Effects of increasing hydrostatic pressures on marine microbial enzymatic activities

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 15, 2025

Abstract High hydrostatic pressure is characteristic of the deep ocean and presumed to influence microbial functions viability. However, marine processes are typically measured only at atmospheric (0.1 MPa), limiting our understanding effects on activities microbes that sink as part biological carbon pump well those reside in ocean. To test functions, we extracellular enzymatic activities—the first step organic matter remineralization—of a moderate piezophile (Photobacterium profundum SS9), communities waters sediments from shallow abyssal (5,500 m) depths their cell-free enzymes (<0.2 µm). Activities were 0.1-100 MPa assess across nearly full range oceanic depths. P. SS9 show varying effects, considerable stimulation optimal (28 MPa) near complete inhibition (100 MPa). Pressure for diverse protein- carbohydrate-degrading phosphorus-acquiring among pelagic benthic communities. The most common effect partial activity reduction, indicating dampening initial remineralization increasing pressures. retention higher pressures was occasionally observed even surface-originating assemblages, functionality down hadal potential piezotolerance. These variable must be considered when quantifying degradation rates sinking deposited particulate

Language: Английский

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Comparative Genomics Reveals Evidence of the Genome Reduction and Metabolic Potentials of Aliineobacillus hadale Isolated from Challenger Deep Sediment of the Mariana Trench

Microorganisms, Journal Year: 2025, Volume and Issue: 13(1), P. 132 - 132

Published: Jan. 10, 2025

Hadal zones account for the deepest 45% of oceanic depth range and play an important role in ocean biogeochemical cycles. As least-explored aquatic habitat on earth, further investigation is still required to fully elucidate microbial taxonomy, ecological significance, metabolic diversity, adaptation hadal environments. In this study, a novel strain Lsc_1132T was isolated from sediment Mariana Trench at 10,954 m depth. Strain contains heterogenous 16S rRNA genes, exhibiting highest sequence similarities type strains Neobacillus drentensis LMG 21831T, dielmonensis, NBRC 102427T, rhizosphaerae, soli 102451T, with 98.60-99.10% identity. The average nucleotide identity (ANI), digital DNA-DNA hybridization (DDH) values, amino acid (AAI) sp. PS3-40 reached 73.5%, 21.4%, 75.54%, respectively. major cellular fatty acids included iso-C15:0, Summed Feature 3 (C16:1ω6c and/or C16:1ω7c), iso-C17:0, anteiso-C15:0, iso-C17:1ω5c. respiratory quinone MK-7. G + C content genomic DNA 40.9%. Based GTDB taxonomy phenotypic data, could represent species genus, proposed as Aliineobacillus hadale gen. nov. (type = MCCC 1K09620T). Metabolically, demonstrates robust carbohydrate metabolism many strain-specific sugar transporters. It also has remarkable capacity metabolizing carboxylic acids. Genomic analysis reveals streamlined genome organism, characterized by significant loss orthologous including those involved cytochrome c synthesis, aromatic compound degradation, polyhydroxybutyrate (PHB) which suggests its low oxygen levels oligotrophic conditions through alternative pathways. addition, reduced number paralogous genes Lsc_1132T, together high protein-coding gene density, may contribute streamlining enhancing efficiency. This research expands our knowledge microorganisms their strategies surviving extreme deep-sea

Language: Английский

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Prophage-encoded chitinase gene supports growth of its bacterial host isolated from deep-sea sediments

The ISME Journal, Journal Year: 2025, Volume and Issue: 19(1)

Published: Jan. 1, 2025

Language: Английский

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Strong Effects of Increased Hydrostatic Pressure on Polysaccharide‐Hydrolyzing Enzyme Activities in Coastal Seawater and Sediments

Journal of Geophysical Research Biogeosciences, Journal Year: 2025, Volume and Issue: 130(2)

