Scheme for the enzymatic degradation of HMF by
P. ostreatus. HMF is metabolized extracellularly by AAO to FDCA, which generates H2O2. These reactions probably involve an intermediate conversion of HMF to HMF acid and further conversion to unknown products. When HMF enters the cell, it is reduced by AAD with NADPH as a co-factor and metabolized to HMF alcohol. HMF alcohol can be secreted and accumulates extracellularly.