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1.
BMC Microbiol ; 23(1): 68, 2023 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-36918804

RESUMO

At particular stages during their life cycles, fungi use multiple strategies to form specialized structures to survive unfavorable environmental conditions. These strategies encompass sporulation, as well as cell-wall melanization, multicellular tissue formation or even dimorphism. The resulting structures are not only used to disperse to other environments, but also to survive long periods of time awaiting favorable growth conditions. As a result, these specialized fungal structures are part of the microbial seed bank, which is known to influence the microbial community composition and contribute to the maintenance of diversity. Despite the importance of the microbial seed bank in the environment, methods to study the diversity of fungal structures with improved resistance only target spores dispersing in the air, omitting the high diversity of these structures in terms of morphology and environmental distribution. In this study, we applied a separation method based on cell lysis to enrich lysis-resistant fungal structures (for instance, spores, sclerotia, melanized yeast) to obtain a proxy of the composition of the fungal seed bank. This approach was first evaluated in-vitro in selected species. The results obtained showed that DNA from fungal spores and from yeast was only obtained after the application of the enrichment method, while mycelium was always lysed. After validation, we compared the diversity of the total and lysis-resistant fractions in the polyextreme environment of the Salar de Huasco, a high-altitude athalassohaline wetland in the Chilean Altiplano. Environmental samples were collected from the salt flat and from microbial mats in small surrounding ponds. Both the lake sediments and microbial mats were dominated by Ascomycota and Basidiomycota, however, the diversity and composition of each environment differed at lower taxonomic ranks. Members of the phylum Chytridiomycota were enriched in the lysis-resistant fraction, while members of the phylum Rozellomycota were never detected in this fraction. Moreover, we show that the community composition of the lysis-resistant fraction reflects the diversity of life cycles and survival strategies developed by fungi in the environment. To the best of our knowledge this is the first time that the fungal diversity is explored in the Salar de Huasco. In addition, the method presented here provides a simple and culture independent approach to assess the diversity of fungal lysis-resistant cells in the environment.


Assuntos
DNA Fúngico , Fungos , Sedimentos Geológicos , Micobioma , Esporos Fúngicos , Ascomicetos/genética , Ascomicetos/fisiologia , Basidiomycota/genética , Basidiomycota/fisiologia , Chile , Fungos/genética , Fungos/fisiologia , Sedimentos Geológicos/microbiologia , Lagos/microbiologia , Microbiota/fisiologia , Micélio/genética , Micélio/isolamento & purificação , Micélio/fisiologia , Micobioma/fisiologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/fisiologia , Esporos Fúngicos/genética , Esporos Fúngicos/isolamento & purificação , Esporos Fúngicos/fisiologia , Áreas Alagadas , DNA Fúngico/genética , DNA Fúngico/isolamento & purificação , DNA Fúngico/fisiologia
2.
BMC Biol ; 20(1): 203, 2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-36104696

RESUMO

BACKGROUND: To disperse in water-unsaturated environments, such as the soil, bacteria rely on the availability and structure of water films forming on biotic and abiotic surfaces, and, especially, along fungal mycelia. Dispersal along such "fungal highways" may be driven both by mycelial physical properties and by interactions between bacteria and fungi. However, we still do not have a way to disentangle the biotic and abiotic elements. RESULTS: We designed and 3D printed two devices establishing stable liquid films that support bacteria dispersal in the absence of biotic interactions. The thickness of the liquid film determined the presence of hydraulic flow capable of transporting non-motile cells. In the absence of flow, only motile cells can disperse in the presence of an energy source. Non-motile cells could not disperse autonomously without flow but dispersed as "hitchhikers" when co-inoculated with motile cells. CONCLUSIONS: The 3D printed devices can be used as an abiotic control to study bacterial dispersal on hydrated surfaces, such as plant roots and fungal hyphae networks in the soil. By teasing apart the abiotic and biotic dimensions, these 3D printed devices will stimulate further research on microbial dispersal in soil and other water-unsaturated environments.


