Abstract
Accumulation of poly hydroxyalkanoate (PHA) from excess activated sludge (EAS) was monitored and controlled via the oxidation-reduction potential (ORP) adjusting process. The ORP was adjusted and controlled by only regulating the gas-flow rate pumped into the cultural broth in which sodium acetate (C2) and propionate (C3) were used as carbon sources. Productivity of PHA and the PHA compositions at various C2 to C3 ratios were also investigated. When ORP was maintained at +30 mV, 35% (w/w) of PHA of cell dry weight obtained when C2 was used as sole carbon source. The PHA copolymer, poly-(3-hydroxybutyrate-co-3-hydroxyvaler-ate) (PHBV), accumulated by EAS with different 3-hydroxyvalarate (3HV) molar fractions ranged from 8% to 78.0% when C2 and C3 was used as sole carbon source, By using ORP to monitor and control the fermentation process instead DO meter, the ORP system provided more precise control to the PHA accumulation process from EAS under low dissolved oxygen (DO) concentrations. Adjusting the C2 to C3 ratios in the media could control the composition such as the 3HV/3HB ratios of the PHBV. Furthermore, it might be an effective way to adjust the 3HV molar fractions in PHBV by controlling the DO concentration via the ORP monitoring system. The 3HV molar fractions in the PHBV declined with increasing ORP from -30 mV to +100 mV by adjusting the gas-flow rate (i.e. the DO concentration). It is concluded that the DO plays a very important role in the synthesis of 3HV subunits in PHBV co-polymer from the EAS. Therefore, a hypothetic metabolic model for PHA synthesis from EAS was proposed to try to explain the results in this study.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
Preview
Unable to display preview. Download preview PDF.
References
Chua, H., Yu, P. H. R, and Ho, L. Y. (1997), Appl. Biochem. Biotechnol. 63, 627–635.
Chua, H., Hu,W.F., and Ho, L. Y. (1997), J. IES Chem. Eng. 37(2), 12–14.
Hu, W. R, Chua, H., and Yu, P. H. F. (1997), Biotech. Letters, 19(7), 695–698.
Satoh, H., Iwamoto, Y, Mino, T., and Matsuo, T. (1998), Wat. Set. Tech. 38(2),103–109.
Satoh, H., Mino, T., and Matsuo, T. (1999), Intl. J. Biolog. Macromol. 25(1–3), 105–109.
Ma, C. K., Chua, H., Yu, P. H. R, and Hong, K. (2000), Appli. Biochem. Biotechnol. 84–86, 981–989.
Takabatake, H., Satoh, H., Mino, T., and Matsuo, T. (2000), Wat. Sci. Tech. 42(3–4), 351–356.
Serafim, L. S., Lemos, P. C, and Reis, M. A. M. (2002), Wat. Sci. Techn. 46(1–2), 353–356.
American Public Health Association (1995), Standard Methods for the Examination of Water and Wastewater. 19th edition, Washington, DC, USA.
Braunegg, G., Sonnleitner, B., and Lafferty, R. M. (1978), Eur. J. Appl. Microbiol. Biotechnol. 6, 29–37.
Pereira, H., Lemos, P. C, Reis, M. A. M., Crespo, J. P. S. G., Carrondo, M. J. T., and Santos, H. (1996), Wat. Res. 30(9),2128–2138.
Yamane, T. (1993), Biotechnol. Bioengineer. 41,165–170.
Dave, H., Ramakrishan, C, and Desai, J. D. (1996), Indian J. Exp. Biol. 34, 216–219.
Choi, G. G., Kim, M. W., Kim, J. Y., and Rhee, Y. H. (2003), Biotechnol. Lett. 25, 665–670.
Doi, Y, Segawa, A., and Kunioka, M. (1990), Intl. J. Biol. Macromol, 12, 106–111.
Satoh, H., Mino, T., and Matsuo, T. (1992), Wat. Sci. Technol. 26(5–6), 933–942.
Liu, W., Mino, T., Nakamura, K., and Matsuo, T. (1996), Water Research 30(1), 75–82.
Randall, A. A. and Liu, Y. H. (2002), Water Research 36, 3473–3478.
Anderson, A. J. and Dawes, E. A. (1990), Microbiology Review 54, 450–472.
Comeau, Y., Hall, K. J., Hancock, R. E. W., and Oldham, W. K. (1986), Water Research, 20, 1511–1521.
Comeau, Y., Oldham, W. K., and Hall, K. J. (1987), Advances in Water Pollution Control. Biological Phosphate Removal from Wastewaters (Ramadori, R. et al.), Pergamon Press pp. 39–55.
Mino, T., Arun, V., Tsuzuki, Y., and Matsuo, T. (1987), Advances in water pollution control: Biological phosphate removal from wastewaters (Ramadori R.), Pergamon Press, Oxford pp. 27–38.
Mino, T., Liu, W. T., Kurisu, E, and Matsuo, T. (1994), Water Science and Technology 31, 25–34.
Mino, T., van Loosdrecht, M. C. M., and Heijnen, J. J. (1998), Wat. Res. 32(11), 3193–3207.
Wentzel, M. C, Lotter, L. H., Loewenthal, R. E., and Marais, G. v. R. (1986), Water SA 12(4), 209–244.
Wentzel, M. C, Lotter, R. H., Ekama, G. A., Loewenthal, R.E., and Marais, G.v.R. (1991), Water Science and Technology 23, 567–576.
Maurer, M., Gujer, W, Hany, R., and Bachmann, S. (1997), Water Research 31(4), 907–917.
Louie, T. M., Mah, T. J., Oldham, W., and Ramey, W. D. (2000), Water Research 34(5), 1507–1514.
Thauer, R. K. (1988), Eur. J. Biochem. 176, 497–508
Author information
Authors and Affiliations
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2005 Humana Press Inc.
About this chapter
Cite this chapter
Hu, W.F., Sin, S.N., Chua, H., Yu, P.H.F. (2005). Synthesis of Polyhydroxyalkanoate (PHA) from Excess Activated Sludge Under Various Oxidation-Reduction Potentials (ORP) by Using Acetate and Propionate as Carbon Sources. In: Davison, B.H., Evans, B.R., Finkelstein, M., McMillan, J.D. (eds) Twenty-Sixth Symposium on Biotechnology for Fuels and Chemicals. ABAB Symposium. Humana Press. https://doi.org/10.1007/978-1-59259-991-2_25
Download citation
DOI: https://doi.org/10.1007/978-1-59259-991-2_25
Publisher Name: Humana Press
Print ISBN: 978-1-58829-697-9
Online ISBN: 978-1-59259-991-2
eBook Packages: Biomedical and Life SciencesBiomedical and Life Sciences (R0)