Consistent with recent reports, we found that Nitrobacter may possess higher affinities for nitrite than previously thought. Surprisingly we also found a complete operon for nitrous oxide reduction in the genome, though we were unable to detect the activity.

Comparative physiological and genomic characterization of a novel Nitrobacter vulgaris strain from a nitrate-contaminated subsurface | Applied and Environmental Microbiology Nitrobacter species play a key role in nitrogen cycling; however, their physiological adaptations and genomic diversity remain largely underexplored. This study characterizes Nitrobacter vulgaris strain MLSD-S22, isolated from a nitrate- and heavy-metal-contaminated subsurface, revealing unexpected genomic and metabolic traits. Higher nitrite and oxygen affinities compared to previous reports indicate that some Nitrobacter are more competitive in low-substrate environments than previously believed. The presence of a complete nitrous oxide (N2O) reduction operon highlights the genomic potential related to N2O reduction within this genus; however, we did not observe N2O reduction under the conditions tested. By expanding Nitrobacter ecophysiology, this work provides a foundation for future research on the metabolic flexibility of Nitrobacter and their contributions to nitrogen transformations in diverse environments.

Our paper describing a novel Nitrobacter strain is out in AEM journals.asm.org/doi/10.1128/... #mevosky #microsky