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1.
J Sci Food Agric ; 102(1): 407-416, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34143900

RESUMO

BACKGROUND: Hydric stress affects the production of wheat (Triticum aestivum L.) worldwide, making some tools necessary to cope with the decrease in rainfall. A sustainable alternative is the use of arbuscular mycorrhizal fungi (AMF) as biofertilisers. Here, we analysed the effects of AMF strains adapted or non-adapted to hyper-arid conditions on the phenolic profiles and antioxidant activities of wheat grains from two cultivars with contrasting tolerance to osmotic stress (Ilustre, moderately tolerant; and Maxi, tolerant) grown with and without hydric stress. RESULTS: Eight phenolic compounds were detected, apigenin-C-pentoside-C-hexoside I being the most abundant and showing an increase of 80.5% when inoculated with the fungus Funneliformis mosseae (FM) obtained from Atacama Desert under normal irrigation with respect to non-mycorrhizal (NM) plants. NM treatments were associated with higher grain yields. FM showed a noticeable effect on most phenolic compounds, with an increase up to 30.2% in apigenin-C-pentoside-C-hexoside III concentration under hydric stress with respect to normal irrigation, being also responsible for high antioxidant activities such as ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) and DPPH (2,2-diphenyl-1-picrylhydrazyl) activities. CONCLUSION: Inoculation with FM adapted to hydric stress produced improvements in phenolics composition and antioxidant activities in grains from wheat plants growing under hydric stress conditions, improving their food quality and supporting the development of further studies to determine whether the use of adapted AMF could be a realistic tool to improve grain quality in a scenario of increasing hydric stress conditions. © 2021 Society of Chemical Industry.


Assuntos
Inoculantes Agrícolas/fisiologia , Antioxidantes/química , Fungos/fisiologia , Micorrizas/fisiologia , Fenóis/química , Sementes/química , Triticum/crescimento & desenvolvimento , Antioxidantes/metabolismo , Fenóis/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Sementes/microbiologia , Triticum/química , Triticum/metabolismo , Triticum/microbiologia
2.
Int J Mol Sci ; 22(17)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34502164

RESUMO

Plant pathogenic bacteria cause significant economic losses in the global food production sector. To secure an adequate amount of high-quality nutrition for the growing human population, novel approaches need to be undertaken to combat plant disease-causing agents. As the currently available methods to eliminate bacterial phytopathogens are scarce, we evaluated the effectiveness and mechanism of action of a non-thermal atmospheric pressure plasma (NTAPP). It was ignited from a dielectric barrier discharge (DBD) operation in a plasma pencil, and applied for the first time for eradication of Dickeya and Pectobacterium spp., inoculated either on glass spheres or mung bean seeds. Furthermore, the impact of the DBD exposure on mung bean seeds germination and seedlings growth was estimated. The observed bacterial inactivation rates exceeded 3.07 logs. The two-minute DBD exposure stimulated by 3-4% the germination rate of mung bean seeds and by 13.4% subsequent early growth of the seedlings. On the contrary, a detrimental action of the four-minute DBD subjection on seed germination and early growth of the sprouts was noted shortly after the treatment. However, this effect was no longer observed or reduced to 9.7% after the 96 h incubation period. Due to the application of optical emission spectrometry (OES), transmission electron microscopy (TEM), and confocal laser scanning microscopy (CLSM), we found that the generated reactive oxygen and nitrogen species (RONS), i.e., N2, N2+, NO, OH, NH, and O, probably led to the denaturation and aggregation of DNA, proteins, and ribosomes. Furthermore, the cellular membrane disrupted, leading to an outflow of the cytoplasm from the DBD-exposed cells. This study suggests the potential applicability of NTAPPs as eco-friendly and innovative plant protection methods.


Assuntos
Doenças das Plantas/prevenção & controle , Gases em Plasma/farmacologia , Sementes/efeitos dos fármacos , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/ultraestrutura , Germinação/efeitos dos fármacos , Humanos , Doenças das Plantas/microbiologia , Gases em Plasma/administração & dosagem , Plântula/efeitos dos fármacos , Sementes/microbiologia , Vigna/efeitos dos fármacos , Vigna/microbiologia
3.
Dokl Biochem Biophys ; 499(1): 260-265, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34426924

RESUMO

Several ascomycetous entomopathogenic fungi, including species in the genera Beauveria, are plant symbionts/endophytes and are termed as endophytic insect-pathogenic fungi. It was shown that the fungus Beauveria bassiana (BBK-1 strain) successfully colonized Vicia faba bean plants in laboratory and field conditions of Western Siberia. The B. bassiana reisolate passed through the plants had significantly higher antagonistic activity against phytopathogens in comparison with the primary stem of entomopahogenic fungi. Pre-sowing faba bean seeds treatment reduced the level of infection of the seed material with phytopathogens, significantly decrease the development and prevalence of root rot disease. A decrease in the disease development index (chocolate spot, powdery mildew, fusariosis and other spots diseases) was found as a result of the use of B. bassiana. The effectiveness and prolonged action of B. bassiana on plants opens up new opportunities both in the creation of biological products and in molecular-genetic research and selection of certain pairs of plants and fungi based on the principle of the greatest synergy.


