Bacterial copolyesters

Cl in conjunction with a direct exposure probe is known as desorption chemical ionization (DCI). [30,89,90] In DCI, the analyte is applied from solution or suspension to the outside of a thin resistively heated wire loop or coil. Then, the analyte is directly exposed to the reagent gas plasma while being rapidly heated at rates of several hundred °C s and to temperatures up to about 1500 °C (Chap. 5.3.2 and Fig. 5.16). The actual shape of the wire, the method how exactly the sample is applied to it, and the heating rate are of importance for the analytical result. [91,92] The rapid heating of the sample plays an important role in promoting molecular species rather than pyrolysis products. [93] A laser can be used to effect extremely fast evaporation from the probe prior to CL [94] In case of nonavailability of a dedicated DCI probe, a field emitter on a field desorption probe (Chap. 8) might serve as a replacement. [30,95] Different from desorption electron ionization (DEI), DCI plays an important role. [92] DCI can be employed to detect arsenic compounds present in the marine and terrestrial environment [96], to determine the sequence distribution of P-hydroxyalkanoate units in bacterial copolyesters [97], to identify additives in polymer extracts [98] and more. [99] Provided appropriate experimental setup, high resolution and accurate mass measurements can also be achieved in DCI mode. [100]... 

Abate, R. Garozzo, D. Rapisardi, R. BalUstreri, A. Montaudo, G. Sequence Distribution of P-Hydroxyalkanoate Units in Bacterial Copolyesters Determined by-DCI-MS. Rapid Commun. Mass Spectrom. 1992, 6,702-706. 

Doi, Y., Kunioka, M., Nakamura, Y., and Soga, K. 1988. Nuclear magnetic resonance studies on unusual bacterial copolyesters of 3-hydroxybutyrate and 4-hydroxybutyrate. Macromolecules, 21,2722-2727. 

With regard to biodegradabihty, the kinetics of ertzymatic degradation is variable depending on the crystalhnity, the stmctnre and the material s thermomechanieal history. Bacterial copolyesters are more easily biodegradable than their equivalents obtained by chemical synthesis [AVE 12]. 

Abdelhad HM, Hafez AMA, El-sayed AA, Khodair TA (2009) Copolymer [P(HB-c< -HV)] production as affected by strains and fermentation techniques. J Appl Sci Res 5 343-353 Abe C, Taima Y, Nakamura Y, Doi Y (1990) New bacterial copolyester of 3-hydroxyalkanoates and 3-hydroxy-0)-fluoroalkanoates produced by Pseudomonas oleovorans. Polym Commun 31 404 06... 

Doi Y, Abe C (1990) Biosynthesis and characterization of a new bacterial copolyester of 3-hydroxyalkanoates and 3-hydroxy-w-chloroalkanoates. Macromol 23 3705—3707 Doi Y, Kitamura S, Abe H (1995) Microbial synthesis and characterization of poly(3-hydroxybu-... 

Johnstone B (1990) A throw away answer. Far Eastern Econ Rev 147 62-63 Joseph B, Ramteke PW, Thomas G (2008) Cold active microbial lipases some hot issues and recent developments. Biotechnol Adv 26 457-470 Jung K, Hany R, Rentsch D, Stomi T, Egh T, Witholt B (2000) Characterization of new bacterial copolyesters containing 3-hydroxyoxoalkanoates and acetoxy-3-hydroxyalkanoates. Macromolecules 33 8571-8575... 

Kunioka M, Nakamura Y, Doi Y (1988) New bacterial copolyesters produced in Alcaligenes eutrophus from organic acids. Polym commun 29 174-176 Kuo CY, Lin HY (2009) Photodegration of C.I. Reactive Red 2 by platinized titanium dioxide. J Hazard Mater 165 1243-1247... 

Adamus, G., Sikorska, W., Montaudo, M.S., Scandola, M., and Kowalczuk, M., Sequence Distribution and Fragmentation Studies of Bacterial Copolyester— Characterization of PHBV Macroinitiator by Electrospray Ion-Trap Multistep Mass Spectrometry, Macromolecules, 33, 5797 (2000). 

Abate, R., BaUistreri, A., Montaudo, G., Garozzo, D., ImpaUomeni, G., Critchley G., and Tanaka, K., Quantitative Applications of Matrix-assisted Laser Desorption/ Ionization with Time-of-flight Mass Spectrometry Determination of Copolymer Composition in Bacterial Copolyesters, Rapid Comm. Mass Spectrom., 7, 1033... 

