Project description:Iron-sulfur minerals such as pyrite are found in many marine benthic habitats. At deep-sea hydrothermal vent sites they occur as massive sulfide chimneys. Hydrothermal chimneys formed by mineral precipitation from reduced vent fluids upon mixing with cold oxygenated sea water. While microorganisms inhabiting actively venting chimneys and utilizing reduced compounds dissolved in the fluids for energy generation are well studied, only little is known about the microorganisms inhabiting inactive sulfide chimneys. We performed a comprehensive meta-proteogenomic analysis combined with radiometric dating to investigate the diversity and function of microbial communities found on inactive sulfide chimneys of different ages from the Manus Basin (SW Pacific). Our study sheds light on potential lifestyles and ecological niches of yet poorly described bacterial clades dominating inactive chimney communities.
Project description:Relentless mining operations have destroyed our environment significantly. Soil inhabiting microbes play a significant role in ecological restoration of these areas. Microbial weathering processes like chemical dissolution of rocks significantly promotes the soil properties and enhances the rock to soil ratio respectively. Earlier studies have reported that bacteria exhibit efficient rock-dissolution abilities by releasing organic acids and other chemical elements from the silicate rocks. However, rock-dissolving mechanisms of the bacterium remain to be unclear till date. Thus, we have performed rock-dissolution experiments followed by genome and transcriptome sequencing of novel Pseudomonas sp.NLX-4 strain to explore the efficiency of microbe-mediated habitat restoration and its molecular mechanisms underlying this biological process. Results obtained from initial rock dissolution experiments revealed that Pseudomonas sp. NLX-4 strain efficiently accelerates the dissolution of silicate rocks by secreting amino acids, exopolysaccharides, and organic acids with elevated concentrations of potassium, silicon and aluminium elements. The rock dissolution experiments of NLX-4 strain exhibited an initial increase in particle diameter variation values between 0-15 days and decline after 15 days-time respectively. The 6,771,445-base pair NLX-4 genome exhibited 63.21 GC percentage respectively with a total of 6041 protein coding genes. Genome wide annotations of NLX-4 strain exhibits 5045-COG, 3996-GO, 5342-InterPro, 4386-KEGG proteins respectively Transcriptome analysis of NLX-4 cultured with/without silicate rocks resulted in 539 (288-up and 251-down) differentially expressed genes (DEGs). Fifteen DEGs encoding for siderophore transport, EPS and amino acids synthesis, organic acids metabolism, and bacterial resistance to adverse environmental conditions were highly up-regulated by cultured with silicate rocks. This study has not only provided a new strategy for the ecological restoration of rock mining areas, but also enriched the applicable bacterial and genetic resources.
Project description:The leaf transcriptome of the nickel hyperaccumulator Leucocroton havanensis (Euphorbiaceae) living on serpentine Cuabal, from Cuba, was compared to the closely related non-accumulator Lasiocroton microphyllus living on Gallery forest on limestone soil, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
Project description:The leaf transcriptome of the nickel hyperaccumulator Geissois pruinosa (Rubiaceae) endemic from New Caledonia was compared to the closely related non-accumulator Geissois racemosa, living respectively in serpentine maquis or rainforest on limestone, to identity differentially expressed genes potentially involved in Ni hyperaccumulation.
