Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland; University of Helsinki, Helsinki Institute of Life Science, Institute of Biotechnology, Viikinkaari 5, 00014, Helsinki, Finland.
Department of Microbiology, Faculty of Agriculture and Forestry, University of Helsinki, Viikinkaari 9, FI-00014, Helsinki, Finland; Center for Nuclear Energy in Agriculture, University of São Paulo, Avenida Centenário 303, Piracicaba, 13400-970, São Paulo, Brazil.
Toxicon. 2023 Aug 15;232:107205. doi: 10.1016/j.toxicon.2023.107205. Epub 2023 Jul 3.
Toxic benthic mats of cyanobacteria are associated with water quality problems and animal poisonings around the world. A strain of the filamentous cyanobacterial genus Kamptonema was isolated from a water bloom in the Baltic Sea four decades ago and later shown to produce cylindrospermopsins. However, the exact habitat of this strain remains unclear and cylindrospermopsins have not yet been reported from water blooms in the Baltic Sea. Here, we report the isolation of Kamptonema sp. UHCC 0994 from a benthic microbial mat collected in shallow water on the coast of Helsinki. We obtained draft genome sequences for the Kamptonema spp. PCC 7926 and UHCC 0994 strains that were isolated from the Baltic Sea. These genomes were 90-96% similar to previously studied Kamptonema sp. PCC 6506 and Kamptonema formosum PCC 6407, which were isolated from benthic and North American freshwater environments, respectively. The genomes of all four Kamptonema strains encode complete cylindrospermopsin biosynthetic gene clusters. We detected the production of cylindrospermopsin and 7-epi-cylindrospermopsin in the four Kamptonema strains using high-resolution liquid chromatography mass spectrometry. The four strains encode genes for producing gas vesicles distributed in two to three different regions of their genomes. Kamptonema spp. UHCC 0994 and PCC 7926 have both retained the ability to regulate their buoyancy when grown in liquid culture. Together this suggests that these toxic cyanobacteria may exhibit a tychoplanktic lifestyle in the Baltic Sea. This study suggests that microbial mats containing cyanobacteria could be a source of environmental toxins in the Baltic Sea.
有毒的蓝细菌底栖垫与世界各地的水质问题和动物中毒有关。四十多年前，从波罗的海的水华分离出丝状蓝细菌属 Kamptonema 的一株，并随后发现其产生柱孢藻毒素。然而，该菌株的确切栖息地仍不清楚，并且尚未从波罗的海的水华报告过柱孢藻毒素。在这里，我们报告了从赫尔辛基海岸浅水区采集的底栖微生物垫中分离出 Kamptonema sp. UHCC 0994。我们获得了从波罗的海分离出的 Kamptonema spp. PCC 7926 和 UHCC 0994 菌株的草图基因组序列。这些基因组与之前从底栖和北美的淡水环境中分离出的 Kamptonema sp. PCC 6506 和 Kamptonema formosum PCC 6407 菌株的相似度为 90-96%。所有四个 Kamptonema 菌株的基因组都编码完整的柱孢藻毒素生物合成基因簇。我们使用高分辨率液相色谱-质谱法检测到这四个 Kamptonema 菌株产生柱孢藻毒素和 7-表柱孢藻毒素。这四个菌株编码用于产生气体囊泡的基因，这些基因分布在其基因组的两个到三个不同区域。Kamptonema spp. UHCC 0994 和 PCC 7926 在液体培养中生长时都保留了调节浮力的能力。这表明这些有毒蓝细菌可能在波罗的海表现出浮游生物生活方式。本研究表明，含有蓝细菌的微生物垫可能是波罗的海环境毒素的来源。