Assuntos
Beauveria/fisiologia , Doenças das Plantas/microbiologia , Vicia faba/microbiologia , Endófitos , Sementes/microbiologia
4.
Sci Rep ; 11(1): 17196, 2021 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-34433897

RESUMO

Heavy metals contaminate the soil that alters the properties of soil and negatively affect plants growth. Using microorganism and plant can remove these pollutants from soil. The present investigation was designed to evaluate the induced effect of Bacillus pumilus on maize plant in Cadmium (Cd) contaminated soil. Three different concentrations of Cd (i.e. 0.25, 0.50 and 0.75 mg kg-1) were applied in soil under which maize plants were grown. The germination percentage, shoot length, leaf length, number of leaves, root length, fresh weight and nutrient uptake by maize plant were determined. The experiment was conducted by using complete randomized design (CRD) with three replicates. The result indicated that germination percentage, Shoot length, leaf length, root length, number of leaves, and plant fresh weight were reduced by 37, 39, 39, 32 and 59% respectively at 0.75 mg kg-1 of CdSO4 concentration but when maize seeds inoculated with Bacillus pumilus significantly increased the germination percentage, shoot length, leaf length, number of leaves, plant fresh weight at different concentrations of CdSO4. Moreover, the plant protein were significantly increased by 60% in T6 (0.25 mg kg-1 of CdSO4 + inoculated seed) and Peroxidase dismutase (POD) was also significantly higher by 346% in T6 (0.25 mg kg-1 of CdSO4 + inoculated seed), however, the Superoxide dismutase (SOD) was significantly higher in T5 (0.75 mg kg-1 of CdSO4 + uninoculated seed) and was 769% higher as compared to control. The Cd contents in Bacillus pumilus inoculated maize roots and shoots were decreased. The present investigations indicated that the inoculation of maize plant with Bacillus pumilus can help maize plants to withstand Cd stress but higher concentration of Cd can harm the plant. The Bacillus pumilus has good potential to remediate Cd from soil, and also have potential to reduce the phyto availability and toxicity of Cd.


Assuntos
Bacillus pumilus/metabolismo , Cádmio/toxicidade , Poluentes do Solo/toxicidade , Zea mays/efeitos dos fármacos , Bacillus pumilus/patogenicidade , Biodegradação Ambiental , Cádmio/metabolismo , Sementes/efeitos dos fármacos , Sementes/metabolismo , Sementes/microbiologia , Poluentes do Solo/metabolismo , Estresse Fisiológico , Zea mays/metabolismo , Zea mays/microbiologia
5.
Int J Food Microbiol ; 354: 109316, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34247020

RESUMO

Fermented soy sauces are used as food seasonings in Eastern countries and all over the world. Depending on their cultural origins, their production differs in parameters such as wheat addition, temperature, and salt concentration. The fermentation of lupine seeds presents an alternative to the use of soybeans; however, the microbiota and influencing factors are currently unknown. In this study, we analyse the microbiota of lupine Moromi (mash) fermentations for a period of six months and determine the influence of different salt concentrations on the microbiota dynamics and the volatile compound composition. Cultured microorganisms were identified by protein profiling using matrix-assisted laser desorption-ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16S rRNA gene amplicon sequencing provided an overview of the microbiota including non-cultured bacteria. The volatile compounds were determined by gas chromatography-mass spectrometry (GC-MS). At all salt concentrations, we found that Tetragenococcus halophilus (up to 1.4 × 109 colony forming units (CFU)/mL on day 21) and Chromohalobacter japonicus (1.9 × 109 CFU/mL, day 28) were the dominating bacteria during Moromi fermentation. Debaryomyces hansenii (3.6 × 108 CFU/mL, day 42) and Candida guilliermondii (2.2 × 108 CFU/mL, day 2) were found to be the most prevalent yeast species. Interestingly, Zygosaccharomyces rouxii and other yeasts described as typical for soy Moromi were not found. With increasing salinity, we found lower diversity in the microbiota, the prevalence-gain of typical species was delayed, and ratios differed depending on their halo- or acid tolerance. GC-MS analysis revealed aroma-active compounds, such as pyrazines, acids, and some furanones, which were mostly different from the aroma compounds found in soy sauce. The absence of wheat may have caused a change in yeast microbiota, and the use of lupine seeds may have led to the differing aromatic composition. Salt reduction resulted in a more complex microbiome, higher cell counts, and did not show any spoiling organisms. With these findings, we show that seasoning sauce that uses lupine seeds as the sole substrate is a suitable gluten-free, soy-free and salt reduced alternative to common soy sauces with a unique flavour.


