title: Cyclic nature of poly(3-hydroxyalkanoate) metabolism in Alcaligenes eutrophus.
abstract: The cyclic process of biosynthesis and degradation of poly(3-hydroxyalkanoate) (PHA) was studied in Alcaligenes eutrophus under conditions of nitrogen-limitation of growth. A. eutrophus cells, which had accumulated poly(3-hydroxybutyrate) (PHB) of 55 wt% content within cells from butyric acid, were transferred into a nitrogen-free medium containing pentanoic acid as the sole carbon source and cultivated at 30 degrees C and pH 7.5. The content of PHB in A. eutrophus cells decreased with time, whereas a copolyester of 3-hydroxybutyrate (HB) and 3-hydroxyvalerate (HV) units, P(HB-co-HV), was accumulated in the presence of pentanoic acid. Conversely, when A. eutrophus cells with 50 wt% content of P(HB-co-56% HV) were incubated in a nitrogen-free medium containing butyric acid, the content of P(HB-co-56% HV) decreased with time, whereas PHB was accumulated. These results indicate the cyclic nature of PHA metabolism in A. eutrophus under these conditions.
authors.affiliation: Research Laboratory of Resources Utilization, Tokyo Institute of Technology, Yokohama, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Doi
authors.forename: A
authors.initials: A
authors.lastname: Segawa
authors.forename: Y
authors.initials: Y
authors.lastname: Kawaguchi
authors.forename: M
authors.initials: M
authors.lastname: Kunioka
mesh_terms: D000421:Alcaligenes / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism*; D002087:Butyrates / Q000378:metabolism; D020148:Butyric Acid; D006885:Hydroxybutyrates / Q000378:metabolism; D009584:Nitrogen / Q000494:pharmacology; D010421:Pentanoic Acids / Q000378:metabolism; D011091:Polyesters / Q000378:metabolism; D000094122:Polyhydroxybutyrates
chemical_list: D002087:Butyrates; D020148:Butyric Acid; D006885:Hydroxybutyrates; D009584:Nitrogen; D010421:Pentanoic Acids; D011091:Polyesters; C052620:poly(3-hydroxybutyrate)-co-(3-hydroxyvalerate); D000094122:Polyhydroxybutyrates; C003182:poly-beta-hydroxybutyrate