Published: Feb. 1, 2025

Abstract Heterotrophic microorganisms are responsible for transforming and respiring a substantial fraction of the organic matter produced by phytoplankton in surface ocean. Much this is composed polysaccharides, high‐molecular weight (HMW) sugars. To initiate degradation must produce extracellular enzymes right structural specificity to hydrolyze these complex structures. date, most measurements enzyme activities made at situ temperatures, but atmospheric pressure. However, previous studies have shown that hydrostatic pressure can impact functionality enzymes. Since deep sea communities may be seeded microbes from shallow waters, we aimed determine if affects performance coastal waters. extent which enzymatic microbial affected pressure, quantified seven polysaccharides under pressures ranging 0.1 MPa (atmospheric) 40 (equivalent 4,000 m). Enzyme pelagic were inhibited with increased while benthic more resistant Addition HMW resulted freely‐dissolved (<0.2 μm) strongly suggesting pressure‐resistant cell‐surface attached. Because inhibition varied polysaccharide, surmise complexity polysaccharide—and therefore number distinct required hydrolysis—is likely closely associated inhibition.

Language: Английский

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Element cycling and microbial life in the hadal realm

Trends in Microbiology, Journal Year: 2024, Volume and Issue: 32(11), P. 1045 - 1048

Published: July 31, 2024

Language: Английский

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Hydrostatic pressure impedes the degradation of sinking copepod carcasses and fecal pellets

Journal of Plankton Research, Journal Year: 2024, Volume and Issue: 46(2), P. 219 - 223

Published: Feb. 1, 2024

Abstract Fast-sinking zooplankton carcasses and fecal pellets appear to contribute significantly the vertical transport of particulate organic carbon (POC), partly because low temperature that decreases microbial degradation during descent into deep ocean. Increasing hydrostatic pressure could further reduce efficiency sinking POC, but this effect remains unexplored. Here, abundant marine copepod Calanus finmarchicus was experimentally studied as a function (0.1–100 MPa). Samples were either exposed elevated in short 1-day incubations or gradual increase, simulating continuous particle 20-day incubation. Both experiments revealed inhibition respiration range 20–100 MPa, corresponding 2–10-km depth. This suggests impedes mineralization fast-sinking enhances deep-sea deposition rate zooplankton-derived material.

Language: Английский

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RotoBOD─Quantifying Oxygen Consumption by Suspended Particles and Organisms

Environmental Science & Technology, Journal Year: 2024, Volume and Issue: 58(20), P. 8760 - 8770

Published: May 8, 2024

Sinking or floating is the natural state of planktonic organisms and particles in ocean. Simulating these conditions critical when making measurements, such as respirometry, because they allow exchange substrates products between sinking water flowing around them prevent that are accustomed to motion from changing their metabolism. We developed a rotating incubator, RotoBOD (named after its capability rotate determine biological oxygen demand, BOD), uniquely enables automated measurements small volumes while keeping samples suspension. This allows highly sensitive rate utilization subsequent characterization single organisms, copepods, jellyfish, protists. As this approach nondestructive, it can be combined with several further during incubation, stable isotope additions molecular analyses. makes instrument useful for ecologists, biogeochemists, potentially other user groups aquaculture facilities. Here, we present technical background our newly apparatus provide examples how utilized production consumption particles.

Language: Английский

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Earth’s most needed uncultivated aquatic prokaryotes

Published: June 24, 2024

Aquatic ecosystems house a significant fraction of Earth’s biosphere, yet most prokaryotes inhabiting these environments remain uncultivated. While recently developed genome-resolved metagenomics and single-cell genomics techniques have underscored the immense genetic breadth metabolic potential residing in uncultivated Bacteria Archaea, cultivation microorganisms is required to study their physiology via systems, confirm predicted biochemical pathways, exploit biotechnological potential, accurately appraise nutrient turnover. Over past two decades, limitations culture-independent investigations highlighted importance bridging this vast knowledge gap. Here, we collected more than 80 highly sought-after lineages aquatic Archaea with global ecological impact. In addition fulfilling critical roles carbon, nitrogen, sulfur cycling, many organisms are thought partake key symbiotic relationships. This review highlights vital contributions uncultured microbes ecosystems, from lakes groundwater surfaces depths oceans will guide current future initiatives tasked cultivating our planet’s elusive, consequential microflora.

Language: Английский

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Earth's most needed uncultivated aquatic prokaryotes

Water Research, Journal Year: 2024, Volume and Issue: 273, P. 122928 - 122928

Published: Dec. 9, 2024

Language: Английский

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