Project description:Land cover change has long been recognized that marked effect the amount of soil organic carbon. However, little is known about microbial-mediated effect processes and mechanism on soil organic carbon. In this study, the soil samples in a degenerated succession from alpine meadow to alpine steppe meadow in Qinghai-Tibetan Plateau degenerated, were analyzed by using GeoChip functional gene arrays.
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.
2022-05-10 | GSE196609 | GEO
Project description:Microbial community in alpine meadow
