Publications by authors named "Xue-Gong Li"

Article Synopsis
  • Scientists found that high hydrostatic pressure (HHP) makes it really hard for certain tiny organisms to divide their cells.
  • They studied a protein called FtsZ, which is super important for cell division, and discovered that FtsZ from deep-sea organisms can handle pressure way better than FtsZ from shallow water organisms.
  • By changing small parts of the FtsZ protein, they figured out which parts help it work well under high pressure, helping us understand how these tiny creatures survive in extreme conditions.
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  • Three psychrophilic bacteria strains (SQ149, SQ345, and S1-1) were isolated from deep-sea sediments in the South China Sea and showed high similarity to strain RZG4-3-1 based on 16S rRNA gene sequences (96.45 to 96.67%).
  • Phylogenetic and genetic analyses indicated that these strains form a distinct cluster and represent novel species, as their genetic markers fall below the species delimitation thresholds.
  • All strains are Gram-negative, rod-shaped, and contain specific fatty acids, respiratory quinones, and polar lipids, leading to their classification as new species within the genus, with proposed names for each strain.
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Rossellomorea sp. y25, a putative new species of yellow pigment-producing, aerobic and chemoheterotrophic bacterium belonging to the family Bacillaceae, was isolated from the sediments at the depth of 1829 m in the South China Sea. In this study, we present the complete genome sequences of strain y25, which consisted of only one circular chromosome with 4,633,006 bp and the content of G + C was 41.

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  • High hydrostatic pressure (HHP) plays a key role in regulating gene expression for microbes in deep-sea environments, with a focus on TMAO reductase which enhances pressure tolerance.
  • Researchers identified that the two-component regulator system, TorR and TorS, controls the expression of TMAO reductase (TorA) in response to HHP, distinguishing it from other known regulatory systems.
  • The study revealed that specific phosphorylation sites on TorS are crucial for functioning under HHP, indicating a complex signaling pathway that could help us better understand microbial adaptation to extreme pressures in the ocean.
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A novel anaerobic heterotrophic bacterium, designated strain SWIR-1, was isolated from a deep-sea hydrothermal vent field sample collected from the Southwest Indian Ridge at a depth of 2700 m. Phylogenetic analysis indicated that strain SWIR-1 belongs to the genus , and the most closely related species are B1 (99.1 % 16S rRNA gene sequence similarity), DV1184 (94.

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  • A new bacterium strain QS115 was discovered in deep-sea sediment from the South China Sea, showing strong genetic similarities to another strain, W43, but enough differences to classify it as a new species.
  • Strain QS115 is characterized as a Gram-negative, rod-shaped bacterium that thrives at low temperatures (10°C) and specific conditions (pH 7.5, 2% NaCl).
  • Key components of QS115 include unique fatty acids, a specific respiratory quinone, and distinct polar lipids, leading to its classification as a novel species in its genus with the proposed name sp. nov.
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  • Tepidibacter sp. SWIR-1 is a newly identified anaerobic bacterium from a deep-sea hydrothermal vent on the Southwest Indian Ridge, showing traits like being mesophilic and endospore-forming.
  • The complete genome sequence of SWIR-1 includes a circular chromosome of over 4 million nucleotides and a plasmid, with a total of 3,861 protein-coding genes identified.
  • This genome reveals that SWIR-1 possesses unique adaptations, including more genes for spore germination and chemotaxis compared to other known Tepidibacter species, highlighting its ability to thrive in extreme environments.
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  • Rossellomorea sp. DA94 is a bacterium isolated from mangrove sediment that has the ability to break down agar and is characterized by its orange pigment.
  • The complete genome of strain DA94 consists of 4.63 Mb, containing 4589 protein-coding sequences (CDSs), 33 rRNA genes, and 110 tRNA genes, with significant enzymes for polysaccharide degradation identified.
  • The study highlights the genetic basis for agar degradation and carotenoid biosynthesis, suggesting potential uses in biotechnology due to the diversity of enzymes involved.
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  • Bioluminescence in deep-sea bacteria plays a key role in protecting against oxidative and UV stresses, but its impact on adaptation to high hydrostatic pressure (HHP) is not well understood.
  • A study compared a non-luminescent mutant strain of the bacterium ANT-2200 with its luminescent counterpart to assess pressure tolerance and oxidative stress response.
  • Findings indicated that bioluminescence acts as a crucial antioxidant system, helping bacteria adapt to the extreme deep-sea environment by managing oxidative stress from HHP.
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  • Deep-sea microorganisms adapt to high hydrostatic pressure through modifications in their respiratory components, but their ATP production strategies are less understood.
  • The study focused on the deep-sea bacterium SS9, revealing that it shows better growth and ATP production in minimal glucose medium compared to a complex medium under varying pressure conditions.
  • Researchers discovered that SS9 has two ATPase systems, with ATPase-I dominating in complex medium and ATPase-II being more prominent in minimal medium, indicating a functional relationship between these systems when under pressure.
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  • A new moderately thermophilic heterotrophic bacterium, strain 143-21, was isolated from a deep-sea hydrothermal vent at a depth of 2,440 m and is proposed as a novel species within its genus.
  • Phylogenetic and genomic analyses showed close relationships to similar bacteria, with 16S rRNA sequence similarities of around 96%.
  • Strain 143-21 grows optimally at temperatures of 50°C and pH 7.0, utilizes various sugars and amino acids, and produces fermentation products like acetate, while exhibiting unique fatty acids and polar lipids.
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Ruegeria sp. YS9, an aerobic and chemoheterotrophic bacterium belonging to marine Roseobacter lineage, was a putative new species isolated from red algae Eucheuma okamurai in the South China Sea (Beihai, Guangxi province). The complete genome sequence in strain YS9 comprised one circular chromosome with 3,244,635 bp and five circular plasmids ranging from 38,085 to 748,160 bp, with a total length of 4.

