The diatom Phaeodactylum tricornutum is considered a promising “cell factory” for high-value products fucoxanthin and EPA. But its potential has not been realized due largely to microbial contamination. In this study, seven protozoan strains were identified, of which a heterolobosean amoeba was identified as the most frequently occurring and destructive predator in P. tricornutum culture. The addition of 400 mg L⁻¹ NH₄HCO₃ inhibited amoeba proliferation with little impact on algal growth. Halting culture mixing at night induced a hypoxia environment that further inhibited amoeba growth. Regardless of culture systems employed, a periodical supply of proper amounts of NH₄HCO₃ alone or in combination with halting culture mixing at night may prevent or treat protozoa contamination in mass culture of P. tricornutum.

硅藻三角褐指藻被认为是高价值产品岩藻黄质和 EPA 的有前途的“细胞工厂”。但由于微生物污染，其潜力尚未实现。在这项研究中，鉴定了七种原生动物菌株，其中异叶变形虫被确定为三角褐指藻培养中最常见和最具破坏性的捕食者。添加400 mg L ^-1 NH ₄ HCO ₃可抑制变形虫增殖，而对藻类生长几乎没有影响。晚上停止混合培养会导致缺氧环境进一步抑制变形虫的生长。无论采用何种培养系统，定期供应适量的 NH ₄ HCO₃单独或与夜间停止混合培养相结合，可预防或治疗三角褐指藻大规模培养中的原生动物污染。