Novel toxic effects associated with a tropical Limnothrix/Geitlerinema-like cyanobacterium.
The presence of a toxic strain of a fine filamentous cyanobacterium belonging to the Oscillatorialean family Pseudanabaenacea was detected during a survey of cyanobacterial taxa associated with the presence of cylindrospermopsin in dams in Central Queensland (Australia). The strain, AC0243, was isolated and cultured, its genomic DNA extracted and 16S RNA gene sequenced. Phylogenetic analysis placed AC0243 with Limnothrix species, although this genus appears polyphyletic. Moreover, not all morphological characters are consistent with this genus but more closely fit the description of Geitlerinema unigranulatum (R.N. Singh) Komárek and Azevedo. The potential toxic effects of AC0243 extract were assessed chemically and biologically. Cell free protein synthesis was inhibited by the extract. Exposure of Vero cells to the extract resulted in a significant reduction in cellular ATP levels following 24-72 h incubation. The presence of cylindrospermopsin was excluded based on the nature of responses obtained in cell and cell-free assays; in addition, (i) it could not be detected by HPLC, LC-MS, or immunological assay, and (ii) no genes currently associated with the production of cylindrospermopsin were found in the genome. Other known cyanobacterial toxins were not detected. The apparent novelty of this toxin is discussed.
Bernard
Catherine
C
Centre for Environmental Management, CQ University, Rockhampton, Queensland, Australia.
Froscio
Suzanne
S
Campbell
Rebecca
R
Monis
Paul
P
Humpage
Andrew
A
Fabbro
Larelle
L
D000255:Adenosine Triphosphate / Q000378:metabolism; D000470:Alkaloids; D000818:Animals; D001427:Bacterial Toxins / Q000378:metabolism / Q000633:toxicity*; D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D000458:Cyanobacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D000087522:Cyanobacteria Toxins; D005798:Genes, Bacterial; D008387:Marine Toxins / Q000378:metabolism / Q000633:toxicity*; D013058:Mass Spectrometry; D052998:Microcystins / Q000378:metabolism / Q000633:toxicity*; D008969:Molecular Sequence Data; D010802:Phylogeny; D011793:Queensland; D014329:Tropical Climate; D014498:Uracil / Q000031:analogs & derivatives* / Q000378:metabolism / Q000633:toxicity; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism / Q000633:toxicity*; D014881:Water Supply / Q000032:analysis
D000470:Alkaloids; D001427:Bacterial Toxins; D000087522:Cyanobacteria Toxins; D008387:Marine Toxins; D052998:Microcystins; D014874:Water Pollutants, Chemical; C089595:cylindrospermopsin; D014498:Uracil; D000255:Adenosine Triphosphate