@misc{EngelbrechtFondengcapMartienssenetal., author = {Engelbrecht, Steffen and Fondengcap, Mbengamina Terence and Martienssen, Marion and Rathsack, Kristina}, title = {Highly efficient long-term storage of carrier-bound anammox biomass}, series = {Water Science \& Technology}, volume = {74}, journal = {Water Science \& Technology}, number = {8}, issn = {0273-1223}, doi = {10.2166/wst.2016.364}, pages = {1911 -- 1918}, abstract = {The anammox process is a potential alternative to the conventional nitrogen removal from wastewater. However, due to large generation times of anammox bacteria, the start-up of treatment reactors may be impeded. An efficient storage technique can handle this drawback and may be also suitable for seasonally operated treatment plants like in touristic areas. In the current study, several storage techniques were investigated with respect to its suitability for the preservation of the specific anammox activity after long-term storage. Storing conditions differed in terms of temperature, redox buffer and nutrient supplementation. The specific activity of immobilized anammox bacteria (Candidatus Kuenenia stuttgartiensis) was determined three times during a long-term preservation of 78 days and 106 days, respectively. The highest activity was ensured at a storing temperature of 4 WC, providing nitrate as redox buffer and a nutrient supplement every 23 days. Thus, 91.4\% of the initial anammox activity could be preserved after a storage of 106 days. Superiority of the presented treatment condition was confirmed by a calculated nitrate-ammonium consumption rate close to the optimal ratio of 1.32. This technique provided an economical and simple method suitable for long-term storage of immobilized anammox biomass.}, language = {en} } @misc{EngelbrechtMozooniRathsacketal., author = {Engelbrecht, Steffen and Mozooni, Mohammad and Rathsack, Kristina and B{\"o}llmann, J{\"o}rg and Martienssen, Marion}, title = {Effect of increasing salinity to adapted and non-adapted Anammox biofilms}, series = {Environmental Technology}, volume = {40}, journal = {Environmental Technology}, number = {22}, issn = {0959-3330}, doi = {10.1080/09593330.2018.1455748}, pages = {2880 -- 2888}, abstract = {The Anammox process is an efficient low energy alternative for the elimination of nitrogen from wastewater. The process is already in use for side stream applications. However, some industrial wastewaters, e.g. from textile industry are highly saline. This may be a limit for the application of the Anammox process. The aim of this study was to evaluate the effects of different NaCl concentrations on the efficiency of adapted and non-adapted Anammox biofilms. The tested NaCl concentrations ranged from 0 to 50 g NaCl*L⁻¹. Concentrations below 30 g NaCl*L⁻¹did not significantly result in different nitrogen removal rates between adapted and non-adapted bacteria. However, adapted bacteria were significantly more resilient to salt at higher concentrations (40 and 50g NaCl*L⁻¹). The IC50 for adapted and non-adapted Anammox bacteria were 19.99 and 20.30 g NaCl*L⁻¹, respectively. Whereas adapted biomass depletes the nitrogen in ratios of NO-₂/NH+₄ around 1.20 indicating a mainly Anammox-driven consumption of the nitrogen, the ratio increases to 2.21 at 40 g NaCl*L⁻¹ for non-adapted biomass. This indicates an increase of other processes like denitrification. At lower NaCL concentrations up to 10 g NaCl*L⁻¹, a stimulating effect of NaCl to the Anammox process has been observed.}, language = {en} } @misc{BoellmannEngelbrechtMartienssen, author = {B{\"o}llmann, J{\"o}rg and Engelbrecht, Steffen and Martienssen, Marion}, title = {Autofluorescent characteristics of Candidatus Brocadia fulgida and the consequences for FISH and microscopic detection}, series = {Systematic and Applied Microbiology}, volume = {42}, journal = {Systematic and Applied Microbiology}, number = {2}, issn = {1618-0984}, doi = {10.1016/j.syapm.2018.09.002}, pages = {135 -- 144}, abstract = {An enrichment culture of Candidatus Brocadia fulgida was identified by three independent methods: analysis of autofluorescence using different microscope filter blocks and a fluorescence spectrometer, fluorescence in situ hybridization (FISH) with anammox-specific probes and partial sequencing of