College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
Laboratory Centre of Life Science, College of Life Science, Nanjing Agricultural University, Nanjing, 210095, China.
J Environ Manage. 2024 Aug;366:121792. doi: 10.1016/j.jenvman.2024.121792. Epub 2024 Jul 14.
Signal transduction is an important mode of algae-bacteria interaction, in which bacterial quorum sensing (QS) may affect microalgal growth and metabolism. Currently, little is known whether acyl homoserine lactones (AHLs) released by bacteria can affect the pollutant removal by algae-bacteria consortia (ABC). In this study, we constructed ABC using Chlorella vulgaris (Cv) with two AHLs-producing bacteria and investigated their performance in the removal of multiple pollutants, including chemical oxygen demand (COD), total nitrogen (TN), phosphorus (P), and cadmium (Cd). The AHLs-producing bacteria, namely Agrobacterium sp. (Ap) and Ensifer adherens (Ea), were capable of forming a symbiosis with C. vulgaris. Consortia of Cv and Ap with ratio of 2:1 (Cv2-Ap1) showed the optimal growth promotion and higher removal of Cd, COD, TN, and P compared to the C. vulgaris monoculture. Cv2-Ap1 ABC removed 36.1-47.5% of Cd, 94.5%-94.6% COD, 37.1%-56.0% TN, and 90.4%-93.5% P from the culture medium. In addition, increase of intracellular neutral lipids and extracellular protein, as well as the types of functional groups on cell surface contributed to Cd removal and tolerance in the Cv2-Ap1 ABC. Six AHLs were detected in the Cv2-Ap1 culture. Among these, 3OC8-HSL and 3OC12-HSL additions promoted the ABC growth and enhanced their Cd accumulation. These findings may contribute to further understanding of AHL-mediated communication between algae and bacteria and provide support bioremediation efforts of metal-containing wastewater.
信号转导是藻类-细菌相互作用的一种重要模式，其中细菌群体感应（QS）可能影响微藻的生长和代谢。目前，尚不清楚细菌释放的酰基高丝氨酸内酯（AHLs）是否会影响藻类-细菌共生体（ABC）对污染物的去除。在这项研究中，我们使用小球藻（Cv）构建了 ABC，并用两种产生 AHL 的细菌进行了研究，并研究了它们在去除多种污染物（包括化学需氧量（COD）、总氮（TN）、磷（P）和镉（Cd））方面的性能。产生 AHL 的细菌，即根癌农杆菌（Ap）和恩斯弗拉根斯（Ea），能够与小球藻形成共生关系。与小球藻的比例为 2:1 的 Cv2-Ap1 共生体表现出最佳的生长促进作用，并且对 Cd、COD、TN 和 P 的去除率高于小球藻的单一培养物。Cv2-Ap1 ABC 从培养基中去除了 36.1%-47.5%的 Cd、94.5%-94.6%的 COD、37.1%-56.0%的 TN 和 90.4%-93.5%的 P。此外，细胞内中性脂质和细胞外蛋白质的增加以及细胞表面官能团的类型有助于 Cv2-Ap1 ABC 中 Cd 的去除和耐受。在 Cv2-Ap1 培养物中检测到六种 AHLs。其中，3OC8-HSL 和 3OC12-HSL 的添加促进了 ABC 的生长，并增强了它们对 Cd 的积累。这些发现可能有助于进一步了解藻类和细菌之间的 AHL 介导的通讯，并为含金属废水的生物修复提供支持。
