Project description:Illumina high-throughput sequencing was used to analyse the intestinal bacteria of these two species during different wintering periods at Shengjin Lake. We tested whether contact time enhances the trans-species spread of gut bacteria. Our results indicate that although intestinal microflora of hooded crane and the bean goose were different, direct or indirect contact in the mixed-species flock caused the spread of gut bacteria trans-species, and a very high proportion of common pathogens among these two hosts.
Project description:Bacterium Sphingomonas glacialis AAP5 isolated from the alpine lake Gossenköllesee contains genes for anoxygenic phototrophy as well as proton-pumping xanthorhodopsin. Here we show that AAP5 expresses xanthorhodopsin when illuminated at temperatures below 16°C. In contrast bacteriochlorophyll-containing reaction centers are expressed between 4 and 22°C in the dark. Thus, cells grown at lower temperature under natural light-dark cycle produced both photosystems. The purified xanthorhodopsin contains carotenoid nostoxanthin serving as an auxiliary antenna and performs the standard photocycle. The xanthorhodopsin-containing cells reduced upon illumination their respiration, increased their ATP synthesis and produced more biomass. This documents that the harvested light energy was utilized in the metabolism, which can represent a competitive advance under carbon-limiting conditions. The presence of Sphingomonas bacteria with dual phototrophy was verified in the metagenomes collected from lake Gossenköllesee. This unique trait may represent a metabolic advantage in alpine lakes where photoheterotrophic organisms facelimited organic substrates, low temperature, and extreme changes in irradiance.
