- Email: [email protected]
Combinatorial optimization of synthetic operons for the microbial production of monolignols in Escherichia coli
New Biotechnology · Volume 31S · July 2014
HIGH VALUE PLANT PRODUCTS
High value plant products PL-01 Effect of pH on chromium and nickel biosorption by Litchi chinensis seeds in single and binary metal systems Liliana Morales Barrera ∗ , Liliana Morales-Barrera, Imelda GuerreroCoronilla, Víctor Zambrano-Pérez, Jessica Reyes-Ledezma, Griselda Chávez-Camarillo, Eliseo Cristiani-Urbina
reached 75% and the clearance rate was above 60%. The solubility of the hydrolysate was as high as 93%. Emulsifying property and the emulsifying stability decreased in the pH range from 3.0 to 5.0, increasing with increased pH. Compared with the measured globulin, the foamability of hydrolysate was significantly increased, lowest at pH 5.0. The viscosity of hydrolysate was reduced during the whole process. http://dx.doi.org/10.1016/j.nbt.2014.05.2011
National Polytechnic Institute
PL-03 The extensive industrial use of hexavalent chromium [Cr(VI)] and divalent nickel [Ni(II)], as well as their improper disposal have led to heavy metal contamination of water [1]. Biosorption is an efficient and low-cost alternative for removing toxic metals from aqueous solutions. The purpose of this work was to evaluate the effect of pH on chromium and Ni(II) removal by Litchi chinensis seeds (LCS) in single and binary metal systems. LCS was able to remove chromium and Ni(II) from monometal solutions, and its removal capacity depended on the pH. LCS exhibited the highest removal capacity of Cr(VI) (86.79 mg/g), total chromium (64.74 mg/g) and Ni(II) (20.0 mg/g) at pH values of 1.0, 2.0 and 7.5, respectively. At a pH value of 1, a difference between Cr(VI) (86.79 mg/g) and total chromium removal capacity (34.4 mg/g) was observed and this was probably due to the fact that part of the Cr(VI) initially present in the solution was reduced to trivalent chromium [Cr(III)] by LCS. In the bimetal systems, Ni(II) did not have any effect on chromium removal at any pH value. Ni(II) biosorption capacity was not affected by the presence of chromium in acidic solutions; in contrast, at neutral pH values the capacity improved significantly. These results suggest that chromium and Ni(II) do not compete between them for the same LCS binding sites. Reference
Philana van Summeren-Wesenhagen ∗ , Raphael Voges, Stephan Noack, Michael Bott, Jan Marienhagen Forschungszentrum Jülich
The monolignol p-coumaryl alcohol is an important precursor of lignans and key building block of the plant polymer lignin, which is widely recognized as cheap source of aromatic compounds. However, due to its complex and irregular structure the uitilization of lignin is technically challenging. In contrast, microbial production of p-coumaryl alcohol and other monolignols represents a promising alternative. Recently, the first synthetic pathway for the production of p-coumaryl alcohol from L-tyrosine in E. coli was published [1]. Here we introduce a fast and robust method to optimize the product titers of this four gene pathway, based on the Phosphorothioate based Ligase-Independent Gene Cloning (PLICing) method [2]. An operon library was generated in which the translation efficiency of every gene was systematically varied by different spacings between the ribosomal binding site and the START-codon. Screening of this library yielded mutants producing up to 55 mg/L p-coumaryl alcohol, 7 times more compared to the starting strain under similar cultivation conditions. References
[1].Park D, Yun YS, Yim KH, Park JM. Effect of Ni(II) on the reduction of Cr(VI) by Ecklonia biomass. Bioresource Technol 2006;97:1592–8.
http://dx.doi.org/10.1016/j.nbt.2014.05.2010
PL-02 Preparation and Functional Characteristics of Peptide from Naked Oat Globulin by Protease Hydrolysis ∗
Meili Zhang , Rui Lin Inner Mongolia Agricultural University
Globulin of naked oat was prepared by the Osborne methods and hydrolyzed by alkaline protease. The degree of protein hydrolysis and clearance rate of hydroxyl free radicals were used to identify the best enzyme hydrolysis process. Solubility, emulsifying property, viscosity and foamability of hydrolysate were tested. The result showed that the optimum conditions were as follows: dose of enzyme, 10000U/g; concentration of substrate, 5%; the temperature, 60◦ C; and pH 9.0. After 3 h, the degree of hydrolysis S158
Combinatorial optimization of synthetic operons for the microbial production of monolignols in Escherichia coli
www.elsevier.com/locate/nbt
[1].Jansen F, Gillessen B, Mueller F, Commandeur U, Fischer R, Kreuzaler F. Metabolic engineering for p-coumaryl alcohol production in Escherichia coli by introducing an artificial phenylpropanoid pathway. Biotechnology and Applied Biochemistry 2014, doi: 10.1002/bab.1222. (published ahead of print). [2].Blanusa M, Schenk A, Sadeghi H, Marienhagen J, Schwaneberg U. Phosphorothioate based Ligase-Independent Gene Cloning - A method for cloning of mutant libraries in directed evolution experiments. Anal Biochem 2010;406:141–6.
