摘要

有机肥料，如畜禽粪便和沼气消化物，通常含有携带抗菌基因（RGs）和可移动遗传元件( MGEs )的细菌。通过田间试验，研究了不同肥料(无机肥、有机肥、消化液)对RG、MGE丰度和微生物群落组成的影响。采用qPCR方法，测定了施肥前后和玉米收获前[ su1、su2、Tet ( A )、Tet ( M )、Tet ( Q )、Tet ( W )、qacE∆1 / qacE ]和MGEs [ intl 1、intl 2、IncP - 1、IncP - 1ε和LowGC质粒在总群落( TC ) - DNA中的相对丰度。通过从TC - DNA扩增的16S rRNA基因片段的Illumina测序分析微生物群落。与无机肥处理相比，有机肥处理增加了土壤中所有RGs的相对丰度，整合子和隶属于拟杆菌属和厚壁菌属的少数几个属的相对丰度，而消化物增加了土壤中的sul 2、Tet ( W )和intl 2。收获时，处理效果在土壤中消失。然而在根际仍可检测到有机肥对RGs效应 [有机肥: intl 1、sul1；消化物: Tet ( W ) ]和梭菌相关序列(消化物)，相对丰度增加。研究结果表明，短期有机肥料对RG，MGEs和散装土壤中微生物群落组成的影响具有长期的消化或肥料施用的历史。

Organic soil fertilizers, such as livestock manure and biogas digestate, frequently contain bacteria carrying resistance genes (RGs) to antimicrobial substances and mobile genetic elements (MGEs). The effects of different fertilizers (inorganic, manure, digestate) on RG and MGE abundance and microbial community composition were investigated in a field plot experiment. The relative abundances of RGs [sul1, sul2, tet(A), tet(M), tet(Q), tet(W), qacEΔ1/qacE] and MGEs [intI1,intI2, IncP-1, IncP-1ε and LowGC plasmids] in total community (TC)-DNA from organic fertilizers, bulk soil and maize rhizosphere were quantified by qPCR before/after fertilization and prior to maize harvest. Microbial communities were analyzed via Illumina sequencing of 16S rRNA gene fragments amplified from TC-DNA. Compared to inorganic fertilization, manure treatments increased relative abundances of all RGs analyzed, integrons and few genera affiliated to Bacteroidetes and Firmicutes in bulk soil, while digestate increased sul2, tet(W) and intI2. At harvest, treatment effects vanished in bulk soil. However, organic fertilizer effects were still detectable in the rhizosphere for RGs [manure:intI1, sul1; digestate: tet(W)] and Clostridium related sequences (digestates) with increased relative abundance. Our data indicated transient organic fertilizer effects on RGs, MGEs and microbial community composition in bulk soil with long-term history of digestate or manure application.

https://academic.oup.com/femsec/article-abstract/94/4/fiy027/4867966