Influence of iron on outer membrane components ofDesulfovibrio vulgaris

Abstract

The outer membranes (OM) ofDesulfovibrio vulgaris were isolated from cells grown in either iron-rich or iron-free medium by the Sarkosyl method. OMs from iron-free cells had a greatly simplified band pattern on PAGE, but retained the lipopolysaccharide and three major polypeptides (OMPs 1, 2, and 3) seen in OMs from iron-rich cells. These OMPs may be involved in iron uptake by the bacteria. Incubation of iron-free cells with ferrous sulfate prior to OM purification resulted in the increased retention of some bands normally seen only in iron-rich OM, indicating that iron may protect these OM proteins from Sarkosyl treatment. Iron is thus an important element in the stabilization of theD. vulgaris OM