title: (Eco)toxicity and biodegradability of protic ionic liquids.
abstract: Ionic liquids (ILs) are often claimed to be "environmentally friendly" compounds however, the knowledge of their potential toxicity towards different organisms and trophic levels is still limited, in particular when protic ionic liquids (PILs) are addressed. This study aims to evaluate the toxicity against various microorganisms and the biodegradability of four PILs namely, N-methyl-2-hydroxyethylammonium acetate, m-2-HEAA; N-methyl-2-hydroxyethylammonium propionate, m-2-HEAPr; N-methyl-2-hydroxyethylammonium butyrate, m-2-HEAB; and N-methyl-2-hydroxyethylammonium pentanoate, m-2-HEAP. The antimicrobial activity was determined against the two bacteria, Sthaplylococcus aureus ATCC-6533 and Escherichia coli CCT-0355; the yeast Candida albicans ATCC-76645; and the fungi Fusarium sp. LM03. The toxicity of all PILs was tested against the aquatic luminescent marine bacterium Vibrio fischeri using the Microtox(®) test. The impact of the PILs was also studied regarding their effect on lettuce seeds (Lactuta sativa). The biodegradability of these PILs was evaluated using the ratio between the biochemical oxygen demand (BOD) and the chemical oxygen demand (COD). The results show that, in general, the elongation of the alkyl chain tends to increase the negative impact of the PILs towards the organisms and biological systems under study. According to these results, m-2-HEAA and m-2-HEAP are the less and most toxic PILs studied in this work, respectively. Additionally, all the PILs have demonstrated low biodegradability.
authors.affiliation: UNIT, Universidade Tiradentes, Av. Murilo Dantas, 300, Farolândia, 49032-490, Aracaju-SE, Brazil.
authors.forename: Maria V S
authors.initials: MV
authors.lastname: Oliveira
authors.affiliation: UNIT, Universidade Tiradentes, Av. Murilo Dantas, 300, Farolândia, 49032-490, Aracaju-SE, Brazil.
authors.forename: Bruna T
authors.initials: BT
authors.lastname: Vidal
authors.affiliation: UNIT, Universidade Tiradentes, Av. Murilo Dantas, 300, Farolândia, 49032-490, Aracaju-SE, Brazil; ITP, Instituto de Tecnologia e Pesquisa, Av. Murilo Dantas, 300-Prédio do ITP, Farolândia, 49032-490, Aracaju-SE, Brazil.
authors.forename: Claudia M
authors.initials: CM
authors.lastname: Melo
authors.affiliation: UNIT, Universidade Tiradentes, Av. Murilo Dantas, 300, Farolândia, 49032-490, Aracaju-SE, Brazil.
authors.forename: Rita de C M
authors.initials: Rde C
authors.lastname: de Miranda
authors.affiliation: UNIT, Universidade Tiradentes, Av. Murilo Dantas, 300, Farolândia, 49032-490, Aracaju-SE, Brazil; ITP, Instituto de Tecnologia e Pesquisa, Av. Murilo Dantas, 300-Prédio do ITP, Farolândia, 49032-490, Aracaju-SE, Brazil.
authors.forename: Cleide M F
authors.initials: CM
authors.lastname: Soares
authors.affiliation: CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: João A P
authors.initials: JA
authors.lastname: Coutinho
authors.affiliation: CICECO - Aveiro Institute of Materials, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
authors.forename: Sónia P M
authors.initials: SP
authors.lastname: Ventura
authors.affiliation: UFBA, Universidade Federal da Bahia, Escola Politécnica, Departamento de Engenharia, Rua Aristides Novis 2, Federação, 40210-630, Salvador-BA, Brazil.
authors.forename: Silvana
authors.initials: S
authors.lastname: Mattedi
authors.affiliation: UNIT, Universidade Tiradentes, Av. Murilo Dantas, 300, Farolândia, 49032-490, Aracaju-SE, Brazil; ITP, Instituto de Tecnologia e Pesquisa, Av. Murilo Dantas, 300-Prédio do ITP, Farolândia, 49032-490, Aracaju-SE, Brazil. Electronic address: aslima2001@yahoo.com.br.
authors.forename: Álvaro S
authors.initials: ÁS
authors.lastname: Lima
mesh_terms: D048908:Aliivibrio fischeri / Q000187:drug effects / Q000378:metabolism; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D000935:Antifungal Agents / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity; D001673:Biodegradation, Environmental; D057919:Biological Oxygen Demand Analysis; D002176:Candida albicans / Q000187:drug effects; D004926:Escherichia coli / Q000187:drug effects; D005670:Fusarium / Q000187:drug effects; D052578:Ionic Liquids / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D018545:Lactuca / Q000187:drug effects / Q000254:growth & development; D049449:Luminescence; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000378:metabolism / Q000633:toxicity*; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000900:Anti-Bacterial Agents; D000935:Antifungal Agents; D052578:Ionic Liquids; D000644:Quaternary Ammonium Compounds
keywords: Antimicrobial activity; Biodegradability; Microtox(®); Phytotoxicity; Protic ionic liquids; Toxicity evaluation