Print Email Facebook Twitter In search of Comammox in oxygen limiting conditions Title In search of Comammox in oxygen limiting conditions Author LU, Mu-En (TU Delft Applied Sciences; TU Delft BT/Environmental Biotechnology) Contributor Kleerebezem, R. (mentor) Stouten, G.R. (mentor) Weissbrodt, D.G. (graduation committee) van Lier, J.B. (graduation committee) Degree granting institution Delft University of Technology Programme Life Science and Technology (LST) Date 2020-08-24 Abstract Comammox bacteria are capable of catalysing the full nitrification pathway – oxidation of ammonium to nitrate – and have been encountered in many ecosystems recently (Lawson & Lücker, 2018). What the ecological role of comammox bacteria is in hypoxic enrichment cultures remains unclear. Based on the thermodynamics and biochemistry of known nitrogen cycle conversion, we propose that comammox is oxidizing ammonium to nitrite with both oxygen and nitrate as electron acceptor in hypoxic condition. Our hypothesis suggests that when comammox cooperates with anammox, they can harvest most energy per unit of oxygen supplied. We tried to cultivate bacteria toward a community of anammox and comammox consortium by limiting the oxygen and supplying ammonium and nitrate. Although the predicted optimal state has not been achieved during this work, we did observe that the community indeed developed towards higher consumption of ammonium under limited oxygen supply. Subject comammoxanammoxnitrificationdenitrificationstoichiometrythermodynamics To reference this document use: http://resolver.tudelft.nl/uuid:d556d05a-766e-4e3f-847a-44160bd7a3d1 Part of collection Student theses Document type master thesis Rights © 2020 Mu-En LU Files PDF Mu_En_Lu_MSc_Thesis.pdf 1.06 MB Close viewer /islandora/object/uuid:d556d05a-766e-4e3f-847a-44160bd7a3d1/datastream/OBJ/view