Assuntos
Alimentos e Bebidas Fermentados , Lupinus , Microbiota , Sementes , Chromohalobacter/metabolismo , Enterococcaceae/metabolismo , Alimentos e Bebidas Fermentados/microbiologia , Microbiologia de Alimentos , Lupinus/química , Microbiota/efeitos dos fármacos , Microbiota/genética , RNA Ribossômico 16S/genética , Saccharomycetales/metabolismo , Sementes/microbiologia , Cloreto de Sódio/farmacologia
6.
J Adv Res ; 31: 75-86, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34194833

RESUMO

Introduction: The seed-associated microbiome has a strong influence on plant ecology, fitness, and productivity. Plant microbiota could be exploited for a more responsible crop management in sustainable agriculture. However, the relationships between seed microbiota and hosts related to the changes from ancestor species to breeded crops still remain poor understood. Objectives: Our aims were i) to understand the effect of cereal domestication on seed endophytes in terms of diversity, structure and co-occurrence, by comparing four cereal crops and the respective ancestor species; ii) to test the phylogenetic coherence between cereals and their seed microbiota (clue of co-evolution). Methods: We investigated the seed microbiota of four cereal crops (Triticum aestivum, Triticum monococcum, Triticum durum, and Hordeum vulgare), along with their respective ancestors (Aegilops tauschii, Triticum baeoticum, Triticum dicoccoides, and Hordeum spontaneum, respectively) using 16S rRNA gene metabarcoding, Randomly Amplified Polymorphic DNA (RAPD) profiling of host plants and co-evolution analysis. Results: The diversity of seed microbiota was generally higher in cultivated cereals than in wild ancestors, suggesting that domestication lead to a bacterial diversification. On the other hand, more microbe-microbe interactions were detected in wild species, indicating a better-structured, mature community. Typical human-associated taxa, such as Cutibacterium, dominated in cultivated cereals, suggesting an interkingdom transfers of microbes from human to plants during domestication. Co-evolution analysis revealed a significant phylogenetic congruence between seed endophytes and host plants, indicating clues of co-evolution between hosts and seed-associated microbes during domestication. Conclusion: This study demonstrates a diversification of the seed microbiome as a consequence of domestication, and provides clues of co-evolution between cereals and their seed microbiota. This knowledge is useful to develop effective strategies of microbiome exploitation for sustainable agriculture.


Assuntos
Domesticação , Grão Comestível/microbiologia , Hordeum/microbiologia , Microbiota , Sementes/microbiologia , Triticum/microbiologia , Aegilops/genética , Aegilops/microbiologia , Evolução Biológica , Produtos Agrícolas/genética , Produtos Agrícolas/microbiologia , Grão Comestível/genética , Endófitos/metabolismo , Hordeum/genética , Humanos , Filogenia , Propionibacteriaceae/classificação , Propionibacteriaceae/genética , RNA Ribossômico 16S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico/métodos , Sementes/genética , Triticum/genética
7.
Int J Food Microbiol ; 352: 109266, 2021 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-34111728

RESUMO

The germination process causes changes in the chemical composition of seeds that improves the nutritional value of sprouts, while decreasing their microbiological safety, since the germination conditions are ideal for bacterial growth as well. This review explores the bacteriological safety of sprouts and their involvement in foodborne illness outbreaks, worldwide. Additionally, approaches to improve the shelf-life and microbiological safety of sprouts are discussed. According to the literature, sprout consumption is associated with more than 60 outbreaks of foodborne illness worldwide, since 1988. Alfalfa sprouts were most commonly involved in outbreaks and the most commonly implicated pathogens were Salmonella and pathogenic Escherichia coli (especially, Shiga toxin producing E. coli). In the pre-harvest stage, the implementation of good agricultural practices is an important tool for producing high-quality seeds. In the post-harvest stage, several methods of seed decontamination are used commercially, or have been investigated by researchers. After germination, seedlings should be kept under refrigeration and, if possible, cooked before consumption. Finally, microbiological analyses should be performed at all stages to monitor the hygiene of the sprout production process.


Assuntos
Microbiologia de Alimentos , Doenças Transmitidas por Alimentos/epidemiologia , Doenças Transmitidas por Alimentos/microbiologia , Plântula/microbiologia , Verduras/microbiologia , Surtos de Doenças/prevenção & controle , Surtos de Doenças/estatística & dados numéricos , Doenças Transmitidas por Alimentos/etiologia , Doenças Transmitidas por Alimentos/prevenção & controle , Humanos , Medicago sativa/microbiologia , Salmonella/crescimento & desenvolvimento , Sementes/microbiologia
8.
Int J Food Microbiol ; 354: 109282, 2021 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-34140187

RESUMO

Coffee fermentation involves the action of microorganisms, whose metabolism has a significant influence on the composition of the beans and, consequently, on the beverage's sensory characteristics. In this study, the microbial diversity during the wet fermentation of Coffea arabica L. in the Sierra Nevada of Santa Marta (SNSM) in Colombia was explored by high-throughput sequencing and the resulting cup quality through the standards of the Specialty Coffee Association. The taxonomic assignment of sequence reads showed a high microbial diversity comprised of 695 bacterial and 156 fungal genera. The microbial community was dominated by the Lactic Acid Bacteria (LAB) Leuconostoc, the yeast Kazachstania, and the Acetic Acid Bacteria (AAB) Acetobacter. Co-occurrence relationships suggested synergistic patterns between populations of LAB-AAB, yeasts-AAB, Leuconostoc-Prevotella, LAB-ABB-Selenomonas, and yeasts-fungi-nonLAB-nonAAB, which may result in the production of metabolites that positively impact the sensory attributes of coffee. The beverages produced were classified as specialty coffees, and their score was positively influenced by the fungal richness and the abundance of unclassified Lactobacillales, Pichia, and Pseudomonas. The findings show the richness and microbial diversity of the SNSM and serve as input for future research such as the analysis of microbial-derived metabolites and the establishment of starter cultures in coffee processing that guarantee the generation of high-quality beverages, the standardization of processes, the reduction of economic losses, and the production of value-added products that allow taking advantage of specialty coffee market.


