Microbial nitrification in Mediterranean sponges: Possible involvement of ammonium-oxidizing Betaproteobacteria
Year: 2008
Type: book-chapter
Abstract: The aim of this study was to assess the potential for nitrification in Aplysina aerophoba Schmidt 1862 using a \ncombined physiological and molecular approach. Whole animals were incubated in experimental aquaria and the concentrations \nof ammonia, nitrate and nitrite were determined in the incubation water using colorimetric assays. Nitrate excretion rates \nreached values of up to 3.6 μmol g-1 fresh weight day-1 (equivalent to 830 nmol g-1 dry weight h-1) and were matched by \nammonia excretion rates of up to 0.56 ± 0.09 μmol g-1 fresh weight day-1. An accumulation of nitrite was not detected in any \nof the experiments. Control experiments without sponges showed no variation in nitrogen species in the incubation water. A \nslight increase in ammonia excretion was observed over 11 days of maintenance in holding tanks that were constantly supplied \nwith fresh, untreated Mediterranean seawater. Other sponges from the same habitat (Dysidea avara Schmidt 1862, Tethya sp., \nChondrosia reniformis Nardo 1847) showed high rates of ammonia excretion but nitrate excretion was significantly reduced \nor absent. Using specific PCR primers, 16S rRNA genes of the betaproteobacterial clade of the Nitrosospira cluster 1 were \nrecovered from A. aerophoba, D. avara and Tethya sp. tissues. In conclusion, this study provides physiological and molecular \nevidence for the presence of nitrifying bacteria in A. aerophoba while the potential for nitrification in the other sponges \nremains to be investigated.
Authors: Kristina Bayer, Susanne Schmitt, Ute Hentschel
Language: English
Subfield: Biotechnology
Domain: Life Sciences
Open Access status: green
Funder: Universität Stuttgart
OpenAlex ID: W2597237425