Biofilms consist of microbial communities embedded in a 3D extracellular matrix. The matrix is composed of a complex array of extracellular polymeric substances (EPS) that contribute to the unique ...attributes of biofilm lifestyle and virulence. This ensemble of chemically and functionally diverse biomolecules is termed the ‘matrixome’. The composition and mechanisms of EPS matrix formation, and its role in biofilm biology, function, and microenvironment are being revealed. This perspective article highlights recent advances about the multifaceted role of the ‘matrixome’ in the development, physical–chemical properties, and virulence of biofilms. We emphasize that targeting biofilm-specific conditions such as the matrixome could lead to precise and effective antibiofilm approaches. We also discuss the limited knowledge in the context of polymicrobial biofilms, and the need for more in-depth analyses of the EPS matrix in mixed communities that are associated with many human infectious diseases.
The 'matrixome' is the inventory of currently known biomolecules (polysaccharides, nucleic acids, proteins, lipids, and lipoproteins) and their molecular, structural, and functional diversity associated with biofilm assembly, and its physicochemical and virulence attributes.The structural and biochemical properties of the matrixome provide the emergent properties of biofilms, including surface adhesion, spatial and chemical heterogeneities, synergistic/competitive polymicrobial interactions, antimicrobial recalcitrance, and biofilm virulence.Combinatorial treatment strategies are crucial to eradicate biofilms by targeting the functionally and structurally complex extracellular polymeric matrix and embedded microbial cells.Due to limited knowledge of the polymicrobial EPS matrix there is an urgent need for more experimental polymicrobial biofilm and in vivo mechanistic studies.
Bacterial biofilms are widely associated with persistent infections. High resistance to conventional antibiotics and prevalent virulence makes eliminating these bacterial communities challenging ...therapeutic targets. We describe here the fabrication of a nanoparticle-stabilized capsule with a multicomponent core for the treatment of biofilms. The peppermint oil and cinnamaldehyde combination that comprises the core of the capsules act as potent antimicrobial agents. An in situ reaction at the oil/water interface between the nanoparticles and cinnamaldehyde structurally augments the capsules to efficiently deliver the essential oil payloads, effectively eradicating biofilms of clinically isolated pathogenic bacteria strains. In contrast to their antimicrobial action, the capsules selectively promoted fibroblast proliferation in a mixed bacteria/mammalian cell system making them promising for wound healing applications.
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•Stable sewage nitrogen removal was obtained in a PNA-SBBR at low temperatures.•Microbial community structure in the PNA biofilm system remained reasonably stable.•Psychrotolerant ...microbes were enriched at low temperature, improving system stability.•Increased secretion of TB-EPS favored the stable nitrogen removal at low temperatures.
Stable sewage nitrogen removal with nitrogen removal efficiency of 87.5 ± 2.2% was achieved in a partial nitrification-anammox (PNA) biofilm system at low temperatures (12.8–16.3 °C). High-throughput sequencing analysis indicated that the microbial community structure in the sequencing batch biofilm reactor (SBBR) remained reasonably stable. Candidatus Brocadia was the only detected anammox genus and remained stable at 0.3–0.5%. Some psychrotolerant microorganisms that could secrete cryoprotective extracellular polymeric substances (EPS), including Flavobacterium and Thermomonas, were enriched at low temperatures. This could be conducive to the stable operation of the PNA-SBBR. Moreover, according to the EPS composition and characteristics analysis, the secretion of tightly-bound EPS that bound to the cell surface containing plentiful protein was stimulated at low temperatures, further improving the system stability. Overall, the reasonably stable microbial community structure, enrichment of psychrotolerant microorganisms, and increased secretion of EPS could play important roles for stable sewage nitrogen removal at low temperatures.
Biofilm-based fermentation has great potential, as it possesses inherent characteristics such as self-immobilization, high resistance to reactants, and long-term activity. This forum focuses on ...research targets for promoting biofilm engineering to maximize the beneficial features of biofilms and to effectively utilize them in biofilm-mediated fermentation.
Biofilm-based fermentation has great potential, as it possesses inherent characteristics such as self-immobilization, high resistance to reactants, and long-term activity. This forum focuses on research targets for promoting biofilm engineering to maximize the beneficial features of biofilms and to effectively utilize them in biofilm-mediated fermentation.
species are fungal pathogens known for their ability to cause superficial and systemic infections in the human host. These pathogens are able to persist inside the host due to the development of ...pathogenicity and multidrug resistance traits, often leading to the failure of therapeutic strategies. One specific feature of
species pathogenicity is their ability to form biofilms, which protects them from external factors such as host immune system defenses and antifungal drugs. This review focuses on the current threats and challenges when dealing with biofilms formed by
, and
, highlighting the differences between the four species. Biofilm characteristics depend on the ability of each species to produce extracellular polymeric substances (EPS) and display dimorphic growth, but also on the biofilm substratum, carbon source availability and other factors. Additionally, the transcriptional control over processes like adhesion, biofilm formation, filamentation, and EPS production displays great complexity and diversity within pathogenic yeasts of the
genus. These differences not only have implications in the persistence of colonization and infections but also on antifungal resistance typically found in
biofilm cells, potentiated by EPS, that functions as a barrier to drug diffusion, and by the overexpression of drug resistance transporters. The ability to interact with different species in
biofilms is also a key factor to consider when dealing with this problem. Despite many challenges, the most promising strategies that are currently available or under development to limit biofilm formation or to eradicate mature biofilms are discussed.
