Abstract
The chemotactic response of bacteria to extracellular products of two bloom algae, Asterionella glacialis (Bacillariophycea) and Chattonella
marina (Rhaphidophycea) was measured using the quantitative capillary tube technique. Genus Vibrio did not show chemotactic response to either algal extracellular product. Pseudomonas 022 which was isolated as a dominant bacterium during the A. glacialis bloom was chemotactic to A. glacialis extracellular product, but not to C. marina extracellular product. The chemotactic response of Pseudomonas 022 was great when the bacterium was preincubated on A. glacialis extracellular product. The chemotactic substance(s) in the extracellular product of A. glacialis has a molecular weight in the range 5, 000-1, 000 daltons with cationic charge and is composed by amino acids.
