title: Morphological and chemical changes of aerosolized E. coli treated with a dielectric barrier discharge.
abstract: This study presents the morphological and chemical modification of the cell structure of aerosolized Escherichia coli treated with a dielectric barrier discharge (DBD). Exposure to DBD results in severe oxidation of the bacteria, leading to the formation of hydroxyl groups and carbonyl groups and a significant reduction in amine functionalities and phosphate groups. Near edge x-ray absorption fine structure (NEXAFS) measurements confirm the presence of additional oxide bonds upon DBD treatment, suggesting oxidation of the outer layer of the cell wall. Electron microscopy images show that the bacteria undergo physical distortion to varying degrees, resulting in deformation of the bacterial structure. The electromagnetic field around the DBD coil causes severe damage to the cell structure, possibly resulting in leakage of vital cellular materials. The oxidation and chemical modification of the bacterial components are evident from the Fourier transform infrared spectroscopy and NEXAFS results. The bacterial reculture experiments confirm inactivation of airborne E. coli upon treating with DBD.
authors.affiliation: NASA Ames Research Center, Moffett Field, California 94035.
authors.forename: Jaione
authors.initials: J
authors.lastname: Romero-Mangado
authors.affiliation: Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Menlo Park, California 94025.
authors.forename: Dennis
authors.initials: D
authors.lastname: Nordlund
authors.affiliation: Novaerus, Inc., 111 N. Canal St. Suite 165, Chicago, Illinois 60606.
authors.forename: Felipe
authors.initials: F
authors.lastname: Soberon
authors.affiliation: Novaerus, Inc., 111 N. Canal St. Suite 165, Chicago, Illinois 60606.
authors.forename: Graham
authors.initials: G
authors.lastname: Deane
authors.affiliation: Novaerus, Inc., 111 N. Canal St. Suite 165, Chicago, Illinois 60606.
authors.forename: Kevin
authors.initials: K
authors.lastname: Maughan
authors.affiliation: Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, Espoo 02150, Finland.
authors.forename: Sami
authors.initials: S
authors.lastname: Sainio
authors.affiliation: National Center for Plasma Science and Technology, Dublin City University, Dublin 9, Ireland.
authors.forename: Gurusharan
authors.initials: G
authors.lastname: Singh
authors.affiliation: National Center for Plasma Science and Technology, Dublin City University, Dublin 9, Ireland.
authors.forename: Stephen
authors.initials: S
authors.lastname: Daniels
authors.affiliation: NASA Ames Research Center, Moffett Field, California 94035.
authors.forename: Ian T
authors.initials: IT
authors.lastname: Saunders
authors.affiliation: NASA Ames Research Center, Moffett Field, California 94035.
authors.forename: David
authors.initials: D
authors.lastname: Loftus
authors.affiliation: NASA Ames Research Center, Moffett Field, California 94035.
authors.forename: M
authors.initials: M
authors.lastname: Meyyappan
authors.affiliation: NASA Ames Research Center, Moffett Field, California 94035.
authors.forename: Jessica
authors.initials: J
authors.lastname: Koehne
authors.affiliation: NASA Ames Research Center, Moffett Field, California 94035 and Universities Space Research Association, Mountain View, California 94043.
authors.forename: Ram P
authors.initials: RP
authors.lastname: Gandhiraman
mesh_terms: D000336:Aerosols; D004560:Electricity; D004926:Escherichia coli / Q000737:chemistry* / Q000166:cytology* / Q000502:physiology; D050296:Microbial Viability; D008854:Microscopy, Electron; D010084:Oxidation-Reduction; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D056928:X-Ray Absorption Spectroscopy
chemical_list: D000336:Aerosols