Report of the cyanotoxins cylindrospermopsin and deoxy-cylindrospermopsin from Raphidiopsis mediterranea Skuja (Cyanobacteria/Nostocales)

A filamentous cyanobacterium isolated from the plankton of a eutrophic reservoir in Queensland (Australia) was, based on morphological features, putatively identified as Raphidiopsis mediterranea Skuja. Strain FSS1-150/1 was screened by HPLC MS/MS for a number of common cyanotoxins and was shown to produce both cylindrospermopsin (CYN) and deoxy-cylindrospermopsin (deoxy-CYN) at concentrations of 917 and 1065 mu g g(-1) dry weight respectively. Evidence for CYN synthesis by strain FSS1-150/1 was further supported by PCR amplification of a fragment of the CyrC gene involved in CYN biosynthesis. Subsequent phylogenetic analyses using a partial sequence of the 16S rRNA gene confirmed its identification and showed that strain FSS1-150/1 was closely related to strains of R mediterranea and R. curvata. These results provide the first evidence of the production of CYN and deoxy-CYN by R. mediterranea and it is the second species of the genus Raphidiopsis known to produce these potent cyanotoxins. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.