An L-glucitol oxidizing dehydrogenase from Bradyrhizobium japonicum USDA 110 for production of D-sorbose with enzymatic or electrochemical cofactor regeneration

Appl Microbiol Biotechnol. 2014 Apr;98(7):3023-32. doi: 10.1007/s00253-013-5180-7. Epub 2013 Sep 6.

Abstract

A gene in Bradyrhizobium japonicum USDA 110, annotated as a ribitol dehydrogenase (RDH), had 87 % sequence identity (97 % positives) to the N-terminal 31 amino acids of an L-glucitol dehydrogenase from Stenotrophomonas maltophilia DSMZ 14322. The 729-bp long RDH gene coded for a protein consisting of 242 amino acids with a molecular mass of 26.1 kDa. The heterologously expressed protein not only exhibited the main enantio selective activity with D-glucitol oxidation to D-fructose but also converted L-glucitol to D-sorbose with enzymatic cofactor regeneration and a yield of 90 %. The temperature stability and the apparent K m value for L-glucitol oxidation let the enzyme appear as a promising subject for further improvement by enzyme evolution. We propose to rename the enzyme from the annotated RDH gene (locus tag bll6662) from B. japonicum USDA as a D-sorbitol dehydrogenase (EC 1.1.1.14).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Biotransformation
  • Bradyrhizobium / enzymology*
  • Bradyrhizobium / genetics
  • Cloning, Molecular
  • Coenzymes / metabolism*
  • Enzyme Stability
  • Fructose / metabolism
  • Gene Expression
  • Kinetics
  • Molecular Weight
  • Oxidation-Reduction
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Sorbitol / metabolism*
  • Sorbose / metabolism*
  • Stenotrophomonas maltophilia / enzymology
  • Stenotrophomonas maltophilia / genetics
  • Sugar Alcohol Dehydrogenases / chemistry
  • Sugar Alcohol Dehydrogenases / genetics
  • Sugar Alcohol Dehydrogenases / metabolism*
  • Temperature

Substances

  • Coenzymes
  • Recombinant Proteins
  • Fructose
  • Sorbitol
  • Sugar Alcohol Dehydrogenases
  • ribitol 2-dehydrogenase
  • Sorbose