Open AccessThe in vivo effect of glucose and extracellular pH on the plasma membrane H + ‐ATPase of Penicillium simplicissimum
Author(s) -
Burgstaller Wolfgang,
Müller Brigitte,
Schinner Franz
Publication year - 1997
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.1574-6968.1997.tb10228.x
Subject(s) - extracellular , in vivo , atpase , chemistry , membrane , penicillium , biochemistry , biophysics , microbiology and biotechnology , biology , enzyme , food science , genetics
The in vivo effect of glucose and a high extracellular buffering capacity on the plasma membrane H + ‐ATPase of Penicillium simplicissimum was investigated. The activity of the H + ‐ATPase of the plasma membrane could be determined specifically in a subcellular fraction containing mainly plasma membranes but not in permeabilized hyphae. The maximum stimulation by glucose was two‐fold after 15 min of carbon starvation. Five hours of carbon starvation did not increase stimulation of the H + ‐ATPase by glucose. The effect of a high extracellular buffering capacity was investigated at pH 6 and 7.5. At pH 7.5, the H + ‐ATPase activity was slightly decreased, whereas at pH 6 it was slightly increased. In summary, neither the presence or absence of glucose nor the extracellular pH led to gross changes in the H + ‐ATPase activity. A relationship between the activity of the H + ‐ATPase and buffer‐stimulated excretion of citrate could not be detected.