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Cryoturbation, the burial of topsoil material into deeper soil horizons by repeated freeze-thaw events, is an important storage mechanism for soil organic matter (SOM) in permafrost-affected soils. Besides abiotic conditions, microbial community structure and the accessibility of SOM to the decomposer community are hypothesized to control SOM decomposition(More)
Rising temperatures in the Arctic can affect soil organic matter (SOM) decomposition directly and indirectly, by increasing plant primary production and thus the allocation of plant-derived organic compounds into the soil. Such compounds, for example root exudates or decaying fine roots, are easily available for microorganisms, and can alter the(More)
DNA is inherently limited by its four natural nucleotides. Efforts to expand the genetic alphabet, by addition of an unnatural base pair, promise to expand the biotechnological applications available for DNA as well as to be an essential first step toward expansion of the genetic code. We have conducted two independent screens of hydrophobic unnatural(More)
Enterotoxigenic anaerobic Bacteroides fragilis is a significant source of inflammatory diarrheal disease and a risk factor for colorectal cancer. Two distinct metalloproteinase types (the homologous 1, 2, and 3 isoforms of fragilysin (FRA1, FRA2, and FRA3, respectively) and metalloproteinase II (MPII)) are encoded by the B. fragilis pathogenicity island.(More)
An expeditious and highly efficient single-step methodology for the introduction of a phenylalanine moiety into position 8 and 6 of the purine scaffold was developed based on aqueous-phase Pd-catalysed Suzuki-Miyaura cross-coupling reactions of unprotected 4-boronophenylalanine with 8-bromo- or 6-chloropurines. The scope of the methodology was demonstrated(More)
We report a scalable and cost-effective technology for generating and screening high-complexity customizable peptide sets. The peptides are made as peptide-cDNA fusions by in vitro transcription/translation from pools of DNA templates generated by microarray-based synthesis. This approach enables large custom sets of peptides to be designed in silico,(More)
[Chemical reaction: See text] Enantiomerically or diastereomerically pure 4-(purin-6-yl)phenylalanines, a novel type of stable amino acid-purine conjugates, were synthesized by palladium-catalyzed cross-coupling reactions of protected 4-boronophenylalanines or 4-(trimethylstanyl)phenylalanines with diverse 6-halopurines (9-benzyl-6-halopurines and(More)
(Purin-6-yl)alanines, a new class of amino acid-nucleobase conjugates, were synthesized by palladium-catalyzed cross-coupling reactions of protected iodozincalanines with 6-iodopurines (9-Bn-6-iodopurine and 9-THP-6-iodopurine as well as acyl-protected 6-iodopurine ribonucleoside and 2-deoxyribonucleoside). Free purine base and nucleosides bearing alanine(More)
Enzyme-mediated decomposition of soil organic matter (SOM) is controlled, amongst other factors, by organic matter properties and by the microbial decomposer community present. Since microbial community composition and SOM properties are often interrelated and both change with soil depth, the drivers of enzymatic decomposition are hard to dissect. We(More)
Although bacterial assemblages are important components of soils in arid ecosystems, the knowledge about composition, life-strategies, and environmental drivers is still fragmentary, especially in remote high-elevation mountains. We compared the quality and quantity of heterotrophic bacterial assemblages between the rhizosphere of the dominant(More)