title: Tetrazolium reduction-malachite green method for assessing the viability of filamentous bacteria in activated sludge.
abstract: A method was developed to assess the activity of filamentous bacteria in activated sludge. It involves the incubation of activated sludge with 2(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride followed by staining with malachite green. Both cells and 2(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyl tetrazolium chloride-formazan crystals can be observed in prepared specimens by using bright-field microscopy. This procedure allowed us to distinguish between inactive and actively metabolizing filaments after chlorine application to control the bulking of activated sludge.
authors.affiliation: Department of Environmental Engineering Sciences, University of Florida, Gainesville, Florida 32611.
authors.forename: G
authors.initials: G
authors.lastname: Bitton
authors.forename: B
authors.initials: B
authors.lastname: Koopman