Assuntos
Bactérias , Microbiologia do Solo , Impressão Tridimensional , Solo , Água
3.
Adv Appl Microbiol ; 106: 49-77, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30798804

RESUMO

Oxalic acid is the most ubiquitous and common low molecular weight organic acid produced by living organisms. Oxalic acid is produced by fungi, bacteria, plants, and animals. The aim of this review is to give an overview of current knowledge about the microbial cycling of oxalic acid through ecosystems. Here we review the production and degradation of oxalic acid, as well as its implications in the metabolism for fungi, bacteria, plants, and animals. Indeed, fungi are well known producers of oxalic acid, while bacteria are considered oxalic acid consumers. However, this framework may need to be modified, because the ability of fungi to degrade oxalic acid and the ability of bacteria to produce it, have been poorly investigated. Finally, we will highlight the role of fungi and bacteria in oxalic acid cycling in soil, plant and animal ecosystems.


Assuntos
Bactérias/metabolismo , Fungos/metabolismo , Ácido Oxálico/metabolismo , Animais , Bactérias/genética , Ecossistema , Fungos/genética , Plantas/metabolismo
4.
Adv Appl Microbiol ; 106: 79-111, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30798805

RESUMO

The production of a highly specialized cell structure called a spore is a remarkable example of a survival strategy displayed by bacteria in response to challenging environmental conditions. The detailed analysis and description of the process of sporulation in selected model organisms have generated a solid background to understand the cellular processes leading to the formation of this specialized cell. However, much less is known regarding the ecology of spore-formers. This research gap needs to be filled as the feature of resistance has important implications not only on the survival of spore-formers and their ecology, but also on the use of spores for environmental prospection and biotechnological applications.


Assuntos
Bactérias/metabolismo , Esporos Bacterianos/crescimento & desenvolvimento , Bactérias/genética , Bactérias/crescimento & desenvolvimento , Biotecnologia , Ecologia , Esporos Bacterianos/genética , Esporos Bacterianos/metabolismo
5.
Adv Appl Microbiol ; 99: 53-81, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28438268

RESUMO

Waste electric and electronic devices (e-waste) represent a source of valuable raw materials of great interest, and in the case of metals, e-waste might become a prized alternative source. Regarding gold, natural ores are difficult to mine due to their refractory nature and the richest ores have almost all been exploited. Additionally, some gold mining areas are present in geopolitically unstable regions. Finally, the gold mining industry produces toxic compounds, such as cyanides. As a result, the gold present in e-waste represents a nonnegligible resource (urban mining). Extraction methods of gold from natural ores (pyro- and hydrometallurgy) have been adapted to this particular type of matrix. However, to propose novel approaches with a lower environmental footprint, biotechnological methods using microorganisms are being developed (biometallurgy). These processes use the extensive metabolic potential of microbes (algae, bacteria, and fungi) to mobilize and immobilize gold from urban and industrial sources. In this review, we focus on the use of fungi for gold biomining. Fungi interact with gold by mobilizing it through mechanical attack as well as through biochemical leaching by the production of cyanides. Moreover, fungi are also able to release Au through the degradation of cyanide from aurocyanide complexes. Finally, fungi immobilize gold through biosorption, bioaccumulation, and biomineralization, in particular, as gold nanoparticles. Overall, the diversity of mechanisms of gold recycling using fungi combined with their filamentous lifestyle, which allows them to thrive in heterogeneous and solid environments such as e-waste, makes fungi an important bioresource to be harnessed for the biorecovery of gold.


Assuntos
Biotecnologia/métodos , Resíduo Eletrônico/análise , Fungos/metabolismo , Ouro/metabolismo , Reciclagem/métodos , Biodegradação Ambiental , Cianatos/metabolismo , Fungos/genética
6.
World J Microbiol Biotechnol ; 32(2): 28, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26748805

