New amorphous amphiphilic triblock copolymers of poly(3-hydroxybutyrate)-poly(ethylene glycol)-poly(3-hydroxybutyrate) (PHB-PEG-PHB) were synthesized using the ring-opening copolymerization of beta-butyrolactone monomer. They were characterized by fluorescence, SEM and (1)H NMR. These triblock copolymers can form biodegradable nanoparticles with core-shell structure in aqueous solution. Compari...

Lundgren, D. G. (Syracuse University, Syracuse, N.Y.), R. Alper, C. Schnaitman and R. H. Marchessault. Characterization of poly-beta-hydroxybutyrate extracted from different bacteria. J. Bacteriol. 89:245-251. 1965.-Poly-beta-hydroxybutyrate (PHB) from different bacterial genera was studied with regard to its crystal structure, infrared absorption, intrinsic viscosity, and electron microscopy. ...

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 c...

Each of the constituent enzymes of the pathway was present with sufficient activity to account for the observed rate of alginate biosynthesis. The information obtained from this work, together with other biochemical information, e.g. knowledge of the mechanisms of nitrogen fixation and respiration (Yates & Jones, 1974) and of the deposition of poly-8-hydroxybutyrate in A . vinelundii (Dawes & S...

Biodegradable thermogelling copolymer hydrogels have great applicative potential in areas such as sustained drug release, gene delivery and tissue engineering. These injectable materials can be implanted in the human body with minimal surgical intervention. The thermosensitive copolymers have been incorporated with a variety of biocompatible and biodegradable components such as poly(D,L-lactic ...

Ralstonia eutropha H16 degraded (mobilized) previously accumulated poly(3-hydroxybutyrate) (PHB) in the absence of an exogenous carbon source and used the degradation products for growth and survival. Isolated native PHB granules of mobilized R. eutropha cells released 3-hydroxybutyrate (3HB) at a threefold higher rate than did control granules of nonmobilized bacteria. No 3HB was released by n...

Exogenous 3-hydroxybutyrate can be utilized by a variety of soil bacteria as a carbon and energy source. However, the membrane transporter responsible for 3-hydroxybutyrate uptake remains unidentified. The Bacillus subtilis strain 168 gene yxjC (herein renamed hbuT) encodes a putative gluconate transporter GntT-type membrane transporter with a previously unknown function. hbuT is organized with...

The growth of Pseudomonas oleovorans on n-octane was characterized by the formation of intracellular structures. These inclusions were isolated and characterized. Morphologically, they resembled the poly-beta-hydroxybutyrate granules found in Bacillus cereus, as shown by freeze-fracture electron microscopy. The elemental analysis of isolated granules showed, however, that they do not contain po...