Chloride transport in the vegetative mycelia of filamentous fungus Trichoderma viride

The influx of chlorides into Trichoderma viride vegetative submerged mycelium was measured by means of the radionuclide 36 Cl − . It was found that the 36 Cl − influx was time‐dependent (the steady‐state was established with t 1/2 = 25 min at 25 °C), pH‐dependent (with pH optimum between 4–5.5), temperature‐dependent (at about 15 °C), and concentration‐dependent (K M  (Cl   – )= 47.6 ± 4.2 μmol · l −1 ; J max = 11.5 ± 0.7 pmol(Cl − ) · min −1 · mg dry mass −1 ). The 36 Cl − influx was inhibited by Br − but not F − , I − , SO 4 2− , HPO 3 2− and HCO 3 − . The presence of vanadate (P‐type ATPase inhibitor) moderately stimulated the 36 Cl − influx but the presence valinomycin (electrogenic K + ionophore), salicylate (known to release Ca 2+ from Trichoderma viride internal stores) were without effect on the 36 Cl − influx. The results suggest that the 36 Cl − influx is mediated by a carrier and that the transport is electroneutral, probably Cl − /OH − antiport. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)