RESUMO

Oxalate is present in environments as diverse as soils or gastrointestinal tracts. This organic acid can be found as free acid or forming metal salts (e.g. calcium, magnesium). Oxalotrophy, the ability to use oxalate as carbon and energy sources, is mainly the result of bacterial catabolism, which can be either aerobic or anaerobic. Although some oxalotrophic bacterial strains are commonly used as probiotics, little is known about the diversity and ecology of this functional group. This review aims at exploring the taxonomic distribution and the phylogenetic diversity of oxalotrophic bacteria across biomes. In silico analyses were conducted using the two key enzymes involved in oxalotrophy: formyl-coenzyme A (CoA) transferase (EC 2.8.3.16) and oxalyl-CoA decarboxylase (EC 4.1.1.8), encoded by the frc and oxc genes, respectively. Our analyses revealed that oxalate-degrading bacteria are restricted to three phyla, namely Actinobacteria, Firmicutes and Proteobacteria and originated from terrestrial, aquatic and clinical environments. Diversity analyses at the protein level suggest that total Oxc diversity is more constrained than Frc diversity and that bacterial oxalotrophic diversity is not yet fully described. Finally, the contribution of oxalotrophic bacteria to ecosystem functioning as well as to the carbon cycle is discussed.


Assuntos
Actinobacteria/classificação , Firmicutes/classificação , Oxalatos/metabolismo , Proteobactérias/classificação , Actinobacteria/genética , Actinobacteria/metabolismo , Acil Coenzima A/genética , Acil Coenzima A/metabolismo , Animais , Biodiversidade , Carboxiliases/genética , Carboxiliases/metabolismo , Ecologia , Firmicutes/genética , Firmicutes/metabolismo , Trato Gastrointestinal/química , Trato Gastrointestinal/microbiologia , Humanos , Proteobactérias/genética , Proteobactérias/metabolismo , Solo/química , Microbiologia do Solo
7.
J Food Sci ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38955792

RESUMO

Food fraud is a problematic yet common phenomenon in the food industry. It impacts numerous sectors, including the market of edible mushrooms. Morel mushrooms are prized worldwide for their culinary and medicinal use. They represent a taxonomically complex group in which food fraud has already been reported. Among the methods to evaluate food fraud, some rely on comparisons of genetic sequences obtained from a sample to existing databases. However, the quality and usefulness of the results are limited by the type of comparison tool and the quality of the database used. The Centroid-based approach is applied by SmartGene in a proprietary artificial intelligence-based method for the generation of automatically curated reference databases that can be further expert curated. In this study, using sequences of the ribosomal internal transcribed spacer (ITS) of the genus Morchella (true morels), we compared this approach to the traditional pairwise alignment tool using two other databases: UNITE and Mycobank (MLST). The Centroid-based approach using an expert-curated database was more performant for the identification of 53 representative ITS sequences corresponding to validated species (83% accuracy, compared to 36% and 47% accuracy for UNITE and MLST, respectively). The Centroid method also revealed an inaccurate taxonomic annotation for sequences of commercial cultivars submitted to public databases. Combined with the web-based commercial software IDNS® available at Smartgene, the Centroid-based approach constitutes a valuable tool to ensure the quality of morel products on the market for actors of the food industry. PRACTICAL APPLICATION: The Centroid-based approach can be used by agri-food actors who need to identify true morels down to the species level without any prior taxonomical knowledge. These include routine laboratories of the food industry, food distributors, and public surveillance agencies. This is a reliable method that requires minimal skills and resources, therefore being particularly adapted for nonspecialists.

8.
Access Microbiol ; 6(2)2024.
Artigo em Inglês | MEDLINE | ID: mdl-38482366

RESUMO

Microbiology is a difficult topic to teach given that the objects of study are mostly invisible to the learner. The majority of university students beginning their training in biology are more interested in natural objects that can be seen with the naked eye. Nonetheless, micro-organisms are key components of the biosphere and a good microbiological background is required for a thorough training in natural sciences. Lectures are still a common teaching format in universities. However, it is a passive learning format and no longer considered the most adequate approach in most teaching situations. Instead, alternatives consisting of more active teaching formats have been recognized to better motivate students to acquire and consolidate knowledge. In addition, transferable skills, such as effective communication, critical thinking and time management, are acquired simultaneously. A similar engagement can be obtained using games as part of the teaching experience. In this study, we designed a card game to teach key concepts in basic bacteriology and mycology to bachelor-level students. The first task consists of creating and designing microbial characters based on a list of species. This proved very useful for second-year bachelor students in terms of grasping concepts such as cell morphologies, taxonomy and life cycles. In the second task, third-year students used the characters created in the second-year class to develop a game based on an ecological function, namely forest litter degradation. In addition, they also considered experimental validation of the microbial activities and incorporated knowledge acquired in other fields.

