title: Microbial Transformation of Multiwalled Carbon Nanotubes by Mycobacterium vanbaalenii PYR-1.
abstract: Carbonaceous nanomaterials are widely used in industry and consumer products, but concerns have been raised regarding their release into the environment and subsequent impacts on ecosystems and human health. Although many efforts have been devoted to understanding the environmental fate of carbonaceous nanomaterials, information about their microbial transformation is still rare. In this study, we found that within 1 month a polycyclic aromatic hydrocarbon-degrading bacterium, Mycobacterium vanbaalenii PYR-1, was able to degrade both pristine and carboxyl-functionalized multiwalled carbon nanotubes (p-MWCNT and c-MWCNT), as demonstrated by consistent results from high resolution transmission electron microscopy, Raman spectroscopy, and confocal Raman microspectroscopy. Statistical analysis of Raman spectra identified a significant increase in the density of disordered or amorphous carbon in p-MWCNT and c-MWCNT after biodegradation. Microbial respiration further suggested potential mineralization of MWCNTs within about 1 month. All of our analyses consistently showed higher degradation or mineralization of c-MWCNT compared to p-MWCNT. These results highlight the potential of using bacteria in engineered systems to remove residual carbonaceous nanomaterials and reduce risk of human exposure and environmental impact. Meanwhile, our finding suggests possible transformation of carbonaceous nanomaterials by polycyclic aromatic hydrocarbon-degrading bacteria in the natural environment, which should be accounted for in predicting the environmental fate of these emerging contaminants and in nanotechnology risk regulation.
authors.affiliation: Department of Civil and Environmental Engineering, University of Nevada , Reno, Nevada 89557, United States.
authors.forename: Yaqi
authors.identifier: 0000-0001-5372-5505
authors.initials: Y
authors.lastname: You
authors.affiliation: Department of Civil and Environmental Engineering, University of Nevada , Reno, Nevada 89557, United States.
authors.forename: Kamol K
authors.initials: KK
authors.lastname: Das
authors.affiliation: Stockbridge School of Agriculture, University of Massachusetts , Amherst, Massachusetts 01003, United States.
authors.forename: Huiyuan
authors.initials: H
authors.lastname: Guo
authors.affiliation: Center for Biophotonics, University of California, Davis , Sacramento, California 95817, United States.
authors.forename: Che-Wei
authors.initials: CW
authors.lastname: Chang
authors.affiliation: Center for Biophotonics, University of California, Davis , Sacramento, California 95817, United States.
authors.forename: Maria
authors.initials: M
authors.lastname: Navas-Moreno
authors.affiliation: Center for Biophotonics, University of California, Davis , Sacramento, California 95817, United States.
authors.forename: James W
authors.initials: JW
authors.lastname: Chan
authors.affiliation: Department of Natural Resources and Environmental Science, University of Nevada , Reno, Nevada 89557, United States.
authors.forename: Paul
authors.initials: P
authors.lastname: Verburg
authors.affiliation: Department of Geological Sciences & Engineering, University of Nevada , Reno, Nevada 89557, United States.
authors.forename: Simon R
authors.initials: SR
authors.lastname: Poulson
authors.affiliation: Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University , Beijing 100871, China.
authors.forename: Xilong
authors.initials: X
authors.lastname: Wang
authors.affiliation: Stockbridge School of Agriculture, University of Massachusetts , Amherst, Massachusetts 01003, United States.
authors.forename: Baoshan
authors.initials: B
authors.lastname: Xing
authors.affiliation: Department of Civil and Environmental Engineering, University of Nevada , Reno, Nevada 89557, United States.
authors.forename: Yu
authors.initials: Y
authors.lastname: Yang
mesh_terms: D046529:Microscopy, Electron, Transmission; D009161:Mycobacterium / Q000378:metabolism*; D036103:Nanotechnology; D037742:Nanotubes, Carbon / Q000737:chemistry*; D011084:Polycyclic Aromatic Hydrocarbons
chemical_list: D037742:Nanotubes, Carbon; D011084:Polycyclic Aromatic Hydrocarbons