DEPLETION OF PENTACHLOROPHENOL BY DEUTEROMYCETES ISOLATED FROM SOIL

1. A study performed on 100 strains of micromycetes cultivated on soli d media with pentachlorophenol (PCP, 0.5 gL(-1)) allowed to select str ains as a function of the appearance of a light blurring around the in oculation spot, Cultivation in liquid synthetic medium with high conce ntration of PCP (1 gL(-1)) showed that biotic depletion depended on th e taxonomic group, The influence of the physiological state of the ino culum and of the amount of glucose have been studied. Cultivation of P homa glomerata in the dark and with light allowed to evaluate the part played by abiotic factors. 2. A screening was performed on 784 strain s of Deuteromycetes cultivated in liquid synthetic medium with PCP (10 0 mgL(-1)), After 5 days, the mean consumption of PCP was 50.7%. The d istribution of efficient strains was very heterogeneous depending on t he groups and genera. Among the most efficient fungi, 168 reached 70% of depletion and 40 reached 80% (Mucedinaceae, 23; Dematiaceae, 14; Sp haeropsidales, 2; Tuberculariales, 1), Abiotic depletion accounted for 5%. 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, af ter 24 hours, only 20% of PCP could be detected. The mechanism of PCP depletion is discussed.