title: Concurrent obtaining of aromatic (R)-2-hydroxyacids and aromatic 2-ketoacids by asymmetric oxidation with a newly isolated Pseudomonas aeruginosa ZJB1125.
abstract: Pseudomonas aeruginosa ZJB1125 harboring a stereoselective 2-hydroxyacid dehydrogenase (2-HADH) can catalyze asymmetric oxidation of mandelic acid and 2-chloromandelic acid into (R)-isomers and corresponding 2-ketoacids with high activity and enantioselectivity, while no consecutive oxidation of 2-ketoacids was observed during whole-cell catalysis. The 2-HADH in P. aeruginosa ZJB1125 is a FMN-dependent flavoprotein and did not require NAD(P)⁺ as cofactors to catalyze the oxidation reaction. Enzyme activity staining identified 2-HADH as the key enzyme that enantioselectively oxidized (S)-hydroxyacid to 2-ketoacid. The 2-HADH in P. aeruginosa ZJB1125 is inducible and 2-chloromandelic acid was found to induce its synthesis efficiently. The bacterium displayed pretty high activity and enantioselectivity for most of the aromatic 2-hydroxyacids examined, and have a potential for the concurrent obtaining of aromatic (R)-2-hydroxyacids and aromatic 2-ketoacids in near theoretical conversions. Using a simple organic extract process, aromatic (R)-2-hydroxyacids and aromatic 2-ketoacids can be effectively separated from the biocatalytic reaction mixture with high yield (>95%). This work provided a novel method for the concurrent obtaining of aromatic (R)-2-hydroxyacids and aromatic 2-ketoacids by oxidation of aromatic 2-hydroxyacids in one-step biotransformation, which would be a valuable process due to its high atom economy.
authors.affiliation: Institute of Bioengineering, Zhejiang University of Technology, Hangzhou 310014, China.
authors.forename: Ya-Ping
authors.initials: YP
authors.lastname: Xue
authors.forename: Fang-Fang
authors.initials: FF
authors.lastname: Tian
authors.forename: Li-Tao
authors.initials: LT
authors.lastname: Ruan
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Liu
authors.forename: Yu-Guo
authors.initials: YG
authors.lastname: Zheng
authors.forename: Yin-Chu
authors.initials: YC
authors.lastname: Shen
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism; D001426:Bacterial Proteins / Q000378:metabolism; D018533:Biomass; D001711:Biotransformation; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D007536:Isomerism; D007651:Keto Acids / Q000737:chemistry / Q000378:metabolism*; D008333:Mandelic Acids / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D010802:Phylogeny; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000201:enzymology / Q000378:metabolism*; D013696:Temperature
chemical_list: C541344:2-chloromandelic acid; D001426:Bacterial Proteins; D007651:Keto Acids; D008333:Mandelic Acids; D000429:Alcohol Oxidoreductases; C083779:2-hydroxyacid dehydrogenase
keywords: (R)-2-Hydroxyacid; 2-Ketoacid; Asymmetric oxidation; Pseudomonas aeruginosa