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1.
J Mol Evol ; 92(2): 169-180, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38502221

RESUMEN

The bacterial strain SECRCQ15T was isolated from seeds of Chenopodium quinoa in Spain. Phylogenetic, chemotaxonomic, and phenotypic analyses, as well as genome similarity indices, support the classification of the strain into a novel species of the genus Ferdinandcohnia, for which we propose the name Ferdinandcohnia quinoae sp. nov. To dig deep into the speciation features of the strain SECRCQ15T, we performed a comparative genomic analysis of the genome of this strain and those of the type strains of species from the genus Ferdinandcohnia. We found several genes related with plant growth-promoting mechanisms within the SECRCQ15T genome. We also found that singletons of F. quinoae SECRCQ15T are mainly related to the use of carbohydrates, which is a common trait of plant-associated bacteria. To further reveal speciation events in this strain, we revealed genes undergoing diversifying selection (e.g., genes encoding ribosomal proteins) and functions likely lost due to pseudogenization. Also, we found that this novel species contains 138 plant-associated gene-cluster functions that are unique within the genus Ferdinandcohnia. These features may explain both the ecological and taxonomical differentiation of this new taxon.


Asunto(s)
Ácidos Grasos , Plantas , Filogenia , Plantas/genética , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Análisis de Secuencia de ADN
2.
Curr Biol ; 33(23): R1246-R1261, 2023 12 04.
Artículo en Inglés | MEDLINE | ID: mdl-38052178

RESUMEN

Climate change threatens global food and nutritional security through negative effects on crop growth and agricultural productivity. Many countries have adopted ambitious climate change mitigation and adaptation targets that will exacerbate the problem, as they require significant changes in current agri-food systems. In this review, we provide a roadmap for improved crop production that encompasses the effective transfer of current knowledge into plant breeding and crop management strategies that will underpin sustainable agriculture intensification and climate resilience. We identify the main problem areas and highlight outstanding questions and potential solutions that can be applied to mitigate the impacts of climate change on crop growth and productivity. Although translation of scientific advances into crop production lags far behind current scientific knowledge and technology, we consider that a holistic approach, combining disciplines in collaborative efforts, can drive better connections between research, policy, and the needs of society.


Asunto(s)
Cambio Climático , Productos Agrícolas , Fitomejoramiento , Agricultura , Producción de Cultivos
3.
Environ Microbiome ; 18(1): 64, 2023 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-37481564

RESUMEN

BACKGROUND: Plant-associated microbial communities play important roles in host nutrition, development and defence. In particular, the microbes living within internal plant tissues can affect plant metabolism in a more intimate way. Understanding the factors that shape plant microbial composition and discovering enriched microbes within endophytic compartments would thus be valuable to gain knowledge on potential plant-microbial coevolutions. However, these interactions are usually studied through reductionist approaches (in vitro models or crop controlled systems). Here, we investigate these ecological factors in wild forest niches using proximally located plants from two distant taxa (blueberry and blackberry) as a model. RESULTS: Although the microbial communities were quite similar in both plants, we found that sampling site had a high influence on them; specifically, its impact on the rhizosphere communities was higher than that on the roots. Plant species and sample type (root vs. rhizosphere) affected the bacterial communities more than the fungal communities. For instance, Xanthobacteraceae and Helotiales taxa were more enriched in roots, while the abundance of Gemmatimonadetes was higher in rhizospheres. Acidobacteria abundance within the endosphere of blueberry was similar to that in soil. Several taxa were significantly associated with either blackberry or blueberry samples regardless of the sampling site. For instance, we found a significant endospheric enrichment of Nevskia in blueberry and of Sphingobium, Novosphingobium and Steroidobacter in blackberry. CONCLUSIONS: There are selective enrichment and exclusion processes in the roots of plants that shapes a differential composition between plant species and sample types (root endosphere-rhizosphere). The special enrichment of some microbial taxa in each plant species might suggest the presence of ancient selection and/or speciation processes and might imply specific symbiosis. The selection of fungi by the host is more pronounced when considering the fungal trait rather than the taxonomy. This work helps to understand plant-microbial interactions in natural ecosystems and the microbiome features of plants.

