Molecular weight and thermal properties of polyhydroxyalkanoates produced from fermented sugar molasses by open mixed cultures

Bengtsson, Stina; Pisco, Ana R.; Johansson, Peter; Lemos, Paulo C.; Reis, Maria A.M.

doi:10.1016/j.jbiotec.2010.03.022

Cited by 123 publications

(73 citation statements)

References 52 publications

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“…it declined from 6.5 9 10 5 to 2.2 9 10 5 Da when 3HV content improved from 15 to 39 % [68]. Moreover, the PHA obtained here with synthetic polymer is more or less homogenous [7]. Interestingly, Bengtsson et al [7], successfully obtained narrow range PDI with fermented waste also.…”

Section: Substrate and Feeding Regimementioning

confidence: 64%

“…In addition to 3HV, presence of propionate in media also promoted 3H2MB and 3H2MV in the polymer as these could be formed through the combination of acetyl-and propionyl-CoA [60,61]. Lactate is more likely to promote 3HB in a polymer by both pure and mixed cultures [7].…”

Section: Substrate and Feeding Regimementioning

confidence: 97%

“…P(3HB:3HV) may be formed with HV content in the range 15-31 %, varying linearly with the amount of propionate and valerate [8]. The enriched cultures of glycogen accumulating organisms were reported to utilize VFA from fermented sugarcane molasses to produce copolymers having 3HB (56-70 mol%), 3HV (13-43 mol%), 3HHx (1-23 mol%), 3H2 MB (0-2 mol%) and 3H2MV (0-2 mol%) which varied with VFA composition [7]. In addition to 3HV, presence of propionate in media also promoted 3H2MB and 3H2MV in the polymer as these could be formed through the combination of acetyl-and propionyl-CoA [60,61].…”

Section: Substrate and Feeding Regimementioning

confidence: 99%

“…In comparison to fermented effluent, polymer with single synthetic acid has higher M w up to 3.0 9 10 6 Da, which may be due to higher rates of polymerization [66]. M w of the copolymers was observed to be 4.5-9 9 10 5 Da with acetate and propionate, 8.5 9 10 5 Da, for P(3HB:3HV) with molasses and 3.5-4.3 9 10 5 Da for copolymer with fermented molasses [7,67]. The disruption of polymer chain by 3HV units causes the average M w to decrease with increasing monomer units, e.g.…”

Section: Substrate and Feeding Regimementioning

confidence: 99%

“…These aspects in PHAs are affected by the type of bacteria, substrate, feeding strategies and physiological conditions. All these components can be manipulated to attain polymer with desirable properties [6][7][8]. PHAs are divided into different classes based on the carbon (C) chain length: (1) short (scl-PHAs; 3-5Cs), (2) medium (mcl-PHAs; 6-14Cs), and (3) long (lcl-PHAs; 17-18Cs).…”

Section: Introductionmentioning

confidence: 99%

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Challenges and Opportunities for Customizing Polyhydroxyalkanoates

et al. 2015

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Polyhydroxyalkanoates (PHAs) as an alternative to synthetic plastics have been gaining increasing attention. Being natural in their origin, PHAs are completely biodegradable and eco-friendly. However, consistent efforts to exploit this biopolymer over the last few decades have not been able to pull PHAs out of their nascent stage, inspite of being the favorite of the commercial world. The major limitations are: (1) the high production cost, which is due to the high cost of the feed and (2) poor thermal and mechanical properties of polyhydroxybutyrate (PHB), the most commonly produced PHAs. PHAs have the physicochemical properties which are quite comparable to petroleum based plastics, but PHB being homopolymers are quite brittle, less elastic and have thermal properties which are not suitable for processing them into sturdy products. These properties, including melting point (T m ), glass transition temperature (T g ), elastic modulus, tensile strength, elongation etc. can be improved by varying the monomeric composition and molecular weight. These enhanced characteristics can be achieved by modifications in the types of substrates, feeding strategies, culture conditions and/or genetic manipulations.

