共查询到20条相似文献,搜索用时 15 毫秒
1.
Multi-species biofilm modeling has been used for many years to understand the interactions between species in different biofilm systems, but the complex symbiotic relationship between species is sometimes overlooked, because models do not always include all relevant species and components. In this paper, we develop and use a mathematical model to describe a model biofilm system that includes autotrophic and heterotrophic bacteria and the key products produced by the bacteria. The model combines the methods of earlier multi-species models with a multi-component biofilm model in order to explore the interaction between species via exchange of soluble microbial products (SMP). We show that multiple parameter sets are able to describe the findings of experimental studies, and that heterotrophs growing on autotrophically produced SMP may pursue either r- or K-strategies to sustain themselves when SMP is their only substrate. We also show that heterotrophs can colonize some distance from the autotrophs and still be sustained by autotrophically produced SMP. This work defines the feasible range of parameters for utilization of SMP by heterotrophs and the nature of the interactions between autotrophs and heterotrophs in multi-species, multi-component biofilms. 相似文献
2.
The enormous diversity of culturable bacteria within the oral microbial community coupled with experimental accessibility renders the human oral cavity a valuable model to investigate genome-genome interactions. The complex interactions of oral bacteria result in the formation of biofilms on the surfaces of the oral cavity. One mechanism thought to be important in biofilm formation is the coaggregation of bacterial partners. In this paper, we examine the role of coaggregation in oral biofilms and develop protocols to elucidate the spatial organization of bacterial species retained within oral biofilms. To explore these issues, we have employed two experimental systems: the saliva-coated flowcell and the retrievable enamel chip. From flowcell studies, we have determined that coaggregation can greatly influence the ability of an oral bacterial species to grow and be retained within the developing biofilm. To examine the spatial architecture of oral biofilms, fluorescent in situ hybridization protocols were developed that successfully target specific members of the oral microbial community. Together, these approaches provide insight into the development of oral biofilms and expand our understanding of genome-genome interactions. 相似文献
3.
Coaggregation is the specific recognition and adherence of genetically distinct microorganisms. Because most biofilms are polymicrobial communities, there is potential for coaggregation to play an integral role in spatiotemporal biofilm development and the moderation of biofilm community composition. However, understanding of the mechanisms contributing to coaggregation and the relevance of coaggregation to biofilm ecology is at a very early stage. The purpose of this review is to highlight recent advances in the understanding of microbial coaggregation within different environments and to describe the possible ecological ramifications of such interactions. Bacteria that coaggregate with many partner species within different environments will be highlighted, including oral streptococci and oral bridging organisms such as fusobacteria, as well as the freshwater sphingomonads and acinetobacters. Irrespective of environment, it is proposed that coaggregation is essential for the orchestrated development of multi-species biofilms. 相似文献
4.
Henriette L. Røder Nanna M. C. Olsen Marvin Whiteley Mette Burmølle 《Environmental microbiology》2020,22(1):5-16
The importance of microbial biofilms has been well-recognized for several decades, and focus is now shifting towards investigating multispecies biofilm communities rather than mono- or dual-species biofilms. Therefore, the demand for techniques that provide a sufficient amount of information at adequate resolution is increasing. One major challenge for multispecies studies is that diversity and spatial organization often lead to a high degree of spatial and chemical heterogeneity. Many current approaches do not account for such heterogeneity and therefore only provide average information (−omics techniques in particular), which could obscure important information about the community. Here, we bring attention to the issues of heterogeneity when analysing synthetic multi-species biofilms, in vitro, and the importance of multi-scale approaches. We provide an overview of current and newer approaches that can be applied to biofilm communities, in order to elucidate interactions at the appropriate scale. 相似文献
5.
