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Borneol is a bicyclic plant monoterpene. It can be degraded by soil microorganisms through the conversion of borneol dehydrogenase (BDH) and a known camphor degradation pathway. Recombinant BDH from Pseudomonas sp. TCU-HL1 was produced in the form of inclusion body. The refolded BDH1 tends to precipitate. Insoluble recombinant BDH1 was converted into a soluble form by adding glycerol in LB medium. The k cat and k cat / K m values of soluble form BDH1 for (+)-borneol turned out to be about 34-fold and 45-fold higher, respectively, than those of the refolded enzyme. On the other hand, a gene knockout mutant, TCU-HL1Δ bdh , was constructed to investigate the possible presence of a second copy of the bdh gene in TCU-HL1 genome. A new gene, bdh2 , encoding a BDH isozyme, was identified, and the recombinant BDH2 protein was produced in a soluble form. Both bdh1 and bdh2 genes are expressed in the crude extract of wild type TCU-HL1, as shown by RT-qPCR results. Both BDH isozymes prefer to degrade (+)-borneol, rather than (−)-borneol, probably because (+)-camphor is the main form present in nature. • Two borneol dehydrogenases (BDH) from Pseudomonas sp. TCU-HL1 were characterized. • Insoluble BDH1 was converted into a soluble form by adding glycerol in LB medium. • The k cat for (+)-borneol of soluble BDH1 is 34-fold higher than that of the refolded. • A new gene, bdh2 , encoding a BDH isozyme, was identified in strain TCU-HL1. • Both BDH1 and BDH2 prefer to degrade (+)-borneol, rather than (−)-borneol. [ABSTRACT FROM AUTHOR]