Université de Lyon, Université Claude Bernard Lyon 1, VetAgro Sup, UMR Ecologie Microbienne, CNRS 5557, INRA 1418, Research team "Bacterial Opportunistic Pathogens and Environment", 69280 Marcy L'Etoile, France.
Université de Lyon, Université Claude Bernard Lyon 1, Institut des Sciences Analytiques, CNRS 5280, 5 rue de la Doua, 69100 Villeurbanne, France.
Sci Total Environ. 2021 May 1;767:145425. doi: 10.1016/j.scitotenv.2021.145425. Epub 2021 Jan 26.
The bTPMT (bacterial thiopurine S-methyltransferase), encoded by the tpm gene, can detoxify metalloid-containing oxyanions and xenobiotics. The hypothesis of significant relationships between tpm distribution patterns and chemical pollutants found in urban deposits was investigated. The tpm gene was found conserved among eight bacterial phyla with no sign of horizontal gene transfers but a predominance among gammaproteobacteria. A DNA metabarcoding approach was designed for tracking tpm-harboring bacteria among polluted urban deposits and sediments recovered for more than six years in a detention basin (DB). This DB recovers runoff waters and sediments from a zone of high commercial activities. The PCR products from DB samples led to more than 540,000 tpm reads after DADA2 or MOTHUR bio-informatic manipulations that were allocated to more than 88 and less than 634 sequence variants per sample. The tpm community patterns were significantly different between the recent urban deposits and those that had accumulated for more than 2 years in the DB, and between those of the DB surface and the DB settling pit. These groups of samples had distinct mixture of priority pollutants. Significant relationships between tpm ordination patterns, sediment accumulation time periods and location, and concentrations in PAH, chlorpyrifos, and 4-nonylphenols (NP) were observed. These correlations matched the higher occurrences of, among others, Aeromonas, Pseudomonas, and Xanthomonas tpm-harboring bacteria in recent urban DB deposits more contaminated with chrysene and alkylphenol ethoxylates. Highly significant drops in tpm reads allocated to Aeromonas species were recorded in the oldest DB sediments accumulating naphthalene and metallic pollutants. Degraders of urban pollutants such as P. aeruginosa and P. putida showed conserved distribution patterns over time but P. syringae phytopathogens were more abundant in the oldest sediments. TPMT-harboring bacteria can be used to assess the incidence of high risk priority pollutants on environmental systems.
细菌硫嘌呤 S-甲基转移酶（bTPMT）由 tpm 基因编码，可解毒含类金属的含氧阴离子和异生物质。研究了 tpm 分布模式与城市沉积物中发现的化学污染物之间存在显著关系的假设。在没有水平基因转移迹象的情况下，在 8 个细菌门中发现 tpm 基因保守，但在γ变形菌中占主导地位。设计了一种 DNA 宏条形码方法，用于追踪受污染的城市沉积物中携带 tpm 的细菌，并对六年来在一个滞留盆地（DB）中回收的沉积物进行了研究。这个 DB 从一个商业活动密集的区域回收径流和沉积物。DB 样品的 PCR 产物经过 DADA2 或 MOTHUR 生物信息学处理后，产生了超过 54 万个 tpm 读数，每个样品分配到超过 88 个和不到 634 个序列变体。最近的城市沉积物与在 DB 中积累超过 2 年的沉积物之间，以及 DB 表面和 DB 沉降坑之间的 tpm 群落模式有显著差异。这些样本组有明显不同的优先污染物混合物。观察到 tpm 排序模式、沉积物积累时间、位置与多环芳烃、毒死蜱和 4-壬基酚（NP）浓度之间存在显著关系。这些相关性与 Aeromonas、Pseudomonas 和 Xanthomonas 等携带 tpm 的细菌在最近的城市 DB 沉积物中更高的出现率相匹配，这些沉积物中含有更多的苊和烷基酚乙氧基化物。在积累萘和金属污染物的最古老的 DB 沉积物中，分配给气单胞菌属的 tpm 读数显著下降。在时间上，对城市污染物具有降解能力的细菌，如 P. aeruginosa 和 P. putida 具有保守的分布模式，但 P. syringae 植物病原体在最古老的沉积物中更为丰富。TPMT 携带细菌可用于评估高风险优先污染物对环境系统的影响。
