title: Interference sources in ATP bioluminescence assay of silica nanoparticle toxicity to activated sludge.
abstract: ATP measurement provides an overview of the general state of microbial activity, and thus it has proven useful for the evaluation of nanoparticle toxicity in activated sludge. ATP bioluminescence assay, however, is susceptible to interference by the components of activated sludge other than biomass. This paper presents the interference identified specific to the use of this assay after activated sludge respiration inhibition test of silica nanoparticles (OECD 209). We observed a high degree of interference (90%) in the presence of 100 mg/L silica nanoparticles and a low level of ATP being measured (0.01 μM); and 30% interference by the synthetic medium regardless of silica nanoparticle concentration and ATP level in the samples. ATP measurement in activated sludge with different MLSS concentrations revealed interference of high biomass content. In conclusion, silica nanoparticles, synthetic medium and activated sludge samples themselves interfere with ATP bioluminescence; this will need to be considered in the evaluation of silica nanoparticle toxicity to activated sludge when this type of assay is used.
authors.affiliation: Department of Environment and Energy, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul, Republic of Korea.
authors.forename: Mark
authors.initials: M
authors.lastname: Sibag
authors.affiliation: Department of Environment and Energy, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul, Republic of Korea.
authors.forename: Seung Hwan
authors.initials: SH
authors.lastname: Kim
authors.affiliation: Department of Environment and Energy, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul, Republic of Korea.
authors.forename: Choah
authors.initials: C
authors.lastname: Kim
authors.affiliation: JIU Corporation, Yangcheon-ro, Gangseo-gu, Seoul, Republic of Korea.
authors.forename: Hee Jun
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Department of Environment and Energy, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul, Republic of Korea. Electronic address: jinwoocho@sejong.edu.
authors.forename: Jinwoo
authors.initials: J
authors.lastname: Cho
mesh_terms: D000255:Adenosine Triphosphate / Q000032:analysis* / Q000378:metabolism; D018533:Biomass; D008163:Luminescent Measurements / Q000379:methods*; D053758:Nanoparticles / Q000633:toxicity*; D012722:Sewage / Q000737:chemistry*; D012822:Silicon Dioxide / Q000633:toxicity
chemical_list: D012722:Sewage; D012822:Silicon Dioxide; D000255:Adenosine Triphosphate
keywords: Activated sludge; Adenosine triphosphate; Bioluminescence interference; Respiration inhibition; Silica nanoparticles