Luiz de Queiroz College of Agriculture (ESALQ), University of São Paulo, Piracicaba, São Paulo, Brazil.
Federal University of Ceará, Fortaleza, Ceará, Brazil.
Sci Total Environ. 2022 Jun 25;827:154239. doi: 10.1016/j.scitotenv.2022.154239. Epub 2022 Mar 2.
Atrazine (ATZ) is one of the most widely used herbicides in the world even though it is classified as a carcinogenic endocrine disruptor. This study focused on how land use (grazing versus cultivation in parallel soils, the latter under no-till with a seven-year history of ATZ application) and bacterial community diversity affected ATZ dissipation. Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, Acidobacteria, Verrucomicrobia, Planctomycetes, and Gemmatimonadetes were the dominant phyla in both soils. The mineralization of ATZ was much higher in soils under cultivation up to the onset of moderate diversity depletion (dilution =10), corresponding to 44-52% of the amount applied (< 5% in the grazed soil). This was attributed to the higher diversity and complexity of the soils´ bacterial communities which consist of microbial groups that were more adapted as a result of previous exposure to ATZ. In these cases, ATZ dissipation was attributed mainly to mineralization (DT = 4-11 d). However, formation of non-extractable ATZ residues was exceptionally important in the other cases (DT = 17-44 d). The cultivated soils also presented a higher number of bacterial genera correlated with ATZ dissipation, in which Acidothermus, Aquicela, Arenimonas, Candidatus_Koribacter, Hirschia, MND1, Nitrospira, Occallatibacter, OM27_clade, and Ralstonia are suggested as potential ATZ-degraders. Finally, ATZ dissipation was mostly associated with an abundance of microbial functions related to energy supply and N-metabolism, suggesting co-metabolism is its first biodegradation step.
莠去津（ATZ）是世界上使用最广泛的除草剂之一，尽管它被归类为致癌内分泌干扰物。本研究重点研究了土地利用（放牧与平行土壤的耕作，后者采用免耕且在过去七年中使用 ATZ）和细菌群落多样性如何影响 ATZ 的消散。变形菌门、拟杆菌门、厚壁菌门、放线菌门、酸杆菌门、疣微菌门、浮霉菌门和芽单胞菌门是两种土壤中的主要门。在耕作土壤中，ATZ 的矿化作用要高得多，直到适度多样性耗竭（稀释=10），这对应于所施用量的 44-52%（放牧土壤中<5%）。这归因于土壤细菌群落的更高多样性和复杂性，这些群落由微生物群体组成，由于先前接触 ATZ，这些微生物群体更适应。在这些情况下，ATZ 的消散主要归因于矿化（DT = 4-11 d）。然而，在其他情况下，不可提取的 ATZ 残留的形成异常重要（DT = 17-44 d）。耕作土壤中还存在与 ATZ 消散相关的更多细菌属，其中 Acidothermus、Aquicela、Arenimonas、Candidatus_Koribacter、Hirschia、MND1、Nitrospira、Occallatibacter、OM27_clade 和 Ralstonia 被认为是潜在的 ATZ 降解菌。最后，ATZ 的消散主要与与能量供应和 N 代谢相关的微生物功能的丰度相关，表明共代谢是其第一个生物降解步骤。