Reproduction is one of the requirements for evolution and a defining feature of life. Yet, across the tree of life, organisms reproduce in many different ways. Groups of cells (e.g., multicellular organisms, colonial microbes, or multispecies biofilms) divide by releasing propagules that can be single-celled or multicellular. What conditions determine the number and size of reproductive propagules? In multicellular organisms, existing theory suggests that single-cell propagules prevent the accumulation of deleterious mutations (e.g., cheaters). However, groups of cells, such as biofilms, sometimes contain multiple metabolically interdependent species. This creates a reproductive dilemma: small daughter groups, which prevent the accumulation of cheaters, are also unlikely to contain the species diversity that is required for ecological success. Here, we developed an individual-based, multilevel selection model to investigate how such multi-species groups can resolve this dilemma. By tracking the dynamics of groups of cells that reproduce by fragmenting into smaller groups, we identified fragmentation modes that can maintain cooperative interactions. We systematically varied the fragmentation mode and calculated the maximum mutation rate that communities can withstand before being driven to extinction by the accumulation of cheaters. We find that for groups consisting of a single species, the optimal fragmentation mode consists of releasing single-cell propagules. For multi-species groups we find various optimal strategies. With migration between groups, single-cell propagules are favored. Without migration, larger propagules sizes are optimal; in this case, group-size dependent fissioning rates can prevent the accumulation of cheaters. Our work shows that multi-species groups can evolve reproductive strategies that allow them to maintain cooperative interactions. 相似文献
6.
7.
Bacterial coaggregation: an integral process in the development of multi-species biofilms 总被引:1,自引:0,他引:1
Coaggregation is a process by which genetically distinct bacteria become attached to one another via specific molecules. Cumulative evidence suggests that such adhesion influences the development of complex multi-species biofilms. Once thought to occur exclusively between dental plaque bacteria, there are increasing reports of coaggregation between bacteria from other biofilm communities in several diverse habitats. A general role for coaggregation in the formation of multi-species biofilms is discussed. 相似文献
8.
AIMS: The objective of this study was to investigate the antagonistic interactions between bacteriocin-producing enteric bacteria in dual species biofilms and the interspecies interactions correlated with sensitivity to biocides. METHODS AND RESULTS: When compared with their single species counterparts, the dual species biofilms formed by bacteriocin-producing strains exhibited a decrease in biofilm size and an increase in sensitivity to the antimicrobial agents hypochlorite, triclosan and benzalkonium chloride. The five dual species biofilms studied all resulted in biofilms containing a mixture of the two strains. This was attributed to the spatial distribution of cells within the biofilm, with each strain forming its own microcolonies. The production of a bacteriocin also gave a strain a competitive advantage when interacting with a bacteriocin-sensitive strain within a biofilm, both in gaining a foothold in a new environment and in preventing the colonization of a potential competitor into a pre-established biofilm. CONCLUSIONS: It was concluded that bacteriocins might be used specifically for interacting with competing strains within a biofilm, as opposed to a planktonic, environment. SIGNIFICANCE AND IMPACT OF THE STUDY: Unlike planktonically grown bacteriocin-producing populations, where one strain will always be out-competed, bacteriocin-producing and bacteriocin-sensitive strains can coexist in biofilm communities, clearly demonstrating major differences between biofilm and planktonic competition. This paper highlights the importance of bacteriocin production in the development of biofilm communities. 相似文献
9.
Chronic wound infections are typically polymicrobial; however, most in vivo studies have focused on monospecies infections. This project was designed to develop an in vivo, polymicrobial, biofilm-related, infected wound model in order to study multispecies biofilm dynamics and in relation to wound chronicity. Multispecies biofilms consisting of both Gram negative and Gram positive strains, as well as aerobes and anaerobes, were grown in vitro and then transplanted onto the wounds of mice. These in vitro-to-in vivo multi-species biofilm transplants generated polymicrobial wound infections, which remained heterogeneous with four bacterial species throughout the experiment. We observed that wounded mice given multispecies biofilm infections displayed a wound healing impairment over mice infected with a single-species of bacteria. In addition, the bacteria in the polymicrobial wound infections displayed increased antimicrobial tolerance in comparison to those in single species infections. These data suggest that synergistic interactions between different bacterial species in wounds may contribute to healing delays and/or antibiotic tolerance. 相似文献
10.
11.
