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International Journal of Molecular... Jan 2023The bacterial genus comprises species found in a variety of different environmental sources. spp. are often recovered from plant material and are capable of both...
The bacterial genus comprises species found in a variety of different environmental sources. spp. are often recovered from plant material and are capable of both benefitting the plants and acting like phytopathogens. Some species of (including ) are considered opportunistic human pathogens capable of causing various infections in immunocompromised subjects. In this study, a strain of (identified by 16S rRNA gene sequencing) was isolated from a dead specimen of an unidentified Latvian grasshopper species. The retrieved strain of was then used as a host for the potential retrieval of phages from the same source material. After rounds of plaque purification and propagation, three high-titer lysates corresponding to putatively distinct phages were acquired. Transmission electron microscopy revealed that one of the phages was a myophage with an unusual morphology, while the two others were typical podophages. Whole-genome sequencing (WGS) was performed for each of these isolated phages. Genome de novo assembly and subsequent functional annotation confirmed that three different strictly lytic phages were isolated. Elaborate genomic characterization of the acquired phages was performed to elucidate their place within the so-far-uncovered phage diversity.
Topics: Humans; Bacteriophages; Pantoea; RNA, Ribosomal, 16S
PubMed: 36768143
DOI: 10.3390/ijms24031820 -
Microorganisms May 2022a gram-negative bacterium belonging to the family, is a well-known phytopathogen isolated from many ecological niches and plant hosts. However, this bacterium also... (Review)
Review
a gram-negative bacterium belonging to the family, is a well-known phytopathogen isolated from many ecological niches and plant hosts. However, this bacterium also provides us with various beneficial characteristics, such as the growth promotion of their host plants and increased crop yield. Some isolated non-pathogenic strains are promising for the microbial production of useful substances. AJ13355 was isolated as an acidophilic bacterium and was used as an excellent host to produce L-glutamic acid under acidic conditions. The genome sequence of AJ13355 was determined, and specific genome-engineering technologies were developed. As a result, was successfully used to construct a bacterial strain that produces cysteine, a sulfur-containing amino acid that has been difficult to produce through fermentation because of complex regulation. Furthermore, by heterologous expression including plant-derived genes, construction of a strain that produces isoprenoids such as isoprene and linalool as secondary metabolites was achieved. is shown to be a useful host for the production of secondary metabolites, as well as amino acids, and is expected to be used as a platform for microbial production of bioactive substances, aromatic substances, and other high-value-added substances of plant origin in the future.
PubMed: 35744651
DOI: 10.3390/microorganisms10061133 -
Microorganisms Dec 2022, the causative agent of fire blight, leads to important economic losses of apple and pear crops worldwide. This study aimed to investigate the potential of the resident...
, the causative agent of fire blight, leads to important economic losses of apple and pear crops worldwide. This study aimed to investigate the potential of the resident microbiota of the apple blossom in combatting plant disease-causing organisms, with a focus on controlling fire blight. We obtained 538 isolates from sites around Canton Zurich, which we tested for activity against and We also evaluated the isolates' activity against oomycete and fungal pathogens. Nine isolates showed activity against , and eight of these against . Furthermore, 117 showed antifungal, and 161 anti-oomycete, activity. We assigned genera and in some cases species to 238 of the isolates by sequencing their 16S RNA-encoding gene. Five strains showed activity against all pathogens and were tested in a detached apple model for anti- activity. Of these five strains, two were able to antagonize , namely #124 and #378. We sequenced the #378 genome and analyzed it for secondary metabolite clusters using antiSMASH, revealing the presence of a putative bacteriocin cluster. We also showed that #124 exhibits strong activity against three different fungi and two oomycetes in vitro, suggesting a broader capacity for biocontrol. Our results showcase the protective potential of the natural apple blossom microbiota. We isolated two candidate biocontrol strains from apple blossoms, suggesting that they might persist at the most common entry point for the causative agent of fire blight. Furthermore, they are probably already part of the human diet, suggesting they might be safe for consumption, and thus are promising candidates for biocontrol applications.
PubMed: 36557734
DOI: 10.3390/microorganisms10122480 -
Microbiology Resource Announcements Nov 2023The Gram-negative bacterium has been isolated from various habitats including disease plants. Here, we present the genome of strain NBBC-01 obtained from rotten...
