Beryllium toxicity in Neurospora crassa.

In Neurospora crassa, 0·44 mM Be2+ caused half-maximal inhibition of growth and this inhibition could be fully counteracted by the addition of 2·5 mM Ca2+ to the medium. Mn2+ and Mg2+ were less effective in reversing the growth inhibition caused by Be2+ and the order of effectiveness was Ca2+ > Mn2+ > Mg2+. Fe3+ and Zn2+ were ineffective in reversing Be2+ toxicity. Pyruvate, malate and succinate also reversed the growth inhibition caused by Be2+ in N. crassa. Pyruvate restored growth by a mechanism not involving control of Be2+ accumulation in the mould. The rate of utilisation of glucose by the mycelia grown in the presence of Be2+ was reduced, while that of pyruvate was not affected. The results indicate that the primary metabolic lesion in Be2+ toxicity in N. crassa is probably a block at some step(s) in the glycolytic sequence.