Crystallization Kinetics of Poly(3-hydroxybutyrate) Granules in Different Environmental Conditions

Michael Porter, Jian Yu

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DOI: 10.4236/jbnb.2011.23037                

Abstract

Poly(3-hydroxybutyrate) (PHB) is a natural biopolyester accumulated in microbial cells as tiny amorphous granules. The nano- micro-particles have a variety of potential applications and behave differently in different environments. In this work, the in situ crystallization of native PHB granules was investigated under different environmental conditions. The isothermal crystallization kinetics of the granules was shown to follow Avrami’s equation. The model parameter describing crystal growth is a function of temperature or pH and estimated from in situ crystallization measurements with attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. Empirical equations describing crystal growth are derived for the parameter values. PHB granules heated at 80-140°C in acidic solution (pH 2) up to 4 hr showed an increase in crystallinity from about 5% to 35% and moderate particle aggregation. PHB granules suspended in alkaline solutions (pH 9-12) at room temperature up to 4 hr showed an increase in crystallinity up to 45% and very little particle aggregation. It was found that the amorphousness of PHB granules in vivo is stabilized by water, lipids and proteins. Upon removal of these impurities, partial crystallization is induced which may inhibit extensive particle aggregation.

Keywords

Avrami model, crystallization kinetics, PHA, PHB granules, biopolyester particles