4.
Microbiol Spectr ; 11(4): e0152323, 2023 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-37310275

RESUMEN

Plasmids are the main mobile elements responsible for horizontal gene transfer (HGT) in microorganisms. These replicons extend the metabolic spectrum of their host cells by carrying functional genes. However, it is still unknown to what extent plasmids carry biosynthetic gene clusters (BGCs) related to the production of secondary or specialized metabolites (SMs). Here, we analyzed 9,183 microbial plasmids to unveil their potential to produce SMs, finding a large diversity of cryptic BGCs in a few varieties of prokaryotic host taxa. Some of these plasmids harbored 15 or more BGCs, and many others were exclusively dedicated to mobilizing BGCs. We found an occurrence pattern of BGCs within groups of homologous plasmids shared by a common taxon, mainly in host-associated microbes (e.g., Rhizobiales, Enterobacteriaceae members). Our results add to the knowledge of the ecological functions and potential industrial uses of plasmids and shed light on the dynamics and evolution of SMs in prokaryotes. IMPORTANCE Plasmids are mobile DNA elements that can be shared among microbial cells, and they are useful for bringing to fruition some microbial ecological traits. However, it is not known to what extent plasmids harbor genes related to the production of specialized/secondary metabolites (SMs). In microbes, these metabolites are frequently useful for defense purposes, signaling, etc. In addition, these molecules usually have biotechnological and clinical applications. Here, we analyzed the content, dynamics, and evolution of genes related to the production of SMs in >9,000 microbial plasmids. Our results confirm that some plasmids act as a reservoir of SMs. We also found that some families of biosynthetic gene clusters are exclusively present in some groups of plasmids shared among closely related microbes. Host-associated bacteria (e.g., plant and human microbes) harbor the majority of specialized metabolites encoded in plasmids. These results provide new knowledge about microbial ecological traits and might enable the discovery of novel metabolites.


Asunto(s)
Bacterias , Familia de Multigenes , Humanos , Bacterias/genética , Metabolismo Secundario/genética , Plásmidos/genética
5.
FEMS Microbiol Ecol ; 99(8)2023 07 21.
Artículo en Inglés | MEDLINE | ID: mdl-37370225

RESUMEN

The European spruce bark beetle, Ips typographus, is a serious pest of spruce forests in Europe, and its invasion and development inside spruce tissues are facilitated by microorganisms. We investigated the core gut bacterial and fungal microbiomes of I. typographus throughout its life cycle in spring and summer generations. We used cultivation techniques and molecular identification in combination with DNA and RNA metabarcoding. Our results revealed that communities differ throughout their life cycle and across generations in proportion of dominantly associated microbes, rather than changes in species composition. The bacteriome consisted mostly of the phylum Gammaproteobacteria, with the most common orders and genera being Enterobacteriales (Erwinia and Serratia), Pseudomonadales (Pseudomonas), and Xanthomonadales. The fungal microbiome was dominated by yeasts (Saccharomycetes-Wickerhamomyces, Kuraishia, and Nakazawaea), followed by Sordariomycetes (Ophiostoma bicolor and Endoconidiophora polonica). We did not observe any structure ensuring long-term persistence of microbiota on any part of the gut epithelium, suggesting that microbial cells are more likely to pass through the beetle's gut with chyme. The most abundant taxa in the beetle's gut were also identified as dominant in intact spruce phloem. Therefore, we propose that these taxa are acquired from the environment rather than specifically vectored between generations.


