The thermal degradation behavior of poly[(R)-3-hydroxybutyrate-co-16 mol%-4-hydroxybutyrate] (P(3HB-co-16 mol%-4HB)) was investigated based on spectroscopic analysis its pyrolyzates and two kinetic modeling approaches. Pyrolyzate revealed that trans-crotonic acid, cis-crotonic γ-butyrolactone, their oligomers (dimers trimers) were produced following P(3HB-co-16 mol%-4HB). analyses confirmed the...

The main objective of the present study is to assess and improve fermentation conditions produce polyhydroxyalkanoates (PHAs), such as homopolymer poly(3-hydroxybutyrate) (PHB) copolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), from renewable inexpensive industrial waste by wild type Cupriavidus necator. Untreated residual glycerol, a byproduct generated biodiesel industry, was used...

The microbial degradation of tensile test pieces made of poly(3-hydroxybutyrate) [P(3HB)] or a copolymer of 90% 3-hydroxybutyric acid and 10% 3-hydroxyvaleric acid was studied in soils incubated at a constant temperature of 15, 28, or 40 degrees C for up to 200 days. In addition, hydrolytic degradation in sterile buffer at temperatures ranging from 4 to 55 degrees C was monitored for 98 days. D...

A series of amphiphilic alternative block polyurethane copolymers based on poly(3-hydroxybutyrate-co-4-hydroxybutyrate) (P3/4HB) and poly(ethylene glycol) (PEG) were synthesized by a coupling reaction between P3/4HB-diol and PEG-diisocyanate, with different 3HB, 4HB, PEG compositions and segment lengths. Stannous octanoate was used as catalyst. The chemical structure, alternative block arrangem...

für Naturforschung in cooperation with the Max Planck Society for the Advancement of Science under a Creative Commons Attribution 4.0 International License. Dieses Werk wurde im Jahr 2013 vom Verlag Zeitschrift für Naturforschung in Zusammenarbeit mit der Max-Planck-Gesellschaft zur Förderung der Wissenschaften e.V. digitalisiert und unter folgender Lizenz veröffentlicht: Creative Commons Namen...

Fused deposition modelling (FDM) is a process of additive manufacturing allowing creating highly precise complex three-dimensional objects for large range applications. The principle FDM an extrusion the molten filament and gradual layers their solidification. Potential applications in pharmaceutical medical fields require development biodegradable biocompatible thermoplastics processing filame...

background poly 3-hydroxybutyrate (phb), a class of poly hydroxyalkanoates (phas), is a group of bacterial storage polymers, produced by various microorganisms in response to nutrient limitation. phas are biodegradable polymers which could be a good substitute for current petrochemical plastics. phb has been synthesized during three enzymatic steps including three genes. objectives our aim was ...

Paracoccus denitrificans PD1222 accumulates short-length polyhydroxyalkanoates, poly(3-hydroxybutyrate), under nitrogen-deficient conditions. Polyhydroxybutyrate metabolism requires the 3-ketoacyl-CoA thiolase PhaA, the acetoacetyl-CoA dehydrogenase/reductase PhaB and the synthase PhaC for polymerization. Additionally, P. denitrificans PD1222 grows aerobically with nitrate as sole nitrogen sour...