title: DIFFERENCES IN THE PRODUCTION AND EXCRETION KINETICS OF OKADAIC ACID, DINOPHYSISTOXIN-1, AND PECTENOTOXIN-2 BETWEEN CULTURES OF DINOPHYSIS ACUMINATA AND DINOPHYSIS FORTII ISOLATED FROM WESTERN JAPAN(1).
abstract: We established clonal cultures of Dinophysis acuminata Clap. et Lachm. and D. fortii Pavill. isolated from western Japan and examined toxin production in them, focusing on intracellular production and extracellular excretion. At the end of incubations, the total amounts of pectenotoxin-2 (PTX-2), dinophysistoxin-1 (DTX-1), and okadaic acid (OA) in the D. acuminata cultures reached up to 672.7 ± 14.7 (mean ± SD), 88.1 ± 2.8, and 539.3 ± 39.7 ng · mL(-1) , respectively, and the excreted extracellular amounts were equivalent to 5.1, 79.5, and 79.5% of the total amounts, respectively. Similarly, at the end of incubations, the total amounts of PTX-2, DTX-1, and OA in the D. fortii cultures reached up to 526.6 ± 52.6 (mean ±SD), 4.4 ± 0.4, and 135.9 ± 3.9 ng · mL(-1) , respectively, and the excreted extracellular amounts were equivalent to 1.8, 80.1, and 86.6% of the total amounts, respectively. Further, we tested the availability of cell debris and dissolved organic substances that originated from the ciliate prey Myrionecta rubra for growth and toxin production in D. acuminata. Although no significant growth was observed in D. acuminata in the medium containing the cell debris and organic substances originated from M. rubra, the toxicity was significantly greater than that in the control (P < 0.05-0.001); this finding suggested the availability of organic substances for toxin production. However, toxin productivity was remarkably lower than that of Dinophysis species feeding on living M. rubra.
authors.affiliation: National Research Institute of Fisheries and Environment of Inland Sea, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, JapanNational Research Institute of Fisheries Science, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa 236-8648, JapanTajima Fisheries Technology Institute, Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, Kasumi, Mikata, Hyogo 669-6541, JapanNational Research Institute of Fisheries and Environment of Inland Sea, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Nagai
authors.affiliation: National Research Institute of Fisheries and Environment of Inland Sea, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, JapanNational Research Institute of Fisheries Science, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa 236-8648, JapanTajima Fisheries Technology Institute, Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, Kasumi, Mikata, Hyogo 669-6541, JapanNational Research Institute of Fisheries and Environment of Inland Sea, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Suzuki
authors.affiliation: National Research Institute of Fisheries and Environment of Inland Sea, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, JapanNational Research Institute of Fisheries Science, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa 236-8648, JapanTajima Fisheries Technology Institute, Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, Kasumi, Mikata, Hyogo 669-6541, JapanNational Research Institute of Fisheries and Environment of Inland Sea, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nishikawa
authors.affiliation: National Research Institute of Fisheries and Environment of Inland Sea, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, JapanNational Research Institute of Fisheries Science, 2-12-4 Fukuura, Kanazawa, Yokohama, Kanagawa 236-8648, JapanTajima Fisheries Technology Institute, Hyogo Prefectural Technology Center for Agriculture, Forestry and Fisheries, Kasumi, Mikata, Hyogo 669-6541, JapanNational Research Institute of Fisheries and Environment of Inland Sea, 2-17-5 Maruishi, Hatsukaichi, Hiroshima 739-0452, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Kamiyama
keywords: Dinophysis acuminata; Dinophysis fortii; Myrionecta rubra; diarrhetic shellfish poisoning; dinophysistoxin-1; growth rate; okadaic acid; pectenotoxin-2; toxin production