Many researchers reported biodegradation of environmental pollutants by white-rot fungi. Toward in situ bioremediation, we have investigated biodegradation of environmental pollutants by litter-decomposing fungi. In our results, lignin-degrading enzymes produced from litter-decomposing fungi are thought to participate in degradation of pentachlorophenol (PCP) and 2,4-dichlorophenoxy acetic acid (2,4-DA). Then, we examined the biodegradation of PCP, 2,4-DA and the analogs of 2,4-DA by purified laccase and the role of redox mediator on laccase reaction. Laccase purified from Calvatia craniiformis decomposed phenolic compounds, PCP and 2,4-dichlorophenol (2,4-DP), but not non-phenolic compounds, 2,4-DA and 2,4-dichlorophenoxy ethanol (2,4-DE), even in the presence of redox mediators. To clarify the reaction mechanism between the substrates and redox mediators, quantum chemical analysis was applied using MOPAC 2009 and Gaussian 03. The results of the heat of formation and the perturbation energy showed that even redox mediator radicals could not oxidize the non-phenolic compounds. Previously several reports showed that laccase-redox mediator systems decomposed non-phnolic compounds, but we propose that the system could not react on the chlorinated aromatic compounds based on the result of quantum analysis.

We report a null detection of 12 C O emission from a sub-condensation in a High Velocity Cloud (HVC). As a consequence of this, an upper limit of n ( H 2 ) X ( C O ) D V / D R ≤ 2 × 10 − 5 was set. This implies that 12 C O abundance is deficient by at least a factor of 10 if the HVC is predominantly molecular, otherwise the CO abundance of the HVC might be normal.