Asunto(s)
Escarabajos , Microbioma Gastrointestinal , Picea , Gorgojos , Animales , Escarabajos/microbiología , Corteza de la Planta , Estaciones del Año , Gorgojos/microbiología , Estadios del Ciclo de Vida , Picea/microbiología
6.
Environ Microbiome ; 18(1): 53, 2023 Jun 09.
Artículo en Inglés | MEDLINE | ID: mdl-37296446

RESUMEN

BACKGROUND: Ips typographus (European spruce bark beetle) is the most destructive pest of spruce forests in Europe. As for other animals, it has been proposed that the microbiome plays important roles in the biology of bark beetles. About the bacteriome, there still are many uncertainties regarding the taxonomical composition, insect-bacteriome interactions, and their potential roles in the beetle ecology. Here, we aim to deep into the ecological functions and taxonomical composition of I. typographus associated bacteria. RESULTS: We assessed the metabolic potential of a collection of isolates obtained from different life stages of I. typographus beetles. All strains showed the capacity to hydrolyse one or more complex polysaccharides into simpler molecules, which may provide an additional carbon source to its host. Also, 83.9% of the strains isolated showed antagonistic effect against one or more entomopathogenic fungi, which could assist the beetle in its fight against this pathogenic threat. Using culture-dependent and -independent techniques, we present a taxonomical analysis of the bacteriome associated with the I. typographus beetle during its different life stages. We have observed an evolution of its bacteriome, which is diverse at the larval phase, substantially diminished in pupae, greater in the teneral adult phase, and similar to that of the larval stage in mature adults. Our results suggest that taxa belonging to the Erwiniaceae family, and the Pseudoxanthomonas and Pseudomonas genera, as well as an undescribed genus within the Enterobactereaceae family, are part of the core microbiome and may perform vital roles in maintaining beetle fitness. CONCLUSION: Our results indicate that isolates within the bacteriome of I. typographus beetle have the metabolic potential to increase beetle fitness by proving additional and assimilable carbon sources for the beetle, and by antagonizing fungi entomopathogens. Furthermore, we observed that isolates from adult beetles are more likely to have these capacities but those obtained from larvae showed strongest antifungal activity. Our taxonomical analysis showed that Erwinia typographi, Pseudomonas bohemica, and Pseudomonas typographi species along with Pseudoxanthomonas genus, and putative new taxa belonging to the Erwiniaceae and Enterobacterales group are repeatedly present within the bacteriome of I. typographus beetles, indicating that these species might be part of the core microbiome. In addition to Pseudomonas and Erwinia group, Staphylococcus, Acinetobacter, Curtobacterium, Streptomyces, and Bacillus genera seem to also have interesting metabolic capacities but are present in a lower frequency. Future studies involving bacterial-insect interactions or analysing other potential roles would provide more insights into the bacteriome capacity to be beneficial to the beetle.

7.
Microbiol Spectr ; 10(6): e0237022, 2022 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-36354324

RESUMEN

Each Earth ecosystem has unique microbial communities. Pseudomonas bacteria have evolved to occupy a plethora of different ecological niches, including living hosts, such as animals and plants. Many genes necessary for the Pseudomonas-niche interaction and their encoded functions remain unknown. Here, we describe a comparative genomic study of 3,274 genomes with 19,056,667 protein-coding sequences from Pseudomonas strains isolated from diverse environments. We detected functional divergence of Pseudomonas that depends on the niche. Each group of strains from a certain environment harbored a distinctive set of metabolic pathways or functions. The horizontal transfer of genes, which mainly proceeded between closely related taxa, was dependent on the isolation source. Finally, we detected thousands of undescribed proteins and functions associated with each Pseudomonas lifestyle. This research represents an effort to reveal the mechanisms underlying the ecology, pathogenicity, and evolution of Pseudomonas, and it will enable clinical, ecological, and biotechnological advances. IMPORTANCE Microbes play important roles in the health of living beings and in the environment. The knowledge of these functions may be useful for the development of new clinical and biotechnological applications and the restoration and preservation of natural ecosystems. However, most mechanisms implicated in the interaction of microbes with the environment remain poorly understood; thus, this field of research is very important. Here, we try to understand the mechanisms that facilitate the differential adaptation of Pseudomonas-a large and ubiquitous bacterial genus-to the environment. We analyzed more than 3,000 Pseudomonas genomes and searched for genetic patterns that can be related with their coevolution with different hosts (animals, plants, or fungi) and environments. Our results revealed that thousands of genes and genetic features are associated with each niche. Our data may be useful to develop new technical and theoretical advances in the fields of ecology, health, and industry.


