Using molecular biology methods (qualitative and quantitative PCR), we determined the occurrence and abundance of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) from a dry inland soil in Basel, Switzerland, and from the riparian zone of Baiyangdian Lake, China. We also determined the contributions of these microorganisms to ammonia oxidization at different depths based on ...

Creation of the femoral tunnel in anterior cruciate ligament (ACL) reconstruction via the anteromedial portal can reproducibly achieve femoral tunnel positioning at the center of the femoral ACL footprint. Anteromedial portal drilling requires knee hyperflexion, which is awkward to perform. Knee hyperflexion to 120° can easily be achieved in the figure-4 position for femoral tunnel drilling via...

Ammonia-oxidizing Archaea (AOA) and ammonia-oxidizing Bacteria (AOB) oxidize ammonia to nitrite, and therefore play essential roles in nitrification and global nitrogen cycling. To better understand the population structure and the distribution of AOA and AOB in the deep Eastern Indian Ocean (EIO), nine surface sediment samples (>3,300 m depth) were collected during the inter-monsoon Spring 201...

Microbial communities present in marine sediments play a central role in nitrogen biogeochemistry at local to global scales. Along the oxidation-reduction gradients present in sediment profiles, multiple nitrogen cycling processes (such as nitrification, denitrification, nitrogen fixation, and anaerobic ammonium oxidation) are active and actively coupled to one another - yet the microbial commu...

Sponge-mediated nitrification is an important process in the nitrogen cycle, however, nothing is known about how nitrification and symbiotic Archaea may be affected by sponge disease and bleaching events. The giant barrel sponge Xestospongia muta is a prominent species on Caribbean reefs that contains cyanobacterial symbionts, the loss of which results in two types of bleaching: cyclic, a recov...

Nitrification, the oxidation of ammonia via nitrite to nitrate, has always been considered to be catalyzed by the concerted activity of ammonia- and nitrite-oxidizing microorganisms. Only recently, complete ammonia oxidizers ("comammox"), which oxidize ammonia to nitrate on their own, were identified in the bacterial genus Nitrospira, previously assumed to contain only canonical nitrite oxidize...

Previous results from a 16S rRNA gene library analysis showed high diversity within the prokaryotic community of a subterranean radioactive thermal spring, the "Franz-Josef-Quelle" (FJQ) in Bad Gastein, Austria, as well as evidence for ammonia oxidation by crenarchaeota. This study reports further characterization of the community by denaturing gradient gel electrophoresis (DGGE) analysis, fluo...

Planktonic Crenarchaea are thought to play a key role in chemolithotrophic ammonia oxidation, a critical step of the marine nitrogen (N) cycle. In this study, we examined the spatial distributions of ammonia-oxidizing Crenarchaea across a large (approximately 5200 km) region of the central Pacific Ocean. Examination of crenarchaeal 16S rRNA, ammonia monooxygenase subunit A (amoA) genes, and amo...

Although nitrification has been well studied in coniferous forests of Western North America, communities of NH(3)-oxidizing bacteria in these forests have not been characterized. Studies were conducted along meadow-to-forest transects at two sites (Lookout and Carpenter) in the H. J. Andrews Experimental Forest, located in the Cascade Mountains of Oregon. Soil samples taken at 10- or 20-m inter...