The Gram-negative bacterium has been isolated from various habitats including disease plants. Here, we present the genome of strain NBBC-01 obtained from rotten potatoes that were infected by . The genome information will prove advantageous in elucidating its ecological role.
PubMed: 37847025
DOI: 10.1128/MRA.00748-23 -
Microorganisms Sep 2020Bacteriophages are viruses capable of recognizing with high specificity, propagating inside of, and destroying their bacterial hosts. The phage lytic life cycle makes...
Bacteriophages are viruses capable of recognizing with high specificity, propagating inside of, and destroying their bacterial hosts. The phage lytic life cycle makes phages attractive as tools to selectively kill pathogenic bacteria with minimal impact on the surrounding microbiome. To effectively harness the potential of phages in therapy, it is critical to understand the phage-host dynamics and how these interactions can change in complex populations. Our model examined the interactions between the plant pathogen , the antagonistic epiphyte , and the bacteriophages that infect and kill both species. strains are used as a phage carrier; their role is to deliver and propagate the bacteriophages on the plant surface prior to the arrival of the pathogen. Using liquid cultures, the populations of the pathogen, carrier, and phages were tracked over time with quantitative real-time PCR. The jumbo phage ϕEa35-70 synergized with both the ϕEa21-4 and ϕEa46-1-A1 and was most effective in combination at reducing growth over 24 h. Phage ϕEa35-70, however, also reduced the growth of . Phage cocktails of ϕEa21-4, ϕEa46-1-A1, and ϕEa35-70 at multiplicities of infections (MOIs) of 10, 1, and 0.01, respectively, no longer inhibited growth of . When this cocktail was grown with for 8 h prior to pathogen introduction, pathogen growth was reduced by over four log units over 24 h. These findings present a novel approach to study complex phage-host dynamics that can be exploited to create more effective phage-based therapies.
PubMed: 32971807
DOI: 10.3390/microorganisms8091449 -
International Journal of Molecular... Jul 2021A novel siphovirus, vB_PagS_MED16 (MED16) was isolated in Lithuania using strain BSL for the phage propagation. The double-stranded DNA genome of MED16 (46,103 bp)...
A novel siphovirus, vB_PagS_MED16 (MED16) was isolated in Lithuania using strain BSL for the phage propagation. The double-stranded DNA genome of MED16 (46,103 bp) contains 73 predicted open reading frames (ORFs) encoding proteins, but no tRNA. Our comparative sequence analysis revealed that 26 of these ORFs code for unique proteins that have no reliable identity when compared to database entries. Based on phylogenetic analysis, MED16 represents a new genus with siphovirus morphology. In total, 35 MED16 ORFs were given a putative functional annotation, including those coding for the proteins responsible for virion morphogenesis, phage-host interactions, and DNA metabolism. In addition, a gene encoding a preQ DNA deoxyribosyltransferase (DpdA) is present in the genome of MED16 and the LC-MS/MS analysis indicates 2'-deoxy-7-amido-7-deazaguanosine (dADG)-modified phage DNA, which, to our knowledge, has never been experimentally validated in genomes of phages. Thus, the data presented in this study provide new information on -infecting viruses and offer novel insights into the diversity of DNA modifications in bacteriophages.
Topics: DNA, Viral; Genome, Viral; Guanosine; Open Reading Frames; Pantoea; Siphoviridae; Viral Proteins
PubMed: 34298953
DOI: 10.3390/ijms22147333 -
The Science of the Total Environment Jul 2022Antimicrobial resistance (AMR) is becoming an increasing global concern and the anaerobic digestion (AD) process represents a potential transmission route when...
