
Evidence for a Na + / H + electrogenic antiporter in an alkaliphilic cyanobacterium Synechocystis
Author(s) -
Buck Damian P.,
Smith Geoffrey D.
Publication year - 1995
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.1574-6968.1995.tb07542.x
Subject(s) - antiporter , synechocystis , sodium , biochemistry , chemistry , alkali metal , nuclear chemistry , potassium , homeostasis , biophysics , cyanobacteria , biology , bacteria , microbiology and biotechnology , genetics , organic chemistry
An alkaliphilic cyanobacterium characterized as a Synechocystis species was purified from a soil sample taken from a village in Java, Indonesia, by its preferential growth at elevated pH; it grew optimally at pH 9.5. Phosphorus nuclear magnetic resonance studies showed that the organism can maintain a ΔpH of over 2 pH units at an external pH of 10. It was observed that the viability of the organism in the dark was dependent on sodium ions. Evidence from experiments in which the extrusion of Na + was measured from cells subjected to an alkali shock suggests that the organism possesses a Na + / H + electrogenic antiporter which is used for the maintenance of pH homeostasis.