- Email: [email protected]
Biological production of hydrogen using metabolic engineering as a tool
S284
Abstracts / Journal of Biotechnology 136S (2008) S276–S289
IL-033 Biological production of hydrogen using metabolic engineering as a tool Jong Moon Park 1,2,∗ , Gyoo Yeol Jung 2 , Han Saem Cho 2 , Young Mi Kim 1 1
School of Environmental Science and Engineering, POSTECH, Pohang, South Korea 2 Department of Chemical Engineering, POSTECH, Pohang, South Korea E-mail address: [email protected] (J.M. Park).
Hydrogen has not only the highest energy content per unit weight among the known gaseous fuels, but also has the clean combustion by-product nothing worse than water vapor and heat energy. Thus, in contrast to fossil fuels, hydrogen does not contribute to the greenhouse effect, depletion of the ozone layer and acid rain. Over 90% of the world’s hydrogen is produced from fossil fuels. Unfortunately, these processes are not always environmentally benign because of emission of carbon dioxide during the processes. On the other hand, evolution of carbon dioxide is zero-sum in the biological hydrogen production. Among various processes of biological hydrogen production anaerobic fermentation has several advantages over the others (Hallenbeck, 2005). It can utilize a wide range of substrates, both pure as well as waste products, and does not rely on the availability of light sources. However, hydrogen production yield per carbon substrate such as glucose is limited in the anaerobic fermentation since the anaerobic metabolism is designed by nature to efficiently remove the reducing power as the forms of organic acids including lactate instead of hydrogen gas (Rupprecht et al., 2006). Therefore, 4 mol H2 /mol glucose is the maximum yield of the anaerobic metabolism found in nature even though electron content of 1 mol glucose is equivalent to 12 mol H2 (Fong and Palsson, 2004) and new anaerobic metabolism with more than 4 mol H2 /mol glucose of hydrogen production yield should be designed. In this presentation, the various efforts to improve hydrogen yield by modify the metabolic pathway designed by nature using metabolic engineering techniques. Conclusively, potentials of the engineered Escherichia coli in the alternative hydrogen production system will be illustrated. References Fong, S.S., Palsson, B.O., 2004. Metabolic gene-deletion strains of Escherichia coli evolve to computationally predicted growth phenotypes. Nat. Genet. 36, 1056–1058. Hallenbeck, P.C., 2005. Fundamentals of the fermentative production of hydrogen. Water Sci. Technol. 52, 21–29. Rupprecht, J., Hankamer, B., Mussgnug, J.H., Ananyev, G., Dismukes, C., Kruse, O., 2006. Perspectives and advances of biological H2 production in microorganisms. Appl. Microbiol. Biotechnol. 72, 442–449.
tion because of their advantages such as biocompatibility, high responsibility. Among them, insulin delivery system based on injectable temperature-sensitive hydrogels (Kim et al., 2001; Ende and Peppas, 1997; Caliceti et al., 2001) showed several advantages in application such as easy to use by subcutaneous injection and single injection for weekly treatment. The mixture of insulin and copolymer solution changes from sol state to gel state after injection into the body due to the temperature increase. However, when the temperature-sensitive hydrogel is subcutaneously injected into the body via syringe, the viscosity of the solution is increased and it tends to form a gel inside the needle, which makes injection difficult (Cui et al., 2006). Although the enhancing agent such as zinc (Kim et al., 2001; Ende and Peppas, 1997; Caliceti et al., 2001) was used to improve the insulin encapsulation, these hydrogels have a limitation in insulin loading because of the physical adsorption by hydrophobic–hydrophobic interactions or locating the drug inside the voids in the hydrogel matrix. Here, we report a novel biomaterials for protein delivery system. This new system is using poly(-amino ester) (PAE) as duofunctional group. Firstly, PAE is used as a pH sensitive moiety (Huynh et al., 2008) to produce a new polymeric material of which aqueous solutions undergo sol-gel transition by pH change, as well as by temperature change. The second is using this block copolymer to encapsulate insulin based on the ionic link between the positive charges of PAE and negative charge of insulin. The release rate of insulin can controlled by controlling the rate of degradation of pH sensitive moiety, poly(-amino ester) that can be easily degrade within 2 or 3 weeks and demonstrated lower glucose level in diabetic animal. The accommodation of the characteristics into insulin delivery systems resulted in the sustained zero-order drug release with insulin concentration in plasma on male Sprague–Dawley (SD) rats and continuous blood glucose normalization in streptozotocininduced diabetic rats (DFR).
