Depletion of pentachlorophenol by deuteromycetes isolated from soil

1. 1. A study performed on 100 strains of micromycetes cultivated on solid media with pentachlorophenol (PCP, 0.5 g L−1) allowed to select strains as a function of the appearance of a light blurring around the inoculation spot. Cultivation in liquid synthetic medium with high concentration of PCP (1 g L−1) showed that biotic depletion depended on the taxonomic group. The influence of the physiological state of the inoculum and of the amount of glucose have been studied. Cultivation of Phoma glomerata in the dark and with light allowed to evaluate the part played by abiotic factors.2. 2. A screening was performed on 784 strains of Deuteromycetes cultivated in liquid synthetic medium with PCP (100 mg L−1). After 5 days, the mean consumption of PCP was 50.7%. The distribution of efficient strains was very heterogeneous depending on the groups and genera. Among the most efficient fungi, 168 reached 70% of depletion and 40 reached 80% (Mucedinaceæ, 23 ; Dematiaceæ, 14 ; Sphæropsidales, 2 ; Tuberculariales, 1). Abiotic depletion accounted for 5%.3. 3. A more detailed study was done on Calcarisporium arbuscula and Oidiodendron echinulatum that both depleted PCP 90% after 5 days. PCP disappeared rapidly from the culture medium of C. arbuscula since, after 24 hours, only 20% of PCP could be detected. The mechanism of PCP depletion is discussed.