Biological effect of aqueous C₆₀ aggregates on Scenedesmus obliquus revealed by transcriptomics and non-targeted...

This work evaluated biological effect of nC₆₀ on Scenedesmus obliquus. The cells were exposed to various concentrations of nC₆₀ for 7days. Low-dose of nC₆₀ was found to have a minor growth inhibitory effect. The transcriptomics and metabolomics were integrated to examine intricate molecular and cellular effects of nC₆₀ on Scenedesmus obliquus. We found that Scenedesmus obliquus cells exposed to nC₆₀ had several significant alterations in cellular transcription and biochemical processes. During the 7-day exposure to nC₆₀, 2234 and 2,448 unigenes were differentially expressed by 0.1mg/L and 1mg/L nC₆₀-treated groups compared with the control, including 2085 or 2247 up-regulated genes and 149 or 201 down-regulated genes, respectively. We successfully identified 22 metabolites, including 6 significantly changed metabolites, such as sucrose, d-glucose, and malic acid. The citrate cycle (TCA cycle) (ko00020) was the main target of both differentially expressed genes and metabolic change. However, accumulation of sucrose (end-product) could have induced feedback inhibition of photosynthesis in Scenedesmus obliquus, explaining the slight growth inhibition observed. The results provided a mechanistic understanding of the growth inhibition of nC₆₀ toxicity. These genes and metabolites are useful biomarkers for future studies and offer new insights into the early detectable changes in Scenedesmus obliquus with nC₆₀ exposure.