Use of White Rot Fungus (Phanerochaete chrysosporium) In Bioremediation of Some Environmental Xenobiotics

Abstract

In the present study thirty eight soil samples were taken from different geographical regions of Palestine, all the collected samples have been transported immediately to the laboratory to carry out the required analysis (chemical and physical analysis). After that P. chrysosporium was isolated from collected soil samples by using soil dilution technique and identified by genotypic DNA methodology, then inoculated the media supplemented with different herbicides (Oxyfluorfen, Glyphosate and 2,4-D) at different concentrations (0-2mg/ml) and the pesticide residue in soil was determined by using HPLC. The second part of xenobiotic bioremediation; the treatment of OMWW by P.chrysosporium was monitored following the parameters: phenol concentration, color, TS, BOD, COD and pH. Also, PDA medium containing Guaiacol was inoculated with P.chrysosporium for detection the laccase production. The results showed that the optimal growth of the fungus was ranged from 35-40°C, less than 3dS/m salinity and the pH ranged 5 to 6 and the growth of the fungus was 0.61 mm/hr, also the fungus grow on media amended with different concentrations of pesticides (Glyphosate, Oxyfluorfen, 2,4-D) individually and the growth were highly influenced by concentration and herbicide type.While the growth of the fungus was decreased with increased herbicide concentrations. Also, the growth of the fungus exhibited on media amended with 1.5 mg/ml Oxyfluorfen herbicide, while no growth at the same concentration of Glyphosate, and 2,4-D. The Oxyfluorfen residue in soil samples was measured by HPLC and the better bioremediation of pesticide was after 45 days of incubation with values of 64.3 – 81.4 %. These results also showed that the fungus has shown succes in reduction of the COD, BOD, and phenol content in both tested concentrations of Olive Mill WasteWater (OMWW) (50%, 100%) to 53.83-69.86%, 56.06-64.51%, and 62.79-76.92% respectively and was able to remove more than 50% of the color within 15 days of treatment, while the pH increased from 4.8 to 7.8 during the treatment period. Moreover, the P.chrysosporium produces laccase enzyme which is responsible for role in reducing xenobiotics toxicity.

Keywords: Phanerochaete chrysosporium, Xenobiotic, Bioremediation, Oxyfluorfen, Glyphosate, 2,4-D, Olive Mill Wastewater, Laccase enzyme.