title: High temperature favors elimination of toxin-producing Microcystis and degradation of microcystins by mixotrophic Ochromonas.
abstract: This study aimed to investigate the influence of temperature on the ability of the mixotrophic flagellate Ochromonas to eliminate a toxic Microcystis population and degrade microcystins. We exposed Microcystis to cultures with or without Ochromonas YZ1 at 20, 25, and 30 °C for 10 days. Results showed that increased temperature promoted the growth of Ochromonas YZ1 and Microcystis, with the latter achieving high abundance without grazing. With increased temperature, Ochromonas YZ1 clearance rate increased, and Microcystis populations were earlier eliminated. Importantly, Ochromonas YZ1 degraded both intracellular and extracellular microcystins by grazing effects. The reduction ratios of Microcystis abundances and microcystins were both approximately 100% after 6 days at high temperature. In addition, more microcystins were released outside at 20 °C than at the higher temperatures. Overall, this study showed that high temperature favors elimination of toxin-producing Microcystis and degradation of microcystins by mixotrophic Ochromonas.
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Gu
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Wei
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Xuexia
authors.initials: X
authors.lastname: Zhu
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China.
authors.forename: Xiaojun
authors.initials: X
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory for Biodiversity and Biotechnology, School of Biological Sciences, Nanjing Normal University, 1 Wenyuan Road, Nanjing, 210023, China. Electronic address: yangzhou@njnu.edu.cn.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Yang
mesh_terms: D006358:Hot Temperature; D052998:Microcystins / Q000378:metabolism*; D046931:Microcystis / Q000254:growth & development* / Q000378:metabolism; D008962:Models, Theoretical; D044663:Ochromonas / Q000254:growth & development*
chemical_list: D052998:Microcystins
keywords: Degradation; Microcystins; Microcystis; Ochromonas; Temperature