The undefined poly(3-hydroxybutyrate)- (PHB-) negative mutant R. eutropha PHB-4 was generated in 1970 by 1-nitroso-3-nitro-1-methylguanidine (NMG) treatment. Although being scientific relevant, its genotype remained unknown since its isolation except a recent first investigation. In this study, the mutation causing the PHA-negative phenotype of R. eutropha PHB-4 was confirmed independently: seq...

Feast and famine cycles are common in activated sludge wastewater treatment systems, and they select for bacteria that accumulate storage compounds, such as poly-beta-hydroxybutyrate (PHB). Previous studies have shown that variations in influent substrate concentrations force bacteria to accumulate high levels of rRNA compared to the levels in bacteria grown in chemostats. Therefore, it can be ...

Polyhydroxybutyrates (PHBs) are polyoxoesters generated from (R)3-hydroxybutyryl coenzyme A by PHB synthase. During the polymerization reaction, the polymers undergo a phase transition and generate granules. Wautersia eutropha can transiently accumulate PHB when it is grown in a nutrient-rich medium (up to 23% of the cell dry weight in dextrose-free tryptic soy broth [TSB]). PHB homeostasis und...

BACKGROUND Over the last 10-15 years, a technology has been developed to engineer bacterial poly(3-hydroxybutyrate) (PHB) inclusions as functionalized beads, for applications such as vaccines, diagnostics and enzyme immobilization. This has been achieved by translational fusion of foreign proteins to the PHB synthase (PhaC). The respective fusion protein mediates self-assembly of PHB inclusions...

Nowadays, there is an increasing interest toward the substitution of oil-based polymers with biobased polymers. Poly(hydroxyalkanoates) (PHAs) emerge as a new class of biopolymers, that have gained more and more attention due to their thermoplastic behaviour, acceptable mechanical properties and biodegradability in compost conditions1. Applications based on PHAs, as a matrix, are generally foun...

This paper reports the thermal, morphological and mechanical properties of environmentally friendly poly(3-hydroxybutyrate) (PHB)/poly(butylene succinate) (PBS) PHB/poly[(butylene succinate)-co-(butylene adipate)] (PBSA) blends, prepared by melt mixing. The blends are known to be immiscible, as also confirmed thermodynamic analysis here presented. A detailed quantification crystalline amorphous...

Traditionally, the structure and properties of natural products have been determined by total synthesis and comparison with authentic samples. We have now applied this procedure to the first nonproteinaceous ion channel, isolated from bacterial plasma membranes, and consisting of a complex of poly(3-hydroxybutyrate) and calcium polyphosphate. To this end, we have now synthesized the 128-mer of ...

Polyhydroxyalkanoates (PHAs) are a class of biodegradable polyoxoesters synthesized from acetyl-CoA that naturally accumulate as intracellular granules in a diverse range of bacteria. Biosynthesis of the simplest PHA (PHB, poly-3-hydroxybutyrate) can be accomplished though the action of three enzymes, beta-ketothiolase, acetoacetyl-CoA reductase and PHA polymerase. We constructed plasmids that ...

Controlled release systems can modify the rate of drugs and direct them to specific sites action, making more effective and/or reducing adverse effects. The objective this study was investigated, poly(β-hydroxybutyrate) (PHB) poly(ε-caprolactone) (PCL) nanospheres improve delivery Simvastatin (SIM). Nanospheres were prepared by emulsion/evaporation technique solvent, varying amount SIM added. q...