FIG 5.

(A and B) SEM observations of UC8547Δ3 and UC8547Δ16 biofilm on stainless steel. S. thermophilus UC8547Δ3 (A) and UC8547Δ16 (B) cells adhered to the surface after 6 h. (C and D) Low-magnification observation of the stainless steel wire at 30 h for S. thermophilus UC8547Δ3 (C) and UC8547Δ16 (D). The biofilm matrix is substantially limited compared to that of the parent strain UC8547. (E and F) Higher magnification of the same sample shows that adhered cells of UC8547Δ3 (E) and UC8547Δ16 (F) are not included in a multilayer biofilm structure.