The Effect of DNA and Sodium Cholate Dispersed Single-Walled Carbon Nanotubes on the Green Algae Chlamydomonas reinhardtii

Abstract

Increasing use of single-walled carbon nanotubes (SWCNTs) will lead to their increased release into the environment. Previous work has shown negative effects of SWCNT on growth and survival of model organisms. The aim of the current study was to determine the effect of SWCNT well-dispersed by either DNA or sodium cholate (SC) on the unicellular green algae Chlamydomonas reinhardtii in stagnant water conditions. Growth measurements were taken up to ten days for algae treated with varied levels of DNA:SWCNT or SC:SWCNT or controls, and chlorophyll content after 10 days was determined. Results show no effect on either growth or chlorophyll content of algae at any concentration or duration. This is in contradiction to prior work showing toxicity of SWCNT to environmental model organisms.

DNA delivery by high aspect ratio nanomaterials to algal chloroplasts

“…Previously, SWCNT directly coated with salmon testes genomic DNA by Π-stacking interactions at 1 : 1 mass ratio concentration were shown to be biocompatible with Chlamydomonas reinhardtii wildtype strain (CC-1690) at concentrations from 0.1 to 100 μg mL −1 through growth curves and extracted chlorophyll a and b . 24 SWCNT have also been shown to protect against Chlamydomonas reinhardtii photosynthetic PSII inactivations and higher rates of photosynthetic electron transport. 25…”

“…Previously, SWCNT directly coated with salmon testes genomic DNA by Π-stacking interactions at 1 : 1 mass ratio concentration were shown to be biocompatible with Chlamydomonas reinhardtii wildtype strain (CC-1690) at concentrations from 0.1 to 100 μg mL −1 through growth curves and extracted chlorophyll a and b. 24 SWCNT have also been shown to protect against Chlamydomonas reinhardtii photosynthetic PSII inactivations and higher rates of photosynthetic electron transport. 25 Overall, population-based assays of ROS for oxidative stress, FDA for living cells, and in vivo chlorophyll content all pointed to 300 fg per cell of DNA-PEI10k-SWCNT and 30 fg per cell of DNA-PEI25k-SWCNT being the concentrations that were deemed to be biocompatible with algal cultures.…”

“…23 In contrast, salmon sperm DNA bound to sodium cholate-coated SWCNTs, at a 1 : 1 mass ratio, showed no inhibitory effect on Chlamydomonas reinhardtii growth or chlorophyll content at concentrations ranging from 0.1 to 100 μg mL −1 for an exposure duration of 10 days. 24 More recently, SWCNT have been reported to protect photosynthetic reactions in Chlamydomonas against photoinhibition. 25 Taken together, these results suggest that there is large potential in studying the nanotechnology applications for green algae and, specifically, the use of surface functionalized carbon nanotubes in C. reinhardtii for advancing biotechnology applications.…”

Nanotechnology Approaches for Chloroplast Biotechnology Advancements

“…These plant nanosensors can detect small amounts of molecules in the environment such as those present in explosives ( Wong et al, 2017 ). Although carbon nanotubes and quantum dots raise environmental toxicity concerns, improved knowledge in plant-nanoparticle interactions is leading to more precise control of the spatial and temporal distribution of nanomaterials in plant organs, such as leaves, for reducing exposure to humans and the environment ( Wang et al, 2008 ; Williams et al, 2014 ). Alternatively, sentinel plants with nanosensors may be deployed throughout an area to determine what other plants within that crop field are experiencing.…”