12th International Conference on Harmful Algae

INTERNATIONAL SOCIETY FOR THE STUDY OF HARMFUL ALGAE12 th <strong>International</strong> <strong>Conference</strong> on Harmful Algae, Copenhagen, Denmark, 4-8 September 2006intense monitoring (every 2h for 24h) of toxins in Dinophysis wascarried out during a cell cycle studyin November. Dinophysis cells andnet-hauls contained OA, DTX2, OAdiol-esters and PTX2; the sametoxins plus PTX2SA and PTX1, butno diol-esters were dissolved inseawater and adsorbed by theresins. Toxins dissolved in seawaterwere detected until the end ofJanuary 2006, at least one monthafter the disappearance ofDinophysis cells. Seasonal and cellcycle variability in toxin content percell (up to 95 pg of okadaiates and38 pg of pectenotoxins) will bediscussed in relation to cell size,phase of the population, and stagesof the cell cycle. The origin and fateof toxins released in the seawaterare discussed.PO.08-07Preliminary cultures in vitro ofpotentially toxic epiphyticdinoflagellates from a northernPhilippine reefSession: PO.08 - ToxicologyGN Pocsidio 1 , LM Dimaano 21 University of the Philippines, QUEZONCITY, Philippines2 University of Santo Tomas, MANILA,PhilippinesStudies were conducted onlaboratory cultures of the epiphyticdinoflagellates Gambierdiscus sp.,Ostreopsis spp., and Prorocentrumspp. collected from depths of 1-1.5m at Lingsat Reef, La Union,Philippines. The initial cultureutilized the ES1 medium instoppered 15-ml culture tubes. At atemperature of 27±20 °C, irradiance3,200 lux, salinity 23 ppt and pH8.0, Gambierdiscus sp., startingfrom 8 cells/ml, reached a density of15 cells/ml in 23 days, Ostreopsisspp. from 9 cells/ml to 22 cells/ml in16 days, Prorocentrum spp. from 7cells/ml to 190 cells/ml in 51 days.The cultures maintained themselvesas follows: Gambierdiscus up to the48th day, Ostreopsis up to the 57thday and Prorocentrum up to morethan 150 days. This study wasfinanced by the U.P. NaturalSciences Research Institute.PO.02-01Comparative genomic analysis ofDNA fragments from a toxiccyanobacterial bloomSession: PO.02 - GenomicsPB Pope, BKC PatelGriffith University, BRISBANE, AustraliaThe variety of secondarymetabolites found in cyanobacterialblooms and the impacts they haveon human health warrants largescaleapproaches intounderstanding the ‘bigger picture’ ofcyanobacterial bloom populationstructure and function. Ametagenomic approach, whichenables studies on genomes ofmixed natural communities, hasbeen utilized to overcome thisproblem of microbe 'unculturability'.We have prepared a bacterialartificial chromosome library (BAC)from the DNA extracted from anaturally occurring toxin-producingcyanobacterial bloom. The 3000clone BAC library, which is the firstreport of a BAC library constructedfrom cyanobacterial bloom DNA,had an average insert size of 30kbwith a number of clones containinginserts >50kb. From metagenomiclibrary 16S rDNA PCR screens anda random BAC-end sequencingsurvey, 10 clones were selected forinsert sequencing completion andanalysis. Approximately 200 kb ofcyanobacterial bloom metagenome264