title: Borneol Dehydrogenase from Pseudomonas sp. Strain TCU-HL1 Catalyzes the Oxidation of (+)-Borneol and Its Isomers to Camphor.
abstract: Most plant-produced monoterpenes can be degraded by soil microorganisms. Borneol is a plant terpene that is widely used in traditional Chinese medicine. Neither microbial borneol dehydrogenase (BDH) nor a microbial borneol degradation pathway has been reported previously. One borneol-degrading strain, Pseudomonas sp. strain TCU-HL1, was isolated by our group. Its genome was sequenced and annotated. The genome of TCU-HL1 consists of a 6.2-Mbp circular chromosome and one circular plasmid, pTHL1 (12.6 kbp). Our results suggest that borneol is first converted into camphor by BDH in TCU-HL1 and is further decomposed through a camphor degradation pathway. The recombinant BDH was produced in the form of inclusion bodies. The apparent Kmvalues of refolded recombinant BDH for (+)-borneol and (-)-borneol were 0.20 ± 0.01 and 0.16 ± 0.01 mM, respectively, and the kcatvalues for (+)-borneol and (-)-borneol were 0.75 ± 0.01 and 0.53 ± 0.01 s-1, respectively. Two plant BDH genes have been reported previously. The kcatand kcat/Kmvalues of lavender BDH are about 1,800-fold and 500-fold lower, respectively, than those of TCU-HL1 BDH.
  
  
  
  The degradation of borneol in a soil microorganism through a camphor degradation pathway is reported in this study. We also report a microbial borneol dehydrogenase. The kcatand kcat/Kmvalues of lavender BDH are about 1,800-fold and 500-fold lower, respectively, than those of TCU-HL1 BDH. The indigenous borneol- and camphor-degrading strain isolated, Pseudomonas sp. strain TCU-HL1, reminds us of the time 100 years ago when Taiwan was the major producer of natural camphor in the world.
authors.affiliation: Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Hoi-Lung
authors.initials: HL
authors.lastname: Tsang
authors.affiliation: Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Jui-Lin
authors.initials: JL
authors.lastname: Huang
authors.affiliation: Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Yu-Hsuan
authors.initials: YH
authors.lastname: Lin
authors.affiliation: Institute of Biological Chemistry, Academia Sinica, Nankang, Taipei, Taiwan.
authors.forename: Kai-Fa
authors.initials: KF
authors.lastname: Huang
authors.affiliation: Department of Bioresources, Da-Yeh University, Changhua, Taiwan.
authors.forename: Pei-Luen
authors.initials: PL
authors.lastname: Lu
authors.affiliation: Department of Microbiology and Immunology, School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Guang-Huey
authors.initials: GH
authors.lastname: Lin
authors.affiliation: Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Aye Aye
authors.initials: AA
authors.lastname: Khine
authors.affiliation: Department of Medical Technology, School of Medicine, Tzu Chi University, Hualien, Taiwan.
authors.forename: Anren
authors.initials: A
authors.lastname: Hu
authors.affiliation: Department of Biochemistry, School of Medicine, Tzu Chi University, Hualien, Taiwan hpchen@mail.tcu.edu.tw.
authors.forename: Hao-Ping
authors.identifier: 0000-0002-6491-2178
authors.initials: HP
authors.lastname: Chen
mesh_terms: D000429:Alcohol Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D055162:Biocatalysis; D001673:Biodegradation, Environmental; D001892:Camphanes / Q000378:metabolism*; D002164:Camphor / Q000378:metabolism*; D007536:Isomerism; D007700:Kinetics; D010084:Oxidation-Reduction; D010936:Plant Extracts; D011549:Pseudomonas / Q000201:enzymology* / Q000378:metabolism
chemical_list: D001892:Camphanes; D010936:Plant Extracts; D002164:Camphor; D000429:Alcohol Oxidoreductases; C053725:borneol dehydrogenase; C022871:isoborneol