Jackson JA Pleass RJ Cable J Bradley JE Tinsley RC 《International journal for parasitology》2006,36(13):1341-1349
Macroparasites of vertebrates usually occur in multi-species communities, producing infections whose outcome in individual hosts or host populations may depend on the dynamics of interactions amongst the different component species. Within a single co-infection, competition can occur between conspecific and heterospecific parasite individuals, either directly or via the host's physiological and immune responses. We studied a natural single-host, multi-parasite model infection system (polystomes in the anuran Xenopus laevis victorianus) in which the parasite species show total interspecific competitive exclusion as adults in host individuals. Multi-species infection experiments indicated that competitive outcomes were dependent on infection species composition and strongly influenced by the intraspecific genetic identity of the interacting organisms. Our results also demonstrate the special importance of temporal heterogeneity (the sequence of infection by different species) in competition and co-existence between parasite species and predict that developmental plasticity in inferior competitors, and the induction of species-specific host resistance, will partition the within-host-individual habitat over time. We emphasise that such local (within-host) context-dependent processes are likely to be a fundamental determinant of population dynamics in multi-species parasite assemblages. 相似文献
12.
Importance of canopy structure on photosynthesis in single- and multi-species assemblages of marine macroalgae 总被引:4,自引:0,他引:4
Plant communities utilize available irradiance with different efficiency depending not only on their photosynthetic characteristics but also on the canopy structure and density. The importance of canopy structure are well studied in terrestrial plant communities but poorly studied in aquatic plant communities. The objective of this study was to evaluate macroalgal community photosynthesis in artificial constructed communities of one to four species with different morphologies along a range of leaf (i.e.=thallus) area densities. In a laboratory set-up we measured net photosynthesis and dark respiration in constructed assemblages of macroalgae, excluding effects other than photosynthesis of individual tissue and distribution of photons in the canopy from influencing metabolism. We hypothezised that 1) canopy structure determines the actual rates of photosynthesis relative to the optimal rates and 2) multi-species communities attain higher maximum photosynthetic rates than single species communities. We found that differences in canopy structure outweighed large differences in tissue photosynthesis resulting in relatively similar maximum community photosynthetic rates among the different single and multi-species assemblages (20.1–40.5 μmol O2 m−2 s−1). Canopy structure influenced community photosynthesis both at low and high leaf area densities because it determines the ability of macroalgae to use the photosynthetic potential of their individual tissues. Due to an averaging effect the photosynthetic rate at high leaf area density was more similar among multi-species community than among single-species communities. Multi-species communities had, on average, a slightly higher photosynthetic production than expected from photosynthesis of single species communities. Moreover multi-species communities were capable of exposing new tissue to irradiance up to high densities thereby avoiding a decrease in net photosynthesis. This finding suggests that multi-species communities may be able to maintain higher biomass per unit ground area than single-species communities. 相似文献
13.
Assembly rules provide a tool to simplify the complexity of interactions that shape ecological communities. The prime objective of this study was to examine an experimental approach to the study of assembly rules, and also to examine some premises of such rules. We investigated possible assembly rules pertaining to interactions among seeds and seedlings during germination. An experiment was made on randomly sampled species pairs from a larger pool of grassland species differing in seed size, and included treatments altering the presence and ordering of species arrival (seed sowing), and nutrient level. The basic premises suggested for the rules were that a congruence exists among species in the response of germination: (i) to environmental variation; and (ii) to the presence of other species. Both of these premises were supported. In nine of 11 investigated species, germination responded to sowing treatments. Germination was commonly enhanced in species sown after another species. Inclusion of a third species did not alter two-species interactions during germination, indicating that increasing complexity may not change fundamental rules of assembly. Seed size had no systematic effect on how species behaved in the germination treatments. We suggest that assembly rules during recruitment may be useful for understanding pattern and process in plant communities, and that a method with random sampling of two-species interactions is useful to handle the complexity of multi-species communities. However, studies under field conditions are necessary to make further advances in the formulation of realistic assembly rules. 相似文献
14.
