2018, Maus, I., Rumming, M., Bergmann, I., Heeg, K., Pohl, M., Nettmann, E., Jaenicke, S., Blom, J., Pühler, A., Schlüter, A., Sczyrba, A., Klocke, M.

Background: Previous studies on the Miscellaneous Crenarchaeota Group, recently assigned to the novel archaeal phylum Bathyarchaeota, reported on the dominance of these Archaea within the anaerobic carbohydrate cycle performed by the deep marine biosphere. For the first time, members of this phylum were identified also in mesophilic and thermophilic biogas-forming biofilms and characterized in detail. Results: Metagenome shotgun libraries of biofilm microbiomes were sequenced using the Illumina MiSeq system. Taxonomic classification revealed that between 0.1 and 2% of all classified sequences were assigned to Bathyarchaeota. Individual metagenome assemblies followed by genome binning resulted in the reconstruction of five metagenome-assembled genomes (MAGs) of Bathyarchaeota. MAGs were estimated to be 65-92% complete, ranging in their genome sizes from 1.1 to 2.0 Mb. Phylogenetic classification based on core gene sets confirmed their placement within the phylum Bathyarchaeota clustering as a separate group diverging from most of the recently known Bathyarchaeota clusters. The genetic repertoire of these MAGs indicated an energy metabolism based on carbohydrate and amino acid fermentation featuring the potential for extracellular hydrolysis of cellulose, cellobiose as well as proteins. In addition, corresponding transporter systems were identified. Furthermore, genes encoding enzymes for the utilization of carbon monoxide and/or carbon dioxide via the Wood-Ljungdahl pathway were detected. Conclusions: For the members of Bathyarchaeota detected in the biofilm microbiomes, a hydrolytic lifestyle is proposed. This is the first study indicating that Bathyarchaeota members contribute presumably to hydrolysis and subsequent fermentation of organic substrates within biotechnological biogas production processes.

2010, Stephan, F., Boulware, C.H., Krasilnikov, M., Bähr, J., Asova, G., Donat, A., Gensch, U., Grabosch, H.J., Hänel, M., Hakobyan, L., Henschel, H., Ivanisenko, Y., Jachmann, L., Khodyachykh, S., Khojoyan, M., Kohler, W., Korepanov, S., Koss, G., Kretzschmann, A., Leich, H., Ludecke, H., Meissner, A., Oppelt, A., Petrosyan, B., Pohl, M., Riemann, S., Rimjaem, S., Sachwitz, M., Schoneich, B., Scholz, T., Schulze, H., Schultze, J., Schwendicke, U., Shapovalov, A., Spesyvtsev, R., Staykov, L., Tonisch, F., Walter, T., Weisse, S., Wenndorff, R., Winde, M., Vu, L.V., Durr, H., Kamps, T., Richter, D., Sperling, M., Ovsyannikov, R., Vollmer, A., Knobloch, J., Jaeschke, E., Boster, J., Brinkmann, R., Choroba, S., Flechsenhar, K., Flottmann, K., Gerdau, W., Katalev, V., Koprek, W., Lederer, S., Martens, C., Pucyk, P., Schreiber, S., Simrock, S., Vogel, E., Vogel, V., Rosbach, K., Bonev, I., Tsakov, I., Michelato, P., Monaco, L., Pagani, C., Sertore, D., Garvey, T., Will, I., Templin, I., Sandner, W., Ackermann, W., Arévalo, E., Gjonaj, E., Muller, W.F.O., Schnepp, S., Weiland, T., Wolfheimer, F., Ronsch, J., Rossbach, J.

The photoinjector test facility at DESY, Zeuthen site (PITZ), was built to develop and optimize photoelectron sources for superconducting linacs for high-brilliance, short-wavelength free-electron laser (FEL) applications like the free-electron laser in Hamburg (FLASH) and the European x-ray free-electron laser (XFEL). In this paper, the detailed characterization of two laser-driven rf guns with different operating conditions is described. One experimental optimization of the beam parameters was performed at an accelerating gradient of about 43 MV/m at the photocathode and the other at about 60 MV/m. In both cases, electron beams with very high phase-space density have been demonstrated at a bunch charge of 1 nC and are compared with corresponding simulations. The rf gun optimized for the lower gradient has surpassed all the FLASH requirements on beam quality and rf parameters (gradient, rf pulse length, repetition rate) and serves as a spare gun for this facility. The rf gun studied with increased accelerating gradient at the cathode produced beams with even higher brightness, yielding the first demonstration of the beam quality required for driving the European XFEL: The geometric mean of the normalized projected rms emittance in the two transverse directions was measured to be 1.260±13 mmmrad for a 1-nC electron bunch. When a 10% charge cut is applied excluding electrons from those phase-space regions where the measured phase-space density is below a certain level and which are not expected to contribute to the lasing process, the normalized projected rms emittance is about 0.9 mmmrad. © 2010 The American Physical Society.

2022, Efremenko, Y., Febbraro, M., Fischer, F., Guitart Corominas, M., Gusev, K., Hackett, B., Hayward, C., Hodák, R., Krause, P., Majorovits, B., Manzanillas, L., Muenstermann, D., Pohl, M., Rouhana, R., Radford, D., Rukhadze, E., Rumyantseva, N., Schilling, I., Schoenert, S., Schulz, O., Schwarz, M., Štekl, I., Stommel, M., Weingarten, J., Hoppe, E., Arnquist, I., Hobbs, K., French, A., diVacri, M., Laubenstein, M., Zuzel, G.

[no abstract available]