A Versatile Filtration Technique to Produce Axenic Cultures of the Armored Dinoflagellates Peridinium bipes and Alexandrium tamarense (Dinophyceae)

ABSTRACT

Using a micro-mesh, a versatile technique for the production of axenic cultures of the dinoflagellates Peridinium bipes and Alexandrium tamarense was developed. Effective bactericidal doses of antibiotics, but not harmful to dinoflagellate cells, were 100 μg mL⁻¹ for streptomycin, 150 μg mL⁻¹ for ampicillin and penicillin G, and 200 μg mL⁻¹ for gentamycin. The purification strategy involved the following steps. The micro-mesh first physically separated algal cells from non-axenic cultures, which were treated with antibiotics to eradicate contaminants, and P. bipes cells were then purified successfully in less than one week. This technique remarkably improved the speed of successful purification of the cells since many healthy cells migrating phototactically were inoculated into subsequent medium. This technique would be suitable for producing axenic cultures of other strains of armored dinoflagellates, including A. tamarense.