Ethan Kolderman Deepti Bettampadi Derek Samarian Scot E. Dowd Betsy Foxman Nicholas S. Jakubovics Alexander H. Rickard 《PloS one》2015,10(5)
The amino acid L-arginine inhibits bacterial coaggregation, is involved in cell-cell signaling, and alters bacterial metabolism in a broad range of species present in the human oral cavity. Given the range of effects of L-arginine on bacteria, we hypothesized that L-arginine might alter multi-species oral biofilm development and cause developed multi-species biofilms to disassemble. Because of these potential biofilm-destabilizing effects, we also hypothesized that L-arginine might enhance the efficacy of antimicrobials that normally cannot rapidly penetrate biofilms. A static microplate biofilm system and a controlled-flow microfluidic system were used to develop multi-species oral biofilms derived from pooled unfiltered cell-containing saliva (CCS) in pooled filter-sterilized cell-free saliva (CFS) at 37oC. The addition of pH neutral L-arginine monohydrochloride (LAHCl) to CFS was found to exert negligible antimicrobial effects but significantly altered biofilm architecture in a concentration-dependent manner. Under controlled flow, the biovolume of biofilms (μm3/μm2) developed in saliva containing 100-500 mM LAHCl were up to two orders of magnitude less than when developed without LAHCI. Culture-independent community analysis demonstrated that 500 mM LAHCl substantially altered biofilm species composition: the proportion of Streptococcus and Veillonella species increased and the proportion of Gram-negative bacteria such as Neisseria and Aggregatibacter species was reduced. Adding LAHCl to pre-formed biofilms also reduced biovolume, presumably by altering cell-cell interactions and causing cell detachment. Furthermore, supplementing 0.01% cetylpyridinium chloride (CPC), an antimicrobial commonly used for the treatment of dental plaque, with 500 mM LAHCl resulted in greater penetration of CPC into the biofilms and significantly greater killing compared to a non-supplemented 0.01% CPC solution. Collectively, this work demonstrates that LAHCl moderates multi-species oral biofilm development and community composition and enhances the activity of CPC. The incorporation of LAHCl into oral healthcare products may be useful for enhanced biofilm control. 相似文献
15.
Jonas Kuppler Tobias Grasegger Birte Peters Susanne Popp Martin Schlager Robert R. Junker 《Arthropod-Plant Interactions》2017,11(4):561-566
Appropriate sampling effort of interaction networks is necessary to extract robust indices describing the structure of species interactions. Here we show that time-invariant variation in the composition and diversity of interaction partners of plant individuals of the same species explains volatility in aggregate network statistics due to undersampling. Within a multi-species pollinator–plant interaction matrix, we replaced the interactions observed on multiple individuals of a single plant species (Sinapis arvensis, pooled interactions) with the plant–insect interactions observed on a single plant individual. In the resampling approach, we considered the interactions of 1 to 84 S. arvensis individuals in different combinations. For each resampled network, several commonly applied aggregated statistics were calculated to test how intraspecific variation affects the properties of a multi-species network. Our results showed that aggregate statistics are sensitive towards qualitative and quantitative intraspecific variation of flower–visitor interactions within a multi-species network, which may affect the ecological interpretation about the properties of a community. These findings challenge the robustness of commonly applied network indices, confirm the urge for a sufficient and representative sampling of interactions, and emphasize the significance of intraspecific variation in the context of communities and networks. 相似文献
16.
Enberg K Fowler MS Ranta E 《Proceedings. Biological sciences / The Royal Society》2006,273(1600):2491-2499
Understanding the effects of population management on the community a target species belongs to is of key importance for successful management. It is known that the removal or extinction of a single species in a community may lead to extinctions of other community members. In our study, we assess the impacts of population management on competitive communities, studying the response of both locally stable and unstable communities of varying size (between four and 10 species) to three different management strategies; harvesting of a target species, harvesting with non-targeted catch, and stocking of the target species. We also studied the consequences of selecting target species with different relative abundances, as well as the effects of varying environmental conditions.We show here how the effects of management in competitive communities extend far beyond the target population. A crucial role is played by the underlying stability properties of the community under management. In general, locally unstable communities are more vulnerable to perturbation through management. Furthermore, the community response is shown to be sensitive to the relative density of the target species. Of considerable interest is the result that even a small (2.5%) increase in the population size of the target species through stocking may lead to extinction of other community members. These results emphasize the importance of considering and understanding multi-species interactions in population management. 相似文献
17.
A model biofilm, formed of multiple species from environmental drinking water, including opportunistic pathogens, was created to explore the tolerance of multi-species biofilms to chlorine levels typical of water-distribution systems. All species, when grown planktonically, were killed by concentrations of chlorine within the World Health Organization guidelines (0.2–5.0?mg?l?1). Higher concentrations (1.6–40-fold) of chlorine were required to eradicate biofilm populations of these strains, ~70% of biofilms tested were not eradicated by 5.0?mg?l?1 chlorine. Pathogenic bacteria within the model multi-species biofilms had an even more substantial increase in chlorine tolerance; on average ~700–1100?mg?l?1 chlorine was required to eliminate pathogens from the biofilm, 50–300-fold higher than for biofilms comprising single species. Confocal laser scanning microscopy of biofilms showed distinct 3D structures and multiple cell morphologies and arrangements. Overall, this study showed a substantial increase in the chlorine tolerance of individual species with co-colonization in a multi-species biofilm that was far beyond that expected as a result of biofilm growth on its own. 相似文献
18.
