title: Early detection of mercury contamination by fluorescence induction of photosynthetic bacteria.
abstract: The induction (sudden dark-to-light transition) of fluorescence of photosynthetic bacteria has proved to be sensitive tool for early detection of mercury (Hg(2+)) contamination of the culture medium. The major characteristics of the induction (dark, variable and maximum fluorescence levels together with rise time) offer an easier, faster and more informative assay of indication of the contamination than the conventional techniques. The inhibition of Hg(2+) is stronger in the light than in the dark and follows complex kinetics. The fast component (in minutes) reflects the damage of the quinone acceptor pool of the RC and the slow component (in hours) is sensitive to the disintegration of the light harvesting system including the loss of the structural organization and of the pigments. By use of fluorescence induction, the dependence of the diverse pathways and kinetics of the mercury-induced effects on the age and the metabolic state of the bacteria were revealed.
authors.affiliation: Department of Biophysics, University of Szeged, Rerrich Béla tér 1, H-6720, Hungary.
authors.forename: Emese
authors.initials: E
authors.lastname: Asztalos
authors.forename: Francesca
authors.initials: F
authors.lastname: Italiano
authors.forename: Francesco
authors.initials: F
authors.lastname: Milano
authors.forename: Péter
authors.initials: P
authors.lastname: Maróti
authors.forename: Massimo
authors.initials: M
authors.lastname: Trotta
mesh_terms: D003470:Culture Media / Q000737:chemistry; D007700:Kinetics; D008027:Light; D008628:Mercury / Q000032:analysis*; D045322:Photosynthetic Reaction Center Complex Proteins / Q000737:chemistry / Q000378:metabolism; D012242:Rhodobacter sphaeroides / Q000187:drug effects* / Q000201:enzymology; D013050:Spectrometry, Fluorescence / Q000379:methods*
chemical_list: D003470:Culture Media; D045322:Photosynthetic Reaction Center Complex Proteins; D008628:Mercury