title: Influence of temperature and salinity on Ostreopsis cf. ovata growth and evaluation of toxin content through HR LC-MS and biological assays.
abstract: In the Mediterranean Sea, blooms of Ostreopsis cf. ovata and Ostreopsis siamensis have become increasingly frequent in the last decade and O. cf. ovata was found to produce palytoxin-like compounds (putative palytoxin, ovatoxin-a, -b, -c, -d and -e), a class of highly potent toxins. The environmental conditions seem to play a key role in influencing the abundance of Ostreopsis spp. High cell densities are generally recorded in concomitance with relatively high temperature and salinity and low hydrodynamics conditions. In this study the effects of temperature and salinity on the growth and toxicity of an Adriatic O. cf. ovata isolate were investigated. The highest growth rates of the Adriatic strain were recorded for cultures grown at 20 °C and at salinity values of 36 and 40, in accordance with natural bloom surveys. Toxicity was affected by growth conditions, with the highest toxin content on a per cell basis being measured at 25 °C and salinity 32. However, the highest total toxin content on a per litre basis was recorded at 20 °C and salinity 36, since under such conditions the growth yield was the highest. O. cf. ovata had lethal effects on Artemia nauplii and juvenile sea basses, and produced haemolysis of sheep erythrocytes. A comparison between haemolysis neutralization assay and HR LC-MS results showed a good correlation between haemolytic effect and total toxin content measured through HR LC-MS. Considering the increasing need for rapid and sensitive methods to detect palytoxin in natural samples, the haemolytic assay appears a useful method for preliminary quantification of the whole of palytoxin-like compounds in algal extracts.
authors.affiliation: Centro Interdipartimentale di Ricerca per le Scienze Ambientali, Università di Bologna, Via S'Alberto 163, 48123 Ravenna, Italy.
authors.forename: Laura
authors.initials: L
authors.lastname: Pezzolesi
authors.forename: Franca
authors.initials: F
authors.lastname: Guerrini
authors.forename: Patrizia
authors.initials: P
authors.lastname: Ciminiello
authors.forename: Carmela
authors.initials: C
authors.lastname: Dell'Aversano
authors.forename: Emma
authors.initials: E
authors.lastname: Dello Iacovo
authors.forename: Ernesto
authors.initials: E
authors.lastname: Fattorusso
authors.forename: Martino
authors.initials: M
authors.lastname: Forino
authors.forename: Luciana
authors.initials: L
authors.lastname: Tartaglione
authors.forename: Rossella
authors.initials: R
authors.lastname: Pistocchi
mesh_terms: D000178:Acrylamides / Q000032:analysis / Q000737:chemistry / Q000633:toxicity; D000818:Animals; D001156:Artemia / Q000187:drug effects; D001681:Biological Assay / Q000379:methods*; D048429:Cell Size; D002853:Chromatography, Liquid; D003064:Cnidarian Venoms; D004141:Dinoflagellida / Q000187:drug effects / Q000254:growth & development*; D004912:Erythrocytes / Q000187:drug effects; D005399:Fishes; D006461:Hemolysis / Q000187:drug effects; D008387:Marine Toxins / Q000032:analysis* / Q000737:chemistry / Q000633:toxicity; D013058:Mass Spectrometry / Q000379:methods*; D054712:Salinity; D012756:Sheep; D013696:Temperature; D018675:Toxicity Tests; D000095702:Polyether Toxins
chemical_list: D000178:Acrylamides; D003064:Cnidarian Venoms; D008387:Marine Toxins; C010272:palytoxin; D000095702:Polyether Toxins