Assuntos
Biodiversidade , Coffea , Fermentação , Microbiota , Sementes , Bactérias/classificação , Bactérias/metabolismo , Coffea/microbiologia , Colômbia , Fungos/classificação , Fungos/metabolismo , Microbiota/fisiologia , Sementes/metabolismo , Sementes/microbiologia
9.
Food Microbiol ; 99: 103805, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34119098

RESUMO

This study was done to develop a method to inactivate Escherichia coli O157:H7 on radish and cabbage seeds using simultaneous treatments with gaseous chlorine dioxide (ClO2) and heat at high relative humidity (RH) without decreasing seeds' viability. Gaseous ClO2 was spontaneously vaporized from a solution containing hydrochloric acid (HCl, 1 N) and sodium chlorite (NaClO2, 100,000 ppm). Using a sealed container (1.8 L), an equation (y = 5687×, R2 = 0.9948) based on the amount of gaseous ClO2 generated from HCl-NaClO2 solution at 60 °C and 85% RH was developed. When radish or cabbage seeds were exposed to gaseous ClO2 at concentrations up to 3,000 ppm for 120 min, germination rates did not significantly decrease (P > 0.05). When seeds inoculated with E. coli O157:H7 were treated with 2,000 or 3,000 ppm of gaseous ClO2 in an atmosphere with 85% RH at 60 °C, populations (6.8-6.9 log CFU/g) on both types of seeds were decreased to below the detection limit for enrichment (-0.5 log CFU/g) within 90 min. This study provides useful information for developing a decontamination method to control E. coli O157:H7 and perhaps other foodborne pathogens on plant seeds by simultaneous treatment with gaseous ClO2 and heat at high RH.


Assuntos
Brassica/crescimento & desenvolvimento , Compostos Clorados/farmacologia , Descontaminação/métodos , Desinfetantes/farmacologia , Escherichia coli O157/efeitos dos fármacos , Óxidos/farmacologia , Raphanus/crescimento & desenvolvimento , Sementes/microbiologia , Brassica/microbiologia , Cloro/farmacologia , Escherichia coli O157/crescimento & desenvolvimento , Germinação/efeitos dos fármacos , Temperatura Alta , Umidade , Viabilidade Microbiana/efeitos dos fármacos , Raphanus/microbiologia , Sementes/química , Sementes/crescimento & desenvolvimento
10.
Appl Environ Microbiol ; 87(16): e0058421, 2021 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-34105982

RESUMO

Metagenomic studies about cocoa fermentation have mainly reported on the analysis of short reads for determination of operational taxonomic units. However, it is also important to determine metagenome-assembled genomes (MAGs), which are genomes deriving from the assembly of metagenomics. For this research, all the cocoa metagenomes from public databases were downloaded, resulting in five data sets: one from Ghana and four from Brazil. In addition, in silico approaches were used to describe putative phenotypes and the metabolic potential of MAGs. A total of 17 high-quality MAGs were recovered from these microbiomes, as follows: (i) for fungi, Yamadazyma tenuis (n = 1); (ii) lactic acid bacteria, Limosilactobacillus fermentum (n = 5), Liquorilactobacillus cacaonum (n = 1), Liquorilactobacillus nagelli (n = 1), Leuconostoc pseudomesenteroides (n = 1), and Lactiplantibacillus plantarum subsp. plantarum (n = 1); (iii) acetic acid bacteria, Acetobacter senegalensis (n = 2) and Kozakia baliensis (n = 1); and (iv) Bacillus subtilis (n = 1), Brevundimonas sp. (n = 2), and Pseudomonas sp. (n = 1). Medium-quality MAGs were also recovered from cocoa microbiomes, including some that, to our knowledge, were not previously detected in this environment (Liquorilactobacillus vini, Komagataeibacter saccharivorans, and Komagataeibacter maltaceti) and others previously described (Fructobacillus pseudoficulneus and Acetobacter pasteurianus). Taken together, the MAGs were useful for providing an additional description of the microbiome of cocoa fermentation, revealing previously overlooked microorganisms, with prediction of key phenotypes and biochemical pathways. IMPORTANCE The production of chocolate starts with the harvesting of cocoa fruits and the spontaneous fermentation of the seeds in a microbial succession that depends on yeasts, lactic acid bacteria, and acetic acid bacteria in order to eliminate bitter and astringent compounds present in the raw material, which will be further roasted and grinded to originate the cocoa powder that will enter the food processing industry. The microbiota of cocoa fermentation is not completely known, and yet it advanced from culture-based studies to the advent of next-generation DNA sequencing, with the generation of a myriad of data that need bioinformatic approaches to be properly analyzed. Although the majority of metagenomic studies have been based on short reads (operational taxonomic units), it is also important to analyze entire genomes to determine more precisely possible ecological roles of different species. Metagenome-assembled genomes (MAGs) are very useful for this purpose; here, MAGs from cocoa fermentation microbiomes are described, and the possible implications of their phenotypic and metabolic potentials are discussed.


