THE FRESHWATER CYANOBACTERIUM PLANKTOTHRIX SP. FP1: MOLECULAR IDENTIFICATION AND DETECTION OF PARALYTIC SHELLFISH POISONING TOXINS

摘要: A filamentous cyanobacterium, belonging to the Order of Oscillatoriales, was found be responsible for a toxic algal bloom in Lake Varese, Italy, during summer 1997. Morphological characters, as well near complete 16S rRNA gene sequencing, revealed that dominant species most closely related genus Planktothrix. In addition, genetic analysis phycocyanin operon Planktothrix sp. FP1 novel primary structure, previously undescribed within cyanobacteria, which used marker rapid detection and identification this strain. The occurrence saxitoxin (STX), principal toxin paralytic shellfish poisoning (PSP), confirmed natural sample by both pre-column post-column derivatization high-performance liquid chromatography (HPLC) analyses, eventually chromatography/mass spectrometry (LC/MS). toxicity field also electrophysiological assays extract inhibited 90% voltage-dependent Na+ current human neuroblastoma cells at STX concentration 80 nM. cultured strain showed lower physiologic activity than (67% blockage 200 nM), detected only HPLC, indicating presence compound structurally close STX. Chemical molecular analyses performed here add growing list diverse cyanobacterial capable synthesizing its compounds.