1999 Volume 53 Issue 8 Pages 1054-1062,036
Microbial degradation of 2, 4, 8-trichlorodibenzofuran (2, 4, 8-TCDF) and dibenzofuran by three fungi (563, V1, V2) isolated by a screening method from natural world and by two wood-rotting fungi (Phanerochaete chrysosporium and Coriolus versicolor) were conducted. The five fungi degraded from 1.9% to 75.9% of 2, 4, 8-TCDF. The maximum degradation ratio of 2, 4, 8-TCDF was obtained by fungus V 1 when the incubation was conducted for 15 days after addition of 1.25 mMol of 2, 4, 8-TCDF to culture medium of each of five fungi. The degradation ratio was 36.2%. In the case of the 30 day's incubation in the same concentration, the maximum degradation ratio was obtained by P. chrysosporium. The degradation ratio was 75.9%. On the other hand, the maximum degradation ratio of 2, 4, 8-TCDF was obtained by C. versicolor when the incubation was conducted for 15 days after addition of 0.25 mMol of 2, 4, 8-TCDF to culture medium of each of five fungi. The degradation ratio was 36.4%. In the case of the 30 day's incubation in the same concentration, the maximum degradation ratio was obtained by fungus V2. The degradation ratio was 72.8%. In addition, a part of 2, 4, 8-TCDF was incorporated into each mycelium of five fungi during the incubation.
Dibenzofuran (DF) could be degraded from 80.6% to 94.5% by P. chrysosporium and fungus V2. The maximum degradation ratios of DF was obtained by fungus V2 when the incubations were conducted for 15 days and 30 days, respectively, after addition of 1.25 mMol of DF to culture medium of each of two fungi. The degradation ratios were 91.7% and 94.5%, respectively. On the other hand, the maximum degradation ratios of DF were obtained by fungus V2 when the incubations were conducted for 15 days and 30 days, respectively, after addition of 0.25 mMol of DF to culture medium of each of two fungi. The degradation ratios were 88.3% and 93.6%, respectively. In addition, a part of DF was incorporated into each mycelium of two fungi during the incubation. In comparison with the degradation ratio between 2, 4, 8-TCDF and DF, it is considered that the degradation ratio of chlorinated DF decrease with the numbers and positions of substituted chlorine atoms at the DF molecule.