Assuntos
Bactérias/isolamento & purificação , Cacau/microbiologia , Chocolate/microbiologia , Fungos/isolamento & purificação , Microbiota , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Cacau/metabolismo , Chocolate/análise , Fermentação , Fungos/classificação , Fungos/genética , Fungos/metabolismo , Metagenoma , Filogenia , Sementes/metabolismo , Sementes/microbiologia
11.
PLoS One ; 16(6): e0252605, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34153055

RESUMO

Metagenomic analysis of food is becoming more routine and can provide important information pertaining to the shelf life potential and the safety of these products. However, less information is available on the microbiomes associated with low water activity foods. Pine nuts and sesame seeds, and food products which contain these ingredients, have been associated with recalls due to contamination with bacterial foodborne pathogens. The objective of this study was to identify the microbial community of pine nuts and sesame seeds using targeted 16S rRNA sequencing technology. Ten different brands of each seed type were assessed, and core microbiomes were determined. A total of 21 and 16 unique taxa with proportional abundances >1% in at least one brand were identified in the pine nuts and sesame seeds, respectively. Members of the core pine nut microbiome included the genera Alishewanella, Aminivibrio, Mycoplasma, Streptococcus, and unassigned OTUs in the families of Desulfobacteraceae and Xanthomonadaceae. For sesame seeds, the core microbiome included Aminivibrio, Chryseolina, Okibacterium, and unassigned OTUs in the family Flavobacteriaceae. The microbiomes of these seeds revealed that these products are dominated by environmental bacterial genera commonly isolated from soil, water, and plants; bacterial genera containing species known as commensal organisms were also identified. Understanding these microbiomes can aid in the risk assessment of these products by identifying food spoilage potential and community members which may co-enrich with foodborne bacterial pathogens.


Assuntos
Microbiota , Pinus/microbiologia , Sesamum/microbiologia , Alteromonadaceae/genética , Alteromonadaceae/isolamento & purificação , Nozes/microbiologia , Pinus/crescimento & desenvolvimento , Análise de Componente Principal , RNA Ribossômico 16S/genética , Sementes/microbiologia , Sesamum/crescimento & desenvolvimento , Streptococcus/genética , Streptococcus/isolamento & purificação
12.
Microbiol Res ; 250: 126794, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34062342

RESUMO

The study of endophytic bacteria in saline-alkali tolerant rice seeds is of great help to the follow-up study of saline-alkali tolerant mechanism and the exploitation of saline-alkali tolerant microbial resources. In this study, high-throughput sequencing technology based on the Illumina Miseq platform was used to reveal the "core microbiota" by examining the diversity and community structures of seed endophytic bacteria in saline-alkali tolerant rice grown under different salt concentrations and explore the effect of salt concentration on its endophytic bacteria. Here, 49 endophytic OTUs were found to coexist in all samples. At the phylum level, the dominant phyla were Proteobacteria (83.90 %-99.87 %). At the genus level, Pantoea (44.65-94.76 %) which represents the core microbiota in saline-alkali tolerant rice seeds, served as the dominant genus that coexisted in all samples tested. Through further analysis, we found that the abundance of Pantoea in saline-alkali tolerant rice seeds was positively proportional to the level of salt concentration. Overall, this study showed that the core microbiota of saline-alkali tolerant rice seeds is Pantoea, and the change of salt concentration is a key factor in the formation of endophytic bacteria in saline-alkali tolerant rice seeds.


Assuntos
Álcalis/metabolismo , Bactérias/genética , Endófitos/genética , Sequenciamento de Nucleotídeos em Larga Escala , Microbiota/genética , Oryza/microbiologia , Sementes/microbiologia , Bactérias/classificação , Variação Genética , Oryza/metabolismo , Filogenia , Análise de Sequência de DNA/estatística & dados numéricos , Solo/química , Microbiologia do Solo
13.
Sci Rep ; 11(1): 13307, 2021 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-34172799

RESUMO

The mutualistic relationship between alien plant species and microorganisms is proposed to facilitate or hinder invasive success, depending on whether plants can form novel associations with microorganisms in the introduced habitats. However, this hypothesis has not considered seed endophytes that would move together with plant propagules. Little information is available on the seed endophytic bacteria of invasive species and their effects on plant performance. We isolated the seed endophytic bacteria of a xerophytic invasive plant, Lactuca serriola, and examined their plant growth-promoting traits. In addition, we assessed whether these seed endophytes contributed to plant drought tolerance. Forty-two bacterial species were isolated from seeds, and all of them exhibited at least one plant growth-promoting trait. Kosakonia cowanii occurred in all four tested plant populations and produced a high concentration of exopolysaccharides in media with a highly negative water potential. Notably, applying K. cowanii GG1 to Arabidopsis thaliana stimulated plant growth under drought conditions. It also reduced soil water loss under drought conditions, suggesting bacterial production of exopolysaccharides might contribute to the maintenance of soil water content. These results imply that invasive plants can disperse along with beneficial bacterial symbionts, which potentially improve plant fitness and help to establish alien plant species.


