Nitrification is a process within the Nitrogen cycle that is conducted by ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB). Although nitrification is essential to the N cycle, in agriculture nitrification competes with plants for ammonia to the detriment of crop production. In the reclamation of wastewater, nitrification is desirable to oxidize the ammonium that is toxic to aquatic life. In this work, we evaluated the requirements for Fe on the growth of the NOB, Nitrobacter winogradskyi, in a chemostat and in batch cultures. N. winogradskyi grown in Fe limiting conditions in a chemostat had up-regulated the expression of genes, Nwi 2301 and Nwi 2302, encoding a putative siderophore. Iron concentration of 1 mM in batch cultures reduced the growth of N. winogradskyi. Nevertheless, N. winogradskyi was able to adapt to low Fe. EDTA in the medium helped N. winogradskyi to acquire Fe, however at 166.67 mM concentration with 6.25 mM Fe, its growth was inhibited. We also evaluated the growth of N. winogradskyi at limited iron concentrations with and without EDTA. In co-culture with the AOB, Nitrosomonas europaea, this response to Fe might be at play.

Nitrobacter winogradskyi responses to Fe limitation

249th National Meeting (2015)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.