Aquatic EcoTechnologies, LLC, Santa Cruz, CA 95065, USA; Department of Biological Sciences, University of Southern California, Los Angeles, CA 90089, USA.
Aquatic EcoTechnologies, LLC, Santa Cruz, CA 95065, USA.
Protist. 2023 Feb;174(1):125927. doi: 10.1016/j.protis.2022.125927. Epub 2022 Nov 4.
Bioassays using cultures of the toxic haptophyte Prymnesium parvum and the ciliate Cyclidium sp. as prey were conducted to test the effect of pH (range = 6.5 - 8.5), salinity (range = 1.50 - 7.50‰), and a combination of pH and salinity on the toxicity of P. parvum. pH had a significant effect on P. parvum toxicity. Toxicity was rapidly (within 24 hr) induced by increasing pH of the medium, or reduced by lowering pH. Conversely, lowering salinity reduced toxicity, albeit less effectively compared to pH, and P. parvum cells remained toxic at the lowest values tested (1.50‰ at pH 7.5). An additional effect between pH and salinity was also observed: low salinity combined with low pH led to not only decreased toxicity, but also resulted in lower P. parvum growth rates. Such effects of pH and salinity on P. parvum growth and toxicity provide insight into the environmental factors supporting community dominance and toxic blooms of the alga.
采用有毒甲藻原甲藻和纤毛虫旋口虫作为猎物的生物测定法进行了实验，以测试 pH 值（范围为 6.5-8.5）、盐度（范围为 1.50-7.50‰）以及 pH 和盐度组合对原甲藻毒性的影响。pH 值对原甲藻毒性有显著影响。通过提高培养基的 pH 值，毒性会迅速（在 24 小时内）诱导，或者通过降低 pH 值来降低毒性。相反，降低盐度会降低毒性，但效果不如 pH 值显著，并且在测试的最低值（pH 值为 7.5 时为 1.50‰）下，原甲藻细胞仍然具有毒性。还观察到 pH 值和盐度之间的另一种相互作用：低盐度与低 pH 值结合不仅导致毒性降低，而且还导致原甲藻生长速率降低。这些 pH 值和盐度对原甲藻生长和毒性的影响为支持藻类群落优势和有毒水华的环境因素提供了深入了解。
