title: Bioreaction Engineering Leading to Efficient Synthesis of L-Glyceraldehyd-3-Phosphate.
abstract: Enantiopure L-glyceraldehyde-3-phosphate (L-GAP) is a useful building block in natural biological and synthetic processes. A biocatalytic process using glycerol kinase from Cellulomonas sp. (EC 2.7.1.30) catalyzed phosphorylation of L-glyceraldehyde (L-GA) by ATP is used for the synthesis of L-GAP. L-GAP has a half-life of 6.86 h under reaction conditions. The activity of this enzyme depends on the Mg2+to ATP molar ratio showing maximum activity at the optimum molar ratio of 0.7. A kinetic model is developed and validated showing a 2D correlation of 99.9% between experimental and numerical data matrices. The enzyme exhibits inhibition by ADP, AMP, methylglyoxal and Ca2+, but not by L-GAP and inorganic orthophosphate. Moreover, equal amount of Ca2+exerts a different degree of inhibition relative to the activity without the addition of Ca2+depending on the Mg2+to ATP molar ratio. If the Mg2+to ATP molar ratio is set to be at the optimum value or less, inorganic hexametaphosphate (PPi6) suppresses the enzyme activity; otherwise PPi6 enhances the enzyme activity. Based on reaction engineering parameters such as conversion, selectivity and specific productivity, evaluation of different reactor types reveals that batchwise operation via stirred-tank reactor is the most efficient process for the synthesis of L-GAP.
authors.affiliation: Institute of Technical Biocatalysis, Hamburg University of Technology, Hamburg, Germany.
authors.forename: Getachew S
authors.initials: GS
authors.lastname: Molla
authors.affiliation: Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany.
authors.forename: Birhanu M
authors.initials: BM
authors.lastname: Kinfu
authors.affiliation: Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Chow
authors.affiliation: Department of Microbiology and Biotechnology, University of Hamburg, Hamburg, Germany.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Streit
authors.affiliation: Sigma-Aldrich Chemie GmbH, Member of Merck Group, Buchs, Switzerland.
authors.forename: Roland
authors.initials: R
authors.lastname: Wohlgemuth
authors.affiliation: Institute of Technical Biocatalysis, Hamburg University of Technology, Hamburg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Liese
mesh_terms: D057005:Bioengineering; D040143:Cellulomonas / Q000201:enzymology; D004926:Escherichia coli / Q000201:enzymology; D005986:Glyceraldehyde 3-Phosphate / Q000096:biosynthesis*; D005991:Glycerol Kinase / Q000378:metabolism*; D006207:Half-Life; D010710:Phosphates / Q000378:metabolism; D015203:Reproducibility of Results; D013302:Streptomyces / Q000201:enzymology; D013816:Thermodynamics
chemical_list: D010710:Phosphates; C005035:hexametaphosphate; D005986:Glyceraldehyde 3-Phosphate; D005991:Glycerol Kinase
keywords: Glycerol kinase; L-Glyceraldehyde-3-phosphate instability; Mg2+ to ATP ratio; Reaction kinetics; Reactor simulation