Assuntos
Asteraceae/microbiologia , Asteraceae/fisiologia , Endófitos/fisiologia , Sementes/microbiologia , Sementes/fisiologia , Bactérias , Secas , Enterobacteriaceae/fisiologia , Desenvolvimento Vegetal/fisiologia , Raízes de Plantas/microbiologia , Raízes de Plantas/fisiologia , Solo , Estresse Fisiológico/fisiologia , Simbiose/fisiologia
14.
Artigo em Inglês | MEDLINE | ID: mdl-33983875

RESUMO

Clavibacter michiganensis is a Gram-stain-positive bacterium with eight subspecies, five of which have been redefined as different species on the basis of their genome sequence data. On the basis of the results of phylogenetic analysis of dnaA gene sequences, strains of members of the genus Clavibacter isolated from barley have been grouped in a separate clade from other species and subspecies of the genus Clavibacter. In this study, the biochemical, physiological, fatty acids and genetic characteristics of strains DM1T and DM3, which represented the barley isolates, were examined. On the basis of results from multi-locus sequence typing and other biochemical and physiological features, including colony colour, carbon source utilisation and enzyme activities, DM1T and DM3 are categorically differentiated from the aforementioned eight species and subspecies of the genus Clavibacter. Moreover, the results of genomic analysis reveal that the DNA G+C contents of DM1T and DM3 are 73.7 and 73.5 %, respectively, and the average nucleotide identity (ANI) values between DM1T and DM3 and other species and subspecies range from 90.4 to 92.0 %. The ANI value between DM1T and DM3 is 98.0 %. These results indicate that DM1T and DM3 are distinct from other known species and subspecies of the genus Clavibacter. Therefore, we propose a novel species, C. zhangzhiyongii, with DM1T (=CFCC 16553 T=LMG 31970T) as the type strain.


Assuntos
Clavibacter/classificação , Hordeum/microbiologia , Filogenia , Doenças das Plantas/microbiologia , Sementes/microbiologia , Austrália , Técnicas de Tipagem Bacteriana , Composição de Bases , China , Clavibacter/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , Tipagem de Sequências Multilocus , Pigmentação , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
15.
Methods Mol Biol ; 2309: 75-89, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34028680

RESUMO

Strigolactones (SLs) are components of root exudates as a consequence of active release from the roots into the soil. Notably, they have been described as stimulants of seed germination in parasitic plants and of the presymbiotic growth in arbuscular mycorrhizal (AM) fungi, which are a crucial component of the plant root beneficial microbiota. SLs have therefore the potential to influence other microbes that proliferate in the soil around the roots and may interact with plants. A direct effect of SL analogs on the in vitro growth of a number of saprotrophic or plant pathogenic fungi was indeed reported.Here we describe a standardized method to evaluate the effect of SLs or their synthetic analogs on AM and filamentous fungi. For AM fungi, we propose a spore germination assay since it is more straightforward than the hyphal branching assay and it does not require deep expertise and skills. For filamentous fungi that can grow in axenic cultures, we describe the assay based on SLs embedded in the solid medium or dissolved in liquid cultures where the fungus is inoculated to evaluate the effect on growth, hyphal branching or conidia germination. These assays are of help to test the activity of natural SLs as well as of newly designed SL analogs for basic and applied research.


Assuntos
Bioensaio , Fungos/efeitos dos fármacos , Compostos Heterocíclicos com 3 Anéis/farmacologia , Lactonas/farmacologia , Micorrizas/efeitos dos fármacos , Reguladores de Crescimento de Plantas/farmacologia , Sementes/microbiologia , Esporos Fúngicos/efeitos dos fármacos , Trifolium/microbiologia , Fungos/crescimento & desenvolvimento , Compostos Heterocíclicos com 3 Anéis/síntese química , Lactonas/síntese química , Micorrizas/crescimento & desenvolvimento , Reguladores de Crescimento de Plantas/síntese química , Esporos Fúngicos/crescimento & desenvolvimento
16.
World J Microbiol Biotechnol ; 37(6): 94, 2021 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-33963474

RESUMO

The application of plant growth-promoting bacteria in agricultural systems is an efficient and environment-friendly strategy to improve crop yields and maintain soil quality. However, as different soils have diverse and specific ecological characteristics and may represent adverse abiotic conditions, in vivo application requires the careful selection of the desired beneficial microorganisms. In this study we report Ensifer adhaerens SZMC 25856 and Pseudomonas resinovorans SZMC 25875 isolates recovered from glyphosate-treated soil to possess yet undiscovered plant growth-enhancing potential. The strains were found to promote the growth of tomato seedlings significantly, to have the ability of synthesizing indole-3-acetic acid and siderophores, to tolerate pH in the range of 6.59-7.96, salinity up to 12.5 g L-1 NaCl and drought up to 125 g L-1 polyethylene glycol 6000, as well as to survive in the presence of various pesticides including glyphosate, diuron, chlorotoluron, carbendazim and thiabendazole, and heavy metals such as Al, Fe, Mn, Zn, Pb and Cu. The plant growth-promoting traits of the examined E. adhaerens and P. resinovorans isolates and their tolerance to numerous abiotic stress factors make them promising candidates for application in different agricultural environments, including soils polluted with glyphosate.


