Comparative sensitivity of aquatic, terrestrial and enzymatic systems to engineered nanoparticles
Abstract
Nanoparticles (NPs) represent a growing class of industrial pollution, affecting multiple environmental compartments. Given their widespread use and inevitable environmental release, this study evaluates the responses of a diverse set of biological test systems representing different environmental niches and levels of biological organization to NP exposure. The investigated test systems included the crustacean Ceriodaphnia affinis , the unicellular alga Chlorella vulgaris , a coupled enzymatic system (NADH:FMN-oxidoreductase–luciferase), a trypsin-based enzymatic system, the higher plant Avena sativa , the wood-decaying fungus Pleurotus ostreatus , fungal conidia of Bipolaris sorokiniana , and the bioluminescent tropical fungus Neonothopanus nambi . Test systems were exposed to widely used engineered NPs: silver nanoparticles (AgNPs; 15–25 nm), titanium dioxide nanoparticles (TiO₂NPs; 100–190 nm), and silicon dioxide nanoparticles (SiO₂NPs; 100–120 nm). All test systems exhibited negative responses to AgNP exposure. EC₅₀ values for AgNPs ranged from 0.15 mg/L ( C. affinis ) to 30 mg/L ( B. sorokiniana ). TiO₂NPs affected maximum root length in A. sativa (EC₅₀ = 90 mg/L) and inhibited both enzyme-based assays, with EC₅₀ values of 13 and 15 mg/L for the coupled and trypsin-based systems, respectively. EC₅₀ values for SiO₂NPs were determined only for C. affinis, C. vulgaris , and the coupled enzymatic system, amounting to 11, 8–16, and 50 mg/L, respectively. The coupled enzymatic system exhibited sensitivity to all investigated nanoparticle types. The highest cumulative sensitivity was observed in aquatic systems ( C. vulgari s and C. affinis ), while terrestrial systems, particularly fungal test objects, demonstrated the highest resistance. Sensitivity patterns were more strongly associated with environmental niche than with the level of biological organization. Considering that engineered NPs predominantly enter the environment via wastewater pathways, these findings indicate that aquatic ecosystems represent particularly vulnerable environmental compartments to NP pollution.