PDF(Pubmed)
Abstract：
Amoeba-bacteria interactions are prevalent in both natural ecosystems and engineered environments. Amoebae, as essential consumers, hold significant ecological importance within ecosystems. Besides, they can establish stable symbiotic associations with bacteria. Copper plays a critical role in amoeba predation by either killing or restricting the growth of ingested bacteria in phagosomes. However, certain symbiotic bacteria have evolved mechanisms to persist within the phagosomal vacuole, evading antimicrobial defenses. Despite these insights, the impact of copper on the symbiotic relationships between amoebae and bacteria remains poorly understood. In this study, we investigated the effects of copper stress on amoebae and their symbiotic relationships with bacteria. Our findings revealed that elevated copper concentration adversely affected amoeba growth and altered cellular fate. Symbiont type significantly influenced the responses of the symbiotic relationships to copper stress. Beneficial symbionts maintained stability under copper stress, but parasitic symbionts exhibited enhanced colonization of amoebae. Furthermore, copper stress favored the transition of symbiotic relationships between amoebae and beneficial symbionts toward the host\'s benefit. Conversely, the pathogenic effects of parasitic symbionts on hosts were exacerbated under copper stress. This study sheds light on the intricate response mechanisms of soil amoebae and amoeba-bacteria symbiotic systems to copper stress, providing new insights into symbiotic dynamics under abiotic factors. Additionally, the results underscore the potential risks of copper accumulation in the environment for pathogen transmission and biosafety.
摘要：
变形虫-细菌相互作用在自然生态系统和工程环境中都很普遍。变形虫,作为重要的消费者，在生态系统中具有重要的生态重要性。此外,它们可以与细菌建立稳定的共生关系。铜通过杀死或限制吞噬体中摄入的细菌的生长，在变形虫的捕食中起着至关重要的作用。然而,某些共生细菌已经进化了在吞噬体液泡中持续存在的机制，逃避抗菌防御。尽管有这些见解,铜对变形虫和细菌之间共生关系的影响仍然知之甚少。在这项研究中,我们研究了铜胁迫对变形虫的影响及其与细菌的共生关系。我们的发现表明，铜浓度升高会对变形虫的生长产生不利影响，并改变细胞命运。共生类型显著影响共生关系对铜胁迫的响应。有益共生体在铜应力下保持稳定，但是寄生共生体表现出变形虫的定殖增强。此外，铜胁迫有利于变形虫和有益共生体之间的共生关系向宿主的利益转变。相反，在铜胁迫下，寄生共生体对宿主的致病作用加剧。本研究揭示了土壤变形虫和变形虫-细菌共生系统对铜胁迫的复杂响应机制。为非生物因素下的共生动力学提供新的见解。此外,结果强调了铜在环境中积累对病原体传播和生物安全的潜在风险。