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	W. D. Luzier, “Materials derived from biomass/biode- gradable materials,” in Proceedings of the National Academy of Sciences of the United States of America, Vol. 89, No. 3, pp. 839-842.
[2]	A. J. Anderson and E. A. Dawes, “Occurrence, metabolism, metabolic role, and industrial uses of bacterial polyhydroxyalkanoates,” in Microbiological Reviews, Vol. 54, pp. 450-472.
[3]	G. N. Barnard and J. K. M. Sanders, “The poly-β-hydroxybutyrate granule in vivo: A new insight based on NMR spectroscopy of whole cells,” in Journal of Biological Chemistry, Vol. 264, No. 6, pp. 3286-3291.
[4]	S. Y. Lee, “Bacterial polyhydroxyalkanoates,” in Biotechnology and Bioengineering, Vol. 49, pp. 1-14.
[5]	T. V. Ojumu, J. Yu and B. O. Solomon, “Production of polyhydroxyalkanoates, a bacterial biodegradable polymer,” in African Journal of Biotechnology, Vol. 3, No. 1, pp. 18-24.
[6]	Y. Chen, J. Chen, C. Yu, G. Du and S. Lun, “Recovery of poly-3-hydroxybutyrate from Alcaligenes eutrophus by surfactant-chelate aqueous system,” in Process Biochemistry, Vol. 34, pp. 153-157.
[7]	J.-I. Choi and S. Y. Lee, “Efficient and economical recovery of poly(3-hydroxybutyrate) from recombinant Escherichia coli by simple digestion with chemicals,” in Biotechnology and Bioengineering, Vol. 62, No. 5, pp. 546-553.
[8]	J. S. Herron, J. D. King and D. C. White, “Recovery of poly-β-hydroxybutyrate from estuarine microflora,” in Applied and Environmental Microbiology, Vol. 35, No. 2, pp. 251-257.
[9]	S. K. Hahn, Y. K. Chang and S. Y. Lee, “Recovery and characterization of poly(3-hydroxybutyric acid) synthesized in Alcaligenes eutrophus and recombinant Escherichia coli,” in Applied and Environmental Microbiology, Vol. 61, pp. 34-39.
[10]	K. Sudesh, H. Abe and Y. Doi, “Synthesis, structure and properties of polyhydroxyalkanoates: Biological polyesters,” in Progress in Polymer Science, Vol. 25, pp. 1503- 1555.
[11]	E. S. Stuart, A. Tehrani, H. E. Valentin, D. Dennis, R. W. Lenz and R. C. Fuller, “Protein organization on the PHA inclusion cytoplasmic boundary,” in Journal of Biotechnology, Vol. 64, pp. 137-144.
[12]	D. M. Horowitz and J. K. M. Sanders, “Amorphous, biomimetic granules of polyhydroxybutyrate: Preparation, characterization, and biological implications,” in Journal of the American Chemical Society, Vol. 116, No. 7, pp. 2695-2702.
[13]	P. J. Barham, A. Keller, E. L. Otun and P. A. Holmes, “Crystallization and morphology of a bacterial thermoplastic: Poly-3-hydroxybutyrate,” in Journal of Materials Science, Vol. 19, pp. 2781-2794.
[14]	L. M. W. K. Gunaratne, R. A. Shanks and G. Amarasinghe, “Thermal history effects on crystallisation and melting of poly(3-hydroxybutyrate),” in Thermochimica Acta, Vol. 423, pp. 127-135.
[15]	D. S. Conti, M. I. Yoshida, S. H. Pezzin and L. A. F. Coelho, “Miscibility and crystallinity of poly(3-hy- droxybutyrate)/poly(3-hydroxybutyrate-co-3-hydroxyl-valerate) blends,” in Thermochimica Acta, Vol. 450, pp. 61-66.
[16]	J. Cornibert and R. H. Marchessault, “Conformational isomorphism. A general 21 helical conformation for poly(β-alkanoates),” in Macromolecules, Vol. 8, No. 3, pp. 296-305.
[17]	A. Padermshoke, Y. Katsumoto, H. Sato, S. Ekgasit, I. Noda and Y. Ozaki, “Melting behavior of poly(3-hydroxybutyrate) investigated by two-dimensional infrared correlation spectroscopy,” in Spectrochimica Acta Part A, Vol. 61, pp. 541-550.
[18]	H. Sato, R. Murakami, A. Padermshoke, F. Hirose, K. Senda, I. Noda and Y. Ozaki, “Infrared spectroscopy studies of CH???O hydrogen bondings and thermal behavior of biodegradable poly(hydroxyalkanoate),” in Macromolecules, Vol. 37, No. 19, pp. 7203-7213.
[19]	W. D. J. Callister, “Materials science and engineering: An introduction,” Hoboken, John Wiley & Sons, Inc., 2003.
[20]	P. J. Barham, “Nucleation behaviour of poly-3-hydroxy- butyrate,” in Journal of Materials Science, Vol. 19, No. 12, pp. 3826-3834.
[21]	J. Zhang, H. Sato, I. Noda and Y. Ozaki, “Conformation rearrangement and molecular dynamics of poly(3-hydroxybutyrate) during the melt-crystallization process investigated by infrared and two-dimensional infrared correlation spectroscopy,” in Macromolecules, Vol. 38, pp. 4274-4281.
[22]	T. Furukawa, H. Sato, R. Murakami, J. Zhang, Y.-X. Duan, I. Noda, S. Ochiai and Y. Ozaki, “Structure, dispersibility, and crystallinity of poly(hydroxybutyrate)/ poly(l-lactic acid) blends studied by FT-IR microspectroscopy and differential scanning calorimetry,” in Macromolecules, Vol. 38, pp. 6445-6454.
[23]	A. S. Myerson. “Molecular modeling applications in crystallization,” Cambridge, University Press, 1999.
[24]	M. D. Ward, “Bulk crystals to surfaces: Combining x-ray diffraction and atomic force microscopy to probe the structure and formation of crystal interfaces,” in Chemical Reviews, Vol. 101, No. 6, pp. 1697-1726.
[25]	K. Grage, A. C. Jahns, N. Parlane, R. Palanisamy, I. A. Rasiah, J. A. Atwood and B. H. A. Rehm, “Bacterial polyhydroxyalkanoate granules: Biogenesis, structure, and potential use as nano-/micro-beads in biotechnological and biomedical applications,” in Biomacromolecules, Vol. 10, pp. 660-669.
[26]	S. Bloembergen, D. A. Holden, G. K. Hamer, T. L. Bluhm and R. H. Marchessault, “Studies of composition and crystallinity of bacterial poly(β-hydroxybutyrate-co- β-hydroxyvalerate),” in Macromolecules, Vol. 19, pp. 2865-2871.
[27]	A. Paermshoke, Y. Katsumoto, H. Sato, S. Ekgasit, I. Noda and Y. Ozaki, “Melting behavior of poly(3-hydroxybutyrate) investigated by two-dimensional infrared correlation spectroscopy,” in Spectrochimica Acta Part A, Vol. 61, pp. 541-550.
[28]	J. Xu, B.-H. Guo, R. Yang, Q. Wu, G.-Q. Chen and Z.-M. Zhang, “In situ FTIR study on melting and crystallization of polyhydroxyalkanoates,” in Polymer, Vol. 43, pp. 6893-6899.
[29]	J. Li, C. Zhou, G. Wang, Y. Tao, Q. Liu and Y. Li, “Isothermal and nonisothermal crystallization kinetics of elastomeric polypropylene,” in Polymer Testing, Vol. 21, No. 5, pp. 583-589.
[30]	M. Liu, Q. Zhao, Y. Wang, C. Zhang, Z. Mo and S. Cao, “Melting behaviors, isothermal and non-isothermal crystallization kinetics of nylon 1212,” in Polymer, Vol. 44, No. 8, pp. 2537-2545.
[31]	Y. An, L. Dong, L. Li, Z. Mo and Z. Feng, “Isothermal crystallization kinetics and melting behavior of poly(β- hydroxybutyrate)/poly(vinyl acetate) blends,” in European Polymer Journal, Vol. 35, No. 3, pp. 365-369.