Correlation of viable cell counts, metabolic activity of sulphur-oxidizing bacteria and chemical parameters of marine sediments

Viable counts of aerobic and anaerobic chemotrophic sulphur-oxidizers as well as phototrophic sulphur bacteria were determined in sediment samples taken from two different areas along the Baltic Sea shore which were known to regularly develop sulphidic conditions. Depth profiles of bacterial cell counts were correlated with concentration profiles of chloride, sulphate, sulphide, nitrate and phosphate in the pore water of these sediments and with potential activities of nitrate reduction, thiosulphate transformation and sulphate formation. The data revealed a complex multilayered structure within the sediments. Sulphide was released into the water from sediments of both sampling areas, but it was found that light and the availability of oxygen significantly reduced this amount. In the highly reduced sediment at Hiddensee, the highest numbers of phototrophic and chemotrophic sulphur-oxidizers were found near the sediment surface. Therefore, it was concluded that the combined action of both groups of bacteria most efficiently oxidizes reduced sulphur compounds in the top layers of the sediments. Nitrate may replace oxygen as final electron acceptor and will support oxidation of sulphide, in particular when oxygen and light are limitin

Robot-Assisted Resection of Left Ventricular Papillary Fibroelastoma Arising From the Mitral Chordal Apparatus

The application of robot-assisted thoracoscopy to cardiac surgery affords an opportunity to leverage the exceptional intraoperative exposure, visualization, and dexterity of the robotic platform. Here, we report the case of a 72-year-old woman who presented to our institution for evaluation of a left ventricular mass that was identified following workup for an embolic event. We present an intraoperative video that provides technical details of the robot-assisted resection of the lesion, which was found to be a left ventricular papillary fibroelastoma arising from the mitral chordal apparatus. This case highlights the advantages provided by the robotic platform, which permitted complete, minimally invasive surgical excision of the lesion while minimizing the burden of surgical trauma

Diversity of thiosulfate-oxidizing bacteria from marine sediments and hydrothermal vents

Author Posting. © American Society for Microbiology, 2000. This article is posted here by permission of American Society for Microbiology for personal use, not for redistribution. The definitive version was published in Applied and Environmental Microbiology 66 (2000): 3125-3133, doi:10.1128/AEM.66.8.3125-3133.2000.Species diversity, phylogenetic affiliations, and environmental occurrence patterns of thiosulfate-oxidizing marine bacteria were investigated by using new isolates from serially diluted continental slope and deep-sea abyssal plain sediments collected off the coast of New England and strains cultured previously from Galapagos hydrothermal vent samples. The most frequently obtained new isolates, mostly from 103- and 104-fold dilutions of the continental slope sediment, oxidized thiosulfate to sulfate and fell into a distinct phylogenetic cluster of marine alpha-Proteobacteria. Phylogenetically and physiologically, these sediment strains resembled the sulfate-producing thiosulfate oxidizers from the Galapagos hydrothermal vents while showing habitat-related differences in growth temperature, rate and extent of thiosulfate utilization, and carbon substrate patterns. The abyssal deep-sea sediments yielded predominantly base-producing thiosulfate-oxidizing isolates related to Antarctic marine Psychroflexus species and other cold-water marine strains of the Cytophaga-Flavobacterium-Bacteroides phylum, in addition to gamma-proteobacterial isolates of the genera Pseudoalteromonas and Halomonas-Deleya. Bacterial thiosulfate oxidation is found in a wide phylogenetic spectrum of Flavobacteria and Proteobacteria.Andreas Teske was supported by DFG postdoctoral fellowship 262-1/1 and a subsequent WHOI postdoctoral fellowship