Increased Nutrient Levels Enhance Bacterial Exopolysaccharides Production in the Context of Algae

Environmental Microbiology Reports, Journal Year: 2025, Volume and Issue: 17(1)

Published: Feb. 1, 2025

ABSTRACT Microbial aggregation is central in environmental processes, such as marine snow and harmful mucilage events. Nutrient enrichment positively correlates with microbial aggregation. This correlation largely attributed to the overgrowth of microalgae overproduction agglomerating exopolysaccharides. However, recent studies highlight significant contribution bacterial exopolysaccharides algal‐bacterial Here, using controlled laboratory experiments metatranscriptomic analysis, we investigate impact nutrient on production, while bacteria are context their algal hosts. Our findings demonstrate a marked increase production response relative inorganic phosphorus nitrogen levels, both lab environment. These results interplay between regimes, physiology ecosystems emphasise gaps our understanding regarding role processes that involve

Language: Английский

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Illuminating microalgal biofilms using advanced photonic imaging techniques

Algal Research, Journal Year: 2025, Volume and Issue: unknown, P. 104018 - 104018

Published: March 1, 2025

Language: Английский

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Metagenomics and plant-microbe symbioses: Microbial community dynamics, functional roles in carbon sequestration, nitrogen transformation, sulfur and phosphorus mobilization for sustainable soil health

Biotechnology Advances, Journal Year: 2025, Volume and Issue: 82, P. 108580 - 108580

Published: April 15, 2025

Language: Английский

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Is the Gelatinous Matrix of Nassellaria (Radiolaria) a Strategy for Coping With Oligotrophy?

Environmental Microbiology, Journal Year: 2025, Volume and Issue: 27(5)

Published: May 1, 2025

Radiolaria are heterotrophic protists abundant in the world's oceans, playing important roles biogeochemical cycles. Some host photosynthetic algae, contributing to primary production. Such mixotrophic behaviour is believed explain their success oligotrophic waters, notably Collodaria, exclusively radiolarians within a gelatinous matrix. Yet, understanding of ecology limited direct observations, as they have so far withstood reproduction culture and lack genome data. Sampling California Current revealed abundant, rarely observed Nassellaria genus Phlebarachnium, characterised live Phylogenetic reconstruction ribosomal DNA suggests that distantly related lineages independently developed ability produce matrix ~150 million years ago. By matching physical samples with genetic data, we identified these organisms global datasets, revealing affinity for conditions. Co-occurrence networks showed distinct biogeography patterns matrix-forming compared those without. Results suggest might be an adaptation increasing effective volume, favouring prey capture, creating larger microenvironment symbionts, thus promoting ecological nutrient-depleted waters. This study advances our poorly known eukaryotic groups, specifically when evolution occurs across lineages.

Language: Английский

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DmdA‐independent lag phase shortening in Phaeobacter inhibens bacteria under stress conditions

FEBS Journal, Journal Year: 2025, Volume and Issue: unknown

Published: May 3, 2025

Bacteria can shorten their lag phase by using methyl groups from compounds like dimethylsulfoniopropionate (DMSP), which are incorporated into cellular components via the methionine cycle. However, role of specific synthases in this process is not fully understood. Using transcriptomics, genetics, and biochemical assays, we investigated involved shortening Phaeobacter inhibens . We focused on a cobalamin‐dependent synthase (MetH)‐like complex encoded three genes: betaine‐homocysteine S‐methyltransferase ( bmt ), cobalamin‐binding protein cbp an intermediate carrier PGA1_c16040 ). Expression profiling revealed transcriptional decoupling among these genes. Deleting disrupted response to DMSP. Functional assays showed that Bmt directly produce DMSP betaine, independent tetrahydrofolate (THF) or cobalamin. Interestingly, under stress conditions, occurred even absence demethylase DmdA, primary demethylase. Under osmotic oxidative stress, expression increased significantly both suggesting alternative methylation route. This highlights as offering cost‐effective strategy for group assimilation. Our findings reveal novel stress‐responsive pathway synthesis demonstrate promoting bacterial adaptation accelerating phase.

Language: Английский

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Chlorella pyrenoidosa-Based Antibiotic Liposomal Gel Promotes Wound Healing by Scavenging Biofilm and Accelerating Regeneration

ACS Applied Materials & Interfaces, Journal Year: 2025, Volume and Issue: unknown

Published: May 9, 2025

The biofilm functions as a physical barrier for bacteria, enhancing their resistance to antibiotics and contributing recurrent infections. Therefore, the scavenging of biofilms has become an important strategy treating chronic In this study, we demonstrated that Chlorella pyrenoidosa (CP) downregulates adhesion genes Staphylococcus aureus inhibits formation. Through combination CP with antibiotic drug berberine hydrochloride (BH) stabilizers (Poloxamer 188 Poloxamer 407), developed biologically active hydrogel system, which termed BHLip@CP gel. Under laser irradiation, gel generated reactive oxygen species, assisted BH effectively inhibit formation in S. reduce production virulence factors. addition, accelerated wound healing infections by promoting angiogenesis skin regeneration. This study proposes innovative simultaneously eliminate bacterial promote via synergistic approach combines chemical photodynamic processes.

