Biological toxicity of cellulose nanocrystals (CNCs) against the luxCDABE-based bioluminescent bioreporter Escherichia coli 652T7

The aim of this study was to evaluate the biological toxicity of cellulose nanocrystals (CNCs) using the constitutively bioluminescent luxCDABE-based bioreporter Escherichia coli 652T7. The effects of CNCs on E. c oli 652T7 biotoxicity were investigated at different CNC concentrations, reaction times, and IC50 values. CNC toxicity was also compared with and without ultrasonic dispersion to establish dispersibility effects. The results demonstrated that CNCs were not significantly toxic at concentrations at or below 250 mg/L. At concentrations higher than 300 mg/L, toxicity increased linearly as CNC concentrations increased up to 2000 mg/L. IC50 calculations demonstrated an increase in cytotoxicity as CNC exposure times increased, and elevated dispersibility of the CNCs were shown to increase cytotoxicity effects. These results suggest that CNCs can impact microbial populations if elevated concentration thresholds are met.