References Caliceti, P., et al., 2001. Controlled release of biomolecules from temperaturesensitive hydrogels prepared by radiation polymerization. J. Control. Release 75, 173–181. Cui, F., Shi, K., Zhang, L., Tao, A., Kawashima, Y., 2006. Biodegradable nanoparticles loaded with insulin–phospholipid complex for oral delivery: preparation, in vitro characterization and in vivo evaluation. J. Control. Release 114, 242–250. Ende, M.T., Peppas, N.A., 1997. Transport of ionizable drugs and proteins in crosslinked poly(acrylic acid) and poly(acrylic acid-co-2-hydroxyethyl methacrylate) hydrogels. II. Diffusion and release studies. J. Control. Release 48, 47–56. Huynh, D.P., et al., 2008. Functionalized injectable hydrogels for controlled insulin delivery. Biomaterials 29, 2527–2534. Kim, Y.J., Choi, S., Koh, J.J., Lee, M., Ko, K.S., Kim, S.W., 2001. Controlled release of insulin from injectable biodegradable triblock copolymer. Pharm. Res. 18, 548–550.
doi:10.1016/j.jbiotec.2008.07.610 doi:10.1016/j.jbiotec.2008.07.609 IL-037 IL-035 Sustained release of protein by injectable biodegradable hydrogels
Strategies in Pichia pastoris fermentation for recombinant protein mass production Shuiquan Tang, Michele Hastie, Nick Carriere, Zisheng Zhang ∗
Doo Sung Lee Department of Polymer Science and Engineering, SungKyunKwan University, Suwon, South Korea E-mail address: [email protected]. Biodegradable polymeric systems, especially biodegradable hydrogels (Kim et al., 2001; Ende and Peppas, 1997; Caliceti et al., 2001) have been interested as an attractive insulin formula-
Department of Chemical and Biological Engineering, University of Ottawa, Ottawa K1N 6N5, Canada Phytase is capable of breaking down phytate and can therefore promote the release of inorganic phosphorus and inositol, as well as proteins, amino acids, trace minerals and other nutrients chelated with phytate (Greiner and Konietzny, 2006). In recent years, this enzyme has been widely used as an additive to the feed
Abstracts / Journal of Biotechnology 136S (2008) S276–S289
IL-033 Biological production of hydrogen using metabolic engineering as a tool Jong Moon Park 1,2,∗ , Gyoo Yeol Jung 2 , Han Saem Cho 2 , Young Mi Kim 1 1
School of Environmental Science and Engineering, POSTECH, Pohang, South Korea 2 Department of Chemical Engineering, POSTECH, Pohang, South Korea E-mail address: [email protected] (J.M. Park).
Hydrogen has not only the highest energy content per unit weight among the known gaseous fuels, but also has the clean combustion by-product nothing worse than water vapor and heat energy. Thus, in contrast to fossil fuels, hydrogen does not contribute to the greenhouse effect, depletion of the ozone layer and acid rain. Over 90% of the world’s hydrogen is produced from fossil fuels. Unfortunately, these processes are not always environmentally benign because of emission of carbon dioxide during the processes. On the other hand, evolution of carbon dioxide is zero-sum in the biological hydrogen production. Among various processes of biological hydrogen production anaerobic fermentation has several advantages over the others (Hallenbeck, 2005). It can utilize a wide range of substrates, both pure as well as waste products, and does not rely on the availability of light sources. However, hydrogen production yield per carbon substrate such as glucose is limited in the anaerobic fermentation since the anaerobic metabolism is designed by nature to efficiently remove the reducing power as the forms of organic acids including lactate instead of hydrogen gas (Rupprecht et al., 2006). Therefore, 4 mol H2 /mol glucose is the maximum yield of the anaerobic metabolism found in nature even though electron content of 1 mol glucose is equivalent to 12 mol H2 (Fong and Palsson, 2004) and new anaerobic metabolism with more than 4 mol H2 /mol glucose of hydrogen production yield should be designed. In this presentation, the various efforts to improve hydrogen yield by modify the metabolic pathway designed by nature using metabolic engineering techniques. Conclusively, potentials of the engineered Escherichia coli in the alternative hydrogen production system will be illustrated. References Fong, S.S., Palsson, B.O., 2004. Metabolic gene-deletion strains of Escherichia coli evolve to computationally predicted growth phenotypes. Nat. Genet. 36, 1056–1058. Hallenbeck, P.C., 2005. Fundamentals of the fermentative production of hydrogen. Water Sci. Technol. 52, 21–29. Rupprecht, J., Hankamer, B., Mussgnug, J.H., Ananyev, G., Dismukes, C., Kruse, O., 2006. Perspectives and advances of biological H2 production in microorganisms. Appl. Microbiol. Biotechnol. 72, 442–449.