Assuntos
Glicina/análogos & derivados , Lycopersicon esculentum/crescimento & desenvolvimento , Pseudomonas/isolamento & purificação , Rhizobiaceae/isolamento & purificação , Glicina/farmacologia , Concentração de Íons de Hidrogênio , Ácidos Indolacéticos/metabolismo , Lycopersicon esculentum/microbiologia , Metais Pesados/farmacologia , Pseudomonas/metabolismo , Pseudomonas/fisiologia , RNA Ribossômico 16S/genética , Rhizobiaceae/metabolismo , Rhizobiaceae/fisiologia , Sementes/crescimento & desenvolvimento , Sementes/microbiologia , Sideróforos/metabolismo , Microbiologia do Solo , Estresse Fisiológico
17.
Sci Rep ; 11(1): 10390, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34001970

RESUMO

Mycological investigations of 25 samples of stored chickpea food seeds (Cicer arietinum L.) from grocery stores of Gurgaon and Gorakhpur revealed occurrence of seventeen fungal species belonging to genus viz., Alternaria, Aspergillus, Chaetomium, Colletotrichum, Curvularia, Fusarium, Penicillium, Rhizopus, Rhizoctonia, and Sclerotium. In these Aspergillus flavus, A. niger, Fusarium oxysporum had dominance in terms of per cent occurrence. Only one species of Bruchid (Callosobruchus chinensis L.) occurred in all the 25 samples. The biodeterioration of seeds inoculated with fungi: A. flavus, A. niger, F. oxysporum and the insect-C. chinensis, revealed their role in seed deterioration. For chickpea food seed protection essential oils were extracted from edible commodity(clove(Lavang and dill(sowa) leaf). Clove(Lavang) oil registered highest antifungal activity inhibiting (100%) mycelial growth of fungi, viz. species Aspergillus flavus, A. niger, Fusarium oxysporum at 300 ppm but was fungicidal at 400 ppm. Dill (Sowa) oil showed complete inhibition at 400 ppm and was fungicidal at 500 ppm. While mixture of both the oils (clove and dill) showed complete inhibition (100%) and fungicidal action at 400 ppm against the dominant fungi. The oils showed 100% insect repellent activity and were found fungicidal at 0.02 ml dose and also insecticidal. The mixture of oils was cidal at 0.02 ml dose. The mixture of oils showed a broad antifungal spectrum at 500 ppm while only 70-93% inhibitory activity at 300 ppm. The oils' mixture's activity was not affected by temp, storage and autoclaving up to 150 days. Oils physico-chemical properties were studied. GC-MS analysis of clove(Lavang) oil depicted major components: 75.63%eugenol while dill(sowa) leaf oil had 25.14% apiole. Formulation of Mixture of oils was more effective showing complete seed protection i.e.no growth of fungi and insects upto 150 days storage than salphos (150 days). While salphos controlled only maximum three fungi (A. terreus, C. dematium, F. moniliforme). The formulated oils mixture did not have any adverse effect on the chickpea seeds and increased their shelf life.


Assuntos
Cicer/microbiologia , Armazenamento de Alimentos , Óleos Voláteis/farmacologia , Sementes/microbiologia , Anethum graveolens/química , Antifúngicos/farmacologia , Aspergillus/efeitos dos fármacos , Aspergillus flavus/efeitos dos fármacos , Óleo de Cravo/farmacologia , Fusarium/efeitos dos fármacos , Óleos Vegetais/farmacologia
18.
BMC Microbiol ; 21(1): 143, 2021 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-33980153

RESUMO

BACKGROUND: Seed dimorphism has been thought to be a bet-hedging strategy that helps plants survive in the disturbed environment and has been widely studied for its ecological adaptation mechanism. Many studies showed that seed-associated microorganisms play an important role in enhancing plant fitness, but information regarding endophytic bacteria associated with dimorphic seeds is limited. This study explores the influence of seed coat structure and seed phytochemical properties on the community composition and diversity of endophytic bacteria of dimorphic seeds of Suaeda glauca. In this study, we used 16S rRNA high-throughput gene sequencing method to compare the community composition and bacterial diversity between brown and black seeds of Suaeda glauca. RESULTS: A significant difference was observed in seed coat structure and phytochemical properties between brown and black seeds of S. glauca. Total 9 phyla, 13 classes, 31 orders, 53 families, 102 genera were identified in the dimorphic seeds. The dominant phyla were Proteobacteria, Firmicutes, and Actinobacteria. The results showed that seed dimorphism had little impact on the diversity and richness of endophytic bacterial communities but significantly differs in the relative abundance of the bacterial community between brown and black seeds. At the phylum level, Actinobacteria tend to be enriched significantly in brown seeds. At the genus level, Rhodococcus, Ralstonia, Pelomonas and Bradyrhizobium tend to be enriched significantly in brown seeds, while Marinilactibacillus was mainly found in black seeds. Besides, brown seeds harbored a large number of bacteria with plant-growth-promoting traits, whereas black seeds presented bacteria with enzyme activities (i.e., pectinase, cellulolytic and xylanolytic activities). CONCLUSION: The endophytic bacterial community compositions were significantly different between dimorphic seeds of Suaeda glauca, and play an important role in the ecological adaptation of dimorphic seeds by performing different biological function roles. The endophytic bacterial communities of the dimorphic seeds may be influenced mainly by the seed coat structureand partly by the seed phytochemical characteristics. These findings provide valuable information for better understanding of the ecological adaptation strategy of dimorphic seeds in the disturbed environment.


