Preface Part I. History, Geology and Technology: Introduction 1. The history of hadal science and exploration 2. Geography and geology 3. Full ocean depth technology Part II. Environmental Conditions and Physiological Adaptations: Introduction 4. The hadal environment 5. Hydrostatic pressure 6. Food supply to the trenches Part III. The Hadal Community: Introduction 7. Microbes, protists and worms 8. Porifera, mollusca and echinodermata 9. Crustacea 10. Cnidaria and fish Part IV. Patterns and Current Perspectives: Introduction 11. Ecology and evolution 12. Current perspectives Appendix References Index.

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The Hadal Zone: Life in the Deepest Oceans

Destructuring plant biomass: Focus on fungal and extremophilic cell wall hydrolases

Eicosapentaenoic acid plays a role in stabilizing dynamic membrane structure in the deep-sea piezophile Shewanella violacea: a study employing high-pressure time-resolved fluorescence anisotropy measurement.

. The temperature responses of sulfate-reducing microbial communities were used as community temperature characteristics for their in situ temperature adaptation, their origin, and dispersal in the deep sea. Sediments were collected from a suite of coastal, continental shelf, and slope sediments from the southwest and southeast Atlantic and permanently cold Arctic fjords from water depths ranging from the intertidal zone to 4327 m. In situ temperatures ranged from 8 °C on the shelf to −1 °C in the Arctic. Temperature characteristics of the active sulfate-reducing community were determined in short-term incubations with 35S-sulfate in a temperature gradient block spanning a temperature range from 0 to 40 °C. An optimum temperature (Topt) between 27 °C and 30 °C for the South Atlantic shelf sediments and for the intertidal flat sediment from Svalbard was indicative of a psychrotolerant/mesophilic sulfate-reducing community, whereas Topt ≤20 °C in South Atlantic slope and Arctic shelf sediments suggested a predominantly psychrophilic community. High sulfate reduction rates (20–50%) at in situ temperatures compared to those at Topt further support this interpretation and point to the importance of the ambient temperature regime for regulating the short-term temperature response of sulfate-reducing communities. A number of cold (

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Temperature characteristics of bacterial sulfate reduction in continental shelf and slope sediments

https://link-springer-com-443.webvpn.jmu.edu.cn/content/pdf/10.1007%2F978-3-642-38922-1_226.pdf

The Family Shewanellaceae

Remineralization of organic matter in deep-sea sediments is important in oceanic biogeochemical cycles, and bacteria play a major role in this process. Shewanella violacea DSS12 is a psychrophilic and piezophilic γ-proteobacterium that was isolated from the surface layer of deep sea sediment at a depth of 5110 m. Here, we report the complete genome sequence of S. violacea and comparative analysis with the genome of S. oneidensis MR-1, isolated from sediments of a freshwater lake. Unlike S. oneidensis, this deep-sea Shewanella possesses very few terminal reductases for anaerobic respiration and no c-type cytochromes or outer membrane proteins involved in respiratory Fe(III) reduction, which is characteristic of most Shewanella species. Instead, the S. violacea genome contains more terminal oxidases for aerobic respiration and a much greater number of putative secreted proteases and polysaccharases, in particular, for hydrolysis of collagen, cellulose and chitin, than are encoded in S. oneidensis. Transporters and assimilatory reductases for nitrate and nitrite, and nitric oxide-detoxifying mechanisms (flavohemoglobin and flavorubredoxin) are found in S. violacea. Comparative analysis of the S. violacea genome revealed the respiratory adaptation of this bacterium to aerobiosis, leading to predominantly aerobic oxidation of organic matter in surface sediments, as well as its ability to efficiently use diverse organic matter and to assimilate inorganic nitrogen as a survival strategy in the nutrient-poor deep-sea floor.

Tatsunari Nishi

Papers

Complete genome sequence and comparative analysis of Shewanella violacea, a psychrophilic and piezophilic bacterium from deep sea floor sediments