Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Viability of Cladosporium herbarum spores under 157 nm laser and vacuum ultraviolet irradiation, low temperature (10 K) and vacuum
Δημιουργός/Συγγραφέας:	[EL] Σαραντοπούλου, Ευαγγελία[EN] Sarantopoulou, Evangelia Stefi A. [EL] Κόλλια, Ζωή[EN] Kollia, Zoe [EL] Παλλές, Δημήτρης[EN] Palles, Dimitris Petrou P.S. Bourkoula A. Koukouvinos G. Velentzas A.D. Kakabakos S. [EL] Κεφαλάς, Αλκιβιάδης Κωνσταντίνος[EN] Cefalas, Alciviadis Constantinos
Εκδότης:	American Institute of Physics Inc.
Ημερομηνία:	2014
Γλώσσα:	Αγγλικά
ISSN:	0021-8979
DOI:	10.1063/1.4894621
Περίληψη:	Ultraviolet photons can damage microorganisms, which rarely survive prolonged irradiation. In addition to the need for intact DNA, cell viability is directly linked to the functionality of the cell wall and membrane. In this work, Cladosporium herbarum spore monolayers exhibit high viability (7%) when exposed to 157 nm laser irradiation (412 kJm-2) or vacuum-ultraviolet irradiation (110-180 nm) under standard pressure and temperature in a nitrogen atmosphere. Spore viability can be determined by atomic-force microscopy, nano-indentation, mass, μ-Raman and attenuated reflectance Fourier-transform far-infrared spectroscopies and DNA electrophoresis. Vacuum ultraviolet photons cause molecular damage to the cell wall, but radiation resistance in spores arises from the activation of a photon-triggered signaling reaction, expressed via the exudation of intracellular substances, which, in combination with the low penetration depth of vacuum-ultraviolet photons, shields DNA from radiation. Resistance to phototoxicity under standard conditions was assessed, as was resistance to additional environmental stresses, including exposure in a vacuum, under different rates of change of pressure during pumping time and low (10 K) temperatures. Vacuum conditions were far more destructive to spores than vacuum-ultraviolet irradiation, and UV-B photons were two orders of magnitude more damaging than vacuum-ultraviolet photons. The viability of irradiated spores was also enhanced at 10 K. This work, in addition to contributing to the photonic control of the viability of microorganisms exposed under extreme conditions, including decontamination of biological warfare agents, outlines the basis for identifying bio-signaling in vivo using physical methodologies.
Τίτλος πηγής δημοσίευσης:	Journal of Applied Physics
Τόμος/Κεφάλαιο:	116
Τεύχος:	10
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry [EL] Εφαρμοσμένη οπτική. Φωτονική[EN] Applied optics. Photonics
Αξιολόγηση από ομότιμους (peer reviewed):	Ναι
Κάτοχος πνευματικών δικαιωμάτων:	© 2014 AIP Publishing LLC.
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο