Effects of culture parameters on pentachloronitrobenzene removal by Sporothrix cyanescens

The ability of S. cyanescens to degrade high concentration of pentachloronitrobenzene (PCNB 100mg/l or 0.34niM) was focused on ways to increase or optimize rates of biodegradation. Experiments were conducted to eyimine the effects of several culture parameters on PCNB revoval. The levels of PCNB in the medium were monitored by HPLC analysis over 5 days. Carbon, nitrogen were shown to strongly influence the extent of its removal. In these experiments, PCNB degradation best results were obtained under low concentrations in these elements corresponding, in term of chemical dose expressed as the ratio of the quantity of chemical to the mass of mycelium inoculated, of a maximum value of 24.5μg/mg. Moreover, S. cyanescens proved to perform a rather efficient degradation (18.9μg/mg) when a complex carbohydrate, starch, was given as the major carbon source. In parallel, the sensitivity of S. cyanescens to PCNB has been determined by measuring growth inhibition on PCNB supplemented solid media. In the range of chemical doses tested (0–150mg/1), no lethal effects were observed.