A suspended membrane bioreactor (SMBR) was employed to treat low carbon to nitrogen (C/N) ratio wastewater. The suspended membranes amplified by Comamonas sp. YSF15 were collected to develop the SMBR, which showed excellent performance for nitrate (NO₃) removal. The maximum nitrate removal efficiency of 95.22% was obtained at an initial nitrate concentration of 20 mg L⁻¹, HRT of 6 h, and C/N=2.5: 1 (molar ratio). In addition, the polysaccharide (PS) and protein (PN) compositions of the soluble microbial products (SMP), extracellular polymeric substances (EPS) and the Fourier transform infrared (FTIR) spectra indicated that the suspended membrane utilized its SMP and EPS as reserve C source to achieve higher denitrification performance under the low C/N ratio. With the increase of pH, the generated SMP and EPS in SMBR continued to increase. The increase in PS content was significantly greater than that of PN, thus forming a suspended membrane with a certain mechanical strength. High-throughput sequencing data indicated that Comamonas sp. YSF15 played a key role in effective nitrate removal by SMBR. It can adapt to a nutrient-deficient environment, especially low (C/N) ratio, and greatly increase in the late operation of the reactor.

采用悬浮膜生物反应器（SMBR）处理低碳氮（C/N）比废水。被毛单胞菌扩增的悬浮膜。收集 YSF15 以开发 SMBR，它显示出优异的硝酸盐 (NO ₃ ) 去除性能。在 20 mg L ^-1的初始硝酸盐浓度下获得了 95.22% 的最大硝酸盐去除效率，HRT 为 6 小时，C/N=2.5:1（摩尔比）。此外，可溶性微生物产物（SMP）的多糖（PS）和蛋白质（PN）组成，胞外聚合物（EPS）和傅里叶变换红外（FTIR）光谱表明悬浮膜利用其SMP和EPS作为储备C源在低C/N比下实现更高的反硝化性能。随着pH值的增加，SMBR中生成的SMP和EPS继续增加。PS含量的增加明显大于PN，从而形成具有一定机械强度的悬浮膜。高通量测序数据表明，Comamonassp. YSF15 在 SMBR 有效去除硝酸盐方面发挥了关键作用。能适应营养缺乏的环境，特别是低（C/N）比，在反应器后期运行中大大增加。