Molecular basis for biosynthesis and accumulation of polyhydroxyalkanoic acids in bacteria

Steinbüchel, Alexander; Hustede, E.; Liebergesell, Matthias; Pieper, Ursula; Timm, Arnulf; Valentin, Henry E.

doi:10.1111/j.1574-6968.1992.tb05841.x

Cited by 123 publications

(22 citation statements)

References 33 publications

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“…PHB with molecular mass around 2 £ 10 5 to 3 £ 10 6 has been reported in the literature for cultures grown on long-chain hydrocarbons, while the molecular mass of the polymers also inXuences the crystallinity of PHA [25]. Bacillus sp.…”

Section: Polymer Analysismentioning

confidence: 98%

Production and characterization of PHB from two novel strains of Bacillus spp. isolated from soil and activated sludge

Thirumala

Reddy

Mahmood

2009

J Ind Microbiol Biotechnol

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The present study reports two bacteria, designated 87I and 112A, which were isolated from soil and activated sludge samples from Hyderabad, India, and that are capable of producing poly-3-hydroxybutyrate (PHB). Based on phenotypical features and genotypic investigations, these microorganisms were identified as Bacillus spp. Their optimal growth occurred between 28 degrees C and 30 degrees C and pH 7. Bacillus sp. 87I yielded a maximum of 70.04% dry cell weight (DCW) PHB in medium containing glucose as carbon source, followed by 55.5% DCW PHB in lactose-containing medium, whereas Bacillus sp. 112A produced a maximum of 67.73% PHB from glucose, 58.5% PHB from sucrose, followed by 50.5% PHB from starch as carbon substrates. The viscosity average molecular mass (M (v)) of the polymers from Bacillus sp. 87I was 513 kDa and from Bacillus sp. 112A was 521 kDa. All the properties of the biopolymers produced by the two strains 87I and 112A were characterized.

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Section: Polymer Analysismentioning

confidence: 98%

Production and characterization of PHB from two novel strains of Bacillus spp. isolated from soil and activated sludge

Thirumala

Reddy

Mahmood

2009

J Ind Microbiol Biotechnol

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“…PHAs can be divided into three classes depending on the number of carbon atoms in their monomer units; short-chain-length (SCL), medium-chainlength (MCL) and long-chain-length polyhydroxyalkanoates (LCL-PHAs), composed of hydroxyacids with 3-5, 6-14 or more than 14 carbon atoms, respectively [2,28]. About more than 100 diVerent monomer units reported so far, none of them contain more than 14 carbon atoms as constituents of PHAs [23].…”

Section: Introductionmentioning

confidence: 99%

Exploitation of inexpensive substrates for production of a novel SCL–LCL-PHA co-polymer by Pseudomonas aeruginosa MTCC 7925

Singh

Mallick

2008

J Ind Microbiol Biotechnol

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Studies conducted with various inexpensive carbon sources such as whey, vegetable oils (palm, mustard, soybean and coconut), a low-cost source of glucose-D, rice and wheat bran, and mustard and palm oil cakes demonstrated palm oil as the best substrate for accumulation of a novel short-chain-length-long-chain-length polyhydroxyalkanoate (SCL-LCL-PHA) co-polymer containing SCL 3HAs [3-hydroxybutyric acid (3HB) and 3-hydroxyvaleric acid (3HV)] and LCL 3HAs of 3-hydroxyhexadecanoic acid (3HHD) and 3-hydroxyoctadecanoic acid (3HOD) units as constituents by a sludge-isolated Pseudomonas aeruginosa MTCC 7925. The co-polymer content reached up to 60% of dry cell weight (dcw) at 48 h of incubation in 0.5% (v/v) palm oil and the extract of 0.5% (v/v) palm oil cake supplemented vessels. The PHAs pool was further enhanced up to 69 and 75% (dcw), when the above culture was subjected to P- and N-limitation, respectively. The mol fraction of 3HB:3HV:3HHD:3HOD units were, respectively, 83.1:7.7:3.8:5.4 and 87.3:5.1:3.6:4.0 in P- and N-limited cultures. Consequently, a co-polymer yield of 5 g l(-1) (approx.) was achieved, which was about 80-fold higher as compared to 69 mg l(-1) of the control culture. On substrate basis, the accumulation reached up to 0.62 g PHAs per g substrate, which was significantly higher as compared to the yield obtained from starch by Haloferax mediterranei and Azotobacter chroococum, from molasses by A. vinelandii UWD, and from lactose and xylose by Pseudomonas cepacia. This novel P(3HB-co-3HV-co-3HHD-co-3HOD) co-polymer exhibited better thermal and mechanical properties as revealed from the differential scanning calorimetry and mechanical property studies, thus opens up new possibilities for various industrial applications.

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“…They are produced by many genera of bacteria as inclusion bodies to serve as carbon sources and electron sink (7). The formation of PHB in bacteria involves three enzymes: ␤-ketothiolase, NADPH-dependent acetoacetyl-CoA reductase, and PHA synthase (for reviews, see refs.…”

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confidence: 99%

Metabolic pathway engineering in cotton: Biosynthesis of polyhydroxybutyrate in fiber cells

John¹,

Keller²

1996

Proc. Natl. Acad. Sci. U.S.A.

204

104

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Alcaligenes eutrophus genes encoding the enzymes, ␤-ketothiolase (phaA), acetoacetyl-CoA reductase (phaB), and polyhydroxyalkanoate synthase (phaC) catalyze the production of aliphatic polyester poly-D-(؊)-3-hydroxybutyrate (PHB) from acetyl-CoA. PHB is a thermoplastic polymer that may modify fiber properties when synthesized in cotton. Endogenous ␤-ketothiolase activity is present in cotton fibers. Hence cotton was transformed with engineered phaB and phaC genes by particle bombardment, and transgenic plants were selected based on marker gene, ␤-glucuronidase (GUS), expression. Fibers of 10 transgenic plants expressed phaB gene, while eight plants expressed both phaB and phaC genes. Electron microscopy examination of fibers expressing both genes indicated the presence of electron-lucent granules in the cytoplasm. High pressure liquid chromatography, gas chromatography, and mass spectrometry evidence suggested that the new polymer produced in transgenic fibers is PHB. Sixty-six percent of the PHB in fibers is in the molecular mass range of 0.6 ؋ 10 6 to 1.8 ؋ 10 6 Da. The presence of PHB granules in transgenic fibers resulted in measurable changes of thermal properties. The fibers exhibited better insulating characteristics. The rate of heat uptake and cooling was slower in transgenic fibers, resulting in higher heat capacity. These data show that metabolic pathway engineering in cotton may enhance fiber properties by incorporating new traits from other genetic sources. This is an important step toward producing new generation fibers for the textile industry.

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Molecular basis for biosynthesis and accumulation of polyhydroxyalkanoic acids in bacteria

Cited by 123 publications

References 33 publications

Production and characterization of PHB from two novel strains of Bacillus spp. isolated from soil and activated sludge

Production and characterization of PHB from two novel strains of Bacillus spp. isolated from soil and activated sludge

Exploitation of inexpensive substrates for production of a novel SCL–LCL-PHA co-polymer by Pseudomonas aeruginosa MTCC 7925

Metabolic pathway engineering in cotton: Biosynthesis of polyhydroxybutyrate in fiber cells

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