9.
Microlife ; 5: uqae004, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38463165

RESUMO

Bacteriophages play a crucial role in shaping bacterial communities, yet the mechanisms by which nonmotile bacteriophages interact with their hosts remain poorly understood. This knowledge gap is especially pronounced in structured environments like soil, where spatial constraints and air-filled zones hinder aqueous diffusion. In soil, hyphae of filamentous microorganisms form a network of 'fungal highways' (FHs) that facilitate the dispersal of other microorganisms. We propose that FHs also promote bacteriophage dissemination. Viral particles can diffuse in liquid films surrounding hyphae or be transported by infectable (host) or uninfectable (nonhost) bacterial carriers coexisting on FH networks. To test this, two bacteriophages that infect Pseudomonas putida DSM291 (host) but not KT2440 (nonhost) were used. In the absence of carriers, bacteriophages showed limited diffusion on 3D-printed abiotic networks, but diffusion was significantly improved in Pythium ultimum-formed FHs when the number of connecting hyphae exceeded 20. Transport by both host and nonhost carriers enhanced bacteriophage dissemination. Host carriers were five times more effective in transporting bacteriophages, particularly in FHs with over 30 connecting hyphae. This study enhances our understanding of bacteriophage dissemination in nonsaturated environments like soils, highlighting the importance of biotic networks and bacterial hosts in facilitating this process.

10.
Proc Biol Sci ; 280(1773): 20132242, 2013 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-24174111

RESUMO

The interactions between bacteria and fungi, the main actors of the soil microbiome, remain poorly studied. Here, we show that the saprotrophic and ectomycorrhizal soil fungus Morchella crassipes acts as a bacterial farmer of Pseudomonas putida, which serves as a model soil bacterium. Farming by M. crassipes consists of bacterial dispersal, bacterial rearing with fungal exudates, as well as harvesting and translocation of bacterial carbon. The different phases were confirmed experimentally using cell counting and (13)C probing. Common criteria met by other non-human farming systems are also valid for M. crassipes farming, including habitual planting, cultivation and harvesting. Specific traits include delocalization of food production and consumption and separation of roles in the colony (source versus sink areas), which are also found in human agriculture. Our study evidences a hitherto unknown mutualistic association in which bacteria gain through dispersal and rearing, while the fungus gains through the harvesting of an additional carbon source and increased stress resistance of the mycelium. This type of interaction between fungi and bacteria may play a key role in soils.


Assuntos
Ascomicetos/fisiologia , Microbiologia do Solo , Ascomicetos/metabolismo , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Biomarcadores/química , Biomarcadores/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Microbiota
11.
Appl Environ Microbiol ; 79(22): 6862-7, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23995942

RESUMO

The maintenance of energetically costly flagella by bacteria in non-water-saturated media, such as soil, still presents an evolutionary conundrum. Potential explanations have focused on rare flooding events allowing dispersal. Such scenarios, however, overlook bacterial dispersal along mycelia as a possible transport mechanism in soils. The hypothesis tested in this study is that dispersal along fungal hyphae may lead to an increase in the fitness of flagellated bacteria and thus offer an alternative explanation for the maintenance of flagella even in unsaturated soils. Dispersal along fungal hyphae was shown for a diverse array of motile bacteria. To measure the fitness effect of dispersal, additional experiments were conducted in a model system mimicking limited dispersal, using Pseudomonas putida KT2440 and its nonflagellated (ΔfliM) isogenic mutant in the absence or presence of Morchella crassipes mycelia. In the absence of the fungus, flagellar motility was beneficial solely under conditions of water saturation allowing dispersal, while under conditions limiting dispersal, the nonflagellated mutant exhibited a higher level of fitness than the wild-type strain. In contrast, in the presence of a mycelial network under conditions limiting dispersal, the flagellated strain was able to disperse using the mycelial network and had a higher level of fitness than the mutant. On the basis of these results, we propose that the benefit of mycelium-associated dispersal helps explain the persistence of flagellar motility in non-water-saturated environments.


