Project description:Archaea are well known for inhabiting areas of our planet that are usually hostile for any form of life, hence they are often termed as “extremophiles”. Although also found in common soil or the digestive tract of vertebrates, some species thrive on acidic or alkaline grounds, in submarine black smokers with temperatures surpassing 100°C or live in aquatic areas with a very high salinity.Haloferax volcanii is a halophilic and mesophilic archaeon that was first discovered in the 1930s and isolated from the hypersaline environment of the Dead Sea. Its optimal growth conditions are at 42 °C in around 2 M NaCl and complex nutrient medium, however it can also grow in different synthetic media and at a wide range of temperatures and NaCl concentrations. While NaCl concentrations up to 0.7 M inhibit growth in synthetic glucose media, a concentration of 0.9 M is sufficient to sustain growth at a reduced rate.Here we show for the first time a transcriptome-wide analysis of differential gene expression of cells grown under low salt condition. We cultivated cells at an optimal NaCl concentration of 2.1 M in glucose media and compared the expression profile of these to cells grown in 0.9 M NaCl after 26 and 68 h.
Project description:Haloferax volcanii is an easily culturable moderate halophile that grows on simple defined media, is readily transformable, and has a relatively stable genome. This, in combination with its biochemical and genetic tractability, has made Hfx. volcanii a key model organism, not only for the study of halophilicity, but also for archaeal biology in general.We report here the sequencing and analysis of the genome of Hfx. volcanii DS2, the type strain of this species. The genome contains a main 2.848 Mb chromosome, three smaller chromosomes pHV1, 3, 4 (85, 438, 636 kb, respectively) and the pHV2 plasmid (6.4 kb).The completed genome sequence, presented here, provides an invaluable tool for further in vivo and in vitro studies of Hfx. volcanii.
Project description:In order to understand extraceluular vesicle (EV) production in Euryarchaea, and in particular halophilic archaea, we used the model archaeal organism, Haloferax volcanii, to investigate the composition of EVs as well as their capacity to transfer their cargo to other organisms. EVs were isolated in tripclicates and purified with a density gradient. Both of two bands (upper and lower band) were isolated from the gradient and analysed seperately. Additionally, cellular membranes were isolated in triplicates and analysed for their protein content, to allow conclusions about proteins that are preferentially enclosed in EVs.
Project description:Transcriptional Landscape and Regulatory Roles of Small Noncoding RNAs in the Oxidative Stress Response of the Haloarchaeon Haloferax volcanii
