korea Atomic Energy Research Institute, P.O. Box 105, Yusong, Taejon 305-600, South Korea.
Phyo
Ki Heon
KH
Kim
Kug Chan
KC
Park
Hyo Kook
HK
Kim
In Gyu
IG
D000421:Alcaligenes / Q000235:genetics; D003470:Culture Media / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D005285:Fermentation; D005947:Glucose / Q000378:metabolism; D006885:Hydroxybutyrates / Q000378:metabolism*; D011091:Polyesters / Q000378:metabolism*; D000094122:Polyhydroxybutyrates
D003470:Culture Media; D005947:Glucose; D006885:Hydroxybutyrates; D011091:Polyesters; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates