An evaluation of the impact of multiwalled carbon nanotubes on soil microbial community structure and functioning.
This study evaluated the impacts of multiwalled carbon nanotubes (MWNTs) on microbial community composition and functioning in a sandy loam soil over 90 d. We used test concentrations in the range of lower MWNT concentrations (10mg/kg) to extremely high MWNT concentrations (10,000 mg/kg) as a worst case scenario. We observed no effects of MWNTs on soil respiration, enzymatic activities, and microbial community composition at 10, 100 and 1,000 mg/kg. However, increases in fungal fatty acid methyl ester markers were observed at the highest treatment. In addition, pyrosequencing demonstrated a decreased abundance of some bacterial genera like Derxia, Holophaga, Opitutus and Waddlia at the highest treatment while bacterial genera that are considered potential degraders of recalcitrant contaminants (such as polycyclic aromatic hydrocarbons) like Rhodococcus, Cellulomonas, Nocardioides and Pseudomonas increased. These results suggest a shift in soil microbial community composition to more tolerant microbial populations in the presence of extremely high MWNT concentrations. It is unlikely that the change observed at 10,000 mg/kg is due to metal or carbon impurities as the MWNTs used in this study were of high purity. Given the need for wide-ranging data for regulation and risk assessment of nanomaterials, this study provides valuable data.
Department of Environmental Toxicology, The Institute of Environmental and Human Health (TIEHH), Texas Tech University, Lubbock, TX, USA.
Babina
B
Shrestha
Veronica
V
Acosta-Martinez
Stephen B
SB
Cox
Micah J
MJ
Green
Shibin
S
Li
Jaclyn E
JE
Cañas-Carrell
D000135:Acid Phosphatase / Q000378:metabolism; D001419:Bacteria / Q000145:classification / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D002245:Carbon Dioxide / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism; D005658:Fungi / Q000187:drug effects / Q000378:metabolism; D006596:Hexosaminidases / Q000378:metabolism; D037742:Nanotubes, Carbon / Q000633:toxicity*; D010088:Oxidoreductases / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*; D001617:beta-Glucosidase / Q000378:metabolism
D004269:DNA, Bacterial; D005227:Fatty Acids; D037742:Nanotubes, Carbon; D012989:Soil Pollutants; D002245:Carbon Dioxide; D010088:Oxidoreductases; D000135:Acid Phosphatase; D006596:Hexosaminidases; D001617:beta-Glucosidase
MWNTs; Nanomaterials; Pyrosequencing; Risk assessment; Soil microbial community