PDF(Pubmed)
Abstract：
BACKGROUND: Bioaugmentation is considered a sustainable and cost-effective methodology to recover contaminated environments, but its outcome is highly variable. Predation is a key top-down control mechanism affecting inoculum establishment, however, its effects on this process have received little attention. This study focused on the impact of trophic interactions on bioaugmentation success in two soils with different pollution exposure histories. We inoculated a 13C-labelled pollutant-degrading consortium in these soils and tracked the fate of the labelled biomass through stable isotope probing (SIP) of DNA. We identified active bacterial and eukaryotic inoculum-biomass consumers through amplicon sequencing of 16S rRNA and 18S rRNA genes coupled to a novel enrichment factor calculation.
RESULTS: Inoculation effectively increased PAH removal in the short-term, but not in the long-term polluted soil. A decrease in the relative abundance of the inoculated genera was observed already on day 15 in the long-term polluted soil, while growth of these genera was observed in the short-term polluted soil, indicating establishment of the inoculum. In both soils, eukaryotic genera dominated as early incorporators of 13C-labelled biomass, while bacteria incorporated the labelled biomass at the end of the incubation period, probably through cross-feeding. We also found different successional patterns between the two soils. In the short-term polluted soil, Cercozoa and Fungi genera predominated as early incorporators, whereas Ciliophora, Ochrophyta and Amoebozoa were the predominant genera in the long-term polluted soil.
CONCLUSIONS: Our results showed differences in the inoculum establishment and predator community responses, affecting bioaugmentation efficiency. This highlights the need to further study predation effects on inoculum survival to increase the applicability of inoculation-based technologies. Video Abstract.
RESULTS: Inoculation effectively increased PAH removal in the short-term, but not in the long-term polluted soil. A decrease in the relative abundance of the inoculated genera was observed already on day 15 in the long-term polluted soil, while growth of these genera was observed in the short-term polluted soil, indicating establishment of the inoculum. In both soils, eukaryotic genera dominated as early incorporators of 13C-labelled biomass, while bacteria incorporated the labelled biomass at the end of the incubation period, probably through cross-feeding. We also found different successional patterns between the two soils. In the short-term polluted soil, Cercozoa and Fungi genera predominated as early incorporators, whereas Ciliophora, Ochrophyta and Amoebozoa were the predominant genera in the long-term polluted soil.
CONCLUSIONS: Our results showed differences in the inoculum establishment and predator community responses, affecting bioaugmentation efficiency. This highlights the need to further study predation effects on inoculum survival to increase the applicability of inoculation-based technologies. Video Abstract.
摘要：
背景：生物强化被认为是一种可持续且具有成本效益的方法，可以恢复受污染的环境，但它的结果是高度可变的。捕食是影响接种物建立的自上而下的关键控制机制，然而,它对这一过程的影响很少受到关注。这项研究的重点是营养相互作用对两种具有不同污染暴露历史的土壤中生物强化成功的影响。我们在这些土壤中接种了13C标记的污染物降解财团，并通过DNA的稳定同位素探测（SIP）追踪了标记生物质的命运。我们通过16SrRNA和18SrRNA基因的扩增子测序与新型富集因子计算相结合，鉴定了活性细菌和真核接种物-生物质消费者。
结果：接种在短期内有效地提高了PAH的去除，但不是在长期污染的土壤中。在长期污染的土壤中，第15天已经观察到接种属的相对丰度下降，虽然在短期污染的土壤中观察到这些属的生长，表明接种物的建立。在这两种土壤中，真核细胞属主要是13C标记生物质的早期掺入物，而细菌在培育期结束时掺入了标记的生物质，可能是通过交叉喂食。我们还发现两种土壤之间的演替模式不同。在短期污染的土壤中，Cercozoa和真菌属以早期掺入者为主，而Ciliophora,在长期污染的土壤中，Ochrophyta和Amoebozoa是主要属。
结论：我们的结果显示了接种物建立和捕食者群落反应的差异，影响生物强化效率。这凸显了需要进一步研究捕食对接种物存活的影响，以增加基于接种的技术的适用性。视频摘要。
结果：接种在短期内有效地提高了PAH的去除，但不是在长期污染的土壤中。在长期污染的土壤中，第15天已经观察到接种属的相对丰度下降，虽然在短期污染的土壤中观察到这些属的生长，表明接种物的建立。在这两种土壤中，真核细胞属主要是13C标记生物质的早期掺入物，而细菌在培育期结束时掺入了标记的生物质，可能是通过交叉喂食。我们还发现两种土壤之间的演替模式不同。在短期污染的土壤中，Cercozoa和真菌属以早期掺入者为主，而Ciliophora,在长期污染的土壤中，Ochrophyta和Amoebozoa是主要属。
结论：我们的结果显示了接种物建立和捕食者群落反应的差异，影响生物强化效率。这凸显了需要进一步研究捕食对接种物存活的影响，以增加基于接种的技术的适用性。视频摘要。
