Fungal and bacterial contributions to N2O production were measured periodically at 4, 8, 16, 28, 44 days following substrate amendments. At each time, four microcosms from each substrate treatment were subjected to four antibiotic treatments, respectively, (1) antibiotic-free control, no antibiotic addition; (2) streptomycin, soil with the addition of streptomycin at 1.0 mg g1 soil; (3) cycloheximide, soil with the addition of cycloheximide at 2.0 mg g1 soil; and (4) both, soil with the addition of both streptomycin and cycloheximide. These antibiotic concentrations were confirmed to have little or no effect on non-target organisms through a preliminary experiment as described in our previous work (Chen et al., 2014) with the same soil and experimental conditions