AB 24:109-115 (2015)  -  DOI: https://doi.org/10.3354/ab00643

ABSTRACT: The marine diatom Phaeodactylum tricornutum is an important basal resource in the marine food chain and is used as a standard test organism in toxicological studies. In this study, in vivo experiments were performed to analyze the effects of 1-octyl-3-methylimidazolium bromide ([C₈mim]Br) on the growth, photosynthetic activity, and antioxidant enzymes of P. tricornutum using 96 h growth tests in a batch-culture system. The results showed that [C₈mim]Br significantly inhibited the growth of P. tricornutum, with a 96 h EC₅₀ of 8.89 mg l^-1, and likely restricts PSII electron transfer and light use efficiency of the diatom. With increasing [C₈mim]Br concentrations, the soluble protein content in the diatom increased by 35.9, 58.5, 123.3, 197.7, and 207.0% in 5, 10, 20, 40, and 80 l^-1 [C₈mim]Br treatments relative to the controls, respectively. Concentrations of [C₈mim]Br ≤10 mg l^-1 caused a slight increase of superoxide dismutase (SOD) activity (from 16.37 to 23.04 U g^-1 protein) in the diatom, but inhibited its activity at concentrations above 10 mg l^-1. These observations indicate that moderate [C₈mim]Br stress (about 10 mg l^-1) likely stimulates the synthesis of proteins and free radical quenching. The general increase in malondialdehyde (MDA) content suggests that the physiological effects of [C₈mim]Br were caused by free radical generation. Thus, potential risks exist if [C₈mim]Br is accidentally released into the aquatic environment.

KEY WORDS: Ionic liquid · Phaeodactylum tricornutum · 1-octyl-3-methylimidazolium bromide · Photosynthetic activity · Antioxidant enzymes

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Cite this article as: Deng XY, Cheng J, Hu XL, Gao K, Wang CH (2015) Physiological and biochemical responses of a marine diatom Phaeodactylum tricornutum exposed to 1-octyl-3-methylimidazolium bromide. Aquat Biol 24:109-115. https://doi.org/10.3354/ab00643 Export citation Share:    Facebook - - linkedIn