Assuntos
Flagelos/fisiologia , Fungos , Aptidão Genética , Pseudomonas putida/fisiologia , Microbiologia do Solo , Meios de Cultura , Hifas , Microscopia Confocal , Modelos Biológicos , Pseudomonas putida/genética
12.
Microlife ; 4: uqad042, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37965130

RESUMO

This study presents an inexpensive approach for the macro- and microscopic observation of fungal mycelial growth. The 'fungal drops' method allows to investigate the development of a mycelial network in filamentous microorganisms at the colony and hyphal scales. A heterogeneous environment is created by depositing 15-20 µl drops on a hydrophobic surface at a fixed distance. This system is akin to a two-dimensional (2D) soil-like structure in which aqueous-pockets are intermixed with air-filled pores. The fungus (spores or mycelia) is inoculated into one of the drops, from which hyphal growth and exploration take place. Hyphal structures are assessed at different scales using stereoscopic and microscopic imaging. The former allows to evaluate the local response of regions within the colony (modular behaviour), while the latter can be used for fractal dimension analyses to describe the hyphal network architecture. The method was tested with several species to underpin the transferability to multiple species. In addition, two sets of experiments were carried out to demonstrate its use in fungal biology. First, mycelial reorganization of Fusarium oxysporum was assessed as a response to patches containing different nutrient concentrations. Second, the effect of interactions with the soil bacterium Pseudomonas putida on habitat colonization by the same fungus was assessed. This method appeared as fast and accessible, allowed for a high level of replication, and complements more complex experimental platforms. Coupled with image analysis, the fungal drops method provides new insights into the study of fungal modularity both macroscopically and at a single-hypha level.

13.
Front Fungal Biol ; 4: 1285531, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38155707

RESUMO

Members of the fungal genus Morchella are widely known for their important ecological roles and significant economic value. In this study, we used amplicon and genome sequencing to characterize bacterial communities associated with sexual fruiting bodies from wild specimens, as well as vegetative mycelium and sclerotia obtained from Morchella isolates grown in vitro. These investigations included diverse representatives from both Elata and Esculenta Morchella clades. Unique bacterial community compositions were observed across the various structures examined, both within and across individual Morchella isolates or specimens. However, specific bacterial taxa were frequently detected in association with certain structures, providing support for an associated core bacterial community. Bacteria from the genus Pseudomonas and Ralstonia constituted the core bacterial associates of Morchella mycelia and sclerotia, while other genera (e.g., Pedobacter spp., Deviosa spp., and Bradyrhizobium spp.) constituted the core bacterial community of fruiting bodies. Furthermore, the importance of Pseudomonas as a key member of the bacteriome was supported by the isolation of several Pseudomonas strains from mycelia during in vitro cultivation. Four of the six mycelial-derived Pseudomonas isolates shared 16S rDNA sequence identity with amplicon sequences recovered directly from the examined fungal structures. Distinct interaction phenotypes (antagonistic or neutral) were observed in confrontation assays between these bacteria and various Morchella isolates. Genome sequences obtained from these Pseudomonas isolates revealed intriguing differences in gene content and annotated functions, specifically with respect to toxin-antitoxin systems, cell adhesion, chitinases, and insecticidal toxins. These genetic differences correlated with the interaction phenotypes. This study provides evidence that Pseudomonas spp. are frequently associated with Morchella and these associations may greatly impact fungal physiology.

