Synthesis of Diblock copolymer poly-3-hydroxybutyrate -<it>block</it>-poly-3-hydroxyhexanoate [PHB-<it>b</it>-PHHx] by a <it>β</it>-oxidation weakened <it>Pseudomonas putida</it> KT2442

<p>Abstract</p> <p>Background</p> <p>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 PH...

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Main Authors: Tripathi Lakshmi, Wu Lin-Ping, Chen Jinchun, Chen Guo-Qiang
Format: Article
Language:English
Published: BMC 2012-04-01
Series:Microbial Cell Factories
Subjects:
Online Access:http://www.microbialcellfactories.com/content/11/1/44
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author Tripathi Lakshmi
Wu Lin-Ping
Chen Jinchun
Chen Guo-Qiang
author_facet Tripathi Lakshmi
Wu Lin-Ping
Chen Jinchun
Chen Guo-Qiang
author_sort Tripathi Lakshmi
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>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-<it>b</it>-PHHx consisting of poly-3-hydroxybutyrate (PHB) block covalently bonded with poly-3-hydroxyhexanoate (PHHx) block were for the first time produced successfully by a recombinant <it>Pseudomonas putida</it> KT2442 with its <it>β</it>-oxidation cycle deleted to its maximum.</p> <p>Results</p> <p>The chloroform extracted polymers were characterized by nuclear magnetic resonance (NMR), thermo- and mechanical analysis. NMR confirmed the existence of diblock copolymers consisting of 58 mol% PHB as the short chain length block with 42 mol% PHHx as the medium chain length block. The block copolymers had two glass transition temperatures (<it>T</it><sub><it>g</it></sub>) at 2.7°C and −16.4°C, one melting temperature (<it>T</it><sub><it>m</it></sub>) at 172.1°C and one cool crystallization temperature (<it>T</it><sub><it>c</it></sub>) at 69.1°C as revealed by differential scanning calorimetry (DSC), respectively. This is the first microbial short-chain-length (scl) and medium-chain-length (mcl) PHA block copolymer reported.</p> <p>Conclusions</p> <p>It is possible to produce PHA block copolymers of various kinds using the recombinant <it>Pseudomonas putida</it> KT2442 with its <it>β</it>-oxidation cycle deleted to its maximum. In comparison to a random copolymer poly-3-hydroxybutyrate-<it>co</it>-3-hydroxyhexanoate (P(HB-<it>co</it>-HHx)) and a blend sample of PHB and PHHx, the PHB-<it>b</it>-PHHx showed improved structural related mechanical properties.</p>
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spelling doaj.art-5288e27ec19d45199397519e26c8e2bc2022-12-22T01:48:42ZengBMCMicrobial Cell Factories1475-28592012-04-011114410.1186/1475-2859-11-44Synthesis of Diblock copolymer poly-3-hydroxybutyrate -<it>block</it>-poly-3-hydroxyhexanoate [PHB-<it>b</it>-PHHx] by a <it>β</it>-oxidation weakened <it>Pseudomonas putida</it> KT2442Tripathi LakshmiWu Lin-PingChen JinchunChen Guo-Qiang<p>Abstract</p> <p>Background</p> <p>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-<it>b</it>-PHHx consisting of poly-3-hydroxybutyrate (PHB) block covalently bonded with poly-3-hydroxyhexanoate (PHHx) block were for the first time produced successfully by a recombinant <it>Pseudomonas putida</it> KT2442 with its <it>β</it>-oxidation cycle deleted to its maximum.</p> <p>Results</p> <p>The chloroform extracted polymers were characterized by nuclear magnetic resonance (NMR), thermo- and mechanical analysis. NMR confirmed the existence of diblock copolymers consisting of 58 mol% PHB as the short chain length block with 42 mol% PHHx as the medium chain length block. The block copolymers had two glass transition temperatures (<it>T</it><sub><it>g</it></sub>) at 2.7°C and −16.4°C, one melting temperature (<it>T</it><sub><it>m</it></sub>) at 172.1°C and one cool crystallization temperature (<it>T</it><sub><it>c</it></sub>) at 69.1°C as revealed by differential scanning calorimetry (DSC), respectively. This is the first microbial short-chain-length (scl) and medium-chain-length (mcl) PHA block copolymer reported.</p> <p>Conclusions</p> <p>It is possible to produce PHA block copolymers of various kinds using the recombinant <it>Pseudomonas putida</it> KT2442 with its <it>β</it>-oxidation cycle deleted to its maximum. In comparison to a random copolymer poly-3-hydroxybutyrate-<it>co</it>-3-hydroxyhexanoate (P(HB-<it>co</it>-HHx)) and a blend sample of PHB and PHHx, the PHB-<it>b</it>-PHHx showed improved structural related mechanical properties.</p>http://www.microbialcellfactories.com/content/11/1/44PolyhydroxyalkanoatesPHBBlock copolymer<it>Pseudomonas putida</it>3-hydroxybutyrate3-hydroxyhexanoateSynthetic biology
spellingShingle Tripathi Lakshmi
Wu Lin-Ping
Chen Jinchun
Chen Guo-Qiang
Synthesis of Diblock copolymer poly-3-hydroxybutyrate -<it>block</it>-poly-3-hydroxyhexanoate [PHB-<it>b</it>-PHHx] by a <it>β</it>-oxidation weakened <it>Pseudomonas putida</it> KT2442
Microbial Cell Factories
Polyhydroxyalkanoates
PHB
Block copolymer
<it>Pseudomonas putida</it>
3-hydroxybutyrate
3-hydroxyhexanoate
Synthetic biology
title Synthesis of Diblock copolymer poly-3-hydroxybutyrate -<it>block</it>-poly-3-hydroxyhexanoate [PHB-<it>b</it>-PHHx] by a <it>β</it>-oxidation weakened <it>Pseudomonas putida</it> KT2442
title_full Synthesis of Diblock copolymer poly-3-hydroxybutyrate -<it>block</it>-poly-3-hydroxyhexanoate [PHB-<it>b</it>-PHHx] by a <it>β</it>-oxidation weakened <it>Pseudomonas putida</it> KT2442
title_fullStr Synthesis of Diblock copolymer poly-3-hydroxybutyrate -<it>block</it>-poly-3-hydroxyhexanoate [PHB-<it>b</it>-PHHx] by a <it>β</it>-oxidation weakened <it>Pseudomonas putida</it> KT2442
title_full_unstemmed Synthesis of Diblock copolymer poly-3-hydroxybutyrate -<it>block</it>-poly-3-hydroxyhexanoate [PHB-<it>b</it>-PHHx] by a <it>β</it>-oxidation weakened <it>Pseudomonas putida</it> KT2442
title_short Synthesis of Diblock copolymer poly-3-hydroxybutyrate -<it>block</it>-poly-3-hydroxyhexanoate [PHB-<it>b</it>-PHHx] by a <it>β</it>-oxidation weakened <it>Pseudomonas putida</it> KT2442
title_sort synthesis of diblock copolymer poly 3 hydroxybutyrate it block it poly 3 hydroxyhexanoate phb it b it phhx by a it β it oxidation weakened it pseudomonas putida it kt2442
topic Polyhydroxyalkanoates
PHB
Block copolymer
<it>Pseudomonas putida</it>
3-hydroxybutyrate
3-hydroxyhexanoate
Synthetic biology
url http://www.microbialcellfactories.com/content/11/1/44
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