Regulation of flagellar morphogenesis by temperature: involvement of the bacterial cell surface in the synthesis of flagellin and the flagellum.

When cells of Proteus vulgaris were transferred from 37 to 42 C, a temperature at which they continue to grow almost optimally, they ceased to form flagella after approximately one generation time. This failure was due to a lesion in the flagellin-synthesizing process rather than the inability of these cells to assemble the organelle from constituents once formed. After transfer back to 37 C, these cells regained their ability to synthesize flagellin and form flagella, after one generation. When added during this period, chloramphenicol, rifampin, or penicillin prevented the synthesis of flagellin. The regeneration of the organelle at 37 C, then, requires growth for one generation, a period during which not only ribonucleic acid and protein synthesis, but also the presence of an intact cell envelope or concurrent synthesis of cell wall, are required.