Serological diversity within a terrestrial ammonia-oxidizing population.

Fluorescent antibodies (FAs) prepared against 16 ammonia-oxidizing nitrifying bacteria were examined as to cross-reactivity in heterologous FA staining tests. Virtually all cross-reactions to the seven Nitrosomonas FAs were confined to the Nitrosomonas isolates. The five Nitrosospira, three Nitrosolobus, and one Nitrosovibrio FAs stained isolates only within their respective genera. Within each genus shared antigens were more common among Nitrosomonas and Nitrosolobus than among Nitrosospira isolates. Isolates obtained from a single soil were stained to examine the effectiveness of the suite of FAs for study of a given ammonia-oxidizing population. Of the seven Nitrosomonas isolates, five were stained effectively through the use of four FAs; six of twelve Nitrosospira isolates were identifiable through use of four different FAs. The one Nitrosolobus isolate was stained well only by one (its homologous) FA.