Composting studies of poly (β-hydroxybutyrate-co-/gb-hydroxyvalerate)

Yue, Caiyan; Gross, Richard A.; McCarthy, Stephen P.

doi:10.1016/0141-3910(95)00201-4

Cited by 25 publications

(11 citation statements)

References 5 publications

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“…Due to the wide range of thermoplastic and elastomeric properties, which can be regulated as a function of polymeric composition, these environmentally biodegradable [78,83,86] and biocompatible [10,63] microbial polyesters are receiving increased attention as alternatives to conventional commodity plastics. Over 125 diVerent hydroxyalkanoates have been identiWed as constituents of PHAs [64].…”

Section: Introductionmentioning

confidence: 99%

Polyhydroxyalkanoate copolymers from forest biomass

Keenan

Nakas

Tanenbaum

2006

J IND MICROBIOL BIOTECHNOL

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The potential for the use of woody biomass in poly-beta-hydroxyalkanoate (PHA) biosynthesis is reviewed. Based on previously cited work indicating incorporation of xylose or levulinic acid (LA) into PHAs by several bacterial strains, we have initiated a study for exploring bioconversion of forest resources to technically relevant copolymers. Initially, PHA was synthesized in shake-flask cultures of Burkholderia cepacia grown on 2.2% (w/v) xylose, periodically amended with varying concentrations of levulinic acid [0.07-0.67% (w/v)]. Yields of poly(beta-hydroxybutyrate-co-beta-hydroxyvalerate) [P(3HB-co-3HV)] from 1.3 to 4.2 g/l were obtained and could be modulated to contain from 1.0 to 61 mol% 3-hydroxyvalerate (3HV), as determined by 1H and 13C NMR analyses. No evidence for either the 3HB or 4HV monomers was found. Characterization of these P(3HB-co-3HV) samples, which ranged in molecular mass (viscometric, Mv) from 511-919 kDa, by differential scanning calorimetry and thermogravimetric analyses (TGA) provided data which were in agreement for previously reported P(3HB-co-3HV) copolymers. For these samples, it was noted that melting temperature (Tm) and glass transition temperature (Tg) decreased as a function of 3HVcontent, with Tm demonstrating a pseudoeutectic profile as a function of mol% 3HV content. In order to extend these findings to the use of hemicellulosic process streams as an inexpensive carbon source, a detoxification procedure involving sequential overliming and activated charcoal treatments was developed. Two such detoxified process hydrolysates (NREL CF: aspen and CESF: maple) were each fermented with appropriate LA supplementation. For the NREL CF hydrolysate-based cultures amended with 0.25-0.5% LA, P(3HB-co-3HV) yields, PHA contents (PHA as percent of dry biomass), and mol% 3HV compositions of 2.0 g/l, 40% (w/w), and 16-52 mol% were obtained, respectively. Similarly, the CESF hydrolysate-based shake-flask cultures yielded 1.6 g/l PHA, 39% (w/w) PHA contents, and 4-67 mol% 3HV compositions. These data are comparable to copolymer yields and cellular contents reported for hexose plus levulinic acid-based shake-flask cultures, as reported using Alcaligenes eutrophus and Pseudomonas putida. However, our findings presage a conceivable alternative, forestry-based biorefinery approach for the production of value-added biodegradable PHA polymers. Specifically, this review describes the current and potential utilization of lignocellulosic process streams as platform precursors to PHA polymers including hemicellulosic hydrolysates, residual cellulose-derived levulinic acid, tall oil fatty acids (Kraft pulping residual), and lignin-derived aromatics.

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Section: Introductionmentioning

confidence: 99%

Polyhydroxyalkanoate copolymers from forest biomass

Keenan

Nakas

Tanenbaum

2006

J IND MICROBIOL BIOTECHNOL

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“…In PHBV, an increased HV content is associated with faster degradation (Renard et al, 2004). Degradation mechanisms under aerobic conditions are different from those in anaerobic situations and reports indicate that PHBV degrades more rapidly than PHB under aerobic conditions (Mergaert et al, 1993;Yue et al, 1996;dos Santos Rosa et al, 2004;Li et al, 2007); however, the opposite effect has been reported by Abou-Zeid et al (2001.…”

Section: Degradabilitymentioning

confidence: 86%

“…The rate of PHA biodegradation is influenced by (1) molar mass, copolymer composition, crystallinity, stereochemistry, hydrophilic/hydrophobic balance, and chain mobility; and (2) environmental factors including the microbial population, temperature, moisture, pH and nutrient supply (Khanna and Srivastava, 2005). Numerous studies have explored the factors determining the biodegradability of PHA materials in soil (Savenkova et al, 2000;dos Santos Rosa et al, 2004;Corre Ãa et al, 2008), fresh water (Kasuya et al, 1998;Kusaka et al, 1999), marine environments (Tsuji and Suzuyoshi, 2002aThellen et al, 2008), sewage environments (Briese et al, 1994;Bucci et al, 2007) and compost media (Yue et al, 1996;Maiti et al, 2007). In general, the higher the polymer crystallinity and melting point, the lower the degradation rate.…”

Section: Degradabilitymentioning

confidence: 98%

Polyhydroxyalkanoates (PHAs) for food packaging

Plackett

Siró

2011

Multifunctional and Nanoreinforced Polymers for Food Packaging

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“…Biodegradation of PHAs has been widely studied under both aerobic and anaerobic conditions and in environments ranging from compost, sewage or soil through to fresh or salt water [2,3,50,[69][70][71][72][73][74]. In general, PHAs are more readily biodegradable than PLAs [28].…”

Section: Biodegradabilitymentioning

confidence: 99%

PHA/Clay Nano-Biocomposites

Plackett

2012

Environmental Silicate Nano-Biocomposites

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Polyhydroxyalkanoates or PHAs were first observed in a laboratory in France in the 1920s and, since then, their creation as a form of energy storage in bacteria as well as their practical uses have been much studied. There has been increased interest in commercial production of PHAs in recent times and, over the past 10 years in particular, there have been various reports on solution-cast or melt-processed PHA/clay nano-biocomposites and their properties. In most studies, these nano-biocomposites exhibit intercalated or mixed exfoliated/intercalated morphologies. The use of plate-like clays as additives can lead to some enhancement in the mechanical and gas barrier properties of PHAs as well as increased thermal stability, although the effects depend significantly on clay type, clay organomodifer and process conditions. The influence of clay addition on PHA biodegradability has been either positive or negative according to the particular study. There has been very little research to date on the migration properties of PHA in the context of use in packaging and none yet in which PHA/clay nano-biocomposites have been the focus. If economic and technical challenges can be solved, PHAs should have a promising future in various uses ranging from packaging through to medicine and PHA/clay nano-biocomposites may also play a role in the future by providing a way for PHA material properties to be tuned according to the particular need.

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Composting studies of poly (β-hydroxybutyrate-co-/gb-hydroxyvalerate)

Cited by 25 publications

References 5 publications

Polyhydroxyalkanoate copolymers from forest biomass

Polyhydroxyalkanoate copolymers from forest biomass

Polyhydroxyalkanoates (PHAs) for food packaging

PHA/Clay Nano-Biocomposites

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