title: Physiological and biochemical responses of Chlorella vulgaris to Congo red.
abstract: Extensive use of synthetic dyes in many industrial applications releases large volumes of wastewater. Wastewaters from dying industries are considered hazardous and require careful treatment prior to discharge into receiving water bodies. Dyes can affect photosynthetic activities of aquatic flora and decrease dissolved oxygen in water. The aim of this study was to evaluate the effect of Congo red on growth and metabolic activity of Chlorella vulgaris after 96h exposure. Exposure of the microalga to Congo red reduced growth rate, photosynthesis and respiration. Analysis of chlorophyll a fluorescence emission showed that the donor side of photosystem II was affected at high concentrations of Congo red. The quantum yield for electron transport (φEo), the electron transport rate (ETR) and the performance index (PI) also decreased. The reduction in the ability to absorb and use the quantum energy increased non-photochemical (NPQ) mechanisms for thermal dissipation. Overall, Congo red affects growth and metabolic activity in photosynthetic organisms in aquatic environments.
authors.affiliation: Laboratorio de Biotecnología de Microalgas, Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. IPN 2508, San Pedro Zacatenco, C.P. 07360 México DF, México. Electronic address: mairim_uam@hotmail.com.
authors.forename: Miriam
authors.initials: M
authors.lastname: Hernández-Zamora
authors.affiliation: Laboratorio de Bioquímica, Unidad de Morfología y Función, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Los Reyes Iztacala, Av. de los Barrios #1, Estado de México, México. Electronic address: hperales@yahoo.com.
authors.forename: Hugo Virgilio
authors.initials: HV
authors.lastname: Perales-Vela
authors.affiliation: Laboratorio de Biogeoquímica, Unidad de Biotecnología y Prototipos, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Los Reyes Iztacala, Av. de los Barrios #1, Estado de México, México. Electronic address: cmflores@servidor.unam.mx.
authors.forename: César Mateo
authors.initials: CM
authors.lastname: Flores-Ortíz
authors.affiliation: Laboratorio de Biotecnología de Microalgas, Departamento de Biotecnología y Bioingeniería, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Av. IPN 2508, San Pedro Zacatenco, C.P. 07360 México DF, México. Electronic address: rcanizar@cinvestav.mx.
authors.forename: Rosa Olivia
authors.initials: RO
authors.lastname: Cañizares-Villanueva
mesh_terms: D019069:Cell Respiration / Q000187:drug effects; D048408:Chlorella vulgaris / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D002734:Chlorophyll / Q000032:analysis; D000077194:Chlorophyll A; D003224:Congo Red / Q000633:toxicity*; D004579:Electron Transport / Q000187:drug effects; D058086:Microalgae / Q000187:drug effects*; D010788:Photosynthesis / Q000187:drug effects*; D045332:Photosystem II Protein Complex / Q000187:drug effects
chemical_list: D045332:Photosystem II Protein Complex; D002734:Chlorophyll; D003224:Congo Red; D000077194:Chlorophyll A
keywords: Chlorella vulgaris; Chlorophyll a fluorescence; Congo red; JIP-test; Photosynthesis; Respiration