CHEMOTAXIS IN A PSYCHROPHILIC MARINE BACTERIUM, VIBRIO SP. STRAIN ABE-1

Several properties of chemotaxis by a psychrophilic marine bacterium, Vibrio sp. strain ABE-1, were examined by swarm formation on a soft agar. This bacterium exhibited a large chemotactic response to succinate, acetate and fumarate. Small but significant response to amino acids such as aspartate, glutamate and serine was also observed. The maximum chemotactic response to succinate was obtained in the presence of 400mM NaCl, 10mM KCl and 25mM NH4Cl. Chemotaxis of this bacterium was observed in the range of pH from 6.0 to 9.0, and the optimum pH for chemotaxis was between 7.5 and 8.0. Chemotactic response by this bacterium was dependent on temperature, the optimum temperature was 15°C, and very high chemotactic response (about 60% of the maximum response) was retained even at low temperature such as 5°C. On the other hand, no response was detectable at 25°C.