Language: Английский

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The bacterial Bmt methionine synthase is involved in lag phase shortening

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: June 21, 2024

Abstract Bacteria can shorten their lag phase by utilizing methyl groups from compounds such as dimethylsulfoniopropionate (DMSP). These are then incorporated into cellular building blocks via the methionine cycle. However, specific contribution of bacterial synthesis, which is critical for assimilating and incorporating groups, remains unclear. In this study, we employed transcriptomics, genetic manipulation biochemical assays to explore involvement synthesis in shortening using model marine bacterium Phaeobacter inhibens . We mapped expression profiles MetH-like synthase components—an enzyme complex that encoded three genes—in response DMSP during phase. Our findings revealed transcriptional decoupling genes. The deletion homocysteine-binding component complex, namely bmt , disrupted DMSP. Through heterologous gene product, show individual Bmt produces directly demethylating betaine vitro reveal a metabolic route was not previously described bacteria. Since does require tetrahydrofolate or cobalamin co-factors its potential act alone demethylase represents cost-effective shortcut group assimilation, could be specifically beneficial under limiting conditions. Indeed, stress conditions, allows cells This study enhances our understanding enzymatic mechanisms underlying shortening, revealing microbial adaptation strategies environmental

Language: Английский

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Sanitization of hydroponic farming facilities in Singapore: what, why, and how

Applied and Environmental Microbiology, Journal Year: 2024, Volume and Issue: 90(7)

Published: July 24, 2024

ABSTRACT This study performed microbial analysis of nutrient film technique (NFT) hydroponic systems on three indoor farms in Singapore (the “what”). To justify the necessity sanitizing systems, strong biofilm-forming bacteria were isolated from facility and investigated for their influence Salmonella colonization polyvinyl chloride (PVC) coupons solutions “why”). Finally, sanitization evaluated with both laboratory-scale field-scale tests “how”). As a result, microbiome composition NFT was found to be highly farm specific. The biofilm formers Corynebacterium tuberculostearicum C2 Pseudoxanthomonas mexicana C3 facilitate attachment PVC coupons. When forming dual-species biofilms, presence also significantly promoted growth ( P < 0.05). Compared hydrogen peroxide (H 2 O ) sodium percarbonate (SPC), hypochlorite (NaOCl) exhibited superior efficacy removal. At 50 ppm, NaOCl reduced Typhimurium, C2, counts <1 log CFU/cm within 12 h, whereas neither 3% H nor 1% SPC achieved this effect. In operational concentration needed achieve elimination increased 500 likely due organic matter accumulated during crop cultivation greater persistence naturally formed multispecies biofilms. Sanitization using ppm h did not impede subsequent plant growth, but chlorination byproduct chlorate detected at high levels solution plants sanitized without rinsing. IMPORTANCE study’s significance lies first its elucidation farming systems. although mostly nonpathogenic, might serve as hotbed pathogen thus pose risk food safety. We explored tests. Of tested sanitizers, most effective economical option, one must note vital importance rinsing after NaOCl.

Language: Английский

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Algal exudates promote conjugation in marine Roseobacters

mBio, Journal Year: 2024, Volume and Issue: 15(10)

Published: Aug. 27, 2024

Horizontal gene transfer (HGT) is a pivotal mechanism driving bacterial evolution, conferring adaptability within dynamic marine ecosystems. Among HGT mechanisms, conjugation mediated by type IV secretion systems (T4SSs) plays central role in the ecological success of bacteria. However, conditions promoting events environment are not well-understood. Roseobacters, abundant bacteria commonly associated with algae, possess multitude T4SSs. Many Roseobacters heterotrophic that rely on algal secreted compounds to support their growth. These attract bacteria, facilitating colonization and attachment cells. Algae metabolites bring into close proximity, potentially HGT. Investigation across various revealed exudates indeed enhance plasmid through conjugation. While do influence transcription conjugative machinery genes, they promote attachment, stabilizing proximity Notably, under where less advantageous, impact reduced. findings suggest algae primarily fostering highlight importance studying context algal-bacterial interactions.

Language: Английский

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Spirulina-Based Multispecies Phototrophic Biofilm Anodic Biocatalyst Endures a Prolonged Dark Phase within Light–Dark Cycle Operations and Enhances Anodic Performance in Biophotovoltaic Cells

ACS ES&T Engineering, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 15, 2024

Phototrophs with heterotrophic bacterial consortium as an electrode biocatalyst are emerging concept for developing naturally sustained biophotovoltaic systems. Herein, Spirulina subsalsa-based mixed community anodic catalyst in a microbial fuel cell (MFC) setup ferricyanide catholyte 78 days light–dark (16–8 h) cycle-based operation was investigated. The biofilm developed inducted recalcitrant comprising Halomonas, Alcanivorax, Pelagibacterium, and Rhizobiales the major genera. In extended dark phase (9 days) within cyclic operation, sequential shift of metabolism from photosynthesis to fermentative states increased population were observed. Under direct contact graphite anode, initiated oscillating open-circuit potentials MFC response circadian trend. delivered maxima 587 μW m–2 418 (at 10 kΩ) under corresponding phases, respectively. potential shifted more negative value, reaching −415.5 mV starvation period. Analyses reaction rates (extracted Tafel plots), corrosion potential, current, polarization resistance, residual redox charges voltammograms) performed understand processes. Two peaks 0.6 V (irreversible, extracellular) 0.26 (reversible, cell-surface attached) attributed mediation this process. Additionally, catholyte-diffused interacts biofilm, getting trapped matrix polymeric structures, thus preventing sudden cytotoxic elimination cells promoting oxidative charge accumulation over its surface, improving potential. Rapid respiratory oxygen consumption, biofilm's structural reorganization, ferricyanide's chemical speciation inside primary factors that govern performance biofuel during prolonged operations. critical findings unveiled through study advance our understanding resilience phototroph-based multispecies catalysts devices long-term

Language: Английский

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