Inhibition of Aspergillus niger Growth by m -Dinitrobenzene and its Reversal by Amino Acids. ∗

Summary

1) A. niger growth was prevented when DNB at a final concentration of 2.5 × 10^-5 M was added to the culture medium at any time up to 30 hours' incubation. When DNB was added at any time later, some additional growth occurred. The DNB effect appeared to be limited to molds and was static rather than cidal. 2) Growth inhibition by DNB was overcome by synthetic mixtures of amino acids, but not by ammonium nitrogen, vitamins or minerals. 3) Nitroaryl compounds can be reduced to relatively nontoxic arylamines by a sulfhydryl-dependent, pyridine nucleotide-linked enzyme from A. niger. 4) The possible significance of these findings is discussed.