Home | My Profile | Contact Us
Research Trends Products  |   order gateway  |   author gateway  |   editor gateway  
Register | Forgot Password

Author Resources
 Author Gateway
 Article submission guidelines

Editor Resources
 Editor/Referee Gateway

 Regional Subscription Agents/Distributors
Trends in Photochemistry & Photobiology   Volumes    Volume 13 
Effects of ultraviolet A radiation on survival and growth of Gram negative bacteria
Oscar J. Oppezzo, Cristina S. Costa, Ramón A. Pizarro
Pages: 37 - 50
Number of pages: 14
Trends in Photochemistry & Photobiology
Volume 13 

Copyright © 2011 Research Trends. All rights reserved

Ultraviolet A radiation (UVA) exerts a complex action on Gram negative bacteria. Within a variety of cellular components absorbing energy in this wavelength range, flavoproteins and cytochromes of the respiratory chain seem to be the chromophores involved in killing the cell. Damaged components of the respiratory chain would produce hydrogen peroxide and superoxide anion, and these compounds would generate hydroxyl radical, which is likely the main intermediary in the induction of oxidative damage. The identity of the targets remains an open question. For a long time, damage to DNA was considered to be the event leading to cell death, but recently energy depletion due to the inactivation of the respiratory chain has been proposed as an alternative mechanism. At sublethal doses UVA produces, among other effects, a transient inhibition of growth without change in viability. The growth lag is due to the inactivation of some tRNAs, which impairs protein synthesis and triggers the stringent response. A photo-protective function was ascribed to this effect. Global genetic regulators have been implicated in UVA response. The rpoS system has a strong influence on bacterial UVA resistance, probably related to the control of the response to oxidative stress, and the quorum sensing system modifies both lethal and sublethal effects of UVA in Pseudomonas. The current knowledge of the lethal action of UVA in bacteria could be improved by further analysis of the UVA response in a variety of bacterial species.
View Full Article  


Buy this article
Buy this volume
Subscribe to this title
Shopping Cart

Quick Links
Search Products
Browse in Alphabetical Order : Journals
Browse by Subject Classification : Journals

Ordering Information Ordering Information
Downloadable forms Downloadable Forms