College of Marine Science and Environment, Dalian Ocean University, 52 Heishijiao Street, Dalian 116023, China; Key Laboratory of Environment Controlled Aquaculture, Ministry of Education, Dalian Ocean University, 52 Heishijiao Street, Dalian 116023, China.
College of Marine Science and Environment, Dalian Ocean University, 52 Heishijiao Street, Dalian 116023, China; Key Laboratory of Environment Controlled Aquaculture, Ministry of Education, Dalian Ocean University, 52 Heishijiao Street, Dalian 116023, China.
Comp Biochem Physiol C Toxicol Pharmacol. 2020 Jul;233:108764. doi: 10.1016/j.cbpc.2020.108764. Epub 2020 Apr 12.
Florfenicol (FFC) is one of the most universally used antibiotics in aquaculture, which is substitute for chloramphenicol extensively, while the massive residues in aquatic environment were assumed to threaten the non-target organisms. Present research investigated the effects of florfenicol on growth, chlorophyll content, photosynthesis, and antioxidant ability of Isochrysis galbana. The results showed that FFC at 0.001-1 mg/L stimulated the growth of I. galbana and increased the content of chlorophyll. In addition, photosynthesis of I. galbana was inhibited and the photosynthetic parameters were uplifted with the increased exposure duration and FFC concentration. Furthermore, superoxide dismutase (SOD), catalase (CAT) activity significantly dropped at 0.01-20 mg/L FFC, while the contents of malondialdehyde (MDA), glutathione (GSH) and reactive oxygen species (ROS) increased after 72 h exposure, indicating that FFC at high concentrations caused a serious oxidative stress on algae. The simultaneous increase of ROS disrupted the equilibration between oxidants and antioxidant systems. Under the high concentration of FFC, the excessive of ROS was generated in algae which affected the membrane permeability and further decreased the cell biomass. Present study showed that acute exposure (72 h) at the environmental relevant concentration (0.01 mg/L) cannot induce the physiological dysfunction of the microalgae I. galbana, but the feeding concentration (20 mg/L) can. Additionally, this study hinted the possible negative impacts on ecosystems with the chronic exposure even at low FFC concentration or with the uncontrolled use of FFC.
氟苯尼考（FFC）是水产养殖中最广泛使用的抗生素之一，它被广泛替代氯霉素，而大量的残留物质在水生环境中被认为会威胁到非目标生物。本研究调查了氟苯尼考对新月菱形藻生长、叶绿素含量、光合作用和抗氧化能力的影响。结果表明，0.001-1mg/L 的 FFC 刺激新月菱形藻的生长并增加叶绿素含量。此外，随着暴露时间和 FFC 浓度的增加，新月菱形藻的光合作用受到抑制，光合参数升高。此外，超氧化物歧化酶（SOD）、过氧化氢酶（CAT）活性在 0.01-20mg/L FFC 时显著下降，而丙二醛（MDA）、谷胱甘肽（GSH）和活性氧（ROS）的含量在 72h 暴露后增加，表明高浓度的 FFC 对藻类造成严重的氧化应激。ROS 的同时增加破坏了氧化剂和抗氧化系统之间的平衡。在高浓度的 FFC 下，藻类中产生了过多的 ROS，影响了膜的通透性，并进一步降低了细胞生物量。本研究表明，在环境相关浓度（0.01mg/L）下进行急性暴露（72h）不会导致微藻新月菱形藻的生理功能障碍，但摄食浓度（20mg/L）会。此外，本研究暗示了即使在低浓度的 FFC 或不受控制地使用 FFC 的情况下，慢性暴露也可能对生态系统产生负面影响。
