FIG. 1.

The formation of MVs (indicated by arrowheads) from the outer membrane of IH-2000 was observed when cells were grown in a medium containing toluene. MV formation would start with the swelling of the outer membrane (A). The outer membrane was not damaged by MV formation (B). The MVs released were also detected, and there were no electron-dense materials enclosed (C). Incomplete MVs (indicated by arrowheads) were produced by a toluene-sensitive mutant, strain 32 (D and E). The MVs of strain 32 were smaller than those of IH-2000 and differed in morphology. Bar = 100 nm.