title: Paralytic shellfish toxin production by the dinoflagellate Alexandrium pacificum (Chinhae Bay, Korea) in axenic, nutrient-limited chemostat cultures and nutrient-enriched batch cultures.
abstract: Blooms of Alexandrium pacificum (formerly Alexandrium tamarense) are common in Chinhae Bay (Korea), presumably linked to anthropogenic eutrophication. Here we examine PSP toxin content and composition in axenic chemostat and batch cultures of A. pacificum using growth conditions that differed according to dilution rate, nutrient limitations, and enrichments. Phosphate (P)-limited cells in chemostat cultures had higher toxin content and a toxin composition that differed from that of nitrogen (N)-limited cells at the highest growth rates. Therefore, toxin composition changes do occur in axenic cultures of A. pacificum following extended growth under steady state conditions. In nutrient-limited batch cultures that received N and P enrichment, the N-enriched cultures showed a more diverse toxin profile than the P-enriched cells; the toxin content of N-enriched cells was lower than in the P-enriched cultures. We infer the following order for the biosynthesis of individual toxins: C1, C2>GTX3>GTX1>neoSTX.
authors.affiliation: Department of Life Science, Hanyang University, Seoul 04763, South Korea.
authors.forename: Myungsoo
authors.initials: M
authors.lastname: Han
authors.affiliation: Department of Life Science, Hanyang University, Seoul 04763, South Korea.
authors.forename: Haeok
authors.initials: H
authors.lastname: Lee
authors.affiliation: Biology Department, Woods Hole Oceanographic Institution, Woods Hole, MA 02543-1049, USA.
authors.forename: Donald M
authors.initials: DM
authors.lastname: Anderson
authors.affiliation: Department of Life Science, Hanyang University, Seoul 04763, South Korea. Electronic address: tigerk@hanyang.ac.kr.
authors.forename: Baikho
authors.initials: B
authors.lastname: Kim
mesh_terms: D061249:Batch Cell Culture Techniques; D061006:Bays; D002851:Chromatography, High Pressure Liquid; D004141:Dinoflagellida / Q000502:physiology*; D008387:Marine Toxins / Q000032:analysis; D056910:Republic of Korea; D012530:Saxitoxin / Q000032:analysis*; D012758:Shellfish / Q000032:analysis; D057096:Shellfish Poisoning
chemical_list: D008387:Marine Toxins; D012530:Saxitoxin
keywords: Alexandrium pacificum; Batch cultures; Chemostat; Dinoflagellate; Nutrient enrichment and limitation; PSP toxin