Ageing phenomena in bacterial poly[(R)-3-hydroxybutyrate]

Local scale-invariance in ageing phenomena

Many materials quenched into their ordered phase undergo ageing and there show dynamical scaling. For any given dynamical exponent z, this can be extended to a new form of local scale-invariance which acts as a dynamical symmetry. The scaling functions of the two-time correlation and response functions of ferromagnets with a non-conserved order parameter are determined. These results are in agr...

Microbial degradation of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in soils.

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...

3-hydroxybutyrate dehydrogenase

The enzymic determination of D-3-hydroxybutyrate and acetoacetate normally involves the use of 3hydroxybutyrate dehydrogenase (HBDH, EC 1.1.1.30) of bacterial origin. We show that HBDH from Rhodopseudomonas spheroides (BCL, grade II) contains a 3-hydroxyisobutyrate dehydrogenase (HIBDH) activity: activity with 3-hydroxyisobutyrate as substrate was > 10% of that with 3-hydroxybutyrate. However, ...

Gas-chromatographic measurement of 3-hydroxybutyrate and lactate in plasma and 3-hydroxybutyrate in whole blood.

We describe two simple, rapid, and sensitive gas-chromatographic methods. One is for determining 3-hydroxybutyrate and lactate in plasma, the other for determining 3-hydroxybutyrate in perchloric acid extracts of blood. Samples are purified by adsorption onto graphitized carbon black (Carbopak B). After desorption, the two hydroxyacids are gas-chromatographically measured. Chromatography is on ...

Chapter 2. Comonomer Unit Compositional Distribution and Sequence Distribution of Bacterial Poly(3-hydroxybutyrate-co-4- hydroxybutyrate)s