Exopolysaccharides Producing Bacteria: A Review

Microorganisms, Journal Year: 2023, Volume and Issue: 11(6), P. 1541 - 1541

Published: June 9, 2023

Bacterial exopolysaccharides (EPS) are essential natural biopolymers used in different areas including biomedicine, food, cosmetic, petroleum, and pharmaceuticals also environmental remediation. The interest them is primarily due to their unique structure properties such as biocompatibility, biodegradability, higher purity, hydrophilic nature, anti-inflammatory, antioxidant, anti-cancer, antibacterial, immune-modulating prebiotic activities. present review summarizes the current research progress on bacterial EPSs properties, biological functions, promising applications various fields of science, industry, medicine, technology, well characteristics isolation sources EPSs-producing strains. This provides an overview latest advances study important industrial xanthan, cellulose, levan. Finally, limitations future directions discussed.

Language: Английский

---

Lighting the way: how the Vibrio fischeri model microbe reveals the complexity of Earth’s “simplest” life forms

Journal of Bacteriology, Journal Year: 2024, Volume and Issue: 206(5)

Published: May 2, 2024

ABSTRACT Vibrio ( Aliivibrio ) fischeri ’s initial rise to fame derived from its alluring production of blue-green light. Subsequent studies probe the mechanisms underlying this bioluminescence helped field discover phenomenon now known as quorum sensing. Orthologs quorum-sensing regulators (i.e., LuxR and LuxI) originally identified in V. were subsequently uncovered a plethora bacterial species, analogous pathways found yet others. Over past three decades, study microbe has greatly expanded unique role exclusive symbiont light organ Hawaiian bobtail squid, Euprymna scolopes . Buoyed by optically amenable host persistent insightful researchers who have applied novel cross-disciplinary approaches, developed into robust model for microbe-host associations. It contributed our understanding how bacteria experience respond specific, often fluxing environmental conditions which impact development their host. also deepened numerous microbial processes such motility chemotaxis, biofilm formation dispersal, competition, relevance specific genes context colonizing an animal Parallels these between studied pathogens are readily apparent, demonstrating functional conservation across diverse associations permitting reinterpretation “pathogenesis.” Collectively, advances built foundation microbiome positioned continue expand frontiers world inside animals.

Language: Английский

---

Vibrio fischeri : a model for host-associated biofilm formation

Journal of Bacteriology, Journal Year: 2024, Volume and Issue: 206(2)

Published: Jan. 25, 2024

ABSTRACT Multicellular communities of adherent bacteria known as biofilms are often detrimental in the context a human host, making it important to study their formation and dispersal, especially animal models. One such model is symbiosis between squid Euprymna scolopes bacterium Vibrio fischeri . Juvenile hatch aposymbiotically selectively acquire symbiont from natural seawater containing diverse environmental microbes. Successful pairing facilitated by ciliary movements that direct quiet zones on surface squid’s symbiotic light organ where V. forms small aggregate or biofilm. Subsequently, disperse enter organ, ultimately reaching colonizing deep crypt spaces. Although transient, critical for optimal colonization tightly controlled. In vitro studies have identified variety polysaccharides proteins comprise extracellular matrix. Some most well-characterized matrix factors include polysaccharide (SYP), cellulose polysaccharide, LapV adhesin. this review, we discuss these components, regulation, other less understood biofilm contributors. We also highlight what currently about dispersal aggregates host cues may promote it. Finally, briefly describe discoveries gleaned isolates. By unraveling complexities involved ’s control over begin understand how environment triggers transient unique relationship.

Language: Английский

---

The global regulation of c‐di‐GMP and cAMP in bacteria

mLife, Journal Year: 2024, Volume and Issue: 3(1), P. 42 - 56

Published: March 1, 2024

Abstract Nucleotide second messengers are highly versatile signaling molecules that regulate a variety of key biological processes in bacteria. The best‐studied examples cyclic AMP (cAMP) and bis‐(3′–5′)‐cyclic dimeric guanosine monophosphate (c‐di‐GMP), which both act as global regulators. Global regulatory frameworks c‐di‐GMP cAMP bacteria show several parallels but also significant variances. In this review, we illustrate the models two nucleotide messengers, compare different between cAMP, discuss mechanisms physiological significance cross‐regulation cAMP. responds to numerous signals dependent on great number metabolic enzymes, it regulates various signal transduction pathways through its huge effectors with varying activities. contrast, due limited quantity, enzymes major effector regulated at levels by diverse signals. performs function primarily controlling transcription large genes via receptor protein (CRP) most This review can help us understand how use typical effectively coordinate integrate processes, providing theoretical guidelines for future research.

Language: Английский

---

LitR and its quorum-sensing regulators modulate biofilm formation by Vibrio fischeri

Journal of Bacteriology, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 29, 2025

ABSTRACT Quorum sensing controls numerous processes ranging from the production of virulence factors to biofilm formation. Biofilms, communities bacteria that are attached one another and/or a surface, common in nature, and when they form, can produce quorum bacteria. One model system study biofilms is bacterium Vibrio fischeri , which forms promotes colonization its symbiotic host. Many promote V. formation vitro including symbiosis polysaccharide (SYP) cellulose, but role currently understudied. Recently, quorum-sensing-dependent transcription factor, LitR, was shown negatively influence context biofilm-overproducing strain. To better understand importance we identified conditions impact LitR on could be observed an otherwise wild-type strain then investigated roles upstream regulators phenotypes. In static conditions, regulators, autoinducer synthases LuxS AinS, contributed control over were both SYP cellulose dependent. shaking liquid AinS primarily modestly inhibited manner depended factor VpsR. These findings expand our understanding quorum-sensing pathway physiology illuminate negative mechanisms prevent robust by under laboratory conditions. IMPORTANCE key regulatory mechanism diverse phenotypes bacteria, . many microbes, has been formation, yet link between This fills knowledge gap identifying for sensing-controlled LuxS, inhibiting specific It also determined inhibits genes required biosynthesis. work thus expands complex regulation.

