ISSN:
0749-503X
Keywords:
Yeast
;
vacuole
;
H+-ATPase
;
citrate transport
;
ΔpH
;
membrane potential
;
growth phase
;
Life and Medical Sciences
;
Genetics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Vacuoles were isolated from Yarrowia lipolytica yeast cells taken at various growth phases under carbon or nitrogen limitation. Vacuoles from the cells at the logarithmic growth phase showed a high activity of vacuolar H+-ATPase (0·9-1·1 U/mg protein) and efficiently generated chemical proton gradient and membrane potential across the tonoplast. Ca2+- and citrate transport were found to be maximal at this growth phase. At growth retardation and then in the stationary phase all the parameters studied decreased irrespective of the method of growth limitation. The citrate-transporting activity of vacuoles completely disappeared at growth retardation, also irrespective of the limitation method and irrespective of whether yeast cells overproduced citrate in the culture medium. The citrate-transporting system of Y. lipolytica vacuolar membrane is concluded not to be involved in citrate efflux and this efflux is probably performed by the plasmalemma transport system.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/yea.320090203
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