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Gilvimarinus sp. DA14, a putative new species isolated from mangrove sediment in the South China Sea (Beihai, Guangxi province), is an aerobic and heterotrophic agar degrading bacterium. Here, we present the complete genome sequence of strain DA14, which comprises 3.

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Crassaminicella sp. 143-21, a putative new species isolated from deep-sea hydrothermal vent chimney on the Central Indian Ridge (CIR), is an anaerobic, thermophilic and rod-shaped bacterium belonging to the family Clostridiaceae. In this study, we present the complete genome sequence of strain 143-21, comprising 2,756,133 bp with a G + C content of 31.

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Article Synopsis
  • Deep-sea hydrothermal vents, traditionally known for their chemosynthetic ecosystems, also potentially support phototrophic populations due to emitted light that may drive photosynthesis.
  • Metagenomic analyses of samples from the Southwest Indian Ridge revealed widespread distribution of phototrophic bacteria, including known chlorophototrophs, and highlighted the presence of complete chlorophyll biosynthetic pathways.
  • The findings suggest that geothermal vent light could provide energy that enhances the competitive advantage of phototrophs, supporting the idea of the ocean as a diverse microorganism seed bank.
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A novel moderately thermophilic, anaerobic, heterotrophic bacterium (strain SY095) was isolated from a hydrothermal vent chimney located on the Southwest Indian Ridge at a depth of 2730 m. Cells were Gram-stain-positive, motile, straight to slightly curved rods forming terminal endospores. SY095 was grown at 45-60 °C (optimum 50-55 °C), pH 6.

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A hyperthermophilic, strictly anaerobic archaeon, designated strain SY113, was isolated from a deep-sea hydrothermal vent chimney on the Southwest Indian Ridge at a water depth of 2770 m. Enrichment and isolation of strain SY113 were performed at 85 °C at 0.1 MPa.

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Hadal trenches are the deepest but underexplored ecosystems on the Earth. Inhabiting the trench bottom is a group of micro-organisms termed obligate piezophiles that grow exclusively under high hydrostatic pressures (HHP). To reveal the genetic and physiological characteristics of their peculiar lifestyles and microbial adaptation to extreme high pressures, we sequenced the complete genome of the obligately piezophilic bacterium DB21MT-5 isolated from the deepest oceanic sediment at the Challenger Deep, Mariana Trench.

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Crassaminicella sp. strain SY095 is an anaerobic mesophilic marine bacterium that was recently isolated from a deep-sea hydrothermal vent on the Southwest Indian Ridge. Here, we present the complete genome sequence of strain SY095.

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species are widely distributed in marine environments, from the shallow coasts to the deepest sea bottom. Most species possess two isoforms of periplasmic nitrate reductases (NAP-α and NAP-β) and are able to generate energy through nitrate reduction. However, the contributions of the two NAP systems to bacterial deep-sea adaptation remain unclear.

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High hydrostatic pressure (HHP) exerts severe effects on cellular processes including impaired cell division, abolished motility and affected enzymatic activities. Transcriptomic and proteomic analyses showed that bacteria switch the expression of genes involved in multiple energy metabolism pathways to cope with HHP. We sought evidence of a changing bacterial metabolism by supplying appropriate substrates that might have beneficial effects on the bacterial lifestyle at elevated pressure.

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Bacteria of the genus Photobacterium thrive worldwide in oceans and show substantial eco-physiological diversity including free-living, symbiotic and piezophilic life styles. Genomic characteristics underlying this variability across species are poorly understood. Here we carried out genomic and physiological analysis of Photobacterium phosphoreum strain ANT-2200, the first deep-sea luminous bacterium of which the genome has been sequenced.

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A taxonomic study employing a polyphasic approach was carried out on strain FT102(T), which was isolated from a deep-sea sediment sample collected in the south-west Indian Ocean at a depth of 2784 m. The strain was Gram-stain-negative, non-motile, rod-shaped and non-spore-forming. It grew optimally at 37-42 °C, pH 6.

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The benzopyran compound obtained by cultivating a mangrove-derived strain, Streptomyces xiamenensis strain 318, shows multiple biological effects, including anti-fibrotic and anti-hypertrophic scar properties. To increase the diversity in the structures of the available benzopyrans, by means of biosynthesis, the strain was screened for spontaneous rifampicin resistance (Rif), and a mutated rpsL gene to confer streptomycin resistance (Str), was introduced into the S. xiamenensis strain M1-94P that originated from deep-sea sediments.

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Article Synopsis
  • Mangrove actinomycetes show potential for producing bioactive compounds, particularly halogenated metabolites, based on genetic screening and antimicrobial testing of 163 isolated strains.
  • Identification of specific genes, like FADH2-dependent halogenases, suggests these organisms can create diverse antibiotics by pairing them with other biosynthetic pathways like PKS or NRPS.
  • The study successfully confirmed a new actinomycete producer of enduracidin and mapped out an ansamycin biosynthesis gene cluster, demonstrating the effectiveness of genome mining in discovering valuable natural products.
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