Open AccessThe antibacterial action of cupric ions in Pseudomonas syringae
Author(s) -
Cabral João P.S.
Publication year - 1991
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1991.tb04546.x
Subject(s) - pseudomonas syringae , respiration , ethylenediaminetetraacetic acid , pseudomonas , chelation , bacteria , cellular respiration , biochemistry , microbiology and biotechnology , nutrient agar , chemistry , copper , intracellular , biology , agar , botany , inorganic chemistry , pathogen , organic chemistry , genetics
Summary Cu 2+ was bactericidal to the phytopathogenic bacterium Pseudomonas syringae in the micromolar range. Cu 2+ also inhibited O 2 consumption with glycerol, glucose or succinate as substrates, but at concentrations lower than those that caused death. The patterns of the alterations in the respiration of these substrates were very similar. Treatment of the cells with 5–10 μM Cu 2+ resulted in an increase in the respiration rate, but higher concentrations were inhibitory. Complete cessation of the respiration was observed with 20–25 μM Cu 2+ . The results suggest that Cu 2+ inhibits components of the respiratory chain and/or the H + ‐ATP synthase. Previous reports from this laboratory have shown that Cu 2+ also induces acute K + loss in P. syringae . In the present study, it was found that most of the cells that had completely blocked respiration and lost most of the intracellular unbound K + , when transferred to nutrient agar, gave rise to colonies, suggesting that these phenomena were reversible. This hypothesis was supported by the observation that the chelating agents, diethyldithiocarbamate or ethylenediaminetetraacetic acid, were able to restore the respiration and to stop the release of K + in Cu 2+ ‐treated cells. It would appear that the constituents of the plating medium were able to remove the copper ions from the inhibitory sites.