Fluorescent-antibody study of natural finger-like zoogloeae

Fluorescent-antibody techniques using Zoogloea ramigera 106 antiserum were used to study fresh activated sludge flocs and finger-like zoogloeae in the microbial film that developed over stored samples of activated sludge. Few cells in fresh activated sludge reacted positively with the fluorescein-labeled antiserum. Finger-like zoogloeae containing reactive cells were readily observed in the microbial film layer over stored activated sludge. Certain of the naturel finger-like projections were entirely composed of cells that reacted positively to the labeled Z. ramigera 106 antiserum, whereas other projections were devoid of reactive cells.