摘要

堆肥一般用于污泥的处理和资源化利用，天然沸石和硝化抑制剂可用于堆肥过程中的氮素保护，而其对ARG控制的影响尚不清楚。因此，建立了三个实验室堆肥反应器：A（对照），B（天然沸石添加剂）和C（硝化抑制剂添加3,4-二甲基吡唑磷酸盐，DMPP）。研究天然沸石和DMPP对ARGs水平的影响，以及重金属，流动性遗传因子（MGEs）和细菌群落在ARGs进化中的作用。结果表明，在反应器A和C中ARG总量分别为2.04和1.95倍，但由于天然沸石引起的重金属共轭和共选择减少，反应器B中ARGs的总量减少了1.5％。尽管一些ARG（blaCTX-M，blaTEM，ermB，ereA和tetW）减少了0.3-2个对数，其他的（ARM，sulI，sulI，tetG，tetX，mefA和aac（6'） - Ib-cr)增加了0.3-1.3个对数。尽管不同阶段的ARGs谱相关基因不同，但部分冗余分析，Mantel检验和Procrustes分析结果表明，与MGEs和重金属相比，细菌群落是ARGs变化的主要原因。网络分析确定了各种ARG的潜在宿主细菌，并进一步证实了我们的结果。

Composting is commonly used for the treatment and resource utilization of sewage sludge, and natural zeolite and nitrification inhibitors can be used for nitrogen conservation during sludge composting, while their impacts on ARGs control are still unclear. Therefore, three lab-scale composting reactors, A (the control), B (natural zeolite addition) and C (nitrification inhibitor addition of 3,4-dimethylpyrazole phosphate, DMPP), were established. The impacts of natural zeolite and DMPP on the levels of ARGs were investigated, as were the roles that heavy metals, mobile genetic elements (MGEs) and the bacterial community play in ARGs evolution. The results showed that total ARGs copies were enriched 2.04 and 1.95 times in reactors A and C, respectively, but were reduced by 1.5% in reactor B due to the reduction of conjugation and co-selection of heavy metals caused by natural zeolite. Although some ARGs (blaCTX-M, blaTEM, ermB, ereA and tetW) were reduced by 0.3–2 logs, others (ermF, sulI,sulII, tetG, tetX, mefA and aac(6′)-Ib-cr) increased by 0.3–1.3 logs after sludge composting. Although the contributors for the ARGs profiles in different stages were quite different, the results of a partial redundancy analysis, Mantel test and Procrustes analysis showed that the bacterial community was the main contributor to the changes in ARGs compared to MGEs and heavy metals. Network analysis determined the potential host bacteria for various ARGs and further confirmed our results.

http://www.sciencedirect.com/science/article/pii/S0043135416300100