Antimicrobial resistance (AMR) is becoming an increasing global concern and the anaerobic digestion (AD) process represents a potential transmission route when digestates are used as fertilizing agents. AMR contaminants, e.g. antibiotic-resistant bacteria (ARB) and plasmid-mediated antibiotic resistance genes (ARGs) have been found in different substrates and AD systems, but not yet been investigated in plant-based substrates. AMR transfer from soils to vegetable microbiomes has been observed, and thus crop material potentially represents a so far neglected AMR load in agricultural AD processes, contributing to AMR spread. In order to test this hypothesis, this study examined the AMR situation throughout the process of three biogas plants using plant-based substrates only, or a mixture of plant-based and manure substrates. The evaluation included a combination of culture-independent and -dependent methods, i.e., identification of ARGs, plasmids, and pathogenic bacteria by DNA arrays, and phylogenetic classification of bacterial isolates and their phenotypic resistance pattern. To our knowledge, this is the first study on AMR in plant-based substrates and the corresponding biogas plant. The results showed that the bacterial community isolated from the investigated substrates and the AD processing facilities were mainly Gram-positive Bacillus spp. Apart from Pantoea agglomerans, no other Gram-negative species were found, either by bacteria culturing or by DNA typing array. In contrast, the presence of ARGs and plasmids clearly indicated the existence of Gram-negative pathogenic bacteria, in both substrate and AD process. Compared with substrates, digestates had lower levels of ARGs, plasmids, and culturable ARB. Thus, digestate could pose a lower risk of spreading AMR than substrates per se. In conclusion, plant-based substrates are associated with AMR, including culturable Gram-positive ARB and Gram-negative pathogenic bacteria-associated ARGs and plasmids. Thus, the AMR load from plant-based substrates should be taken into consideration in agricultural biogas processing.
Topics: Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Anti-Bacterial Agents; Bacteria; Biofuels; Drug Resistance, Bacterial; Genes, Bacterial; Gram-Negative Bacteria; Phylogeny
PubMed: 35306061
DOI: 10.1016/j.scitotenv.2022.154556 -
Plant Disease Feb 2023Jackfruit (Artocarpus heterophyllus) is an important tropical commercial fruit crop grown in Hainan province, China. In recent years, severe jackfruit bronzing disease...
Jackfruit (Artocarpus heterophyllus) is an important tropical commercial fruit crop grown in Hainan province, China. In recent years, severe jackfruit bronzing disease has been found in 11 cities and counties in Hainan. On average, 80% of trees in a jackfruit orchard are affected once bronzing disease is detected. The disease is characterized by yellow-orange to reddish discoloration of the pulp and rags of infected fruit (Hernández-Morales et al. 2017). Jackfruit bronzing disease has been reported previously in the Philippines (Gapasin et al. 2012), Malaysia (Zulperi et al. 2017), and Mexico (Hernández-Morales et al. 2017). Diseased samples of jackfruit 'Tai Eight' with the bronzing symptoms were collected from a plantation in Changjiang, Hainan. The samples were sterilized with 75% ethanol for 30 s, then soaked with 1% sodium hypochlorite for 8 min, and rinsed with sterilized distilled water. The sterilized tissues were ground in 2 mL sterile water, and allowed to stand for 30 min. Then, 500 μL of the supernatant was spread on Glucose-Yeast agar medium and incubated overnight at 28ºC. Representative bacterial colonies were lemon-yellow, convex and smooth, transparent with entire edges. Colonies were Gram-negative, positive for catalase and gelatin liquefaction, which were consistent with the characteristics of P. stewartii subsp. stewartii. In PCR amplifications, an 920 bp amplicon of strain JTPE2 with the primers ES16/ESIG2c (Coplin et al. 2002) and an 1100 bp amplicon of strain JTPC2 with the primers CPSL1/CPSR2c (Ibrahim et al. 2019) were obtained, whereas no bands were observed for the negative control samples. The ES16/ESIG2c and CPSL1/CPSR2c fragments were sequenced for nucleotide BLAST (BLASTn) searches of the NCBI database and phylogenetic tree construction. The obtained ES16/ESIG2c sequences (SAR accession no. SRR22405292) showed 99.07%-99.60% similarity with P. stewartii subsp. stewartii (CP017581, AJ311838 and MF598163). The obtained CPSL1/CPSR2c sequences (SAR accession no. SRR22405293) showed 99.40%-99.99% similarity with P. stewartii subsp. stewartii (MW971422, MH752485 and MH257287). Phylogenetic analysis based on cpsDE sequences (Ibrahim et al. 2019) using the maximum likelihood method revealed that strains JTPE2 and JTPC2 were clustered together with P. stewartii subsp. stewartii. A pathogenicity test was conducted by injecting 2 mL of 108 CFU/ml bacterial suspension into pulp from healthy, surface-sterilized jackfruit. Pulp injected with sterilized distilled water served as a negative control. All inoculated samples produced bronzing symptoms from 2-3 weeks post-inoculation similar to the field-observed symptoms, whereas control fruit were asymptomatic. The strains were reisolated from symptomatic jackfruit pulp to complete Koch's postulates. The bacterial suspension was inoculated on 2-week-old maize seedlings to supplement in vivo pathogenicity testing. Typical Stewart's disease leaf symptoms were visible at 2 weeks post-inoculation. Based on morphological, biochemical, and physiological evidence, pathogenicity tests, and molecular analyses, the pathogenic bacterium isolated from 'Tai Eight' jackfruit was identified as P. stewartii subsp. stewartii. To our knowledge, this is the first report of bronzing disease caused by P. stewartii subsp. stewartii on jackfruit in China, which may assist in preventing the global spread of jackfruit bronzing disease.
