A novel approach to the recycling of polystyrene is reported here; polystyrene is converted to a biodegradable plastic, namely polyhydroxyalkanoate (PHA). This unique combinatorial approach involves the pyrolysis of polystyrene to styrene oil, followed by the bacterial conversion of the styrene oil to PHA by Pseudomonas putida CA-3 (NCIMB 41162). The pyrolysis (520 degrees C) of polystyrene in ...

Sequencing batch reactor (SBR) systems were used for the development of a system and operating procedures for the high production and storage of polyhydroxyalkanoates (PHAs) by wastewater treatment (activated sludge) bacterial cultures. The systems were maintained at a nominal hydraulic retention time (HRT) of 10 hours, and a temperature of 20°C. The solids retention time (SRT) was maintained a...

Recombinant Escherichia coli harboring the medium-chain-length (MCL) polyhydroxyalkanoate (PHA) synthase gene has been shown to accumulate MCL-PHAs from fatty acids when FadB is inactive. However, the enzymes in fadB mutant E. coli responsible for channeling the beta-oxidation intermediates to PHA biosynthesis have not been fully elucidated. Only recently, two enzymes encoded by yfcX and maoC h...

P HYTOHEMAGGLUTININ (PHA), an extract of the red kidney bean, agglutinates erythrocytes,’ leukocytes,’ and other types of cells.2 Lymphocytes, stimulated by PHA, show an increase in the synthesis of DNA, RNA, and protein. These metabolic changes are accompanied by cell enlargement and mitosis. Little is known about the site where PHA attaches to the cell or of the mechanism underlying its mitog...

Organ development is a complex process involving the coordination of cell proliferation, differentiation, and morphogenetic events. Using a screen to identify genes that function coordinately with lin-35/Rb during animal development, we have isolated a weak loss-of-function (LOF) mutation in pha-1. lin-35; pha-1 double mutants are defective at an early step in pharyngeal morphogenesis leading t...

Polyhydroxyalkanoates (PHAs) composed of a mixture of short-chain-length-medium-chain-length (SCL-MCL) hydroxyacyl monomers are biologically produced polyesters that have properties ranging from thermoplastic to elastomeric, dependent on the molar ratio of SCL to MCL monomers incorporated into the copolymer. Because of the potential wide range of properties and applications for SCL-MCL PHA copo...

A passive hemagglutination (PHA) assay for antibody to Pseudomonas aeruginosa exotoxin is described which utilizes chromic chloride-treated ovine erythrocytes coated with purified toxin. PHA antitoxin titers correlated well with those obtained by a cytotoxicity neutralization assay (r = 0.91, P less than 0.001), whereas the PHA assay was four to eight times as sensitive. The mean serum PHA tite...

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...