Microalgae are recognized for their potential in the bioremediation of acid mine drainage (AMD), despite the challenges posed by AMD's low pH, high heavy metal content, and oligotrophic conditions. However, the impact of AMD chemoautotrophic microorganisms on microalgal growth and remediation efforts within AMD has been largely overlooked. This study aims to elucidate the effects the chemoautotrophic microorganism, Acidithiobacillus ferrooxidans, on the growth activity and metabolism of acid-tolerant microalgae, and to explore the molecular mechanisms of microalgal response. Our findings reveal that the presence of A. ferrooxidans inhibits the growth and alkaline production of Parachlorella sp. MP1, resulting in a 90.86% reduction in biomass. Physiological, biochemical, and transcriptomic studies, indicate that oxidative stress, photosynthesis, and energy metabolism are the metabolic processes most affected by A. ferrooxidans. Specifically, A. ferrooxidans introduces an increased production of reactive oxygen species (ROS) in Parachlorella sp. MP1, leading to an upregulation of genes and enzymes associated with peroxisome activity and intensifying oxidative stress within the cells. Downregulation of photosynthesis-related genes disrupts the electron transport chain, inhibiting photosynthesis. Furthermore, alterations in the gene expression of pyruvate and acetyl-CoA metabolic pathways result in energetic pathway disruption. These insights contribute to a better understanding of how A. ferrooxidans influence the growth metabolism of acid-tolerant microalgae in AMD environments and inform the optimization of microalgal application strategies in AMD bioremediation engineering.

中文翻译：

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亚铁氧化酸杆菌引起的微藻分子破坏：酸性矿山排水中的光合作用、氧化应激和能量代谢


尽管 AMD 的低 pH 值、高重金属含量和寡营养条件带来了挑战，但微藻因其在酸性矿山排水 （AMD） 生物修复中的潜力而得到认可。然而，AMD 化学自养微生物对 AMD 内部微藻生长和修复工作的影响在很大程度上被忽视了。本研究旨在阐明化学自养微生物 Acidithiobacillus ferrooxidans 对耐酸微藻生长活性和代谢的影响，并探讨微藻反应的分子机制。我们的研究结果表明，A. ferrooxidans 的存在抑制了 Parachlorella sp. MP1 的生长和碱性产生，导致生物量减少 90.86%。生理学、生化和转录组学研究表明，氧化应激、光合作用和能量代谢是受 A. ferrooxidans 影响最大的代谢过程。具体来说，A. ferrooxidans 在副小球藻 sp. MP1 中引入了活性氧 （ROS） 的产生增加，导致与过氧化物酶体活性相关的基因和酶的上调，并加剧了细胞内的氧化应激。光合作用相关基因的下调会破坏电子传递链，抑制光合作用。此外，丙酮酸和乙酰辅酶 A 代谢途径基因表达的改变导致能量途径中断。这些见解有助于更好地了解 A. ferrooxidans 如何影响 AMD 环境中耐酸微藻的生长代谢，并为 AMD 生物修复工程中微藻应用策略的优化提供信息。