Although plastic is ubiquitous in marine systems, our current knowledge of transport mechanisms is limited. Much of the plastic entering the ocean sinks; this is intuitively obvious for polymers such ...as polystyrene (PS), which have a greater density than seawater, but lower density polymers like polyethylene (PE) also occur in sediments. Biofouling can cause large plastic objects to sink, but this phenomenon has not been described for microplastics <5 mm. We incubated PS and PE microplastic particles in estuarine and coastal waters to determine how biofouling changes their sinking behavior. Sinking velocities of PS increased by 16% in estuarine water (salinity 9.8) and 81% in marine water (salinity 36) after 6 weeks of incubation. Thereafter sinking velocities decreased due to lower water temperatures and reduced light availability. Biofouling did not cause PE to sink during the 14 weeks of incubation in estuarine water, but PE started to sink after six weeks in coastal water when sufficiently colonized by blue mussels Mytilus edulis, and its velocity continued to increase until the end of the incubation period. Sinking velocities of these PE pellets were similar irrespective of salinity (10 vs. 36). Biofilm composition differed between estuarine and coastal stations, presumably accounting for differences in sinking behavior. We demonstrate that biofouling enhances microplastic deposition to marine sediments, and our findings should improve microplastic transport models.
The clinical impact of bacterial biofilms Høiby, Niels; Ciofu, Oana; Johansen, Helle Krogh ...
International journal of oral science,
04/2011, Letnik:
3, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Bacteria survive in nature by forming biofilms on surfaces and probably most, if not all, bacteria （and fungi） are capable of forming biofilms. A biofilm is a structured consortium of bacteria ...embedded in a self-produced polymer matrix consisting of polysaccharide, protein and extracellular DNA. Bacterial biofilms are resistant to antibiotics, disinfectant chemicals and to phagocytosis and other components of the innate and adaptive inflammatory defense system of the body. It is known, for example, that persistence of staphylococcal infections related to foreign bodies is due to biofilm formation. Likewise, chronic Pseudomonas aeruginosa lung infections in cystic fibrosis patients are caused by biofilm growing mucoid strains. Gradients of nutrients and oxygen exist from the top to the bottom of biofilms and the bacterial cells located in nutrient poor areas have decreased metabolic activity and increased doubling times. These more or less dormant cells are therefore responsible for some of the tolerance to antibiotics. Biofilm growth is associated with an increased level of mutations. Bacteria in biofilms communicate by means of molecules, which activates certain genes responsible for production of virulence factors and, to some extent, biofilm structure. This phenomenon is called quorum sensing and depends upon the concentration of the quorum sensing molecules in a certain niche, which depends on the number of the bacteria. Biofilms can be prevented by antibiotic prophylaxis or early aggressive antibiotic therapy and they can be treated by chronic suppressive antibiotic therapy. Promising strategies may include the use of compounds which can dissolve the biofilm matrix and quorum sensing inhibitors, which increases biofilm susceptibility to antibiotics and phagocytosis.
Attachment of microorganisms to food contact surfaces and the subsequent formation of biofilms may cause equipment damage, food spoilage and even diseases. Mixed-species biofilms are ubiquitous in ...the food industry and they generally exhibit higher resistance to disinfectants and antimicrobials compared to single-species biofilms. The physiology and metabolic activity of microorganisms in mixed-species biofilms are however rather complicated to study, and despite targeted research efforts, the potential role of mixed-species biofilms in food industry is still rather unexplored. In this review, we summarize recent studies in the context of bacterial social interactions in mixed-species biofilms, resistance to disinfectants, detection methods, and potential novel strategies to control the formation of mixed-species biofilms for enhanced food safety and food quality.
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•Highly dynamic multifunctional biofilm formed on fiber surfaces of the O2-MBfR.•The MBfR achieved high and simultaneous organics and nitrogen removal at HRT of 7.68 h.•DO variation ...induced the biofilm formation with aerobic, anoxic, and anaerobic layers.•Nitrification and aerobic denitrification in aerobic biofilm achieved organics and nitrogen removal.•Partial nitrification and anaerobic denitrification exist in aerobic-anoxic-anaerobic biofilm.
A bench-scale oxygen-based membrane biofilm reactor (O2-MBfR) was used to treat greywater for organics and nitrogen removal. Highly dynamic multifunctional biofilm formed on fiber surfaces of the O2-MBfR. With an organics loading up to 4.26 g COD/m2-day, the MBfR successfully achieved simultaneous organics and nitrogen reduction, with average removal ratios of 95% for total chemical oxygen demand (TCOD), 98% for linear alkylbenzene sulfonates (LAS), and 99% for inorganic nitrogen (InON). Increasing feed loading rates led to the gradually decrease of dissolved oxygen (DO) concentration from 1.67 to 0.37 mg/L in the reactor, inducing the formation of complex biofilm containing distinct aerobic, aerobic-anoxic, and aerobic-anoxic-anaerobic layers; these all contributed to the simultaneous removal of both organics and nitrogen in MBfR. Mechanisms of organics and nitrogen removal included nitrification and aerobic denitrification in aerobic biofilm, partial nitrification in the aerobic-anoxic biofilm, and partial nitrification and anaerobic denitrification in the aerobic-anoxic-anaerobic biofilm due to the co-existence of multifarious functional microorganisms in the O2-MBfR. This study lays the foundation of process optimization and cost-cutting for the practical application of O2-MBfR for greywater treatment.
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