Effects of silicate limitation on production of domoic acid, a neurotoxin, by the diatom Pseudo-nitzschia multiseries. II. Continuous culture studies

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 131:235-243 (1996) - doi:10.3354/meps131235 Effects of silicate limitation on production of domoic acid, a neurotoxin, by the diatom Pseudo-nitzschia multiseries. II. Continuous culture studies Pan Y, Subba Rao DV, Mann KH, Li WKW, Harrison WG Production of domoic acid (DA) by Pseudo-nitzschia multiseries (Hasle) was studied using continuous cultures with growth rates ranging from 0.06 to 0.67 d-1. At steady states, DA concentrations were 1.65 to 553.20 ug l-1 and production rates were 0.007 to 1.354 pg DA cell-1 d-1. Both were negatively correlated with rates of growth and silicate uptake. DA production was studied further by stopping the addition of fresh medium, thus producing batch mode experiments, in some of which silicate was allowed to decline, while in another silicate was increased to 85 uM. In those where silicate declined, DA production increased by a factor of 3. The maximum production rate attained was 3.17 pg DA cell-1 d-1 and the highest DA concentration in the culture was 768.5 ug DA l-1, of which 664 ug l-1 was in the cells (11.9 pg DA cell-1). In the experiment where silicate was enriched, DA production was suspended soon after the enrichment, but resumed when silicate in the medium became low. The results suggested differences in kinetics of DA production and growth under different supply rates of silicate. There appear to be 2 types of conditions associated with DA production. When dissolved silicate is moderately low and there is a decline in overall physiological activity, intrinsic factors probably trigger the formation of a moderate amount of DA. When dissolved silicate is severely limiting, the extrinsic stress leads to considerably enhanced production of DA. Pseudo-nitzschia multiseries . Domoic acid . Silicate limitation . Chemostat . Continuous cultures Full text in pdf format PreviousNextExport citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 131. Publication date: February 08, 1996 Print ISSN:0171-8630; Online ISSN:1616-1599 Copyright © 1996 Inter-Research.