Formation and function of Vibrio parahaemolyticus lateral flagella

Formation of the lateral flagella (L flagella) of V. parahaemolyticus was studied immunologically, using specific antiserum against L flagella. On solid medium, L flagella were formed at both high (37°C) and low (25° temperatures, although at high temperatures they became dissociated from the cells and decomposed in the medium. L. flagella were not formed in liquid or soft agar medium. Formation of L flagella was decreased by lowering the pH of the medium and repressed by transferring the cells from solid medium to liquid medium. Mutants possessing L flagella but not a polar monotrichous flagellum (M flagellum) swarmed on solid medium, whereas mutants possessing an M flagellum but not L flagella did not. When the former mutants were grown on solid medium and then transferred to liquid medium, the cells oscillated until they lost L flagella. It is postulated that L flagella are locomotive organelles on solid medium and in some cases also in liquid medium, whereas M flagella are locomotive organelles only in liquid medium.