Copper uptake by yeast-like cells, hyphae, and chlamydospores of Aureobasidium pullulans

TY - JOUR

T1 - Copper uptake by yeast-like cells, hyphae, and chlamydospores of Aureobasidium pullulans

AU - Gadd, Geoffrey M.

AU - Mowll, Jonathan L.

N1 - Funding Information: G.M.G. gratefully acknowledges the receipt of a grant from the Natural Environment Research Council (NERC GR1314520). Thanks are also due to Dr. J. E. Whitley and Mr. A. Wilson of the SURRC, East Kil-bride, for the provision of the 64 CuSO,. Copyright © 1985 Published by Elsevier Inc.

PY - 1985/9

Y1 - 1985/9

N2 - All cell types of Aureobasidium pullulans could bind copper to surfaces, the efficiency of binding being in the order chlamydospores >yeast-like cells >mycelium. Chlamydospores were the least sensitive cell type to copper and only yeast-like cells and mycelium exhibited a second phase of energy-dependent Cu2+ influx at nontoxic concentrations. This followed Michaelis-Menten kinetics and was inhibited at 4°C or in the presence of 2-deoxy-d-glucose, potassium cyanide, high Ca2+ concentrations, and the uncouplers carbonylcyanide-p-trifluoromethoxyphenylhydrazone and dinitrophenol, but was stimulated by nigericin. Concomitant with Cu2+ influx was K+ efflux, and two K+ ions were released for every Cu2+ taken up. Cu2+ influx was inhibited when intracellular K+ was low or when extracellular K+ was high. The results suggested that Cu2+ influx was driven by the membrane potential. There was Cu2+ efflux from loaded cells which was independent of the presence of glucose, and kinetic analysis showed that the cells acted as two-compartment systems. Most of the intracellular copper could be removed by washing the cells with nitrilotriacetic acid.

AB - All cell types of Aureobasidium pullulans could bind copper to surfaces, the efficiency of binding being in the order chlamydospores >yeast-like cells >mycelium. Chlamydospores were the least sensitive cell type to copper and only yeast-like cells and mycelium exhibited a second phase of energy-dependent Cu2+ influx at nontoxic concentrations. This followed Michaelis-Menten kinetics and was inhibited at 4°C or in the presence of 2-deoxy-d-glucose, potassium cyanide, high Ca2+ concentrations, and the uncouplers carbonylcyanide-p-trifluoromethoxyphenylhydrazone and dinitrophenol, but was stimulated by nigericin. Concomitant with Cu2+ influx was K+ efflux, and two K+ ions were released for every Cu2+ taken up. Cu2+ influx was inhibited when intracellular K+ was low or when extracellular K+ was high. The results suggested that Cu2+ influx was driven by the membrane potential. There was Cu2+ efflux from loaded cells which was independent of the presence of glucose, and kinetic analysis showed that the cells acted as two-compartment systems. Most of the intracellular copper could be removed by washing the cells with nitrilotriacetic acid.

KW - Aureobasidium pullulans

KW - chlamydospores

KW - copper binding

KW - copper uptake

KW - energy-dependent Cu influx

KW - hyphae

KW - yeast-like cells

UR - https://www.scopus.com/pages/publications/0021966967

U2 - 10.1016/0147-5975(85)90019-2

DO - 10.1016/0147-5975(85)90019-2

M3 - Article

AN - SCOPUS:0021966967

SN - 0147-5975

VL - 9

SP - 0

EP - 40

JO - Experimental Mycology

JF - Experimental Mycology

IS - 3

ER -