FIG. 4.

Western blotting analysis of P21 in A. ferrooxidans grown under different conditions. (A) Equivalent amounts of total cell proteins from A. ferrooxidans grown in ferrous iron (lane a), elemental sulfur (lane b), thiosulfate (lane c), pyrite (lane d), copper sulfide (lane e), zinc sulfide (lane f), and a sample of pure recombinant P21 (2 μg) (lane g) were separated by SDS-PAGE and were then transferred to a PVDF membrane, followed by reaction with antiserum against rP21 and colorimetric development as described in Materials and Methods. (B) Quantification of the bands in panel A by using the Scion image-processing program. The values shown are relative to those obtained in sulfur grown cells taken as 100%.