Axenic Culture of the Heterotrophic Dinoflagellate Pfiesteria shumwayae in a Semi‐Defined Medium

Abstract

ABSTRACT. A semi-defined, biphasic culture medium was developed that supported the axenic growth of three strains of the heterotrophic dinoflagellate Pfiesteria shumwayae. Maximum cell yields and division rates in the semi-defined medium ranged from 0.1 Â 10 5 to 4.0 Â 10 5 cells/ml and 0.5 to 1.7 divisions/day, respectively, and depended on the concentration of the major components in the medium as well as the P. shumwayae strain. The medium contained high concentrations of certain dissolved and particulate organic compounds, including amino acids and lipids. Pfiesteria shumwayae flagellated cells were attracted to insoluble lipids present in the medium and appeared to feed on the lipid particles, suggesting that phagocytosis may be required for growth in axenic culture. Development of a semi-defined medium represents significant progress toward a completely defined axenic culture medium and subsequent determination of the biochemical requirements of P. shumwayae, needed to advance understanding of the nutritional ecology of this species. Further, this medium provides an economical, simplified method for generating high cell densities of P. shumwayae in axenic culture that will facilitate controlled investigations on the physiology and biochemistry of this heterotrophic dinoflagellate.

THE TOXIC DINOFLAGELLATEGYMNODINIUM CATENATUM(DINOPHYCEAE) REQUIRES MARINE BACTERIA FOR GROWTH1

“…2005a). Both Pfiesteria shumwayae (Skelton et al. 2009) and the mixotroph Gyrodinium resplendens (Skovgaard 2000) require amino acids, fatty acids, and other undefined organic factors that have been presumed to be gained via the dinoflagellate cells feeding on bacteria or other prey.…”

Transfection of choanoflagellates illuminates their cell biology and the ancestry of animal septins

“…The AK seawater formulation (Supplemental Table S1) has been used to culture marine algae (Hallegraeff et al. , 2004) and dinoflagellates (Skelton et al. , 2009) and has a calcium concentration of 2.7 mM.…”

Genome editing enables reverse genetics of multicellular development in the choanoflagellateSalpingoeca rosetta

“…Although we are unsure of the mechanism that led to this mutation, its presence suggests that large mutations could be incorporated into S. rosetta via genome editing. 290 (Hallegraeff et al, 2004;Skelton et al, 2009), high 295 nutrient media (modified from , and low nutrient media. Table S2: Oligonucleotide sequences Sequences for gRNAs, repair oligonucleotides, and primers that were used to construct and to 300 validate genome edited strains.…”