Language: Английский

---

pelD is required downstream of c-di-GMP for host specialization of Pseudomonas lurida

Research Square (Research Square), Journal Year: 2025, Volume and Issue: unknown

Published: March 21, 2025

Background The bacterial second messenger c-di-GMP is known to influence the formation of biofilms and thereby persistence pathogenic beneficial bacteria in hosts. A previous evolution experiment with Pseudomonas lurida MYb11, occasional symbiont nematode Caenorhabditis elegans, led emergence host-specialized variants elevated intracellular c-di-GMP. Thus far, molecular underpinnings c-di-GMP-mediated host specialization were unknown this symbiosis. Therefore, current study aimed at identifying candidate processes by combining transcriptomic functional genetic analyses. Results We found that MYb11 specialists differentially expressed genes related attachment, motility biofilm production, including pelD from pel gene cluster. deletion resulted reduced intra-host competitive fitness, lower numbers C. elegans loss biomass. Conclusion Our results identify as a previously key modulator symbiont-host associations acts downstream

Language: Английский

---

PelD is required downstream of c-di-GMP for host specialization of Pseudomonas lurida

BMC Microbiology, Journal Year: 2025, Volume and Issue: 25(1)

Published: April 16, 2025

Abstract Background The bacterial second messenger c-di-GMP is known to influence the formation of biofilms and thereby persistence pathogenic beneficial bacteria in hosts. A previous evolution experiment with Pseudomonas lurida MYb11, occasional symbiont nematode Caenorhabditis elegans , led emergence host-specialized variants elevated intracellular c-di-GMP. Thus far, molecular underpinnings c-di-GMP-mediated host specialization were unknown this symbiosis. Therefore, current study aimed at identifying candidate processes by combining transcriptomic functional genetic analyses. Results We found that MYb11 specialists differentially expressed genes related attachment, motility biofilm production, including pelD from pel gene cluster. deletion resulted reduced intra-host competitive fitness, lower numbers C. loss biomass. Conclusion Our results identify as a previously key modulator symbiont-host associations acts downstream

Language: Английский

---

A Label-Free Approach for Relative Spatial Quantitation of c-di-GMP in Microbial Biofilms

Analytical Chemistry, Journal Year: 2024, Volume and Issue: 96(21), P. 8308 - 8316

Published: May 16, 2024

Microbial biofilms represent an important lifestyle for bacteria and are dynamic three-dimensional structures. Cyclic dimeric guanosine monophosphate (c-di-GMP) is a ubiquitous signaling molecule that known to be tightly regulated with biofilm processes. While measurements of global levels c-di-GMP have proven valuable toward understanding the genetic control production, there need tools observe local changes production in We developed label-free method direct detection microbial colony using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI). applied this enteric pathogen Vibrio cholerae, marine symbiont V. fischeri, opportunistic Pseudomonas aeruginosa PA14 detected spatial temporal signal accompanied alterations factors synthesize degrade compound. further demonstrated how can simultaneously detect additional metabolites interest from single sample.

Language: Английский

---

Transcriptional pathways across colony biofilm models in the symbiont Vibrio fischeri

mSystems, Journal Year: 2023, Volume and Issue: 9(1)

Published: Dec. 21, 2023

Beneficial microbial symbionts that are horizontally acquired by their animal hosts undergo a lifestyle transition from free-living in the environment to associating with host tissues. In model symbiosis between Hawaiian bobtail squid and its symbiont

Language: Английский

---

A cyclic di‐GMP‐binding adaptor protein interacts with a N5‐glutamine methyltransferase to regulate the pathogenesis in Xanthomonas citri subsp. citri

Molecular Plant Pathology, Journal Year: 2024, Volume and Issue: 25(7)

Published: July 1, 2024

Abstract The second messenger cyclic diguanylate monophosphate (c‐di‐GMP) regulates a wide range of bacterial behaviours through diverse mechanisms and binding receptors. Single‐domain PilZ proteins, the most widespread abundant known c‐di‐GMP receptors in bacteria, act as trans ‐acting adaptor proteins that enable to control signalling pathways with high specificity. This study identifies single‐domain protein, XAC3402 (renamed N5MapZ), from phytopathogen Xanthomonas citri subsp. (Xcc), which modulates Xcc virulence by directly interacting methyltransferase HemK. Through yeast two‐hybrid, co‐immunoprecipitation immunofluorescent staining, we demonstrated N5MapZ HemK interact under both vitro vivo conditions, strength protein–protein interaction decreasing at concentrations. finding distinguishes other characterized it was previously enhances between those PilZs their protein partners. observation is further supported fact binding‐defective mutant R10A can inhibit methylation class 1 translation termination release factor PrfA. Additionally, found plays an important role pathogenesis, deletion hemK leads extensive phenotypic changes, including reduced citrus plants, decreased motility, production extracellular enzymes stress tolerance. Gene expression analysis has revealed HemK‐mediated pathway regulate multiple effector uncovering novel regulatory mechanism mediating PrfA via N5MapZ.

Language: Английский

---