Assuntos
Bactérias/metabolismo , Chenopodiaceae/microbiologia , Endófitos/metabolismo , Plantas Tolerantes a Sal/microbiologia , Sementes/microbiologia , Bactérias/genética , Biodiversidade , RNA Ribossômico 16S/genética
19.
Toxins (Basel) ; 13(3)2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33799633

RESUMO

Maize silage, which in Europe is the main feed for dairy cattle in winter, can be contaminated by mycotoxins. Mycotoxigenic Fusarium spp. originating from field infections may survive in badly sealed silages or re-infect at the cutting edge during feed-out. In this way, mycotoxins produced in the field may persist during the silage process. In addition, typical silage fungi such as Penicillium spp. and Aspergillus spp. survive in silage conditions and produce mycotoxins. In this research, 56 maize silages in Flanders were sampled over the course of three years (2016-2018). The concentration of 22 different mycotoxins was investigated using a multi-mycotoxin liquid chromatography-tandem mass spectrometry (LC-MS/MS) method, and the presence of DNA of three Fusarium spp. (F. graminearum, F. culmorum and F. verticillioides) was analyzed in a selection of these samples using quantitative polymerase chain reaction (qPCR). Every maize silage contained at least two different mycotoxins. Nivalenol (NIV) and deoxynivalenol (DON) were the most prevalent (both in 97.7% of maize silages), followed by ENN B (88.7%). Concentrations often exceeded the EU recommendations for DON and zearalenone (ZEN), especially in 2017 (21.3% and 27.7% of the maize silages, respectively). No correlations were found between fungal DNA and mycotoxin concentrations. Furthermore, by ensiling maize with a known mycotoxin load in a net bag, the mycotoxin contamination could be monitored from seed to feed. Analysis of these net bag samples revealed that the average concentration of all detected mycotoxins decreased after fermentation. We hypothesize that mycotoxins are eluted, degraded, or adsorbed during fermentation, but certain badly preserved silages are prone to additional mycotoxin production during the stable phase due to oxygen ingression, leading to extremely high toxin levels.


Assuntos
Ração Animal/microbiologia , Microbiologia de Alimentos , Armazenamento de Alimentos , Fungos/metabolismo , Micotoxinas/análise , Sementes/microbiologia , Zea mays/microbiologia , Criação de Animais Domésticos , Animais , Bélgica , Cromatografia Líquida , Indústria de Laticínios , Fungos/genética , Micotoxinas/toxicidade , Reação em Cadeia da Polimerase , Espectrometria de Massas em Tandem , Fatores de Tempo
20.
Food Microbiol ; 98: 103767, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33875203

RESUMO

The variable quality of cocoa produced by farmers is still a problem in the value chain, strongly depending on microbial activities. We analyzed the variability of cocoa microbiota from all twelve producing regions in Cote d'Ivoire, and described the geographical distribution of isolated microbiota, using a mapping. Microbial species were identified by ribosomal genes sequencing, strains were typed by RFLP and their techno-functional capacities were further investigated. Results showed a restricted diversity of lactic acid bacteria (LAB) and acetic acid bacteria (AAB) with respectively 10 and 5 strains. The dominant LAB and AAB strains, notably Lactobacillus plantarum 1 A, Acetobacter pasteurianus 1 A, Acetobacter okinawensis 2 A, and Acetobacter tropicalis 3 A, were found in all regions assuming that the acid microbiota was weakly variable. In contrast, the distribution of their functional performance such as acidification capability was variable, stronger in strains from Nawa and Haut-Sassandra regions and weaker in Indenie-Djuablin and San Pedro; this distribution seemed to be random. Moreover, the study also revealed a complex yeasts population showing a wide genetic diversity with 22 species and 45 strains indicating an intraspecific heterogeneity. Strains were generally different from a region to another and the resulting yeasts microbiota was globally variable in the regions. Likewise, the functional capacities such as pectinolytic was weak in P. kudriazevii strain 2 K from Gboklè and strong in P. kudriazevii strain 2 A from Loh-Djiboua. Additionally, the quality of fermented beans was also variable in the regions. The great variation of yeasts strains in the different regions may be the main microbial factors responsible for variation of the fermented cocoa quality observed.


Assuntos
Bactérias/isolamento & purificação , Bactérias/metabolismo , Cacau/microbiologia , Microbiota , Leveduras/isolamento & purificação , Leveduras/metabolismo , Ácido Acético/metabolismo , Bactérias/classificação , Bactérias/genética , Biodiversidade , Cacau/metabolismo , Costa do Marfim , Fermentação , Alimentos e Bebidas Fermentados/microbiologia , Ácido Láctico/metabolismo , Sementes/metabolismo , Sementes/microbiologia , Leveduras/classificação , Leveduras/genética
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