Steroid-1-dehydrogenases in nocardioform bacteria studied by electrophoresis and immuno blotting techniques

Fifteen noncardioform bacteria strains, capable of transforming steroid compounds were investigated with regard to their range of inducible steroid-1-dehydrogenase (St1DH)1 activities. The St1DHs of these bacteria were compared due to their immuno reactivity in Western blot experiments with a rabbit antiserum raised against the purified St1DH of Rhodococcus rhodochrous 7030. Four strains exhibited a strong immuno reactivity, irrespective of differences in the electrophoretic mobility of the enzymes. Five strains revealed significantly diminished reactivities, and in five strains with a very low St1DH content, no reactivity was found. One strain, designated as Nocardiaspec. 7151, exhibited a high, inducible St1DH activity, but no immunoreaction was found. The absence of immuno reactivity is discussed in connection with the considerably diminished electrophoretic mobility of this enzyme.