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Environmental biodegradability of [ 14 C] single‐walled carbon nanotubes by Trametes versicolor and natural microbial cultures found in New Bedford Harbor sediment and aerated wastewater treatment plant sludge
Author(s) -
Parks Ashley N.,
Chandler G. Thomas,
Ho Kay T.,
Burgess Robert M.,
Ferguson P. Lee
Publication year - 2015
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1002/etc.2791
Subject(s) - biodegradation , trametes versicolor , aeration , environmental chemistry , sewage treatment , chemistry , carbon nanotube , organic matter , carbon fibers , sediment , microbial biodegradation , waste management , organic chemistry , materials science , environmental engineering , laccase , environmental science , biology , microorganism , nanotechnology , bacteria , paleontology , genetics , composite number , engineering , composite material , enzyme
Little is known about environmental biodegradability or biotransformations of single‐walled carbon nanotubes (SWNT). Because of their strong association with aquatic organic matter, detailed knowledge of the ultimate fate and persistence of SWNT requires investigation of possible biotransformations (i.e., biodegradation) in environmental media. In the present study, [ 14 C]SWNT were utilized to track biodegradation over 6 mo by pure liquid culture of the fungus Trametes versicolor and mixed bacterial isolates from field‐collected sediment or aerated wastewater treatment plant sludge. The mixed cultures were chosen as more environmentally relevant media where SWNT will likely be deposited under both aerobic and anaerobic conditions. Activity of [ 14 C] was assessed in solid, aqueous, and 14 CO 2 gaseous phases to determine amounts of intact SWNT, partially soluble SWNT degradation products, and mineralized SWNT, respectively, during the 6 mo of the experiment. Mass balances based on radiocarbon activity were approximately 100% over 6 mo, and no significant degradation of SWNT was observed. Approximately 99% of the [ 14 C] activity remained in the solid phase, 0.8% in the aqueous phase, and less than 0.1% was mineralized to 14 CO 2 , regardless of culture type. These results suggest that SWNT are not readily biodegraded by pure fungal cultures or environmental microbial communities, and are likely persistent in environmental media. Environ Toxicol Chem 2014;9999:1–5. © 2014 SETAC