Asunto(s)
Ecosistema , Pseudomonas , Animales , Filogenia , Pseudomonas/genética , Genómica , Adaptación Fisiológica/genética
8.
Front Microbiol ; 13: 981507, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36274741

RESUMEN

Endophytic fungi of crops can promote plant growth through various mechanisms of action (i.e., improve nutrient uptake and nutrient use efficiency, and produce and modulate plant hormones). The genus Brassica includes important horticultural crops, which have been little studied in their interaction with endophytic fungi. Previously, four endophytic fungi were isolated from kale roots (Brassica oleracea var. acephala), with different benefits for their host, including plant growth promotion, cold tolerance, and induction of resistance to pathogens (Xanthomonas campestris) and pests (Mamestra brassicae). In the present work, the molecular and morphological identification of the four different isolates were carried out, describing them as the species Acrocalymma vagum, Setophoma terrestris, Fusarium oxysporum, and the new species Pyrenophora gallaeciana. In addition, using a representative crop of each Brassica U's triangle species and various in vitro biochemical tests, the ability of these fungi to promote plant growth was described. In this sense, the four fungi used promoted the growth of B. rapa, B. napus, B. nigra, B. juncea, and B. carinata, possibly due to the production of auxins, siderophores, P solubilization or cellulase, xylanase or amylase activity. Finally, the differences in root colonization between the four endophytic fungi and two pathogens (Leptosphaeria maculans and Sclerotinia sclerotiorum) and the root glucosinolate profile were studied, at different times. In this way, how the presence of progoitrin in the roots reduces their colonization by endophytic and pathogenic fungi was determined, while the possible hydrolysis of sinigrin to fungicidal products controls the colonization of endophytic fungi, but not of pathogens.

9.
Microb Genom ; 8(2)2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-35195510

RESUMEN

Microbes host a huge variety of biosynthetic gene clusters that produce an immeasurable array of secondary metabolites with many different biological activities such as antimicrobial, anticarcinogenic and antiviral. Despite the complex task of isolating and characterizing novel natural products, microbial genomic strategies can be useful for carrying out these types of studies. However, although genomic-based research on secondary metabolism is on the increase, there is still a lack of reports focusing specifically on the genus Pseudomonas. In this work, we aimed (i) to unveil the main biosynthetic systems related to secondary metabolism in Pseudomonas type strains, (ii) to study the evolutionary processes that drive the diversification of their coding regions and (iii) to select Pseudomonas strains showing promising results in the search for useful natural products. We performed a comparative genomic study on 194 Pseudomonas species, paying special attention to the evolution and distribution of different classes of biosynthetic gene clusters and the coding features of antimicrobial peptides. Using EvoMining, a bioinformatic approach for studying evolutionary processes related to secondary metabolism, we sought to decipher the protein expansion of enzymes related to the lipid metabolism, which may have evolved toward the biosynthesis of novel secondary metabolites in Pseudomonas. The types of metabolites encoded in Pseudomonas type strains were predominantly non-ribosomal peptide synthetases, bacteriocins, N-acetylglutaminylglutamine amides and ß-lactones. Also, the evolution of genes related to secondary metabolites was found to coincide with Pseudomonas species diversification. Interestingly, only a few Pseudomonas species encode polyketide synthases, which are related to the lipid metabolism broadly distributed among bacteria. Thus, our EvoMining-based search may help to discover new types of secondary metabolite gene clusters in which lipid-related enzymes are involved. This work provides information about uncharacterized metabolites produced by Pseudomonas type strains, whose gene clusters have evolved in a species-specific way. Our results provide novel insight into the secondary metabolism of Pseudomonas and will serve as a basis for the prioritization of the isolated strains. This article contains data hosted by Microreact.


