Isolation, selection and characterization of a cyanide-degrading fungus from an industrial effluent

Amongst 14 fungi isolates from a cyanide-containing industrial effluent, a strain of Fusarium oxysporum developed a particularly high tolerance for cyanide when incubated in a medium containing cyanide. Tolerance apparently involves the ability of the fungus to convert cyanide to non-toxic formamide by formamide hydro-lyase enzyme. The contribution of the alternate cyanide insensitive respiratory system to ensure the formamide hydro-lyase induction was assessed. When the cytochromes were blocked and the cyanide-insensitive respiratory pathway accounted for 100% of the oxygen uptake associated with respiration, formamide hydro-lyase activity was positively correlated with activity of alternate pathway.