FIG. 7.

TasA production and pre-TasA processing during growth and sporulation. (A) Samples of DSM cultures of strain AH94 (gerE36) were harvested during the logarithmic phase of growth (lane 1), at T₀ (lane 2), T₂ (lane 3), T₄ (lane 4), and T₆ (lane 5), and whole-cell extracts were prepared. The cultures were allowed to sporulate, and coat material was then isolated from spores purified 24 h after T₀ (lane 6). DSM cultures of a ς^H mutant (strain AH17; lane 7) or of a gerE tasA insertional mutant (strain AH1827, lane 8) were also collected at T₂. (B) Samples of supernatants of a culture of a tasA⁺ strain (AH94, lane 1) or of a tasA mutant (AH1700, lane 2) were collected at T₂, and the proteins were concentrated as described in Materials and Methods. (C) The inducer IPTG was added to a DSM culture of the P_spac-tasA strain AH1802 at T₀. Samples were collected at 30 (lane 1), 60 (lane 2), 90 (lane 3), and 120 min (lane 4) after the addition of IPTG, and whole-cell lysates were prepared. Samples of DSM cultures of a tasA mutant (lane 5) and of a tasA⁺ strain (lane 6) at T₂ were also analyzed. Proteins in all samples were resolved on 12.5% polyacrylamide gels containing SDS and transferred to nitrocellulose membranes. The membranes were probed with an anti-TasA antiserum. The arrows indicate the positions of the TasA antigen. Molecular mass markers (in kilodaltons) are also indicated.