tion because of their advantages such as biocompatibility, high responsibility. Among them, insulin delivery system based on injectable temperature-sensitive hydrogels (Kim et al., 2001; Ende and Peppas, 1997; Caliceti et al., 2001) showed several advantages in application such as easy to use by subcutaneous injection and single injection for weekly treatment. The mixture of insulin and copolymer solution changes from sol state to gel state after injection into the body due to the temperature increase. However, when the temperature-sensitive hydrogel is subcutaneously injected into the body via syringe, the viscosity of the solution is increased and it tends to form a gel inside the needle, which makes injection difficult (Cui et al., 2006). Although the enhancing agent such as zinc (Kim et al., 2001; Ende and Peppas, 1997; Caliceti et al., 2001) was used to improve the insulin encapsulation, these hydrogels have a limitation in insulin loading because of the physical adsorption by hydrophobic–hydrophobic interactions or locating the drug inside the voids in the hydrogel matrix. Here, we report a novel biomaterials for protein delivery system. This new system is using poly(-amino ester) (PAE) as duofunctional group. Firstly, PAE is used as a pH sensitive moiety (Huynh et al., 2008) to produce a new polymeric material of which aqueous solutions undergo sol-gel transition by pH change, as well as by temperature change. The second is using this block copolymer to encapsulate insulin based on the ionic link between the positive charges of PAE and negative charge of insulin. The release rate of insulin can controlled by controlling the rate of degradation of pH sensitive moiety, poly(-amino ester) that can be easily degrade within 2 or 3 weeks and demonstrated lower glucose level in diabetic animal. The accommodation of the characteristics into insulin delivery systems resulted in the sustained zero-order drug release with insulin concentration in plasma on male Sprague–Dawley (SD) rats and continuous blood glucose normalization in streptozotocininduced diabetic rats (DFR).
References Caliceti, P., et al., 2001. Controlled release of biomolecules from temperaturesensitive hydrogels prepared by radiation polymerization. J. Control. Release 75, 173–181. Cui, F., Shi, K., Zhang, L., Tao, A., Kawashima, Y., 2006. Biodegradable nanoparticles loaded with insulin–phospholipid complex for oral delivery: preparation, in vitro characterization and in vivo evaluation. J. Control. Release 114, 242–250. Ende, M.T., Peppas, N.A., 1997. Transport of ionizable drugs and proteins in crosslinked poly(acrylic acid) and poly(acrylic acid-co-2-hydroxyethyl methacrylate) hydrogels. II. Diffusion and release studies. J. Control. Release 48, 47–56. Huynh, D.P., et al., 2008. Functionalized injectable hydrogels for controlled insulin delivery. Biomaterials 29, 2527–2534. Kim, Y.J., Choi, S., Koh, J.J., Lee, M., Ko, K.S., Kim, S.W., 2001. Controlled release of insulin from injectable biodegradable triblock copolymer. Pharm. Res. 18, 548–550.
doi:10.1016/j.jbiotec.2008.07.610 doi:10.1016/j.jbiotec.2008.07.609 IL-037 IL-035 Sustained release of protein by injectable biodegradable hydrogels
Strategies in Pichia pastoris fermentation for recombinant protein mass production Shuiquan Tang, Michele Hastie, Nick Carriere, Zisheng Zhang ∗
Doo Sung Lee Department of Polymer Science and Engineering, SungKyunKwan University, Suwon, South Korea E-mail address: [email protected]. Biodegradable polymeric systems, especially biodegradable hydrogels (Kim et al., 2001; Ende and Peppas, 1997; Caliceti et al., 2001) have been interested as an attractive insulin formula-
Department of Chemical and Biological Engineering, University of Ottawa, Ottawa K1N 6N5, Canada Phytase is capable of breaking down phytate and can therefore promote the release of inorganic phosphorus and inositol, as well as proteins, amino acids, trace minerals and other nutrients chelated with phytate (Greiner and Konietzny, 2006). In recent years, this enzyme has been widely used as an additive to the feed