Theme 1
Project 1052

Biogeochemistry of archaeal and bacterial nitrification in coastal ecosystems
Project leader: Prof. dr. J.J. Middelburg
Researcher(s): Dr. B. Veuger
Starting date: 1-jul-07

Nitrification is a two step process involving ammonia oxidizers and nitrite oxidizers. Traditionally, ammonia oxidizers were assumed to be restricted to the bacterial domain, but recently it has been shown that marine Crenarchaeota are capable of oxidizing ammonia to nitrite while fixing carbon dioxide. Using 15N techniques we will determine nitrification rates in estuarine and North Sea water in close collaboration with the RU partner and at the same time will measure the growth of bacterial and archaeal nitrifiers via the incorporation of 13C-labelled DIC in biomarkers specific for bacteria (phospholipid-derived fatty acids) and archaea (glycerol di- and tetraethers) in close collaboration with the NIOZ partner. This will allow us to assess the relative importance of bacterial and archaeal nitrification under natural conditions and as well provide information on the controlling factors. There is some molecular biology evidence for archaeal nitrification in sediments and we will therefore measure nitrifier activity and growth in sediments as well. Finally, we will use double labelled amino acids (13C and 15N) to investigate if dissolved organic matter is taken up for energy or nutrient requirements by marine Crenarchaeota. This is expected to generate crucial information in the functioning of the biogeochemical N-cycle.

Cook, P.L.M., Veuger, B., Böer, S., Middelburg, J.J. (2007). Effect of nutrient availability on carbon and nitrogen incorporation and flows through benthic algae and bacteria in near-shore sandy sediment . Aquatic Microbial Ecology49: 165-180.
Darwin Center authors: Middelburg J.J., Veuger B.

Veuger, B., Eyre, B.D., Maher, D., Middelburg, J.J. (2007). Nitrogen incorporation and retention by bacteria, algae, and fauna in a subtropical intertidal sediment: An in situ 15N-labeling study . Limnology and Oceanography52 (5): 1930-1942.
Darwin Center authors: Middelburg J.J., Veuger B.

Teugels, B., Bouillon, S., Veuger, B., Middelburg, J.J., Koedam, N. (2008). Kleptoplasts mediate nitrogen acquisition in the sea slug Elysia viridis.
Darwin Center authors: Middelburg J.J., Veuger B.

Evrard, V., Cook, P.L.M., Veuger, B., Huettel, M., Middelburg, J.J. (2008). Tracing carbon and nitrogen incorporation and pathways in the microbial community of a photic subtidal sand . Aquatic Microbial Ecology53 (3): 257-269.
Darwin Center authors: Middelburg J.J., Veuger B.

Gribsholt, B., Veuger, B., Tramper, A., Middelburg, J.J., Boschker, H.T.S. (2009). Long-term 15N-nitrogen retention in tidal freshwater marsh sediment: Elucidating the microbial contribution . Limnology and Oceanography54 (1): 13-22.
Darwin Center authors: Boschker H. T. S., Middelburg J.J., Veuger B.

Hardison AK, Canuel EA, Anderson IC, Veuger B. (2010). Fate of macroalgae in benthic systems: Carbon and nitrogen cycling within the microbial community. Marine Ecology Progress Series414: 41-55.
Darwin Center authors: Veuger B.

Bart Veuger and Dick van Oevelen (2011). Long-term pigment dynamics and diatom survival in dark sediment. Limnology and OceanographyVolume 56, Issue 3: 1065-1074.
Darwin Center authors: Veuger B.

William R. Hunter, Bart Veuger and Ursula Witte (2012). Macrofauna regulate heterotrophic bacterial carbon and nitrogen incorporation in low-oxygen sediments. The ISME Journal1-12:
Darwin Center authors: Veuger B.

Tom Van Engeland, Tjeerd J. Bouma, Edward P. Morris, Fernando G. Brun, Gloria Peralta, Miguel Lara, Iris E. Hendriks, Pieter van Rijswijk, Bart Veuger, Karline Soetaert, Jack J. Middelburg (2013). Dissolved organic matter uptake in a temperate seagrass ecosystem. MARINE ECOLOGY PROGRESS SERIES478: 87-100.
Darwin Center authors: Middelburg J.J., Soetaert K. E. R., Veuger B.