Enrichment versus biofilm culture: a functional and phylogenetic comparison of polycyclic aromatic hydrocarbon-degrading microbial communities 总被引:1,自引:0,他引:1
The effect that culture methods have on the diversity of degradative microbial communities is not well understood. We compared conventional batch enrichment with a biofilm culture method for the isolation of polycyclic aromatic hydrocarbon (PAH)-degrading microbial communities from a PAH-contaminated soil. The two methods were assessed by comparing: (i) the diversity of culturable bacteria; (ii) the diversity of PAH-catabolic genes in isolated bacteria; (iii) the inter- and intraspecific diversity of active PAH-catabolic gene classes; (iv) the diversity of bacteria present in 16S rRNA gene libraries generated from RNA extracted from the two communities and soil; and (v) the estimated diversity of active bacteria in the soil and culture systems. Single-strand conformation polymorphism analysis showed that the biofilm culture yielded 36 bacterial and two fungal species compared with 12 bacterial species from the enrichment culture. Application of accumulation and non-parametric estimators to clone libraries generated from 16S rRNA confirmed that the biofilm community contained greater diversity. Sequencing of clones showed that only species from the Proteobacteria were active in the enrichment culture, and that these species were expressing an identical nahAc-like naphthalene dioxygenase. 16S rRNA clones generated from the biofilm community indicated that species from the Cytophaga/Flavobacterium, high G+C bacteria and Proteobacteria were active at the time of sampling, expressing cndA-, nahAc- and phnAc-like naphthalene dioxygenases. The diversity of active species in the biofilm culture system closely matched that in the PAH-contaminated source soil. The results of this study showed that biofilm culture methods are more appropriate for the study of community-level interactions in PAH-degrading microbial communities. The study also indicated that cultivation of microbial communities on solid media might be the primary source of bias in the recovery of diverse species. 相似文献
19.
Goodnight CJ 《Philosophical transactions of the Royal Society of London. Series B, Biological sciences》2011,366(1569):1401-1409
A metacommunity can be defined as a set of communities that are linked by migration, and extinction and recolonization. In metacommunities, evolution can occur not only by processes that occur within communities such as drift and individual selection, but also by among-community processes, such as divergent selection owing to random differences among communities in species composition, and group and community-level selection. The effect of these among-community-level processes depends on the pattern of migration among communities. Migrating units may be individuals (migrant pool model), groups of individuals (single-species propagule pool model) or multi-species associations (multi-species propagule pool model). The most interesting case is the multi-species propagule pool model. Although this pattern of migration may a priori seem rare, it becomes more plausible in small well-defined 'communities' such as symbiotic associations between two or a few species. Theoretical models and experimental studies show that community selection is potentially an effective evolutionary force. Such evolution can occur either through genetic changes within species or through changes in the species composition of the communities. Although laboratory studies show that community selection can be important, little is known about how important it is in natural populations. 相似文献
20.
David García-Callejas Oscar Godoy Lisa Buche María Hurtado Jose B. Lanuza Alfonso Allen-Perkins Ignasi Bartomeus 《Ecology letters》2023,26(6):831-842
Theory posits that the persistence of species in ecological communities is shaped by their interactions within and across trophic guilds. However, we lack empirical evaluations of how the structure, strength and sign of biotic interactions drive the potential to coexist in diverse multi-trophic communities. Here, we model community feasibility domains, a theoretically informed measure of multi-species coexistence probability, from grassland communities comprising more than 45 species on average from three trophic guilds (plants, pollinators and herbivores). Contrary to our hypothesis, increasing community complexity, measured either as the number of guilds or community richness, did not decrease community feasibility. Rather, we observed that high degrees of species self-regulation and niche partitioning allow for maintaining larger levels of community feasibility and higher species persistence in more diverse communities. Our results show that biotic interactions within and across guilds are not random in nature and both structures significantly contribute to maintaining multi-trophic diversity. 相似文献