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  1. Society has long been exposed to naturally-occurring nanoparticles. Due to their ubiquitous nature, biological systems have adapted and built protection against their potential effects. However, for the past decades, there have been onslaughts of newly engineered nanoparticles being released in the environment with no known effects on ecosystems. Although these materials offer distinct advantages in manufacturing processes, such as odor-free fabric or controlled drug delivery, their fate in nature has yet to be thoroughly investigated. As the size of an already-large NPs market is expected to grow, due to advances in synthetic biology, it is vital that we increase our understanding of their impacts on human, food and natural ecosystems. Recent studies have shown that NPs affect phytoplankton biomass and diversity in the ocean, solely by regulating micronutrients bioavailability. These types of changes could ultimately impact several biogeochemical cycles, as phytoplankton are responsible for almost half of the primary production on earth. Consequently, this study was designed to evaluate the impact of various concentrations (0µM, 20µM, 40µM, 80µM and 100µM) of several manufactured nanoparticles (gold, carbon and iron) on the dynamics of four economically important microalgae strains. Responses, such as chlorophyll content, protein, lipid content, lipid profile, biomass and cell morphology were monitored over a period of two weeks. No significant acute toxicity was exhibited within the first 24 hours of exposure. However, after 4 days, a remarkably high mortality rate was detected with increasing NPs concentrations of Fe60, C80 and Au60. Iron suspensions were found to be more toxic to the microalgae strains tested than those of Gold and Carbon under comparable regimes. Further investigations with other, either positively or negatively charged nanoparticles, should provide a deeper understanding on the impacts on these engineered materials in our ecosystems. 
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  2. null (Ed.)
    Society has long been exposed to naturally-occurring nanoparticles. Due to their ubiquitous nature, biological systems have adapted and built protection against their potential effects. However, for the past decades, there have been onslaughts of newly engineered nanoparticles being released in the environment with no known effects on ecosystems. Although these materials offer distinct advantages in manufacturing processes, such as odor-free fabric or controlled drug delivery, their fate in nature has yet to be thoroughly investigated. As the size of an already-large NPs market is expected to grow, due to advances in synthetic biology, it is vital that we increase our understanding of their impacts on human, food and natural ecosystems. Recent studies have shown that NPs affect phytoplankton biomass and diversity in the ocean, solely by regulating micronutrients bioavailability. These types of changes could ultimately impact several biogeochemical cycles, as phytoplankton are responsible for almost half of the primary production on earth. Consequently, this study was designed to evaluate the impact of various concentrations (0μM, 20μM, 40μM, 80μM and 100μM) of several manufactured nanoparticles (gold, carbon and iron) on the dynamics of four economically important microalgae strains. Responses, such as chlorophyll content, protein, lipid content, lipid profile, biomass and cell morphology were monitored over a period of two weeks. No significant acute toxicity was exhibited within the first 24 hours of exposure. However, after 4 days, a remarkably high mortality rate was detected with increasing NPs concentrations of Fe60, C80 and Au60. Iron suspensions were found to be more toxic to the microalgae strains tested than those of Gold and Carbon under comparable regimes. Further investigations with other, either positively or negatively charged nanoparticles, should provide a deeper understanding on the impacts on these engineered materials in our ecosystems. 
    more » « less