College of Safety and Environment Engineering, Shandong University of Science & Technology, Qingdao, 266510, China.
Institute of Yellow River Delta Earth Surface Processes and Ecological Integrity, Shandong University of Science & Technology, Qingdao, 266510, China.
World J Microbiol Biotechnol. 2024 Oct 24;40(11):364. doi: 10.1007/s11274-024-04171-z.
The phenolic antioxidant 2,6-Di-tert-butyl-p-cresol (BHT) has been detected in various environments and is considered a potential threat to aquatic organisms. Algal-bacterial interactions are crucial for maintaining ecosystem balance and elemental cycling, but their response to BHT remains to be investigated. This study analyzed the physiological and biochemical responses of the microalga Isochrysis galbana and the changes of associated bacterial communities under different concentrations of BHT stress. Results showed that the biomass of I. galbana exhibited a decreasing trend with increasing BHT concentrations up to 40 mg/L. The reduction in chlorophyll, carotenoid, and soluble protein content of microalgal cells was also observed under BHT stress. The production of malondialdehyde and the activities of superoxide dismutase, peroxidase, and catalase were further determined. Scanning electron microscopy analysis revealed that BHT caused surface rupture of the algal cells and loss of intracellular nutrients. Proteomic analysis demonstrated the upregulation of photosynthesis and citric acid cycle pathways as a response to BHT stress. Additionally, BHT significantly increased the relative abundance of specific bacteria in the phycosphere, including Marivita, Halomonas, Marinobacter, and Alteromonas. Further experiments confirmed that these bacteria had the ability to utilize BHT as the sole carbon resource for growth, and genes related to the degradation of phenolic compounds were detected through pangenome analysis.
酚类抗氧化剂 2,6-二叔丁基对甲酚（BHT）已在各种环境中被检测到，被认为是对水生生物的潜在威胁。藻类-细菌相互作用对于维持生态系统平衡和元素循环至关重要，但它们对 BHT 的反应仍有待研究。本研究分析了微藻新月菱形藻在不同 BHT 浓度胁迫下的生理生化响应及其相关细菌群落的变化。结果表明，随着 BHT 浓度的增加，新月菱形藻的生物量呈下降趋势，最高可达 40mg/L。在 BHT 胁迫下，微藻细胞的叶绿素、类胡萝卜素和可溶性蛋白含量也减少。还进一步测定了丙二醛的产生以及超氧化物歧化酶、过氧化物酶和过氧化氢酶的活性。扫描电子显微镜分析表明，BHT 导致藻细胞表面破裂和细胞内营养物质流失。蛋白质组学分析表明，光合作用和柠檬酸循环途径的上调是对 BHT 胁迫的响应。此外，BHT 显著增加了噬菌体内特定细菌的相对丰度，包括 Marivita、Halomonas、Marinobacter 和 Alteromonas。进一步的实验证实，这些细菌具有利用 BHT 作为唯一碳源进行生长的能力，并且通过泛基因组分析检测到与酚类化合物降解相关的基因。
