Microbial life inhabits deeply buried marine sediments, but the extent of this vast ecosystem remains poorly constrained. Here we provide evidence for the existence of microbial communities in ~40° to 60°C sediment associated with lignite coal beds at ~1.5 to 2.5 km below the seafloor in the Pacific Ocean off Japan. Microbial methanogenesis was indicated by the isotopic compositions of methane and carbon dioxide, biomarkers, cultivation data, and gas compositions. Concentrations of indigenous microbial cells below 1.5 km ranged from <10 to ~10(4) cells cm(-3). Peak concentrations occurred in lignite layers, where communities differed markedly from shallower subseafloor communities and instead resembled organotrophic communities in forest soils. This suggests that terrigenous sediments retain indigenous community members tens of millions of years after burial in the seabed.
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http://dx.doi.org/10.1126/science.aaa6882 | DOI Listing |
Appl Microbiol Biotechnol
January 2025
State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
Identifying hormone-like quorum sensing (QS) molecules in streptomycetes is challenging due to low production levels but is essential for understanding secondary metabolite biosynthesis and morphological differentiation. This work reports the discovery of a novel γ-butenolide-type signaling molecule (SFB1) via overexpressing its biosynthetic gene (orf18) in Streptomyces fradiae. SFB1 was found to be essential for production of tylosin through dissociating the binding of its receptor TylP (a transcriptional repressor) to target genes, thus activating the expression of tylosin biosynthetic gene cluster (tyl).
View Article and Find Full Text PDFProc Natl Acad Sci U S A
January 2025
Department of Mathematics and Mathematical Statistics, Umeå University, Umeå 90187, Sweden.
Multicellularity spans a wide gamut in terms of complexity, from simple clonal clusters of cells to large-scale organisms composed of differentiated cells and tissues. While recent experiments have demonstrated that simple forms of multicellularity can readily evolve in response to different selective pressures, it is unknown if continued exposure to those same selective pressures will result in the evolution of increased multicellular complexity. We use mathematical models to consider the adaptive trajectories of unicellular organisms exposed to periodic bouts of abiotic stress, such as drought or antibiotics.
View Article and Find Full Text PDFAppl Environ Microbiol
January 2025
State Key Laboratory of Biocatalysis and Enzyme Engineering, Environmental Microbial Technology Center of Hubei Province, College of Life Sciences, Hubei University, Wuhan, China.
is an important bioresource to produce various antibacterial natural products, however, the time-consuming and labor-intensive genome editing toolkits hindered the construction and application of engineered strains, and this study aimed to establish an efficient CRISPR/Cas9n genome editing system in . Initially, the CRISPR/Cas9-mediated editing tool was employed to replace those awkward genome editing tools that relied on homologous recombination, while the off-target Cas9 exhibited high toxicity to Sf01. Therefore, the nickase mutation D10A, high-fidelity mutations including N497A, R661A, Q695A, and Q926A, and thiostrepton-induced promotor P were incorporated into the Cas9 expression cassette, which reduced its toxicity.
View Article and Find Full Text PDFAppl Environ Microbiol
January 2025
Department of Earth, Environmental and Planetary Sciences, Washington University in St. Louis, St. Louis, Missouri, USA.
Microorganisms adapted to high hydrostatic pressures at depth in the oceans and within the subsurface of Earth's crust represent a phylogenetically diverse community thriving under extreme pressure, temperature, and nutrient availability conditions. To better understand the microbial function, physiological responses, and metabolic strategies at conditions requires high-pressure (HP) continuous culturing techniques that, although commonly used in bioengineering and biotechnology applications, remain relatively rare in the study of the Earth's microbiomes. Here, we focus on recent developments in the design of HP chemostats, with particular emphasis on adaptations for delivery and sampling of dissolved gases.
View Article and Find Full Text PDFActa Physiol (Oxf)
February 2025
Department of Pediatric Pneumology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany.
Over the past two decades, it has become clear that against earlier assumptions, the respiratory tract is regularly populated by a variety of microbiota even down to the lowest parts of the lungs. New methods and technologies revealed distinct microbiome compositions and developmental trajectories in the differing parts of the respiratory tract of neonates and infants. In this review, we describe the current understanding of respiratory microbiota development in human neonates and highlight multiple factors that have been identified to impact human respiratory microbiome development including gestational age, mode of delivery, diet, antibiotic treatment, and early infections.
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