Oxidative stress responses and cellular energy allocation changes in microalgae following exposure to different human antibiotics

Abstract

Event Abstract Back to Event Oxidative stress responses and cellular energy allocation changes in microalgae following exposure to different human antibiotics Adeolu O. Aderemi1*, Sara C. Novais2, Luís M. Alves2, Marco F. Lemos2 and Colin Hunter1 1 School of Engineering and Built Environment, Glasgow Caledonian University, United Kingdom 2 MARE – Marine and Environmental Sciences Centre, ESTM, Instituto Politécnico de Leiria, Portugal The continuous discharge of pharmaceutical residues into the aquatic environment has become a growing concern due to the threat they represent to non-target organisms. Green algae as primary producers are vital for the sustenance of the aquatic ecosystem. In an effort to assess the individual effect of selected human antibiotics on microalgae, Raphidocelis subcapitata was exposed to sublethal levels of erythromycin, clarithromycin, ciprofloxacin, and sulfamethoxazole for 120 h. The effects were assessed by analyzing cell yield and several biochemical parameters related with: 1) antioxidant capacity and oxidative damage by measuring superoxide dismutase (SOD) enzyme activity and lipid peroxidation (LPO) levels; and 2) cellular energy allocation (CEA) by quantifying the content in energy reserves (total lipid, carbohydrate and protein), which represents the energy available (Ea), and the electron transport system activity that represents a measure of oxygen and energy consumption (Ec). Growth inhibitory concentrations of sulfamethoxazole (18-30%) and clarithromycin (28.7%) were found to elicit a considerable increase in energy consumption, thereby causing a significant decrease in the cellular energy allocation. The elevated Ec can be a result of the need to respond to oxidative stress occurring under those conditions since a significant increase in SOD activity was observed for both drugs at these levels. However, with sulfamethoxazole the antioxidant response does not seem to be enough to cope with the reactive oxygen species and prevent oxidative damage, given the elevated LPO levels observed. Regarding erythromycin, a significant concentration dependent decrease in the total carbohydrate content was observed, along with a significant increase in Ec, decrease in CEA and induction of SOD activity, at concentrations inhibiting growth by 17% and 39%. Ciprofloxacin, at the highest concentration tested, caused 28% inhibition of cell yield accompanied by a reduction in CEA. Moreover, at the lowest concentrations of this drug, a stimulatory effect on growth was observed (up to 16%), which was also highly correlated with the increase in the net energy budget (CEA). By revealing stress effects of R. subcapitata at the cellular level, induced at sublethal concentrations of the tested antibiotic drugs, this study suggests CEA as a reliable indicator of the organisms’ physiological status. Acknowledgements This study had the support of the Fundação para a Ciência e a Tecnologia (FCT) Strategic Project UID/MAR/04292/2013 granted to MARE. Sara C. Novais wish to acknowledge the financial support given by FCT (SFRH/BPD/94500/2013). Adeolu Aderemi was supported by a PhD studentship from SEBE, GCU. Keywords: Ecotoxicology, pharmaceuticals, Microalgae, biomarkers, Growth inhibition Conference: IMMR | International Meeting on Marine Research 2016, Peniche, Portugal, 14 Jul - 15 Jul, 2016. Presentation Type: Poster presentation Topic: Biodiversity, Conservation and Coastal Management Citation: Aderemi AO, Novais SC, Alves LM, Lemos MF and Hunter C (2016). Oxidative stress responses and cellular energy allocation changes in microalgae following exposure to different human antibiotics. Front. Mar. Sci. Conference Abstract: IMMR | International Meeting on Marine Research 2016. doi: 10.3389/conf.FMARS.2016.04.00005 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 14 May 2016; Published Online: 12 Jul 2016. * Correspondence: Mr. Adeolu O Aderemi, School of Engineering and Built Environment, Glasgow Caledonian University, Glasgow, United Kingdom, Adeolu.Aderemi@gcu.ac.uk Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Adeolu O Aderemi Sara C Novais Luís M Alves Marco F Lemos Colin Hunter Google Adeolu O Aderemi Sara C Novais Luís M Alves Marco F Lemos Colin Hunter Google Scholar Adeolu O Aderemi Sara C Novais Luís M Alves Marco F Lemos Colin Hunter PubMed Adeolu O Aderemi Sara C Novais Luís M Alves Marco F Lemos Colin Hunter Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.