Key Laboratory of Marine Ecology and Environmental Sciences, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
Laboratory of Marine Ecology and Environmental Science, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
Mar Drugs. 2022 Sep 30;20(10):624. doi: 10.3390/md20100624.
Algicidal bacteria are important in the control of toxic dinoflagellate blooms, but studies on the environmental behavior of related algal toxins are still lacking. In this study, S3 (S3) showed the highest algicidal activity against (Group IV) out of six strains. When treated with 0.5% (/) S3 bacterial culture and sterile supernatant, the algicidal rates were 69.74% and 70.22% at 12 h, respectively, and algicidal substances secreted by S3 were considered the mechanism of algicidal effect. During the algicidal process, the rapid proliferation of sp. in the phycosphere of may have accelerated the algal death. Moreover, the algicidal development of S3 released large amounts of intracellular paralytic shellfish toxins (PSTs) into the water, as the extracellular PSTs increased by 187.88% and 231.47% at 12 h, compared with the treatment of bacterial culture and sterile supernatant at 0 h, respectively. Although the total amount of PSTs increased slightly, the total toxicity of the algal sample decreased as GTX1/4 was transformed by S3 into GTX2/3 and GTX5. These results more comprehensively reveal the complex relationship between algicidal bacteria and microalgae, providing a potential source of biological control for harmful algal blooms and toxins.
杀藻细菌在控制有毒甲藻水华方面具有重要作用，但有关相关藻类毒素的环境行为的研究仍较为缺乏。在本研究中，S3（S3）对六种菌株中的（第四组）表现出最高的杀藻活性。当用 0.5%（/）S3 细菌培养液和无菌上清液处理时，在 12 h 时的杀藻率分别为 69.74%和 70.22%，并且 S3 分泌的杀藻物质被认为是杀藻作用的机制。在杀藻过程中，sp. 在 的藻体周围的快速增殖可能加速了藻类的死亡。此外，S3 的杀藻作用会将大量的细胞内麻痹性贝类毒素（PSTs）释放到水中，与 0 h 时的细菌培养液和无菌上清液处理相比，在 12 h 时，胞外 PSTs 分别增加了 187.88%和 231.47%。尽管 PSTs 的总量略有增加，但由于 S3 将 GTX1/4 转化为 GTX2/3 和 GTX5，藻类样品的总毒性降低。这些结果更全面地揭示了杀藻细菌和微藻之间的复杂关系，为有害藻华和毒素的生物防治提供了潜在的来源。