Ballistreri, A., Giuffrida, M., Lenz, R.W., Fuller, C.R., Kim, Y.B., and Montaudo, G., Determination of Sequence Distributions in Bacterial Copolyesters Containing Higher Alkyl and Alkenyl Pendant Groups, Macrotnolecules, 25,1845, 1992. 

Sequence distribution and chemical structure of mass-selected macromolecules of macroinitiators derived from selected biopolyesters were accomplished recently with the aid of ESI-Mtechnique. The NMR and ESI-MS evaluation of the chemical structure of macroinitiators obtained by partial depolymerization of natural PHB, PHBV and PHO revealed that due to the elimination reaction they contain olefinic and carboxylic end groups. Based on the ESI-MS" studies of PHBV macroinitiator obtained by partial alkaline depolymerization of natural PHBV (containing 5 mole % of hydroxyvalerate units) the microstructure of this bacterial copolyester was assessed, starting from dimer up to the oligomer containing 22 repeat units. ... 

Lee, M.Y. and Park, WH. (2000) Preparation of bacterial copolyesters with improved hydrophilicity by carboxylation. Macromolecular Chemistry and Physics, 201, 2771-2774. 

Largely unsaturated PHAs have been cross-linked by a very slow chemical procedure (it usually takes days), which implies the conversion of double bonds into epoxy groups and exposure to air (Ashby et al. 20(X)). Other epoxidized bacterial copolyesters, poly[(/ )-3-hydroxyoctanoate-co-(/ )-3-hydroxy-10,ll-epoxyunde-canoate], were cross-linked with succinic anhydride in the presence of 2-ethyM-methylimidazole or with hexamethylene diamine without a catalyst at 90°C (Lee et al. 1999a Lee and Park 1999). 

Jung K, Hany R, Rentsch D, Storni T, EgU T, Witholt B (2000) Characterization of new bacterial copolyesters containing 3-hydroxyoxoalkanoates and acetoxy-3-hydroxyalkanoates. 

Abe C, Taima Y, Nakamura Y, Doi Y (1990) New bacterial copolyester of 3-hydroxyalkanoates and 3-hydroxy-fluoroalkanoates produced by Pseudomonas oleovorans. Polym Commun 31 404 06... 

Kunioka, M., Tamaki, A. and Doi, Y. (1989b) Crystalline and thermal properties of bacterial copolyesters poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and poly(3-hydroxybuty rate-co-4-hydroxybutyTate), Macromolecules, 22, 694 697. 

Due to the difference in structure, the synthetic polyesters are less susceptible to enzymatic degradation than the bacterial polyester. The bacterial copolyesters are mainly isotactic with random atactic stereo sequences, whereas the synthetic polyesters have blocks of only partial stereoregularity. In the latter case the [S]-stereo block hinders the enzymatic degradation, making difficult for depolymerase to penetrate into the surface and access the available [R]-stereo blocks. 

Blends of the bacterial copolyester with PS, PCL, and PLA were completely immiscible as determined by the DSC. This conclusion was based on a negligible effect of blending on the glass transition for each component. 

The Solid-State Structure, Thermal and Crystalline Properties of Bacterial Copolyesters of (R)-3-Hydroxybutyric Acid with (R)-3-Hydroxyhexanoic Acid... 

Poly(3-hydroxybutyric acid-co-3-hydroxyhexanoic acid) [P(3HB-co-3HH)] is another bacterial copolyester. Our laboratory has found that random copolyesters of 3HB with 3HH are produced from plant oils by the Aeromonas caviae bacterium isolated from soil The basic characterization on the crystallization and physical properties of P(3HB-co-3HH) random copolyesters with 3HH contents varying from 0 to 25 mol% has indicated that 3HH units are excluded from the P(3HB) crystal lattice, and that both the crystallinity and crystallization rate are reduced as 3HH content increases. The elongation at break of the copolyester film is near 10 times that of P(3HB) homopolymer . These results have shown that the mechanical properties of P(3HB-co-3HH) random copolyesters can be modified although they have the same crystal structure of P(3HB) homopolymer, and they suggested that the copolyesters have better processability and more extensive applicable areas. 

The bacterial copolyesters of (/ )-3-hydroxybutyric acid (3HB) and (/ )-3-hydroxyhexanoic acid (3HH) [P(3HB-co-3HH)] were supplied from Procter Gamble Company. Poly[(R)-3-hydroxybutyric acid] was supplied... 

As mentioned, previously, a bacterial copolyester (poly(3-hydroxyoctanoate-co-3-hydroxyundecenoate), PHOU) containing repeating units with terminal... 

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