Moulia V, Ait-Mouheb N, Lesage G, Hamelin J, Wéry N, Bru-Adan V, Kechichian L, Heran M
IEM, University of Montpellier, Montpellier, France; INRAE, UMR G-EAU, University of Montpellier, Montpellier, France; INRAE, Univ Montpellier, LBE, 102 avenue des Étangs, 11100, Narbonne, France.
INRAE, UMR G-EAU, University of Montpellier, Montpellier, France.
Sci Total Environ. 2023 Nov 25;901:166028. doi: 10.1016/j.scitotenv.2023.166028. Epub 2023 Aug 6.
To investigate the effect of wastewater (WW) treatment on soil bacterial communities, water of different quality was used to irrigate eight lettuces per tank: raw municipal wastewater (RWW), WW treated with an aerated constructed wetland (CWW) and WW treated with a membrane bioreactor (MBW), and tap water (TW). The physicochemical and microbiological characteristics (quality indicators) of these water types were characterized, and the water and soil bacterial communities were monitored by quantitative PCR (qPCR) and 16S rRNA gene sequencing. Despite marked differences in microbial load and diversity of waters, soil communities remained remarkably stable after irrigation. Microbial biomass was increased only in soils irrigated with RWW. At the end of the irrigation period (day 84), soil and water shared a large fraction of their bacterial communities, from 43 % to 70 %, depending on the water quality, indicating a transfer of bacterial communities from water to soil. Overall, the relative abundance of Proteobacteria and Acidobacteria was increased and that of Actinobacteria was decreased in soils irrigated with MBW, CWW and even more with RWW. Multivariate ordination clearly separated soils in three groups: soils irrigated with the cleanest water (TW), with treated WW (MBW and CWW), and with untreated WW (RWW). Nitrifying, denitrifying, and nitrogen-fixing bacteria were quantified by qPCR targeting amoA, narG, and nifH, respectively. Nitrifying bacteria were the most affected by the water quality, as indicated by amoA copy number increase in RWW-irrigated soil and decrease in CWW-irrigated soil. Overall, the abundance of all three genes was positively influenced by RWW treatment. In conclusion, the 84 days of irrigation influenced the soil microbial communities, and the impact depended on the quality of the used water.
为研究废水处理对土壤细菌群落的影响，采用不同水质的水对每个水箱中的八株生菜进行灌溉：未经处理的城市污水（RWW）、经曝气人工湿地处理的废水（CWW）、经膜生物反应器处理的废水（MBW）以及自来水（TW）。对这些水类型的理化和微生物特性（质量指标）进行了表征，并通过定量PCR（qPCR）和16S rRNA基因测序对水和土壤细菌群落进行了监测。尽管不同水质的微生物负荷和多样性存在显著差异，但灌溉后土壤群落仍保持显著稳定。仅在用RWW灌溉的土壤中微生物生物量有所增加。在灌溉期结束时（第84天），土壤和水共享了很大一部分细菌群落，比例从43%到70%不等，具体取决于水质，这表明细菌群落从水转移到了土壤。总体而言，在用MBW、CWW甚至RWW灌溉的土壤中，变形菌门和酸杆菌门的相对丰度增加，而放线菌门的相对丰度降低。多变量排序将土壤明显分为三组：用最清洁的水（TW）灌溉的土壤、用处理后的废水（MBW和CWW）灌溉的土壤以及用未经处理的废水（RWW）灌溉的土壤。分别通过靶向amoA、narG和nifH的qPCR对硝化细菌、反硝化细菌和固氮细菌进行定量。如amoA拷贝数在RWW灌溉土壤中增加而在CWW灌溉土壤中减少所示，硝化细菌受水质影响最大。总体而言，RWW处理对所有三个基因的丰度均有正向影响。总之，84天的灌溉影响了土壤微生物群落，且影响程度取决于所用灌溉水的质量。