14.
IMA Fungus ; 13(1): 14, 2022 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-35996182

RESUMO

Morels are highly prized edible fungi where sexual reproduction is essential for fruiting-body production. As a result, a comprehensive understanding of their sexual reproduction is of great interest. Central to this is the identification of the reproductive strategies used by morels. Sexual reproduction in fungi is controlled by mating-type (MAT) genes and morels are thought to be mainly heterothallic with two idiomorphs, MAT1-1 and MAT1-2. Genomic sequencing of black (Elata clade) and yellow (Esculenta clade) morel species has led to the development of PCR primers designed to amplify genes from the two idiomorphs for rapid genotyping of isolates from these two clades. To evaluate the design and theoretical performance of these primers we performed a thorough bioinformatic investigation, including the detection of the MAT region in publicly available Morchella genomes and in-silico PCR analyses. All examined genomes, including those used for primer design, appeared to be heterothallic. This indicates an inherent fault in the original primer design which utilized a single Morchella genome, as the use of two genomes with complementary mating types would be required to design accurate primers for both idiomorphs. Furthermore, potential off-targets were identified for some of the previously published primer sets, but verification was challenging due to lack of adequate genomic information and detailed methodologies for primer design. Examinations of the black morel specific primer pairs (MAT11L/R and MAT22L/R) indicated the MAT22 primers would correctly target and amplify the MAT1-2 idiomorph, but the MAT11 primers appear to be capable of amplifying incorrect off-targets within the genome. The yellow morel primer pairs (EMAT1-1 L/R and EMAT1-2 L/R) appear to have reporting errors, as the published primer sequences are dissimilar with reported amplicon sequences and the EMAT1-2 primers appear to amplify the RNA polymerase II subunit (RPB2) gene. The lack of the reference genome used in primer design and descriptive methodology made it challenging to fully assess the apparent issues with the primers for this clade. In conclusion, additional work is still required for the generation of reliable primers to investigate mating types in morels and to assess their performance on different clades and across multiple geographical regions.

15.
FEMS Microbiol Rev ; 46(6)2022 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-36001464

RESUMO

This review highlights new advances in the emerging field of 'Fungi-on-a-Chip' microfluidics for single-cell studies on fungi and discusses several future frontiers, where we envisage microfluidic technology development to be instrumental in aiding our understanding of fungal biology. Fungi, with their enormous diversity, bear essential roles both in nature and our everyday lives. They inhabit a range of ecosystems, such as soil, where they are involved in organic matter degradation and bioremediation processes. More recently, fungi have been recognized as key components of the microbiome in other eukaryotes, such as humans, where they play a fundamental role not only in human pathogenesis, but also likely as commensals. In the food sector, fungi are used either directly or as fermenting agents and are often key players in the biotechnological industry, where they are responsible for the production of both bulk chemicals and antibiotics. Although the macroscopic fruiting bodies are immediately recognizable by most observers, the structure, function, and interactions of fungi with other microbes at the microscopic scale still remain largely hidden. Herein, we shed light on new advances in the emerging field of Fungi-on-a-Chip microfluidic technologies for single-cell studies on fungi. We discuss the development and application of microfluidic tools in the fields of medicine and biotechnology, as well as in-depth biological studies having significance for ecology and general natural processes. Finally, a future perspective is provided, highlighting new frontiers in which microfluidic technology can benefit this field.


Assuntos
Ecossistema , Microfluídica , Humanos , Simbiose , Fungos , Dispositivos Lab-On-A-Chip
16.
FEMS Microbiol Lett ; 369(1)2022 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-35325127

RESUMO

Bacterial-fungal interactions (BFI) play a major role on ecosystem functioning and might be particularly relevant at a specific development stage. For instance, in the case of biological control of fungal pathogens by bacteria, a highly relevant kind of BFI, in-vitro experiments often assess the impact of a bacterium on the inhibition of actively growing mycelia. However, this fails to consider other stages of plant infection such as the germination of a spore or a sclerotium. This study aims to present novel experimental platforms for in-vitro experiments with fungal spores, in order to assess the effect of bacteria on germination and fungal growth control, to recover the metabolites produced in the interaction, and to enhance direct visualisation of BFI. Botrytis cinerea, a phytopathogenic fungus producing oxalic acid (OA) as pathogenicity factor, was used as model. Given that oxalotrophic bacteria have been shown previously to control the growth of B. cinerea, the oxalotrophic bacteria Cupriavidus necator and Cupriavidus oxalaticus were used as models. The experiments performed demonstrated the suitability of the methods and confirmed that both bacteria were able to control the growth of B. cinerea, but only in media in which soluble OA was detected by the fungus. The methods presented here can be easily performed in any microbiology laboratory and are not only applicable to screen for potential biocontrol agents, but also to better understand BFI.


