Over the years, the use of plastics has complicated the problem of disposal of solid wastes. One strategy to reduce plastic waste is the use of biodegradable plastics. A group of these plastics are polyhydroxyalkanoates (PHAs). To date more than 250 different microorganisms are known to synthesize and accumulate PHA. Most Pseudomonas strains are able to accumulate mcl-PHA. In previous studies, ...

BACKGROUND Block polyhydroxyalkanoates (PHA) were reported to be resistant against polymer aging that negatively affects polymer properties. Recently, more and more attempts have been directed to make PHA block copolymers. Diblock copolymers PHB-b-PHHx consisting of poly-3-hydroxybutyrate (PHB) block covalently bonded with poly-3-hydroxyhexanoate (PHHx) block were for the first time produced su...

The gasification of organic waste materials to synthesis gas (syngas), followed by microbial fermentation, provides a significant resource for generating bioproducts such as polyhydroxyalkanoates (PHA). The anaerobic photosynthetic bacterium, Rhodospirillum rubrum, is an organism particularly attractive for the bioconversion of syngas into PHAs. In this study, a quantitative physiological analy...

By Erik Robert Coats, Ph.D. Washington State University December 2005 Chairs: Michael P. Wolcott, Frank J. Loge Biologically-derived polyesters known as polyhydroxyalkanoates (PHAs) represent a potentially sustainable replacement to fossil fuel-based thermoplastics. However, current production practices do not achieve this objective. Herein we report on the production of PHA with a mixed microb...

To date, limited reports are available on the regulatory systems exerting control over bacterial synthesis of the biodegradable polyester group known as polyhydroxyalkanoates (PHAs). In this study, we performed random mini-Tn5 mutagenesis of the Pseudomonas putida CA-3 genome and screened transconjugants on nitrogen-limited medium for reduced PHA accumulation phenotypes. Disruption of a GacS se...

Polyhydroxyalkanoates (PHAs) are aliphatic polyesters that biosynthesized and accumulate in bacterial cells. Among PHAs, poly(3-hydroxybutyrate-co‑3-hydroxyhexanoate)s [P(3HB‑co‑3HHx)s] known to be practical PHA copolymers with an appropriate degree of flexibility. In the biosynthesis PHA, ethanol induces chain transfer (CT) reaction, resulting low-molecular-weight PHA. this study, P(3HB‑co‑3HH...

Polyhydroxyalkanoates (PHA) are biodegradable bioplastics of interest as potential substitutes petroleum-derived plastics that can be produced starting from lignocellulosic-derived residues. This study presents the combined solid-state enzymatic hydrolysis (SSEH) and fermentation (SSF) a sustainable approach for obtaining PHA using leftovers brewer's spent grain (BSG), grape pomace (GP) olive-m...

The effectiveness of polyhydroxyalkanoates (PHA) production with mixed microbial cultures (MMC) largely depends on the selection PHA-storing microorganisms, conventionally performed in sequencing batch reactors (SBR). These, although easily allow establishment required feast and famine (FF) regime, can represent a factor cost increase when process is scaled up. Here, novel continuous-flow for M...

Abstract Polyhydroxyalkanoates (PHA) production via a combination of mixed microbial culture (MMC) and waste carbon substrate has shown to be more economical solution compared pure process. Although crude glycerol been proven as promising feedstock, there are still limited study on the effect operating conditions such pH nutrient feeding strategy PHA using glycerol. This aims investigate feasib...