title: Rapid ecotoxicological bioassay using delayed fluorescence in the marine cyanobacterium Cyanobium sp. (NIES-981).
abstract: The use of delayed fluorescence intensity as an endpoint for rapid estimation of the effective concentration (ECx) has been reported as an alternative to standard growth inhibition (at 72 h after exposure) in some algal species including Pseudokirchneriella subcapitata. In marine algae, although an approach of bioassaying using delayed fluorescence measurements has not been performed yet, its development would provide many benefits for marine environmental risk assessment. In this study, we selected marine cyanobacterium Cyanobium sp. (NIES-981) as our test algal species and demonstrated that this species is valid for the standard growth inhibition test based on criteria provide by Organization for Economic Co-operation and Development guidelines. Furthermore, standard inhibition tests and shorter period test using DF were performed in NIES-981 using five chemicals (3,5-DCP, simazine, diflufenican, K2Cr2O7, and CuSO4), and their EC50and low-toxic-effect values (EC10, EC5, and NOEC) were determined from two dose-response curves. Based on comparisons of the two dose-response curves and the EC50values, we conclude that DF intensity is useful as an endpoint for rapid estimation of EC50in NIES-981.
authors.affiliation: Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yamagishi
authors.affiliation: Central Research Laboratory, Hamamatsu Photonics K. K., 5000 Hirakuchi, Higashi-ku, Hamamatsu, Shimokanzo, 434-8601, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Katsumata
authors.affiliation: Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
authors.forename: Haruyo
authors.initials: H
authors.lastname: Yamaguchi
authors.affiliation: Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Shimura
authors.affiliation: Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kawachi
authors.affiliation: Center for Regional Environmental Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Koshikawa
authors.affiliation: Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
authors.forename: Yoshifumi
authors.initials: Y
authors.lastname: Horie
authors.affiliation: Research Center for Environmental Risk, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan. tatarazako.norihisa@nies.go.jp.
authors.forename: Norihisa
authors.identifier: http://orcid.org/0000-0002-7306-596X
authors.initials: N
authors.lastname: Tatarazako
mesh_terms: D001681:Biological Assay / Q000379:methods*; D000458:Cyanobacteria / Q000187:drug effects* / Q000502:physiology; D054750:Ecotoxicology; D004784:Environmental Monitoring / Q000379:methods; D005453:Fluorescence; D008163:Luminescent Measurements; D014874:Water Pollutants, Chemical / Q000633:toxicity*
chemical_list: D014874:Water Pollutants, Chemical
keywords: Algal growth inhibition test; Cyanobium sp.; Delayed fluorescence; Marine cyanobacteria