Barrios Cesar Alejandro Zamora, Nandini S, Sarma S S S
Laboratory of Aquatic Zoology, Division of Research and Postgraduate Studies, National Autonomous University of Mexico, Campus Iztacala, Av. de Los Barrios No. 1, C.P. 54090, Los Reyes, Tlalnepantla, State of Mexico, Mexico.
Laboratory of Aquatic Zoology, Division of Research and Postgraduate Studies, National Autonomous University of Mexico, Campus Iztacala, Av. de Los Barrios No. 1, C.P. 54090, Los Reyes, Tlalnepantla, State of Mexico, Mexico.
Toxicon. 2017 Dec 1;139:45-53. doi: 10.1016/j.toxicon.2017.09.013. Epub 2017 Sep 25.
Unlike temperate regions, tropical ecosystems are characterized by high temperatures (>18 °C) all year, promoting blooms of cyanobacteria which often produce secondary metabolites toxic to zooplankton. Nabor Carillo and the Recreational Lake are part of the saline, Lake Texcoco, in Central Mexico which is filled nowadays with treated waste water. Both water bodies are dominated by Planktothrix, Anabaenopsis, Spirulina and Microcystis. In this study we present the concentration of microcystins in these waterbodies over an annual cycle. We also evaluated the chronic effects of cyanobacterial crude extracts from both lakes on two clones of the rotifer Brachionus calyciflorus, one from Nabor Carrillo Lake and the other from a canal in the shallow, Lake Xochimilco. The experiments on population growth were performed, beginning with 10 individuals per container for each of the following treatments: control (no crude extract), concentrated crude extract, and diluted crude extract (50:50) with moderately hard water and Chlorella vulgaris in a concentration of 0.5 × 10 cells ml. The cyanotoxin levels were measured using an ELISA test and ranged between 0.20 and 2.4 μg L in the lake water. The results showed that the Recreational Lake extracts were more toxic, killing the rotifers in less than five days. The r values ranged from -1.74 to 0.48 in the presence of the crude extracts and 0.16 and 0.24 in the controls. The results have been discussed with emphasis on the importance of conducting regular studies to test ecotoxicological impacts of cyanobacterial blooms in tropical waters.
与温带地区不同，热带生态系统的特点是全年高温（>18°C），这促使蓝藻大量繁殖，而蓝藻通常会产生对浮游动物有毒的次生代谢产物。纳博尔·卡里略湖和休闲湖是墨西哥中部盐碱化的特斯科科湖的一部分，如今该湖已被处理后的废水填满。这两个水体中主要的蓝藻种类有席藻属、拟鱼腥藻属、螺旋藻属和微囊藻属。在本研究中，我们展示了这些水体中微囊藻毒素在一年周期内的浓度。我们还评估了来自这两个湖泊的蓝藻粗提物对萼花臂尾轮虫的两个克隆品系的慢性影响，其中一个克隆品系来自纳博尔·卡里略湖，另一个来自浅水区的霍奇米尔科湖的一条运河。进行了种群增长实验，每个容器起始放入10个个体，设置以下处理组：对照组（无粗提物）、浓缩粗提物组以及用中等硬度水和浓度为0.5×10个细胞/毫升的普通小球藻稀释（50:50）的粗提物组。使用酶联免疫吸附测定（ELISA）测试来测量蓝藻毒素水平，湖水样本中的毒素水平在0.20至2.4微克/升之间。结果表明，休闲湖的提取物毒性更强，在不到五天的时间内就杀死了轮虫。在存在粗提物的情况下，r值在-1.7至0.48之间，而对照组的r值为0.16和0.24。我们对研究结果进行了讨论，重点强调了定期开展研究以测试热带水域蓝藻水华的生态毒理学影响的重要性。
