Abstract：
Microbial co-culture has been proven as an effective technique for environmental remediation. In this study, co-culture mechanism of Rhodococcus ruber HJM-8 and Paracoccus communis YBH-X during N,N-dimethylacetamide (DMAC) degradation was studied. The comparison of degradation performance in monoculture and co-culture was presented; due to the efficient cooperation between the two strains via parallel and cascaded degradation, the removal efficiency of total nitrogen (TN) in co-culture could reach 90.1%, which was 1.35 and 1.21 times higher than that of HJM-8 and YBH-X, respectively. Then the communication mode of co-culture during DMAC degradation was determined as contact-independent and contact-dependent interactions between microorganisms. Meanwhile, intercellular nanotube between HJM-8 and YBH-X was found as a unique contact-dependent interaction. The cell staining experiments and RNA sequencing analyses revealed that the nanotube could be used as a bridge to exchange cytoplasmic molecules, and thus improved material transfer and enhanced cell connection in co-culture. The results of KEGG pathway showed that differentially expressed genes in co-culture have an association with cell metabolism, nanotube generation, and genetic material transfer. Furthermore, a mechanism diagram of DMAC biodegradation was proposed for co-culture, indicating that bidirectional cooperation was established between HJM-8 and YBH-X which was mediated by the conversions of acetate and nitrogen. Finally, the co-culture system was validated for treatment of an actual wastewater; results indicated that removal efficiencies of 100% and 68.2% were achieved for DMAC and TN, respectively, suggesting that co-culture had the potential for application.
摘要：
微生物共培养已被证明是一种有效的环境修复技术。在这项研究中,红球菌HJM-8与公鸡副球菌YBH-X在N，研究了N-二甲基乙酰胺（DMAC）的降解。比较了单一培养和共培养的降解性能；由于两个菌株之间通过并行和级联降解的有效合作，共培养对总氮(TN)的去除效率可达90.1%,比HJM-8和YBH-X高1.35和1.21倍，分别。然后确定DMAC降解过程中共培养的通讯模式为微生物之间的接触非依赖性和接触依赖性相互作用。同时,发现HJM-8和YBH-X之间的细胞间纳米管是独特的接触依赖性相互作用。细胞染色实验和RNA测序分析表明，纳米管可以用作交换细胞质分子的桥梁，从而改善了共培养中的物质转移和增强了细胞连接。KEGG通路的结果表明,共培养中差异表达的基因与细胞代谢有关,纳米管产生，和遗传物质转移。此外，提出了一种用于共培养的DMAC生物降解机理图，表明HJM-8和YBH-X之间建立了双向合作，这是由乙酸和氮的转化介导的。最后,共培养系统对实际废水的处理进行了验证；结果表明，DMAC和TN的去除效率分别为100%和68.2%，分别,表明共培养有应用的潜力。
