Localized Insertion of New S-Layer During Growth of Bacillus stearothermophilus Strain PV72

Abstract

Bacillus stearothermophilus PV72 carries a crystalline surface layer (S-layer) with hexagonal symmetry (Sleytr and Messner 1983). Sites of insertion of newly synthesized subunits into the regular lattice during cell growth have been determined using the indirect fluorescent antibody technique (Hughes and Stokes 1971) and the protein A/colloidal gold marker system (Mühlpfort 1982, Smit and Agabian 1982). In both systems, cells from a logarithmic growing culture have been incubated with anti-S-layer serum in order to completely cover the cells and then reincubated in fresh medium. Samples were extracted at intervals and reacted with fluoresceinisothiocyanate conjugated goat-anti-rabbit-IgG or protein A/colloidal gold conjugate. S-layer material incorporated into the lattice after reincubation had no IgG attached to it and therefore did not bind the marker.