the 16S rDNA, hydrazine synthase hzsA and hydrazine oxidoreductase hzo. The filter block BV-2A (400-440, 470 LP, Nikon) was suitable for preliminary detection of Ca. B. fulgida. An excitation-emission matrix revealed three pairs of excitation-emission maxima: 288-330 nm, 288-478 nm and 417-478 nm. Several autofluorescent cell clusters could not be stained with DAPI or by FISH, suggesting empty but intact cells (ghost cells) or inhibited permeability. Successful staining of autofluorescent cells with the FISH probes Ban162 and Bfu613, even at higher formamide concentrations, suggested insufficient specificity of Ban162. Under certain conditions, Ca. B. fulgida lost its autofluorescence, which reduced the reliability of autofluorescence for identification and detection. Non-fluorescent Ca. Brocadia cells could not be stained with Ban162, but with Bfu613 at higher formamide concentrations, suggesting a dependency between both parameters. The phylogenetic analysis showed only good taxonomical clustering of the 16S rDNA and hzsA. In conclusion, careful consideration of autofluorescent characteristics is recommended when analysing and presenting FISH observations of Ca. B. fulgida to avoid misinterpretations and misidentifications.}, language = {en} } @phdthesis{Engelbrecht, author = {Engelbrecht, Steffen}, title = {Mikrobielle Stickstoffelimination mit kombinierter partieller Nitrifikation / Anammox (PN/A) in membranbel{\"u}fteten hochsalinen und Niedrigtemperatur-Festbettreaktoren}, address = {Cottbus}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-48848}, pages = {232}, abstract = {Durch anthropogene Aktivit{\"a}t hat sich der N{\"a}hrstoffeintrag in die Umwelt stark erh{\"o}ht. Die Hauptquellen sind die Landwirtschaft, kommunales und industrielles Abwasser. Erh{\"o}hte Stickstofffrachten haben einen starken Einfluss auf den Stickstoffkreislauf. Das {\"U}berangebot an Stickstoff f{\"u}hrt zu Eutrophierung in Gew{\"a}ssern und somit zu einem weniger diversen, instabileren {\"O}kosystem. Die Stickstoffeliminierung aus Abw{\"a}ssern ist essentiell f{\"u}r den Schutz der {\"O}kosysteme. Das etablierte System der Nitrifikation/Denitrifikation ist aufgrund des hohen Sauerstoffbedarfs sehr energie- und somit auch kostenintensiv. Der Anammox-Prozess (anaerobe Ammonium Oxidation) ist eine potentielle Alternative zur konventionellen Stickstoffelimination. Anammox-Bakterien nutzen Ammonium und Nitrit als Elektronenakzeptor. Durch Nutzung der partiellen Nitrifikation in Kombination mit Anammox (PN/A) kann bis zu 60 \% der Bel{\"u}ftungsenergie eingespart werden. Trotz Erfolgen in der Teilstrombehandlung ist der Prozess noch nicht erfolgreich in der Hauptstrombehandlung eingesetzt worden. Die gr{\"o}ßten Herausforderungen sind die niedrigen Temperaturen, geringe Zulaufkonzentrationen und hohe Konzentrationen organischen Kohlenstoffs. Die vorliegende Arbeit konnte die Wirksamkeit von membranbel{\"u}fteten Biofilm Reaktoren unter Verwendung von synthetischem Abwasser bei niedrigen Temperaturen (18 - 8 °C) belegen. Die Innovation in diesem System ist die r{\"a}umliche Trennung von nitrifizierenden Bakterien und Anammox Bakterien. Die regelm{\"a}ßige mechanische Entfernung des Nitrifikanten-Biofilms erm{\"o}glichte einen langzeitstabilen Reaktorbetrieb. Diese Reaktorkonfiguration konnte auch erfolgreich f{\"u}r hochsaline Abw{\"a}sser (5 -30 g NaCl*L-1) bei einer Reaktortemperatur von 30 °C und auch unter Zugabe von TOC (40-100 mg TOC*L-1) genutzt werden. Weiterhin wurden Untersuchungen zur Aktivit{\"a}t von salzadaptierter Anammox-Biomasse und nicht adaptierter Biomasse in einem Bereich von 0 bis 50 g NaCl*L-1 durchgef{\"u}hrt. Bei Konzentrationen unter 30 g NaCl*L-1 konnten keine signifikanten Unterschiede im Abbauverhalten festgestellt werden. Allerdings war adaptierte Biomasse bei h{\"o}heren Salzkonzentrationen konkurrenzst{\"a}rker. Außerdem wurden Langzeitlagerungsversuche durchgef{\"u}hrt. Die Lagerungsbedingungen variierten in der Lagerungstemperatur, im Redoxpuffer und der N{\"a}hrstoffversorgung. Nach 106 Tagen bei 4 °C konnte die Anammox-Biomasse noch 91 \% ihrer urspr{\"u}nglichen Aktivit{\"a}t erhalten. Somit konnte eine einfache und kosteng{\"u}nstige Lagerungsmethode f{\"u}r Anammo-Bakterien entwickelt werden.}, language = {de} }