Publications by authors named "Charmaine C M Yung"

Marine plastic pollution is a pervasive environmental issue, with microplastics serving as novel substrates for microbial colonization in aquatic ecosystems. This study investigates the succession of plastisphere communities on four common plastic types (polyethylene, polypropylene, polyethylene terephthalate, and polystyrene) in subtropical coastal waters of Hong Kong SAR. Over a 42-day period, we analysed the temporal development of microbial communities using a three-domain universal metabarcoding method.

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Mamiellophyceae are a ubiquitous class of unicellular green algae in the global ocean. Their ecological importance is highlighted in studies focused on the prominent genera Micromonas, Ostreococcus, and Bathycoccus. Mamiellophyceae are susceptible to prasinoviruses, double-stranded DNA viruses belonging to the nucleocytoplasmic large DNA virus group.

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Article Synopsis
  • - Unicellular green picophytoplankton, part of the Mamiellales order, are common in marine ecosystems and can be infected by prasinoviruses, large DNA viruses.
  • - Researchers developed a new method to enrich and sequence these viruses, successfully assembling 80 prasinovirus genomes from samples in the South China Sea, and found strong links between genome similarity and host range with 94% accuracy.
  • - The study revealed unexpected host-switching among different algal lineages and instances of horizontal gene transfer, indicating active viral evolution and co-evolutionary dynamics that influence marine virus-host interactions.
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Article Synopsis
  • A two-year study in the South China Sea has deepened knowledge about marine microbes, revealing their adaptability and complex interactions through metagenomics and metatranscriptomics.
  • Seasonal changes significantly affect microbial communities, with cyanobacteria dominating in warmer months and photosynthetic protists in colder ones, while photosynthesis processes remain active year-round despite these shifts.
  • The study highlights how environmental factors, especially temperature and salinity, shape microbial dynamics, and identifies 37 phytoplankton metagenome-assembled genomes (MAGs) showcasing their genetic diversity and metabolic capabilities tailored to changing environments.
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Marine eukaryotic phytoplankton are fundamental to the marine food web, yet the lack of reference genomes or just a single genome representing a taxon has led to an underestimation of their taxonomic, adaptive, and functional diversity. Here, we integrated strain isolation with metagenomic binning to recover genomes from the cosmopolitan picophytoplankton genus Bathycoccus, traditionally considered monospecific. Our recovery and analysis of 37 Bathycoccus genomes delineated their global genomic diversity and established four evolutionary clades (BI, BII, BIII, BIV).

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Polyphosphate (polyP) is found in plankton of diverse aquatic ecosystems and is important for plankton ecology and biogeochemical cycling. However, our knowledge of polyP in aquatic environments is hindered by a lack of data due to the limitations of quantification methods. The estimate of polyP in model organisms using phenol-chloroform extraction followed by enzymatic hydrolysis is complicated and fails for environmental samples.

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Mamiellophyceae are dominant marine algae in much of the ocean, the most prevalent genera belonging to the order Mamiellales: , and , whose genetics and global distributions have been extensively studied. Conversely, the genus , despite its potential ecological importance, remains relatively under-characterised. In this study, we isolated and characterised a novel species of Mamiellophyceae, , from subtropical coastal waters in the South China Sea.

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Bacterial communities directly influence ecological processes in the ocean, and depth has a major influence due to the changeover in primary energy sources between the sunlit photic zone and dark ocean. Here, we examine the abundance and diversity of bacteria in Monterey Bay depth profiles collected from the surface to just above the sediments (e.g.

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is a key member of open-ocean primary producer communities. Despite its importance, little is known about the predators that consume this cyanobacterium and make its biomass available to higher trophic levels. We identify potential predators along a gradient wherein abundance increased from near detection limits (coastal California) to >200,000 cells mL (subtropical North Pacific Gyre).

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Microbial predators such as choanoflagellates are key players in ocean food webs. Choanoflagellates, which are the closest unicellular relatives of animals, consume bacteria and also exhibit marked biological transitions triggered by bacterial compounds, yet their native microbiomes remain uncharacterized. Here we report the discovery of a ubiquitous, uncultured bacterial lineage we name Candidatus Comchoanobacterales ord.

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The marine picoeukaryote Bathycoccus prasinos has been considered a cosmopolitan alga, although recent studies indicate two ecotypes exist, Clade BI (B. prasinos) and Clade BII. Viruses that infect Bathycoccus Clade BI are known (BpVs), but not that infect BII.

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Photosynthesis in eukaryotes first arose through phagocytotic processes wherein an engulfed cyanobacterium was not digested, but instead became a permanent organelle. Other photosynthetic lineages then arose when eukaryotic cells engulfed other already photosynthetic eukaryotic cells. Some of the resulting lineages subsequently lost their ability for phagocytosis, while many others maintained the ability to do both processes.

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The Antarctic Dry Valleys are unable to support higher plant and animal life and so microbial communities dominate biotic ecosystem processes. Soil communities are well characterized, but rocky surfaces have also emerged as a significant microbial habitat. Here, we identify extensive colonization of weathered granite on a landscape scale by chasmoendolithic microbial communities.

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