http://dx.doi.org/10.1016/j.nbt.2014.05.2012
HIGH VALUE PLANT PRODUCTS
High value plant products PL-01 Effect of pH on chromium and nickel biosorption by Litchi chinensis seeds in single and binary metal systems Liliana Morales Barrera ∗ , Liliana Morales-Barrera, Imelda GuerreroCoronilla, Víctor Zambrano-Pérez, Jessica Reyes-Ledezma, Griselda Chávez-Camarillo, Eliseo Cristiani-Urbina
reached 75% and the clearance rate was above 60%. The solubility of the hydrolysate was as high as 93%. Emulsifying property and the emulsifying stability decreased in the pH range from 3.0 to 5.0, increasing with increased pH. Compared with the measured globulin, the foamability of hydrolysate was significantly increased, lowest at pH 5.0. The viscosity of hydrolysate was reduced during the whole process. http://dx.doi.org/10.1016/j.nbt.2014.05.2011
National Polytechnic Institute
PL-03 The extensive industrial use of hexavalent chromium [Cr(VI)] and divalent nickel [Ni(II)], as well as their improper disposal have led to heavy metal contamination of water [1]. Biosorption is an efficient and low-cost alternative for removing toxic metals from aqueous solutions. The purpose of this work was to evaluate the effect of pH on chromium and Ni(II) removal by Litchi chinensis seeds (LCS) in single and binary metal systems. LCS was able to remove chromium and Ni(II) from monometal solutions, and its removal capacity depended on the pH. LCS exhibited the highest removal capacity of Cr(VI) (86.79 mg/g), total chromium (64.74 mg/g) and Ni(II) (20.0 mg/g) at pH values of 1.0, 2.0 and 7.5, respectively. At a pH value of 1, a difference between Cr(VI) (86.79 mg/g) and total chromium removal capacity (34.4 mg/g) was observed and this was probably due to the fact that part of the Cr(VI) initially present in the solution was reduced to trivalent chromium [Cr(III)] by LCS. In the bimetal systems, Ni(II) did not have any effect on chromium removal at any pH value. Ni(II) biosorption capacity was not affected by the presence of chromium in acidic solutions; in contrast, at neutral pH values the capacity improved significantly. These results suggest that chromium and Ni(II) do not compete between them for the same LCS binding sites. Reference
Philana van Summeren-Wesenhagen ∗ , Raphael Voges, Stephan Noack, Michael Bott, Jan Marienhagen Forschungszentrum Jülich
The monolignol p-coumaryl alcohol is an important precursor of lignans and key building block of the plant polymer lignin, which is widely recognized as cheap source of aromatic compounds. However, due to its complex and irregular structure the uitilization of lignin is technically challenging. In contrast, microbial production of p-coumaryl alcohol and other monolignols represents a promising alternative. Recently, the first synthetic pathway for the production of p-coumaryl alcohol from L-tyrosine in E. coli was published [1]. Here we introduce a fast and robust method to optimize the product titers of this four gene pathway, based on the Phosphorothioate based Ligase-Independent Gene Cloning (PLICing) method [2]. An operon library was generated in which the translation efficiency of every gene was systematically varied by different spacings between the ribosomal binding site and the START-codon. Screening of this library yielded mutants producing up to 55 mg/L p-coumaryl alcohol, 7 times more compared to the starting strain under similar cultivation conditions. References
[1].Park D, Yun YS, Yim KH, Park JM. Effect of Ni(II) on the reduction of Cr(VI) by Ecklonia biomass. Bioresource Technol 2006;97:1592–8.
http://dx.doi.org/10.1016/j.nbt.2014.05.2010
PL-02 Preparation and Functional Characteristics of Peptide from Naked Oat Globulin by Protease Hydrolysis ∗
Meili Zhang , Rui Lin Inner Mongolia Agricultural University
Globulin of naked oat was prepared by the Osborne methods and hydrolyzed by alkaline protease. The degree of protein hydrolysis and clearance rate of hydroxyl free radicals were used to identify the best enzyme hydrolysis process. Solubility, emulsifying property, viscosity and foamability of hydrolysate were tested. The result showed that the optimum conditions were as follows: dose of enzyme, 10000U/g; concentration of substrate, 5%; the temperature, 60◦ C; and pH 9.0. After 3 h, the degree of hydrolysis S158
Combinatorial optimization of synthetic operons for the microbial production of monolignols in Escherichia coli
www.elsevier.com/locate/nbt
[1].Jansen F, Gillessen B, Mueller F, Commandeur U, Fischer R, Kreuzaler F. Metabolic engineering for p-coumaryl alcohol production in Escherichia coli by introducing an artificial phenylpropanoid pathway. Biotechnology and Applied Biochemistry 2014, doi: 10.1002/bab.1222. (published ahead of print). [2].Blanusa M, Schenk A, Sadeghi H, Marienhagen J, Schwaneberg U. Phosphorothioate based Ligase-Independent Gene Cloning - A method for cloning of mutant libraries in directed evolution experiments. Anal Biochem 2010;406:141–6.
http://dx.doi.org/10.1016/j.nbt.2014.05.2012