Increasing N,N-Dimethylacetamide Degradation and Mineralization Efficiency by Co-Culture of Rhodococcus Ruber Hjm-8 and Paracoccus Communis Ybh-X

In this work, Rhodococcus ruber HJM-8 and Paracoccus communis YBH-X were isolated and used to enhance N,N-dimethylacetamide (DMAC) degradation and mineralization efficiencies. The monoculture and co-culture of the two strains for DMAC degradation were compared; results indicated that, a degradation efficiency of 97.62% was obtained in co-culture, which was much higher than that of monocultures of HJM-8 (57.34%) and YBH-X (34.02%). The degradation mechanism showed that co-culture could efficiently improve extracellular polymeric substances production, electron transfer, and microbial activity. Meanwhile, the mineralization mechanism suggested that acetate was the dominant intermediate which had a inhibitory effect on HJM-8, and co-culture was conducive to mineralization due to the high performance of acetate conversion and Na + K + -ATPase vitality. Besides, a pathway of DMAC biodegradation was proposed for co-culture: BMAC was degraded into acetate by HJM-8, then the accumulated acetate was mineralized by YBH-X. Additionally, the co-culture system was further optimized by Box-Behnken design