title: Differences in Physical and Biochemical Properties of Thermus scotoductus SA-01 Cultured with Dielectric or Convection Heating.
abstract: A thermophile, Thermus scotoductus SA-01, was cultured within a constant-temperature (65°C) microwave (MW) digester to determine if MW-specific effects influenced the growth and physiology of the organism. As a control, T. scotoductus cells were also cultured using convection heating at the same temperature as the MW studies. Cell growth was analyzed by optical density (OD) measurements, and cell morphologies were characterized using electron microscopy imaging (scanning electron microscopy [SEM] and transmission electron microscopy [TEM]), dynamic light scattering (DLS), and atomic force microscopy (AFM). Biophysical properties (i.e., turgor pressure) were also calculated with AFM, and biochemical compositions (i.e., proteins, nucleic acids, fatty acids) were analyzed by attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. Gas chromatography-mass spectrometry (GC-MS) was used to analyze the fatty acid methyl esters extracted from cell membranes. Here we report successful cultivation of a thermophile with only dielectric heating. Under the MW conditions for growth, cell walls remained intact and there were no indications of membrane damage or cell leakage. Results from these studies also demonstrated that T. scotoductus cells grown with MW heating exhibited accelerated growth rates in addition to altered cell morphologies and biochemical compositions compared with oven-grown cells.
authors.affiliation: Chemistry Division, U.S. Naval Research Laboratory, Washington, DC, USA.
authors.forename: Allison L
authors.initials: AL
authors.lastname: Cockrell
authors.affiliation: Chemistry Division, U.S. Naval Research Laboratory, Washington, DC, USA.
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Fitzgerald
authors.affiliation: Chemistry Division, U.S. Naval Research Laboratory, Washington, DC, USA.
authors.forename: Kathleen D
authors.initials: KD
authors.lastname: Cusick
authors.affiliation: Chemistry Division, U.S. Naval Research Laboratory, Washington, DC, USA.
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Barlow
authors.affiliation: Chemistry Division, U.S. Naval Research Laboratory, Washington, DC, USA.
authors.forename: Stanislav D
authors.initials: SD
authors.lastname: Tsoi
authors.affiliation: Center for Bio/Molecular Science and Engineering, U.S. Naval Research Laboratory, Washington, DC, USA.
authors.forename: Carissa M
authors.initials: CM
authors.lastname: Soto
authors.affiliation: Acoustics Division, U.S. Naval Research Laboratory, Washington, DC, USA.
authors.forename: Jeffrey W
authors.initials: JW
authors.lastname: Baldwin
authors.affiliation: Geosciences Division, U.S. Naval Research Laboratory, Stennis Space Center, Mississippi, USA.
authors.forename: Jason R
authors.initials: JR
authors.lastname: Dale
authors.affiliation: Chemistry Division, U.S. Naval Research Laboratory, Washington, DC, USA.
authors.forename: Robert E
authors.initials: RE
authors.lastname: Morris
authors.affiliation: Geosciences Division, U.S. Naval Research Laboratory, Stennis Space Center, Mississippi, USA.
authors.forename: Brenda J
authors.initials: BJ
authors.lastname: Little
authors.affiliation: Chemistry Division, U.S. Naval Research Laboratory, Washington, DC, USA Justin.biffinger@nrl.navy.mil.
authors.forename: Justin C
authors.initials: JC
authors.lastname: Biffinger
mesh_terms: D018533:Biomass; D055598:Chemical Phenomena; D000067493:Dynamic Light Scattering; D005227:Fatty Acids / Q000032:analysis; D008401:Gas Chromatography-Mass Spectrometry; D006361:Heating / Q000379:methods; D053858:Metabolic Networks and Pathways; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009696:Nucleic Acids / Q000032:analysis; D011506:Proteins / Q000032:analysis; D013053:Spectrophotometry; D017550:Spectroscopy, Fourier Transform Infrared; D013824:Thermus / Q000737:chemistry / Q000254:growth & development* / Q000528:radiation effects* / Q000648:ultrastructure
chemical_list: D005227:Fatty Acids; D009696:Nucleic Acids; D011506:Proteins