title: Dynamics of C2 toxin and chlorophyll-a formation in the dinoflagellate Alexandrium tamarense during large scale cultivation.
abstract: The production of paralytic shellfish toxins (PSTs) by the dinoflagellate Alexandrium tamarense ATCI01, a toxigenic strain isolated from South China coastal waters, was studied in batch cultures in relatively large volumes (20l). Under nutrient-replete conditions, this strain produced C2 toxin (C2T) as a predominant PST. In a 15-day production culture, phosphate was depleted by day 4, the stationary phase began at day 6, and the toxin productivity peaked at day 10, in which the cell content of C2T reached 76 fmol per cell. Much of the toxin was produced after the depletion of phosphate in the medium suggesting that C2T is a secondary metabolite. Aeration with small bubbles was useful in increasing cell mass and toxin yield. Chlorophyll-a (Chl-a) was formed in algal cells until the culture entered the stationary phase, after which Chl-a began to disappear rapidly from the culture while the C2T content continued to rise. These results suggest a metabolic relationship between Chl-a and C2T.
authors.affiliation: Department of Biology, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, People's Republic of China.
authors.forename: D
authors.initials: D
authors.lastname: Wang
authors.forename: D P
authors.initials: DP
authors.lastname: Hsieh
mesh_terms: D000388:Air; D000818:Animals; D001429:Bacteriochlorophylls / Q000096:biosynthesis*; D018533:Biomass; D001905:Botulinum Toxins / Q000096:biosynthesis* / Q000378:metabolism* / Q000633:toxicity; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D018929:Cell Culture Techniques / Q000379:methods*; D002681:China; D002851:Chromatography, High Pressure Liquid; D004141:Dinoflagellida / Q000737:chemistry* / Q000254:growth & development* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D008027:Light; D008387:Marine Toxins / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D011065:Poly(ADP-ribose) Polymerases / Q000378:metabolism; D012623:Seawater; D013223:Statistics as Topic; D013997:Time Factors
chemical_list: D001429:Bacteriochlorophylls; D008387:Marine Toxins; D010758:Phosphorus; D011065:Poly(ADP-ribose) Polymerases; D002265:Carboxylic Ester Hydrolases; C092629:paralytic shellfish poisoning toxin carbamoylase; D001905:Botulinum Toxins; C096324:botulinum toxin type C