Two oxidoreductases, XDH and LAD, were found in the same operon that was involved in sugar metabolism in Pantoea ananatis. LAD, whose endogenous substrate was unknown, was recombinantly prepared and biochemically analyzed. Consequently, LAD was identified as L-arabitol 2-dehydrogenase and its substrate specificity was complementary to that of XDH. (C) 2012, The Society for Biotechnology, Japan. All rights reserved.