The biodegradable polymer poly-β-hydroxybutyrate (PHB) is a promising carbon source for biological mitigation of nitrogen pollution, a significant problem in aquaculture that physical and chemical methods have not provided a comprehensive solution. Here we investigated the impact of PHB on the zero-water-change largemouth bass culture by 30- and 40-day experiments. PHB loaded into the filter circulation pump at 4 g L⁻¹, optimum value determined by the first experiment, significantly reduced the levels of nitrate by 99.65%, nitrite by 95.96%, and total nitrogen by 85.22% compared to the control without PHB. PHB also significantly increased denitrifying bacteria (e.g., Proteobacteria and Fusobacteria) and expression of denitrification genes (e.g., nirK and nirS) in the microbial community, improving growth and health parameters of largemouth bass. While the impact may vary in other culture systems, PHB thus demonstrated its remarkable utility in aquaculture, highlighting ecological assessment and application to larger aquaculture operations as future considerations.

可生物降解的聚合物聚β-羟基丁酸酯（PHB）是一种很有前景的生物缓解氮污染的碳源，氮污染是水产养殖中物理和化学方法尚未提供全面解决方案的重大问题。在这里，我们通过 30 天和 40 天的实验研究了 PHB 对零换水大口黑鲈养殖的影响。 PHB以4 g·L ^{− 1} 加载到过滤器循环泵中，这是第一个实验确定的最佳值，显着降低了硝酸盐含量99.65%，亚硝酸盐含量降低了95.96%，与不含PHB的对照相比，总氮减少了85.22%。 PHB 还显着增加微生物群落中的反硝化细菌（例如变形杆菌和梭杆菌）和反硝化基因（例如 nirK 和 nirS）的表达，从而改善大口黑鲈的生长和健康参数。虽然对其他养殖系统的影响可能有所不同，但 PHB 因此证明了其在水产养殖中的显着效用，强调了生态评估和在更大的水产养殖作业中的应用作为未来的考虑因素。