An organism found to be growing on moist double-base propellant, containing nitrocellulose (NC) and nitroglycerine aerobically degraded NC in submerged cultivation. This organism, which was subsequently identified as Penicillium corylophilum Dierckx, was able to degrade the NC (13.17% N) when it was present as the sole nitrogen source, in conjunction with either starch or xylan as a carbon source. It was found that 20% of the NC was utilized in a 3-day period. Also, NC degradation was studied utilizing Fusarium solani IFO 310393, a denitrifying fungus, in combination with P. corylophilum; however, no increased utilization was observed. Evidence for the degradation includes a decrease in the NC weight, an increase in the biomass weight, the presence of cellulolytic and denitrifying enzymes, and other appropriate growth parameters.