Asunto(s)
Productos Biológicos , Pseudomonas , Productos Biológicos/metabolismo , Genómica , Familia de Multigenes , Filogenia , Pseudomonas/genética
10.
Front Biosci (Landmark Ed) ; 26(10): 928-947, 2021 10 30.
Artículo en Inglés | MEDLINE | ID: mdl-34719216

RESUMEN

Climate change, water scarcity, population growth, and food shortage are some of the threatening challenges being faced in today's world. Among different types of stresses, drought stress presents a persistent challenge for global food production, however, its harshness and intensity are supposed to expand in the imminent future. The most striking effects of drought stress on plants are stunted growth, severe damage to photosynthetic apparatus, reduction in photosynthesis, reduction in seed germination, and nutrient uptake. To deal with the destructive effect of drought stress on plants, it is necessary to consider its effects, mechanisms of action, the agronomic and genetic basis for sustainable management. Therefore, there is an urgent need for sustainable solutions to cope up with the negative impact of drought stress. This review focuses on the detrimental effects of drought stress on plants' morphological, physiological, and biochemical characteristics and recommends suitable drought management techniques to reduce the severity of drought stress. We summarize the effect of drought stress on physiological and biochemical parameters (such as germination, photosynthesis, biomass, water status, and nutrient uptake) and yield. Overall, in this article, we have reviewed the role of different phytohormones, osmolytes, exogenous compounds, proteins, plant growth-promoting microbes (PGPM), omics approaches, and genome editing technologies like clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (CRISPR-Cas9) in alleviating drought effects in plants. We also proposed that developing drought-tolerant plant varieties requires the combined use of biotechnological and agronomic approaches and cutting-edge genome editing (GE) tools.


Asunto(s)
Sistemas CRISPR-Cas , Sequías , Edición Génica , Plantas , Estrés Fisiológico
11.
Biology (Basel) ; 10(8)2021 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-34440014

RESUMEN

Pseudomonas is a large and diverse genus broadly distributed in nature. Its species play relevant roles in the biology of earth and living beings. Because of its ubiquity, the number of new species is continuously increasing although its taxonomic organization remains quite difficult to unravel. Nowadays the use of genomics is routinely employed for the analysis of bacterial systematics. In this work, we aimed to investigate the classification of species of the genus Pseudomonas on the basis of the analyses of the type strains whose genomes are currently available. Based on these analyses, we propose the creation of three new genera (Denitrificimonas gen nov. comb. nov., Neopseudomonas gen nov. comb. nov. and Parapseudomonas gen nov. comb. nov) to encompass several species currently included within the genus Pseudomonas and the reclassification of several species of this genus in already described taxa.

12.
Biology (Basel) ; 10(2)2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33669823

RESUMEN

Symbiosis between microbes and insects has been raised as a promising area for understanding biological implications of microbe-host interactions. Among them, the association between fungi and bark beetles has been generally recognized as essential for the bark beetle ecology. However, many works investigating bark beetle bacterial communities and their functions usually meet in a common finding: Pseudomonas is a broadly represented genus within this holobiont and it may provide beneficial roles to its host. Thus, we aimed to review available research on this microbe-host interaction and point out the probable relevance of Pseudomonas strains for these insects, in order to guide future research toward a deeper analysis of the importance of these bacteria for the beetle's life cycle.

13.
Microb Ecol ; 81(2): 471-482, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-32901388

RESUMEN

The pine engraver beetle, Ips acuminatus Gyll, is a bark beetle that causes important damages in Scots pine (Pinus sylvestris) forests and plantations. As almost all higher organisms, Ips acuminatus harbours a microbiome, although the role of most members of its microbiome is not well understood. As part of a work in which we analysed the bacterial diversity associated to Ips acuminatus, we isolated the strain Arthrobacter sp. IA7. In order to study its potential role within the bark beetle holobiont, we sequenced and explored its genome and performed a pan-genome analysis of the genus Arthrobacter, showing specific genes of strain IA7 that might be related with its particular role in its niche. Based on these investigations, we suggest several potential roles of the bacterium within the beetle. Analysis of genes related to secondary metabolism indicated potential antifungal capability, confirmed by the inhibition of several entomopathogenic fungal strains (Metarhizium anisopliae CCF0966, Lecanicillium muscarium CCF6041, L. muscarium CCF3297, Isaria fumosorosea CCF4401, I. farinosa CCF4808, Beauveria bassiana CCF4422 and B. brongniartii CCF1547). Phylogenetic analyses of the 16S rRNA gene, six concatenated housekeeping genes (tuf-secY-rpoB-recA-fusA-atpD) and genome sequences indicated that strain IA7 is closely related to A. globiformis NBRC 12137T but forms a new species within the genus Arthrobacter; this was confirmed by digital DNA-DNA hybridization (37.10%) and average nucleotide identity (ANIb) (88.9%). Based on phenotypic and genotypic features, we propose strain IA7T as the novel species Arthrobacter ipsi sp. nov. (type strain IA7T = CECT 30100T = LMG 31782T) and suggest its protective role for its host.


