Polyhydroxyalkanoates (PHAs) are biodegradable polymers produced by microbes to overcome environmental stress. Commercial production of PHAs is limited by the high cost of production compared to conventional plastics. Another hindrance is the brittle nature and low strength of polyhydroxybutyrate (PHB), the most widely studied PHA. The needs are to produce PHAs, which have better elastomeric pr...

Background The plastics derived from petrochemicals have many applications. However, public concern and environmental laws led to conservation policies and establish programs that stimulate the research and use of new products based on renewable resources. Polyhydroxyalkanoates (PHAs) are biopolymers synthesized by microorganisms under conditions of nutrient stress with similar properties to co...

Polyhydroxyalkanoates (PHAs) is reported as polyesters of hydroxyalkanoates (HAs) which is generally synthesized by numerous bacteria and it is stored in the cytoplasm of cells as an intracellular carbon and energy sources compound. It has been considered as a replacement for conventional plastics. Microbial cell such as Alcaligenes, Pseudomonas, recombinant Escherichia coli and methylotrophs a...

The cell growth on H2 and O2 as the energy source and CO2 as the sole carbon source in the autotrophic culture condition was tested for the gram-negative bacteria Paracoccus spp. The aerobic growth in the autotrophic condition was only observed in Paracoccus denitrificans NBRC13301 and P.pantotrophus NBRC102493. Both strains were sensitive to O2 in particular the growth of P.pantotrophus was co...

The macromolecular composition of activated sludge (lipids, intracellular proteins and intracellular polysaccharides) was studied together with its capacity to store macromolecules such as polyhydroxybutyrate (PHB) in a conventional activated sludge system fed with synthetic sewage water at an organic load rate of 1.0 kg COD/(m(3)·d), varying the dissolved oxygen (DO) and temperature. Six DO co...

Pseudomonas sp. 14-3 is an Antarctic bacterium that shows high stress resistance in association with high polyhydroxybutyrate (PHB) production. In this paper genes involved in PHB biosynthesis (phaRBAC) were found within a genomic island named pha-GI. Numerous mobile elements or proteins associated with them, such as an integrase, insertion sequences, a bacterial group II intron, a complete Typ...

Concepts from previous biofilm models were integrated to create a framework for the implementation of multidimensional (2D and 3D) multispecies biofilm models. The framework is here described at three levels: (i) mathematical representation of the processes involved in biofilm formation, (ii) numerical implementation into a computer program (freely available from our website http://www.biofilms...

This study proposed and demonstrated the application of a new Raman microscopy-based method for metabolic state-based identification and quantification of functionally relevant populations, namely polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs), in enhanced biological phosphorus removal (EBPR) system via simultaneous detection of multiple intracellular pol...

The early molecular dialogue between soybean and the bacterium Bradyrhizobium japonicum is crucial for triggering their symbiotic interaction. Here we found a single large genomic locus that is widely separated from the symbiosis island and was conspicuously induced within minutes after the addition of genistein. This locus (named BjG30) contains genes for the multidrug efflux pump, TetR family...

Comamonas acidovorans YM1609 secreted a polyhydroxybutyrate (PHB) depolymerase into the culture supernatant when it was cultivated on poly(3-hydroxybutyrate) [P(3HB)] or poly(3-hydroxybutyrate-co-3-hydroxyvalerate) [P(3HB-co-3HV)] as the sole carbon source. The PHB depolymerase was purified from culture supernatant of C. acidovorans by two chromatographic methods, and its molecular mass was det...