Flow Cytometry Assessment of Microalgae Physiological Alterations under CO2 Injection

• Published in: Cytometry. Part A 2020-11, Vol.97 (11), p.1136-1144
• Main Authors: Galotti, Andréa, Jiménez‐Gómez, Francisco, Parra, Gema
• Format: Article
• Language: English
• Subjects: Biomarkers; biomarkers of effect; Carbon dioxide; Carbon sequestration; CO2 injection; Deoxyribonucleic acid; DNA; ecophysiology; Esterase; Flow cytometry; Growth rate; Injection; Leakage; Membrane potential; Membranes; Mitigation; model species; Monitoring; New technology; pH effects; phytoplankton; Risk assessment; Scenedesmus (Acutodesmus) obliquus
• ISSN: 1552-4922; 1552-4930
• DOI: 10.1002/cyto.a.24028

Growth rate (GR), esterase activity (EA), membrane potential (MP), and DNA content were measured by flow cytometry to test if this powerful tool could be included in risk assessment and monitoring programs. This study tests a battery of endpoints that were measured on Scenedesmus (Acutodesmus) obliquus as model species, under high levels of injected CO2 to be proposed as biomarkers of effect. New technologies such as carbon capture and storage (CCS) bring positive consequences on CO2 mitigation strategies but also could have negative consequences if a CO2 leakage occurs during injection. Under this scenario, pH might drop down to 4 pH units around the pipe where the leakage happens. The study focus on to ascertain if the endpoints fulfill the requirements such as sensitiveness, be timely and cost‐effective, be easy to measure and interpret, and be nondestructive, valuable attributes in effective biomarkers. CO2 injected at high levels significantly affects the EA, the membrane polarization, as well as GRs. However the DNA content did not shown a clear response under this condition. In conclusion, the GR, the EA, and the MP analyzed by flow cytometry fulfilled the attributes mentioned above and are proposed as biomarkers of effect in CCS monitoring programs. © 2020 International Society for Advancement of Cytometry Different techniques were tested to give rapid responses in situation of CO2 leakage during carbon capture and storage (CCS). Mainly esterase activity and membrane potential of unicellular green algae showed significant differences in relation to control cells when cultured under low pH (6.5). These techniques are recommended as biomarkers on CCS locations in order to control alterations efficiently as they accomplish with important attributes like sensitiveness, timely and cost‐effectiveness, easiness to measure and to interpret and also nondestructive.