Assuntos
Basidiomycota , Ecossistema , Bactérias , Botrytis/fisiologia , Micélio , Doenças das Plantas/microbiologia , Esporos Fúngicos
17.
R Soc Open Sci ; 9(12): 211592, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36483758

RESUMO

The coexistence of competing species is a long-lasting puzzle in evolutionary ecology research. Despite abundant experimental evidence showing that the opportunity for coexistence decreases as niche overlap increases between species, bacterial species and strains competing for the same resources are commonly found across diverse spatially heterogeneous habitats. We thus hypothesized that the spatial scale of competition may play a key role in determining bacterial coexistence, and interact with other mechanisms that promote coexistence, including a growth-motility trade-off. To test this hypothesis, we let two Pseudomonas putida strains compete at local and regional scales by inoculating them either in a mixed droplet or in separate droplets in the same Petri dish, respectively. We also created conditions that allow the bacterial strains to disperse across abiotic or fungal hyphae networks. We found that competition at the local scale led to competitive exclusion while regional competition promoted coexistence. When competing in the presence of dispersal networks, the growth-motility trade-off promoted coexistence only when the strains were inoculated in separate droplets. Our results provide a mechanism by which existing laboratory data suggesting competitive exclusion at a local scale is reconciled with the widespread coexistence of competing bacterial strains in complex natural environments with dispersal.

18.
Microbiol Resour Announc ; 11(9): e0018122, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-35924938

RESUMO

Here, we report the complete genome sequences of the soil oxalotrophic bacterium Cupriavidus oxalaticus Ox1 and a derived mCherry-tagged strain. The genome size is approximately 6.69 Mb, with a GC content of 66.9%. The genome sequence of C. oxalaticus Ox1 contains a complete operon for the degradation and assimilation of oxalate.

19.
Microorganisms ; 9(5)2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-34062900

RESUMO

The oxalate-carbonate pathway (OCP) is a biogeochemical process linking oxalate oxidation and carbonate precipitation. Currently, this pathway is described as a tripartite association involving oxalogenic plants, oxalogenic fungi, and oxalotrophic bacteria. While the OCP has recently received increasing interest given its potential for capturing carbon in soils, there are still many unknowns, especially regarding the taxonomic and functional diversity of the fungi involved in this pathway. To fill this gap, we described an active OCP site in Madagascar, under the influence of the oxalogenic tree Tamarindus indica, and isolated, identified, and characterized 50 fungal strains from the leaf litter. The fungal diversity encompassed three phyla, namely Mucoromycota, Ascomycota, and Basidiomycota, and 23 genera. Using various media, we further investigated their functional potential. Most of the fungal strains produced siderophores and presented proteolytic activities. The majority were also able to decompose cellulose and xylan, but only a few were able to solubilize inorganic phosphate. Regarding oxalate metabolism, several strains were able to produce calcium oxalate crystals while others decomposed calcium oxalate. These results challenge the current view of the OCP by indicating that fungi are both oxalate producers and degraders. Moreover, they strengthen the importance of the role of fungi in C, N, Ca, and Fe cycles.

20.
Commun Biol ; 4(1): 262, 2021 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-33637874

RESUMO

Routinely, fungal-fungal interactions (FFI) are studied on agar surfaces. However, this format restricts high-resolution dynamic imaging. To gain experimental access to FFI at the hyphal level in real-time, we developed a microfluidic platform, a FFI device. This device utilises microchannel geometry to enhance the visibility of hyphal growth and provides control channels to allow comparisons between localised and systemic effects. We demonstrate its function by investigating the FFI between the biological control agent (BCA) Clonostachys rosea and the plant pathogen Fusarium graminearum. Microscope image analyses confirm the inhibitory effect of the necrotrophic BCA and we show that a loss of fluorescence in parasitised hyphae of GFP-tagged F. graminearum coincides with the detection of GFP in mycelium of C. rosea. The versatility of our device to operate under both water-saturated and nutrient-rich as well as dry and nutrient-deficient conditions, coupled with its spatio-temporal output, opens new opportunities to study relationships between fungi.


Assuntos
Fusarium/fisiologia , Hifas/fisiologia , Hypocreales/fisiologia , Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas/instrumentação , Microscopia de Fluorescência , Controle Biológico de Vetores , Fusarium/genética , Fusarium/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Hypocreales/genética , Hypocreales/metabolismo , Viabilidade Microbiana , Fatores de Tempo
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