Ammonium effects on methane oxidation.
Activity is expressed as dpm of 14C ml of standard
inoculum' 24 h-1. Symbols: (0) Nitrosococcus oceanus,
14C02 produced; (0) N. oceanus, 14C-cellular
material; (O) Nitrosomonas europaea, 14CO2 produced;
(N) N. europaea, "4C-cellular material.