Klebsiella pneumoniae ATCC 25955 (formerly named Aerobacter aerogenes PZH 572, Warsaw), which is known to produce coenzyme-B12-dependent
glycerol dehydratase when grown anaerobically in a
glycerol medium, formed coenzyme-B12-dependent
diol dehydratase in a 1,2-propanediol-containing medium. Both the
diol dehydratase and the
glycerol dehydratase produced by the organism catalyzed the conversion of
glycerol,
1,2-propanediol and
1,2-ethanediol to the corresponding
aldehydes and underwent concomitant inactivation during the catalysis of
glycerol dehydration, as does the
diol dehydratase of K. pneumoniae (A. aerogenes) ATCC 8724. However, the two
enzymes were distinguishable from each other by the
monovalent-cation-selectivity pattern and by substrate specificity; that is,
glycerol dehydratase preferred
glycerol to
1,2-propanediol as a substrate, whereas
diol dehydratase preferred
1,2-propanediol to
glycerol, as judged from initial velocity studies. Ouchterlony double-diffusion analysis and immunochemical titration with rabbit antiserum against
diol dehydratase of K. pneumoniae ATCC 8724 established clearly that the
diol dehydratase of K. pneumoniae ATCC 25955 is immunologically similar to that of K. pneumoniae ATCC 8724, while the
glycerol dehydratase of the former is different from the
diol dehydratase of both strains. Both the
enzymes were found to be distributed in several bacteria of the family Enterobacteriaceae.