Asunto(s)
Arthrobacter/fisiología , Escarabajos/microbiología , Genoma Bacteriano/genética , Corteza de la Planta/parasitología , Animales , Antibiosis , Arthrobacter/clasificación , Arthrobacter/genética , ADN Bacteriano/genética , Hongos/crecimiento & desarrollo , Genes Bacterianos/genética , Interacciones Microbiota-Huesped , Fenotipo , Filogenia , Pinus/parasitología , Enfermedades de las Plantas/parasitología , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
14.
Insects ; 11(9)2020 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-32899185

RESUMEN

European Bark Beetle Ips typographus is a secondary pest that affects dead and weakened spruce trees (Picea genus). Under certain environmental conditions, it has massive outbreaks, resulting in the attacks of healthy trees, becoming a forest pest. It has been proposed that the bark beetle's microbiome plays a key role in the insect's ecology, providing nutrients, inhibiting pathogens, and degrading tree defense compounds, among other probable traits yet to be discovered. During a study of bacterial associates from I. typographus, we isolated three strains identified as Pseudomonas from different beetle life stages. A polyphasic taxonomical approach showed that they belong to a new species for which the name Pseudomonas typographi sp nov. is proposed. Genome sequences show their potential to hydrolyze wood compounds and synthesize several vitamins; screening for enzymes production was verified using PNP substrates. Assays in Petri dishes confirmed cellulose and xylan hydrolysis. Moreover, the genomes harbor genes encoding chitinases and gene clusters involved in the synthesis of secondary metabolites with antimicrobial potential. In vitro tests confirmed the capability of the three P. typographi strains to inhibit several Ips beetles' pathogenic fungi. Altogether, these results suggest that P. typographi aids I. typographi nutrition and resistance to fungal pathogens.

15.
Microorganisms ; 7(9)2019 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-31540065

RESUMEN

Plants harbor a diversity of microorganisms constituting the plant microbiome. Many bioinoculants for agricultural crops have been isolated from plants. Nevertheless, plants are an underexplored niche for the isolation of microorganisms with other biotechnological applications. As a part of a collection of canola endophytes, we isolated strain CDVBN77T. Its genome sequence shows not only plant growth-promoting (PGP) mechanisms, but also genetic machinery to produce secondary metabolites, with potential applications in the pharmaceutical industry, and to synthesize hydrolytic enzymes, with potential applications in biomass degradation industries. Phylogenetic analysis of the 16S rRNA gene of strain CDVBN77T shows that it belongs to the genus Microvirga, its closest related species being M. aerophila DSM 21344T (97.64% similarity) and M. flavescens c27j1T (97.50% similarity). It contains ubiquinone 10 as the predominant quinone, C19:0 cycloω8c and summed feature 8 as the major fatty acids, and phosphatidylcholine and phosphatidylethanolamine as the most abundant polar lipids. Its genomic DNA G+C content is 62.3 (mol %). Based on phylogenetic, chemotaxonomic, and phenotypic analyses, we suggest the classification of strain CDVBN77T within a new species of the genus Microvirga and propose the name Microvirga brassicacearum sp. nov. (type strain CDVBN77T = CECT 9905T = LMG 31419T).

