Toxin production in cyanobacterial mats from ponds on the McMurdo Ice Shelf, Antarctica
Toxin production in cyanobacterial mats from ponds on the McMurdo Ice Shelf, Antarctica
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DOI：
10.1016/s0041-0101(00)00103-3
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发表时间：
2000-12-01
期刊：
影响因子：
2.8
通讯作者：
Dietrich, DR
中科院分区：
文献类型：
--
作者：
Hitzfeld, BC;Lampert, CS;Dietrich, DR
众所周知，蓝藻会产生肝毒性物质，但这些毒素的功能和生态作用在很大程度上仍不清楚。研究人员调查了在南极洲收集的蓝藻的毒性，以确定在这些环境条件下是否也能发现产毒物种。样本是在1997年到1999年的夏天从南极洲麦克默多冰架的融水池塘中收集的。这些池塘被底栖藻类和蓝藻垫定植。淡水池塘中主要分类群为振荡藻属、结节藻属和Nostoc sp.，咸淡水和咸水池塘中缺少Nostoc sp.。从浮垫、沉垫或底栖垫中提取样本，提取后进行体外毒性测试。采用磷酸酶抑制法和高效液相色谱法测定毒素的存在。在肝细胞中研究了提取物的细胞毒性，测定了3-（4,5-二甲基噻唑-2-基）-2,5-二苯基溴化四唑的代谢和台苯蓝染料的排除。结果表明，所有蓝藻提取物均表现出抑制磷酸酶的活性，其中约一半的抑制活性显著大于50%。采用高效液相色谱法确定了其中存在结节素和微囊藻毒素lr。细胞毒性，独立于磷酸酶抑制活性，也检测。因此，在南极洲也可以发现有毒的蓝藻菌株，这一发现可能会进一步深入了解蓝藻磷酸酶抑制毒素的潜在生态作用。(C) 2000 Elsevier Science Ltd.版权所有。
Cyanobacteria are known to produce hepatotoxic substances, the functional and ecological role of these toxins, however, remains largely unclear. Toxic properties of cyanobacteria collected in Antarctica were investigated to determine whether toxin-producing species can also be found under these environmental conditions. Samples were collected from meltwater ponds on the McMurdo Ice Shelf, Antarctica in the summers of 1997 to 1999. These ponds are colonized by benthic algae and cyanobacterial mats. Oscillatoriales, Nodularia sp., and Nostoc sp. constituted the major taxa in freshwater ponds, while Nostoc sp. was missing from brackish and saline ponds. Samples were taken from either floating, submerged or benthic mats, and extracted for in vitro toxicity testing. The presence of toxins was determined by the phosphatase-inhibition assay and by high performance liquid chromatography. The cytotoxic properties of the extracts were investigated in hepatocytes determining 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide metabolism and trypan blue dye exclusion. The results show that all cyanobacterial extracts display phosphatase-inhibiting activity, of which approximately half had significantly greater than 50% inhibiting activity. The presence of nodularin and microcystin-LR was established by high performance liquid chromatography. Cytotoxic properties, independent of the phosphatase inhibiting activity,were also detected. Toxic strains of cyanobacteria can therefore also be found in Antarctica and this finding may lead to further insight into potential ecological roles of cyanobacterial phosphatase inhibiting toxins. (C) 2000 Elsevier Science Ltd. All rights reserved.