A methanogenic sludge showed denitrifying activity for acetate, glucos
e and effluents from methanogenic treatments as substrates; denitrifie
rs were present in a relatively high number. When glucose was used as
substrate dissimilatory reduction of nitrate to ammonium occurred. Met
hane production from acetate was inhibited by denitrification and resu
med after nitrite and nitrous oxide depletion.