16.
Front Microbiol ; 9: 913, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29867824

RESUMEN

Antimicrobial resistance is a worldwide problem that threatens the effectiveness of treatments for microbial infection. Consequently, it is essential to study unexplored niches that can serve for the isolation of new microbial strains able to produce antimicrobial compounds to develop new drugs. Bark beetles live in phloem of host trees and establish symbioses with microorganisms that provide them with nutrients. In addition, some of their associated bacteria play a role in the beetle protection by producing substances that inhibit antagonists. In this study the capacity of several bacterial strains, isolated from the bark beetles Ips acuminatus, Pityophthorus pityographus Cryphalus piceae, and Pityogenes bidentatus, to produce antimicrobial compounds was analyzed. Several isolates exhibited the capacity to inhibit Gram-positive and Gram-negative bacteria, as well as fungi. The genome sequence analysis of three Pseudomonas isolates predicted the presence of several gene clusters implicated in the production of already described antimicrobials and moreover, the low similarity of some of these clusters with those previously described, suggests that they encode new undescribed substances, which may be useful for developing new antimicrobial agents. Moreover, these bacteria appear to have genetic machinery for producing antitumoral and antiviral substances. Finally, the strain IA19T showed to represent a new species of the genus Pseudomonas. The 16S rRNA gene sequence analysis showed that its most closely related species include Pseudomonas lutea, Pseudomonas graminis, Pseudomonas abietaniphila and Pseudomonas alkylphenolica, with 98.6, 98.5 98.4, and 98.4% identity, respectively. MLSA of the housekeeping genes gyrB, rpoB, and rpoD confirmed that strain IA19T clearly separates from its closest related species. Average nucleotide identity between strains IA19T and P. abietaniphila ATCC 700689T, P. graminis DSM 11363T, P. alkylphenolica KL28T and P. lutea DSM 17257T were 85.3, 80.2, 79.0, and 72.1%, respectively. Growth occurs at 4-37°C and pH 6.5-8. Optimal growth occurs at 28°C, pH 7-8 and up to 2.5% NaCl. Respiratory ubiquinones are Q9 (97%) and Q8 (3%). C16:0 and in summed feature 3 are the main fatty acids. Based on genotypic, phenotypic and chemotaxonomic characteristics, the description of Pseudomonas bohemica sp. nov. has been proposed. The type strain is IA19T (=CECT 9403T = LMG 30182T).

17.
Sci Total Environ ; 619-620: 9-17, 2018 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-29136536

RESUMEN

Bark beetles reproduce and overwinter under the bark of trees, and are associated with bacteria that may influence the fitness of their hosts. As regard the aim of this study was to test the metabolic potential of bacterial strains, isolated from the bark beetle species Cryphalus piceae, Ips typographus and Pityophthorus pityophthorus and collected in the Czech Republic from fir, spruce and pine trees, respectively, to degrade plant cell compounds. The bacterial strains were identified as belonging to the genera Curtobacterium, Erwinia, Pantoea, Pseudomonas, Rahnella, Staphylococcus, and Yersinia. Several activities related to the degradation of lignocellulosic materials, such as cellulose, xylan and starch, were found. Moreover, the genomes of three of these strains were sequenced and analyzed, and the presence of the enzymatic machinery required for biomass hydrolysis was discovered. This finding supports the idea that bacteria aid in the provision of nutrients to the beetle from the hydrolysis of tree compounds, results that are relevant for studying the ecological implication of bacterial strains in the bark beetle life cycle. In addition, the activities found in association with the bacterial strains could be useful in biotechnological processes, such as the production of biofuels from biomass, colorant degradation, in the textile industry and for wastewater treatments. Furthermore, the gene sequences of the lignocellulolytic enzymes found within the genomes serve as a basis for future studies regarding the potential application of these bacteria, and their metabolic machinery, in processes such as biomass hydrolysis and bioremediation.


Asunto(s)
Bacterias/metabolismo , Escarabajos/microbiología , Bosques , Lignina/metabolismo , Abies , Animales , República Checa , Picea , Pinus , Corteza de la Planta
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