Test Medium for the Growth of Nitrosomonas europaea

Abstract

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 specific growth rate was enhanced by increasing the inoculum and was linearly correlated with the inoculum-to-total-culture volume ratio on a semilog scale. A reproducible growth rate for N. europaea was obtained with this medium under controlled experimental conditions.

Nutrient transport suggests an evolutionary basis for charged archaeal surface layer proteins

“…Similar findings were reported from in situ nitrification measurements [23], and for other AOA [24]. In contrast, k m values of characterized AOB are at least one to two orders of magnitude higher [25,26]. AOB cultures often require concentrations in the micromolar to millimolar range to sustain growth, signifying that AOA have evolved competitive advantages in environments where AOB cannot survive.…”

Estimation of Nitrifying Bacterial Activities by Measuring Oxygen Uptake in the Presence of the Metabolic Inhibitors Allylthiourea and Azide

“…The nitrifying biomass used in this study was enriched and developed from an activated sludge (from Morainvilliers, France) by repeated lab subculturing in mineral medium (14) over several months. This biomass contained nitrite and ammonia oxidizers and, presumably, heterotrophs.…”

“…Oxygen uptake measurements were obtained with a batch type respirometer (model 5300 biological oxygen monitor; Yellow Springs Instruments, Yellow Springs, Ohio) at 20°C and pH 7.6. Washed biomass was added to two incubation chambers filled with 10 ml of oxygen-saturated mineral medium (14).…”

Characterization of effects of copper, cadmium and nickel on the growth of Nitrosomonas Europaea

“…To summarize the test conditions, pH and temperature were constant, precipitation was minimal and chemical speciation was approximately fixed, especially during the early stage of the experiments when the specific growth rate of the bacteria was measured. Under these conditions, N. europaea was capable of producing consistent results [ 7 ] . The organisms demonstrated much slower growth rates (generation time of 5.5 h) than those of many heterotrophic bacteria, but they may be much more sensitive to toxic heavy metals.…”