College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Ministry of Education, Peking University, Beijing 100871, China.
Canadian Museum of Nature, P.O. Box 3443, Station D, Ottawa, Ontario K1P 6P4, Canada.
J Hazard Mater. 2024 Apr 15;468:133787. doi: 10.1016/j.jhazmat.2024.133787. Epub 2024 Feb 14.
Bioadsorption, bioaccumulation and biodegradation processes in algae, play an important role in the biomagnification of antibiotics, or other organic pollutants, in aquatic food chains. In this study, the bioadsorption, bioaccumulation and biodegradation of norfloxacin [NFX], sulfamethazine [SMZ] and roxithromycin [RTM]) is investigated using a series of culture experiments. Chlorella vulgaris was exposed to these antibiotics with incubation periods of 24, 72, 120 and 168 h. Results show the bioadsorption concentration of antibiotics in extracellular matter increases with increasing alkaline phosphatase activity (AKP/ALP). The bioaccumulation concentrations of NFX, SMZ and RTM within cells significantly increase after early exposure, and subsequently decrease. There is a significant positive antibiotics correlation to superoxide dismutase (SOD), the photosynthetic electron transport rate (ETR) and maximum fluorescence after dark adaptation (F/F), while showing a negative correlation to malondialdehyde (MDA). The biodegradation percentages (P) of NFX, SMZ and RTM range from 39.3 - 97.2, 41.3 - 90.5, and 9.3 - 99.9, respectively, and significantly increase with increasing F/F density and chlorophyll-a. The accumulation of antibiotics in extracellular and intracellular substances of C. vulgaris is affected by antibiotic biodegradation processes associated with cell physiological state. The results succinctly explain relationships between algal growth during antibiotics exposure and the bioadsorption and bioaccumulation of these antibiotics in cell walls and cell matter. The findings draw an insightful understanding of the accumulation of antibiotics in algae and provide a scientific basis for the better utilization of algae treatment technology in antibiotic contaminated wastewaters. Under low dose exposures, the biomagnification of antibiotics in algae is affected by bioadsorption, bioaccumulation and biodegradation.
藻类中的生物吸附、生物积累和生物降解过程在抗生素或其他有机污染物在水生食物链中的生物放大中起着重要作用。在这项研究中，使用一系列培养实验研究了诺氟沙星[NFX]、磺胺甲恶唑[SMZ]和罗红霉素[RTM]的生物吸附、生物积累和生物降解。用这些抗生素培养小球藻，孵育期为 24、72、120 和 168 小时。结果表明，抗生素在细胞外物质中的生物吸附浓度随着碱性磷酸酶活性（AKP/ALP）的增加而增加。NFX、SMZ 和 RTM 在细胞内的生物积累浓度在早期暴露后显著增加，随后减少。超氧化物歧化酶（SOD）、光合作用电子传递率（ETR）和暗适应后的最大荧光（F/F）与抗生素呈显著正相关，而与丙二醛（MDA）呈负相关。NFX、SMZ 和 RTM 的生物降解百分比（P）分别为 39.3-97.2、41.3-90.5 和 9.3-99.9，并且随着 F/F 密度和叶绿素-a 的增加而显著增加。抗生素在 C. vulgaris 细胞内外物质中的积累受到与细胞生理状态相关的抗生素生物降解过程的影响。结果简洁地解释了抗生素暴露期间藻类生长与这些抗生素在细胞壁和细胞物质中的生物吸附和生物积累之间的关系。这些发现深入了解了抗生素在藻类中的积累，并为更好地利用藻类处理技术处理抗生素污染废水提供了科学依据。在低剂量暴露下，抗生素在藻类中的生物放大受生物吸附、生物积累和生物降解的影响。
