Characteristics of heterotrophic nitrification and aerobic denitrification of a penicillium strain

A penicillium strain was isolated from activated sludge under moderate temperature aerobic conditions.It was shown that many of the carbonaceous compounds and nitrogenous compounds were utilized as the sole source of C and N for the strain.The strain has the capabilities of simultaneous heterotrophic nitrification and denitrification;that is,it can turn the nitrogenous compounds into nitrite nitrogen and deoxidize the nitrate under aerobic conditions.In the experiment in which ammonium compounds were the medium,the NO-2 concentration reached 0.35 μg/mL after a 24-hour culture,and the liquid had strong reduction activity on the nitrate.When the solution was cultured for 24～72 hours,the NO-2 concentration was 3～5 μg/mL.The experimental results also showed that 90-97.7% of the ammonium-nitrogen in the artificial wastewater was removed when the solution was cultured for 48 hours and the pH was 5～11.