Ion-exclusion high-pressure liquid chromatography (HPLC) was used to measure poly-beta-hydroxybutyrate (PHB) in Rhizobium japonicum bacteroids. The products in the acid digest of PHB-containing material were fractionated by HPLC on Aminex HPX-87H ion-exclusion resin for organic acid analysis. Crotonic acid formed from PHB during acid digestion was detected by its intense absorbance at 210 nm. T...

The acetoacetyl-CoA reductase and the polyhydroxyalkanoate (PHA) synthase from Ralstonia eutropha (formerly Alcaligenes eutrophus) were expressed in Escherichia coli, Klebsiella aerogenes, and PHA-negative mutants of R. eutropha and Pseudomonas putida. While expression in E. coli strains resulted in the accumulation of poly(3-hydroxybutyrate) [PHB], strains of R. eutropha, P. putida and K. aero...

Poly(3-hydroxybutyrate) (PHB) is an interesting biopolymer for replacing petroleum-based plastics, its biological production is performed in natural and engineered microorganisms. Current metabolic engineering approaches rely on high-throughput strain construction and screening. Analytical procedures have to be compatible with the small scale and speed of these approaches. Here, we present a me...

Abstract Microbial polyhydroxyalkanoates (PHAs) as an ideal choice of biomaterial for specific applications. In this study, PHA was synthesized and purified from Pseudomonas mendocina PSU. These obtained then determined its monomer composition found that 3-hydroxybutyrate (3HB) a major component, in addition, the molecular weight were also investigated. The average Mw 8.39 ×10 4 when grown MSM ...

Poly(3-hydroxybutyrate) (PHB) depolymerase from Alcaligenes faecalis T1 is composed of three domains: the catalytic (C) domain, the fibronectin type III-like (F) domain, and the substrate-binding (S) domain. We constructed domain deletion, inversion, chimera, and extra-F-domain mutants and examined their enzyme activity and PHB-binding ability. In addition, we performed substitution of 214Asp a...

Considering the industrial interest of biodegradable polymer poly-3-hydroxybutyrate (PHB), the marine bacteria Neptunomonas antarctica was studied for its ability to accumulate PHB. The extracted polymer was confirmed to be PHB by nuclear magnetic resonance analysis. In shake flask cultures using natural seawater as medium components, PHB was produced up to 2.12 g/L with a yield of 0.18 g PHB/g...

Alcaligenes faecalis AE122 that used poly(3-hydroxybutyrate) (PHB) as a sole source of carbon was newly isolated from a coastal seawater sample. The strain required seawater for growth on PHB as well as in a nutrient broth, in which seawater could be replaced by an appropriate concentration of NaCl. PHB depolymerase was purified to homogeneity from the culture supernatant of A. faecalis AE122 b...

Biodegradable polymeric materials can be used as temporary implants and may be able to carry out specific functions for a pre-determined period prior to their degradation in vivo. In order to be used they must present characteristics of biocompatibility. When a material comes into contact with blood, the instantaneous adsorption of protein occurs on its surface. Coverage of the surface by γ-glo...

Ilyobacter delafieldii produced an extracellular poly-[3-hydroxybutyrate (PHB) depolymerase when grown on PHB; activity was not detected in cultures grown on 3-hydroxybutyrate, crotonate, pyruvate or lactate. PHB depolymerase activity was largely associated with the PHB granules (supplied as growth substrate), and only 16 % was detected free in the culture supernatant. Monomeric 3-hydroxybutyra...