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Section: Substrate and Feeding Regimementioning

confidence: 64%

Section: Substrate and Feeding Regimementioning

confidence: 97%

Section: Substrate and Feeding Regimementioning

confidence: 99%

Section: Substrate and Feeding Regimementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Challenges and Opportunities for Customizing Polyhydroxyalkanoates

et al. 2015

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Characterization of polyhydroxybutyrate biosynthesized from crude glycerol waste using mixed microbial consortia

McDonald

Coats

2012

J of Applied Polymer Sci

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This study focused on the characterization of polyhydroxybutyrate (PHB) produced from crude glycerol (CG) using mixed microbial consortia (MMC). PHB recovered from two biomass drying treatments (65°C oven drying and lyophilization) was characterized comparatively along with a commercially sourced PHB (PHB‐C). Characterization results showed that oven‐drying method caused PHB partial hydrolysis, as indicated by its lower molecular weight (Mw) (PHB‐O, 144,000 g mol−1), which further affected its physical and chemical properties. Lyophilization helped alleviate PHB hydrolysis during drying process, leading to PHB (PHB‐L) of higher Mw (309,000 g mol−1) and material properties comparable with commercial PHB. Furthermore, crystallization and morphological studies showed that PHB‐L featured faster crystallization rates and smaller spherulites as compared with PHB‐C, probably due to its lower Mw. In general, the results from this study suggested that CG‐MMC‐derived PHB‐L possessed material properties comparable with those of pure substrate/culture produced PHB. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

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Production of butanol and polyhydroxyalkanoate from industrial waste byClostridium beijerinckiiASU10

et al. 2019

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Summary This study demonstrated a biotechnological approach for simultaneous production of low‐cost H2, liquid biofuels, and polyhydroxyalkanoates (PHAs) by solventogenic bacterium (Clostridium beijerinckii) from renewable industrial wastes such as molasses and crude glycerol. C beijerinckii ASU10 (KF372577) exhibited considerable performance for hydrogen production of 5.1 ± 0.84 and 11 ± 0.44 mL H2 h−1 on glycerol and sugarcane molasses, respectively. The total acetone‐butanol‐ethanol (ABE) generation from glycerol and molasses was 9.334 ± 2.98 and 10.831 ± 4.1 g L−1, respectively. ABE productivity (g L−1 h−1) was 0.0486 and 0.0564 with a yield rate (g g−1) up to 0.508 and 0.493 from glycerol and molasses fermentation, respectively. The PHA yields from glycerol and sugarcane molasses were 84.37% and 37.97% of the dried bacterial biomass, respectively. Additionally, the ultrathin section of C beijerinckii ASU10 showed that PHA granules were accumulated more densely on glycerol than molasses. Gas chromatography–mass spectrometry (GC‐MS) analysis confirmed that the PHAs obtained from molasses fermentation included 3‐hydroxybutyrate (47.3%) and 3‐hydroxyoctanoate (52.7%) as the main constituents. Meanwhile, 3‐hydroxybutyrate represented the sole monomer of PHA produced from glycerol fermentation. This study demonstrated that C beijerinckii ASU10 (KF372577) is a potent strain for low‐cost PHA production depending on its high potential to produce high‐energy biofuel and other valuable compounds from utilization of organic waste materials.

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Molecular weight and thermal properties of polyhydroxyalkanoates produced from fermented sugar molasses by open mixed cultures

Cited by 123 publications

References 52 publications

Challenges and Opportunities for Customizing Polyhydroxyalkanoates

Challenges and Opportunities for Customizing Polyhydroxyalkanoates

Characterization of polyhydroxybutyrate biosynthesized from crude glycerol waste using mixed microbial consortia

Production of butanol and polyhydroxyalkanoate from industrial waste byClostridium beijerinckiiASU10

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