Nitrifying Soil Bacterium Nitrosomonas europaea: Operational Improvement of Standard Culture Medium

Morphology of Nitrosomonas europaea and classification of the nitrifying bacteria.

This medium, dispensed in 100-mi amounts in 250-ml Erlenmeyer flasks, was inoculated with an agar block containing L colonies which had been growing 5 days following 15 passages on a staphylococcal L form maintenance agar (Marston, J. Infectious Diseases, 108, 75-84, 1961). Slight turbidity and a granular sediment developed in the liquid medium in 4 days at 37 C and serial transfer of the sedim...

Test Medium for the Growth of Nitrosomonas europaea.

A mineral medium for studying the growth of Nitrosomonas europaea was developed and examined. The medium was defined in terms of chemical speciation by using chemical equilibrium computer models. The medium significantly increased the metabolic activity of the organisms compared with previously developed media, yielding a specific growth rate as high as 3.0 day (generation time, 5.5 h). The spe...

The isolation of Nitrosomonas europaea in pure culture.

Methane oxidation by Nitrosomonas europaea.

Methane inhibited NH4+ utilization by Nitrosomonas europaea with a Ki of 2mM. O2 consumption was not inhibited. In the absence of NH4+, or with hydrazine as reductant, methane caused nearly a doubling in the rate of O2 uptake. The stimulation was abolished by allylthiourea, a sensitive inhibitor of the oxidation of NH4+. Analysis revealed that methanol was being formed in these experiments, wit...

Cytochrome aa3 from Nitrosomonas europaea.

Cytochrome c oxidase has been purified from the ammonia oxidizing chemoautotroph Nitrosomonas europaea by ion-exchange chromatography in the presence of Triton X-100. The enzyme has absorption maxima at 420 and 592 nm in the resting state and at 444 and 598 nm in the dithionite-reduced form; optical extinction coefficient (598 nm minus 640 nm) = 21.9 cm-1 nM-1. The enzyme has approximately 11 n...