Interaction between an ammonium-oxidizer,Nitrosomonas sp., and two heterotrophic bacteria,Nocardia atlantica andPseudomonas sp.: A note.

Closed culture experiments showed that the ability of an estuarine chemolithotrophic ammonium-oxidizer,Nitrosomonas sp., to convert ammonium to nitrite was substantially increased by as much as 150% and 50% when grown in the presence of two heterotrophs isolated from the same environment. The heterotrophs were identified asNocardia atlantica andPseudomonas sp. The growth of the heterotrophs was stimulated by as much as one order of magnitude in the presence of the ammonium-oxidizer.