PubMed: 36825316
DOI: 10.1094/PDIS-11-22-2740-PDN -
Folia Microbiologica Jun 2022One of the key factors affecting seed quality is microbial communities residing on and in the seeds. In this study, microbial populations of seeds of conventionally and... (Review)
Review
One of the key factors affecting seed quality is microbial communities residing on and in the seeds. In this study, microbial populations of seeds of conventionally and organically produced wheat, barley, and maize were analyzed using two different approaches: the cultivation method and metagenomics. For cultivation, three basic media were used: DG18 (for fungi), and nutrient agar or tryptic soy agar supplemented with cycloheximide or nystatin (for bacteria). Metagenomic sequencing was performed using the Illumina MiSeq platform. A total of 452 bacterial isolates comprising 36 genera and 5 phyla and 90 fungal isolates comprising 10 genera and 3 phyla were obtained from the seed surfaces. Among bacteria, representatives from the genera Bacillus, Pantoea, Paenibacillus, and Curtobacterium predominated, and among fungi, Aspergillus predominated. A total of 142 fungal OTUs and 201 bacterial OTUs were obtained from all the samples. Proteobacteria, Firmicutes, Bacteroides, and Actinobacteria comprised most of the bacterial OTUs, and Ascomycota comprised most of the fungal OTUs. Only 3 fungal OTUs (representatives of Curvibasidium, Venturia, and Dermateaceae) were exclusively present only within seeds and not on the seed surfaces. Barley seeds had the highest microbial load and richness, whereas corn had the lowest. Wheat and barley shared a higher number of OTUs than either of them did with corn with higher overlap between conventionally grown cereals than between organically grown cereals. Some OTUs were farming specific. This study demonstrates that the microbiome of cereal seeds is greatly dependent on the species of the host and is less affected by agricultural practices.
Topics: Agar; Ascomycota; Bacteria; Crops, Agricultural; Fungi; Metagenomics; Seeds; Triticum
PubMed: 35220558
DOI: 10.1007/s12223-022-00958-5 -
BMC Plant Biology Oct 2023In nature, beneficial bacteria triggering induced systemic resistance (ISR) may protect plants from potential diseases, reducing yield losses caused by diverse...
BACKGROUND
In nature, beneficial bacteria triggering induced systemic resistance (ISR) may protect plants from potential diseases, reducing yield losses caused by diverse pathogens. However, little is known about how the host plant initially responds to different beneficial bacteria. To reveal the impact of different bacteria on barley (Hordeum vulgare), bacterial colonization patterns, gene expression, and composition of seed endophytes were explored.
RESULTS
This study used the soil-borne Ensifer meliloti, as well as Pantoea sp. and Pseudomonas sp. isolated from barley seeds, individually. The results demonstrated that those bacteria persisted in the rhizosphere but with different colonization patterns. Although root-leaf translocation was not observed, all three bacteria induced systemic resistance (ISR) against foliar fungal pathogens. Transcriptome analysis revealed that ion- and stress-related genes were regulated in plants that first encountered bacteria. Iron homeostasis and heat stress responses were involved in the response to E. meliloti and Pantoea sp., even if the iron content was not altered. Heat shock protein-encoding genes responded to inoculation with Pantoea sp. and Pseudomonas sp. Furthermore, bacterial inoculation affected the composition of seed endophytes. Investigation of the following generation indicated that the enhanced resistance was not heritable.
CONCLUSIONS
Here, using barley as a model, we highlighted different responses to three different beneficial bacteria as well as the influence of soil-borne Ensifer meliloti on the seed microbiome. In total, these results can help to understand the interaction between ISR-triggering bacteria and a crop plant, which is essential for the application of biological agents in sustainable agriculture.
Topics: Hordeum; Pseudomonas; Endophytes; Bacteria; Iron; Soil; Plant Roots
PubMed: 37789272
DOI: 10.1186/s12870-023-04484-5