Presentation on theme: "Bolbfish The blobfish (Psychrolutes marcidus) is a fish that inhabits the deep waters off the coasts of Australia and Tasmania. Due to the inaccessibility."— Presentation transcript:
1 BolbfishThe blobfish (Psychrolutes marcidus) is a fish that inhabits the deep waters off the coasts of Australia and Tasmania. Due to the inaccessibility of its habitat, it is rarely seen by humans.Blobfish are found at depths greater than 5000 m, which would likely make gas bladders inefficient. To remain buoyant, the flesh of the blobfish is primarily a gelatinous mass with a density slightly less than water; this allows the fish to float above the sea floor without expending energy on swimming. The relative lack of muscle is not a disadvantage as it primarily swallows edible matter that floats by in front it
2 Key QuestionsWhat are the different biomes that are important to the deep carbon cycle?TerrestrialmarineWhat is the magnitudes, rates and kinds of microbial activity in the different biomes?Temporal/spatial scalesWhat are the sources and sinks of organic carbon in deep environments (biotic, abiotic, and modified)?What limits deep life? Coupled temp-pressure- energy- porosity/perm.
3 Terrestrial BiomesMany are hydrogen driven systems
4 Terrestrial subsurface SLiME - subsurface lithoautotrophic microbial ecosystemsDeep cratonsColumbia River basaltsNealson et al. 2005
5 Marine biomes Complex sources and sinks for carbon Pelagic environmentsLight-driven and dark CO2 fixationCarbon flux to benthos, crust etcDeep sedimentsHydrothermal vents and subseafloor crustNew eruptions and linkagesRock hosted including the deep subseafloorSubduction zones
7 Taking the Pulse of a Plate: Hydrogeological-Biological Observatories There are over 15,000 seamounts -hydrothermal “breathing” holes?The oceanic crust is the largest fractured aquifer on Earth85% of the Earths magmaticbudget is focused at mid-oceanridgesThe margins host ~10,000gigatons of hydrateThe subseafloor biosphere may rival that on the continents?
9 Size spectrum of organic matter and other “things” in the ocean From Verdugo 2004
10 Colloids in the marine environment: the most abundant form of carbon Colloids range in size from extremely small (5-200 nm) to large (0.4-1µm). Small colloids are more abundant and can reach 109/ml whereas the larger colloids are less abundant (~107/ml)Most of the colloids are refractory carbohydratesThere are multiple sources for colloidsNothing known about the the possible degradation of colloids and the role bacteria play in production and consumption
11 Depth distribution of small (5-200 nm) colloid particles-concentrations (X 109 ml-1) from Wells and Goldberg, 1994
13 Incidence, diversity and physiology of “deep” microbial communities Incidence and diversityMetabolism of CO2 fixing microbesPhysiology of isolated microorganisms
14 Number and metabolic diversity of microorganisms in vent and other deep-sea environments SamplesNumber of microorganismsMetabolic and/or phylogenetic groupsSulfide structures>108 per gram sulfide on outer layers; 105 per gram in interiorOuter layers have both bacteria and archaea and include metal oxidizers and methanogens; inner layers contain archaea of unknown physiologiesDiffuse-flow fluids (2°C to ~80°C)105->109 ml-1; high numbers from Galapagos particlesExtremely high diversity of bacteria and archaea (all thermal groups)Smoker fluids (<200°C to ~400°C)Not detected to 107 ml-1; high numbers correlate with phase separationHyperthermophilic bacteria and archaea from culture and molecular analysesHydrothermal vent plume water (2°C in horizontal plume~105 to >106 ml-1H2, CH4 and Mn2+ oxidizing bacteria detected by activity measurementsDeep SW surrounding vents (2°C)103 to <105 ml-1Limited diversity of bacteria and archaea detected and enumerated by molecular methods
15 Number of microorganisms Metabolic and/or phylogenetic groups Number and metabolic diversity of microorganisms in deep-sea environments - continuedSamplesNumber of microorganismsMetabolic and/or phylogenetic groupsSubseafloor crustNumbers unknown on axis; ~105 ml-1 in old crust (>4 Ma)Different thermal groups of bacteria and archaea detected from new eruptions; unique archaea isolated from subsurface fluidsMicrobial mats>108 bacteria per gramHigh numbers of S-oxidizing bacteria including Beggiatoa spp and uncultured -ProteobacteriaSediments>108 bacteria per gram in the surface decreasing numbers with depthSame as for microbial mats in surface layer with sulfate-reducing bacteria and methanogens dominating the deeper layers
17 Questions and Issues - I: Primary Production What is the phylogenetic and physiological diversity of the primary producers in deep-sea environments (deep sediments, crust, diffuse flow vents, sulfides, animal symbionts, plumes, microbial mats, etc)?What is metabolic versatility of the primary producers? (CO2 fixation)How significant is the abiotic synthesis of organic compounds (C1 - Cn) to primary production? (coupling the oxidation of organic compounds with the reduction of FeIII and S°)How do the primary producers effect biogeochemical cycles (Metal, S, P and N)?What is the primary production rates in situ in different vent environments?What is the diversity of N2 fixing microorganisms and how important is nitrogen fixation to primary production?What are the sources and sinks for biologically utilizable phosphate?
18 Ax99-59 isolated from Axial Volcano Strict anaerobeThermophilicCO2 is carbon sourceH2 as energy sourceReduces sulfur species32 min doubling time underoptimal conditionsG+C ratio if 40%New genus in theAquifacales*Also -Proteobacteria are important primary producersScanning electron micrograph of Ax99-59.Under most culturing conditions thisorganism produce copious amount of exo-polysaccharide, which may be involved inBiofilm formation. Scale bar is 1 µmHuber, unpublished
19 PNAS 102: , 2005A Green-sulfur photosynthetic bacteria was isolated from a submarine hydrothermal vent smoker where the only source of light is geothermal radiation that includes wavelengths absorbed by photosynthetic pigments. This organisms is an obligate anaerobe and reduces CO2 coupled with oxidation of sulfur compoundsPhotosyntheticbacteriaChlorosomesMorphology and ultrastructureof GSB1 cells. Bar, 300 nm2HCO3- + H2S 2CH2O + SO42-
20 ExperimentsDesign experiments to investigate the effect of spatial gradients on microbial activityLaying the groundwork for doing focused experimental studies (with potential industrial/societal/environmental impacts)Better descriptions of physiology of microbesExperiments to better understand OM processing at high temperatures and pressures versus transformations to acetate, methane, etc.Relate microbial physiology to the carbon budget at organism to community scales.
21 FieldworkSome environments are readily accessible and some require longer term planning and how best to sample them)85% of magmatic budget focused at ridge, but only 2 actual observations- need more data!There are heterotrophs in deep subsurface environments (deep OM processing)Organic sources are potentially metabolites of the autotrophsNeed to delineate sources of metabolitesHow many spores are we missing?/or cyst-like states (survival)
22 Conclusions and Implications Astrobiology (ice habitats and impact sites)Origin of life and paleo issuesMetabolism vs. timePhysiologya. Metabolismb. Survival strategies/stress responsesc. Consortial strategiesd. Genome evolutions (HGT)Need to better define and delineate deep life and deep habitatsPossible applicationsSequestration, biofuels, etc
23 From Martin, Baross, Kelley and Russell, Nature Microbiology Rev From Martin, Baross, Kelley and Russell, Nature Microbiology Rev. submitted
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